Nervous System

 Chapter -9 

NERVOUS SYSTEM

Introduction to Nervous System 

The nervous system consists of the brain, spinal cord, sensory organs, and all of the nerves that connect these organs with the rest of the body. Together, these organs are responsible for the control of the body and communication among its parts. The brain and spinal cord form the control center known as the central nervous system (CNS), where information is evaluated and decisions made. The sensory nerves (afferent) and sense organs of the peripheral nervous system (PNS) monitor conditions inside and outside of the body and send this information to the CNS. Motor nerves (efferent) in the PNS carry signals from the control center to the muscles, glands, and organs to regulate their functions. The nervous system uses both electrical and chemical means to send and receive messages.

Neurons: The basic building block of the nervous system is a nerve cell or neuron. Neurons are shaped differently depending on where they are in the body and what role they play. All neurons have finger-like projections called dendrites and a long fiber called an axon. 

In many cases, the axon is coated by a specialized membrane called myelin sheath. The axon feathers out and has a number of bumps on it. Each bump sits near to a dendrite from another neuron. The space between the bump and the dendrite is called a synapse. Messages jump the synapse from one neuron to the next, using special chemicals called neurotransmitters. Unlike other cells in the body, neurons are not easily replaced if they die or are damaged by infection or injury.

Central Nervous System: The brain and spinal cord make up the central nervous system. They are wrapped in a thin lining called meninges and bathed with cerebrospinal fluid (CSF).  

Brain: The brain is powerhouse of the body, even though it only makes up two percent of the body’s weight. This soft, jelly like organ has countless billions of neural cross-connections. Brain organize and supervize the workings of the body, while its higher functions give us consciousness and personality. 

Spinal Cord: The spinal cord connects to the brain and runs the length of the body. It is protected by the bones of the spine (vertebrae). Nerves branch off from the spinal cord into the arms, legs and torso.

Peripheral Nervous System (PNS): The portion of the nervous system lying outside the brain and spinal cord. It is made up of two main parts: the autonomic and the somatic nervous systems. 

Autonomic Nervous System (ANS): The autonomic nervous system is part of the peripheral nervous system. One of its main roles is to regulate glands and organs without any effort from conscious minds.

Somatic Nervous System: The somatic nervous system is also a part of the peripheral nervous system. One of its roles is to relay information from the eyes, ears, skin and muscle to the central nervous system. It also obeys commands from the central nervous system and makes muscles contract or relax, allowing us to move.  

Synapse: A synapse is the tiny gap across which a nerve impulse passes from one nerve cell to another nerve cell, a muscle cell or a gland cell.

Synaptic cleft: The gap between two cells at a synapse is called the synaptic cleft. The signal sending cell is called the presynaptic neuron, and the signal receiving cell is called the postsynaptic neuron.

 Neurotransmitters: Neurotransmitters are the brain chemicals that communicate information throughout brain and body. They relay signals between nerve cells. The brain uses neurotransmitters to regulate activities such as heart to beat, lungs to breathe, and stomach to digest. They can also affect mood, sleep, concentration, weight, and can cause altered functions when they are out of balance. Neurotransmitter levels can be depleted many ways.

Excitatory neurotransmitters are glutamate, aspartate, norepinephrine, dopamine and epinephrine.

Epilepsy 

Seizure is the transient occurrence of signs and/or symptoms due to abnormal, excessive, or synchronous neuronal activity in the brain. Signs or symptoms may include alterations of consciousness, motor, sensory, autonomic, or psychic events. Epilepsy is a condition characterized by the occurrence of two or more seizures that are not acutely provoked by other illnesses or conditions. Medications control rather than curing the seizure disorder. Adherence to the medication regimen is important.

Classification of Epileptic Seizures: Epileptic seizures are classified as either focal or generalized, based on how the abnormal brain activity begins.

Generalized Seizures (Convulsive or Non-convulsive):  Seizures that appear to involve all areas of the brain are called generalized seizures. Six types of generalized seizures exist.

• (i) Absence seizures (Petit Mal): Petit Mal or Absence seizures are characterized by staring and subtle body movement. These seizures can cause a brief loss of awareness.
• (ii) Tonic seizures: Tonic seizures cause stiffening muscles. These seizures usually affect muscles in back, arms and legs and may cause to fall to the ground.
• (iii) Clinic seizures: Clinic seizures are associated with rhythmic, jerking muscle movements. These seizures usually affect the neck, face and arms. 
• (iv) Myoclonic seizures: These usually appear as sudden brief jerks or twitches of arms and legs. 
• (v) Atonic seizures: Atonic seizures, also known as drop seizures, because a loss of muscle control, which may result in suddenly collapse or fall down. 
• (vii) Tonic-conic seizures (Grand Mal): Tonic-conic seizures are characterized by a loss of consciousness, body stiffening and shaking, and sometimes loss of bladder control or biting tongue. 

Status epilepticus is defined as either continuous seizures lasting at least for 5 minutes, or two or more discrete seizures between which there is incomplete recovery of consciousness. 

Febrile seizures occur in upto 8% of children between 6 months and 6 years of age. Long term treatment or prophylaxis for simple febrile seizures is not recommended.

Unclassified epileptic seizures: Not all seizure types can be classified as partial or generalized. This appears to be especially true of seizures that occur in neonates and infants. The distinctive phenotypes of seizures at these early ages likely result, in part, from differences in neuronal function and connectivity in the immature versus mature CNS.

Epidemiology 

There are over 2.5 million people diagnosed with epilepsy every year. Epilepsy is one of the most common serious neurological disorders affecting about 65 million people globally. It affects 1% of the population by age 20 and 3% of the population by age 75. It is more common in males than females with the overall difference being small. Most of those with the disease (80%) are in the developing world.

Epilepsy is usually present in childhood or adolescence but may occur for the first time at any age. About 5% of the population suffers a single seizure at some time. About 0.5-1% of the population have recurrent seizure epilepsy. About 70% patients are well controlled with drugs (prolonged remissions) and 30% epilepsy patients are at least partially resistant to drug treatments.

Intractable Epilepsy: It is a symptom of numerous disorders, but in the majority of sufferers the cause remains unclear despite careful history taking, examination and investigation.  

Causes 

Epilepsy has no identifiable cause in about half of those, with the condition. In about half the people with epilepsy, the condition may be traced to various factors.

Genetic Influence: 

Some types of epilepsy, which are categorized by the type of seizure experience, run in families. In these cases, it is likely that there is a genetic influence.

Researchers have linked some types of epilepsy to specific genes, though it is estimated that upto 500 genes could be tied to the condition. For most people, genes are only part of the cause of epilepsy. Certain genes may make a person more sensitive to environmental conditions that trigger seizures. 

Head trauma: Head trauma that occurs due to a car accident or other traumatic injury can cause epilepsy.  

Brain conditions: Brain conditions that result in damage to the brain, such as brain tumors or strokes, also can cause epilepsy. Stroke is a leading cause of epilepsy in adults older than age 35. 

Infectious diseases: Infectious diseases, such as meningitis, AIDS and viral encephalitis, can cause epilepsy.

Prenatal injury: Before birth, babies are sensitive to brain damage that could be caused by several factors, such as an infection in the mother, poor nutrition or oxygen deficiencies. This brain damage can result in epilepsy or cerebral palsy. 

Developmental disorders: Epilepsy can sometimes be associated with developmental disorders, such as autism and neurofibromatosis. 

Stroke and other vascular diseases: Stroke and other blood vessel (vascular) diseases can lead to brain damage that may trigger epilepsy. 

Dementia: Dementia can increase the risk of epilepsy in older adults. 

Pathophysiology

Mechanisms of Seizure Initiation and Propagation:

The hypersynchronous discharges that occur during a seizure may begin in a very discrete region of cortex and then spread to neighboring regions. Seizure initiation is characterized by two concurrent events: 1) high-frequency bursts of action potentials, and 2) hype synchronization of a neuronal population. The synchronized bursts from a sufficient number of neurons result in a so-called spike discharge on the EEG. At the level of single neurons, epileptiform activity consists of sustained neuronal depolarization resulting in a burst of action potentials, a plateau-like depolarization associated with completion of the action potential burst, and then a rapid repolarization followed by hyperpolarization. This sequence is called the paroxysmal depolarizing shift. The bursting activity resulting from the relatively.

prolonged depolarization of the neuronal membrane is due to influx of extracellular Ca++, which leads to the opening of voltage dependent Na+ channels, influx of Na+ , and generation of repetitive action potentials. The subsequent hyperpolarizing after potential is mediated by GABA receptors and Cl− influx, or by K+ efflux, depending on the cell type.

Seizure propagation, the process by which a partial seizure spreads within the brain, occurs when there is sufficient activation to recruit surrounding neurons. This leads to a loss of surrounding inhibition and spread of seizure activity into contiguous areas via local cortical connections, and to more distant areas via long association pathways such as the corpus callosum. 

 Symptoms 

Because epilepsy is caused by abnormal activity in brain cells, seizures can affect any process that brain co-ordinates. Both partial and generalized seizures at the same time, or one can precede the other. The symptoms can last anywhere from a few seconds to 15 minutes per episode.

Sometimes, symptoms occur before the seizure takes place. These include: 

• A sudden feeling of fear or anxiousness, 
• A feeling of being sick to your stomach, 
• Dizziness, 
• A change in vision, 
• A jerky movement of the arms and legs that may cause you to drop things, 
• An out of body sensation, 
• A headache.  

Symptoms that indicate a seizure is in progress include:

• Losing consciousness, which is followed by confusion, 
• Having uncontrollable muscle spasms, 
• Drooling or frothing at the mouth, 
• Falling, 
• Having a strange taste in mouth, 
• Clenching teeth, 
• Biting of tongue, 
• Having sudden, rapid eye movements, 
• Making unusual noises, such as grunting, 
• Losing control of bladder or bowel function, 
• Having sudden mood changes. 

Tests and Diagnosis 

Physical examination: Physical examination helps in the diagnosis of specific epileptic syndromes that cause abnormal findings, such as dermatologic abnormalities. In addition, patients who for years have had intractable generalized tonic-conic seizures are likely to have suffered injuries requiring stitches. Several tests to diagnose epilepsy and determine the cause of seizures includes.

Neurological examination: A neurological examination looks at how well brain and the rest of nervous system are functioning and may test behavior, motor abilities, mental function and other areas to diagnose condition and determine the type of epilepsy. 

Blood tests: There are a number of blood tests that may be recommended to check for signs of infections, genetic conditions or other conditions like electrolyte imbalances which may be associated with seizures.

Electroencephalogram (EEG): An electroencephalography test can help to diagnose a seizure. These tests measure brain waves. Viewing brain waves during a seizure can help to diagnose the type of seizure.  

Neuroimaging: Imaging scans such as a Computerized tomography (CT) scan, Magnetic resonance imaging (MRI), Functional MRI (fMRI), Positron emission tomography (PET) or Single-photon emission computerized tomography (SPECT) also can help by providing a clear picture of the brain. These scans allow to see abnormalities like blocked blood flow or a tumor. 

Neuropsychological tests: These tests are performed to assess thinking, memory and speech skills. The test results help to determine which areas of brain are affected.

 Treatments and Drugs

The majority of epileptic seizures are controlled through drug therapy, particularly anticonvulsant drugs. The type of treatment prescribed will depend on several factors including the frequency and severity of the seizures as well as the person’s age, overall health, and medical history. An accurate diagnosis of the type of epilepsy is also critical to choosing the best treatment.

The different antiepileptic drugs (AEDs) act by affecting one or more of these processes. Specific mechanisms of action of the AEDs include:

• Modulation of voltage dependent ion channels: Carbamazepine, Phenytoin, Valproic acid.  
• Enhancement of activity of the major inhibitory neurotransmitter in the brain, GABA: Phenobarbital, Benzodiazepines, Tiagabine. 
• Suppression of excitatory neurotransmission: Lamotrigine, Felbamate.
• Surgery: Surgery includes removal of the area of brain causing the seizures. 

Parkinson’s disease 

In 1817, British Physician Dr. James Parkinson published a case series describing six patients afflicted with the “shaking palsy” (paralysis agita's), a chronic and progressive neurologic disorder called Parkinsonism i.e. loss of control of movement. Parkinson’s occurs when certain nerve cells in a part of the brain called the substantia nigral die or become impaired. Normally, these cells produce a vital chemical known as dopamine. Dopamine allows smooth, coordinated function of the body’s muscles and movement. When approximately 70% of the dopamine producing cells is damaged, the symptoms of Parkinson disease appear. Parkinson disease (PD) is recognized as one of the most common neurologic disorders, affecting approximately 1% of individuals older than 60 years. It is a progressive movement disorder marked by tremors, rigidity, slow movement (bradykinesia), and posture instability.

The motor symptoms of Parkinson's disease result from the death of dopaminegenerating cells in the substantia nigari, a region of the midbrain; the cause of this cell death is unknown. Sometimes it is genetic, but most cases do not seem to run in families. Exposure to chemicals in the environment might play a role.

It usually begin in a person's late fifties or early sixties. Parkinson disease causes progressive decline in movement controls, affecting the ability to control initiation, speed and smoothness of motion. Symptoms of Parkinson's disease are seen in 15% of the people in the age 65-74 and almost 30% of people in age 75-84.

Most cases of Parkinson's disease are sporadic. In that, there is a spontaneous and permanent change in nucleotide sequences. Sporadic mutations also involve unknown environmental factors in combination with genetic defects. The abnormal gene (mutated gene) will form an altered end product or protein. This will cause abnormalities in specific areas in the body where the protein is used. Some evidence suggests that the disease is transmitted by autosomal dominant inheritance. This implies that an affected parent has a 50% chance of transmitting the disease to any child.

Causes 

The immediate cause of PD is degeneration of brain cells in the area known as the substantia nigra, one of the movement control centers of the brain. Damage to this area leads to the cluster of symptoms known as "Parkinsonism".

Genetic: Researchers have identified specific genetic mutations such as α–synuclein and parkin, that can cause Parkinson's disease, but these are uncommon except in rare cases with many family members affected by Parkinson's disease. Recent studies suggest that dysfunction of the ubiquitin–proteasome system (UPS) and the resultant accumulation of misfolded proteins and endoplasmic reticulum stress may cause the death of Dopaminergic (DA) neurons. 

The presence of Lewy bodies: Clumps of specific substances within brain cells are microscopic markers of Parkinson's disease. These are called Lewy bodies, and researchers believe these Lewy bodies hold an important clue to the cause of Parkinson's disease.

 A synuclein is found within Lewy bodies: Although many substances are found within Lewy bodies, scientists believe the most important of these is the natural and widespread protein called α-synuclein. It is found in all Lewy bodies in a clumped form that cells cannot break down. This is currently an important focus among Parkinson's disease researchers.

Parkinsonism may be seen in other degenerative conditions, known as the "Parkinsonism plus" syndromes, such as progressive supranuclear palsy.

 Risk Factors 

Age: Young adults rarely experience Parkinson's disease. It ordinarily begins in middle or late life, and the risk increases with age. People usually develop the disease around age 60 or older.

Heredity: Having a close relative with Parkinson's disease increases the chances to develop the disease. However, risks are still small unless many relatives in family with Parkinson's disease. 

Sex: Men are more likely to develop Parkinson's disease than are women.

Exposure to toxins: Ongoing exposure to herbicides and pesticides may slightly increase risk of Parkinson's disease.

Pathophysiology

No specific, standard criteria exist for the neuropathologic diagnosis of Parkinson disease, as the specificity and sensitivity of its characteristic findings have not been clearly established. However, the following are the 2 major neuropathologic findings in Parkinson disease:

 Loss of pigmented dopaminergic neurons of the substantia nigral pars compacta. 

The presence of Lewy bodies and Lewy neurites.

The loss of dopamine neurons occurs most prominently in the ventral lateral substantia nigral. Approximately 60-80% of dopaminergic neurons are lost before the motor signs of Parkinson's disease emerge. 

Some individuals who were thought to be normal neurologically at the time of their deaths are found to have Lewy bodies on autopsy examination. These incidental Lewy bodies have been hypothesized to represent the presymptomatic phase of Parkinson disease. The prevalence of incidental Lewy bodies increases with age. Nonetheless, they are a characteristic pathology finding of Parkinson disease.

Symptoms 

Parkinson's disease symptoms and signs may vary from person to person. Early signs may be mild and may go unnoticed. Symptoms often begin on one side of body and usually remain worse on that side, even after symptoms begin to affect both sides.

Parkinson's signs and symptoms may include:

Tremors: Usually begins in a limb, often hand or fingers. The classic tremor of Parkinson's disease is called as “Pill-rolling tremor”, because the movement resembles rolling a pill between the thumb and fore finger. This tremor occurs at a frequency of about three per second.

Slowed movement (Bradykinesia): It may involve slowing down or stopping in the middle of familiar tasks such as walking, eating or shaving, this may include freezing in place during movements (akinesia). 

Rigid muscle: Muscle rigidity or stiffness, occurring with jerky movements replacing smooth motion. The stiff muscles can limit range of motion and cause pain.

Impaired posture and balance: Postural instability or balance difficulty occurs. This may lead to a rapid, shuffling gait (festination) to prevent falling. 

Loss of automatic movements: In Parkinson's disease, ability to perform unconscious movements, including blinking, smiling or swinging arms when walking may decrease. In most cases, there is a “masked face”, with little facial expression and decreased eye blinking. 

Speech changes: Speech may be more of a monotone rather than with the usual inflections. Patient may speak softly, quickly, slur or hesitate before talking. 

Writing changes: Handwriting changes, with letters becoming smaller across the page (micrographic) and become difficult. Progressive problems with intellectual function (dementia).

Bladder problems: Parkinson's disease may cause bladder problems, including being unable to control urine or having difficulty urinating. 

Constipation: Many people with Parkinson's disease develop constipation, mainly due to a slower digestive tract. 

Smell dysfunction: Problems with sense of smell, may have difficulty identifying certain odours or the difference between odors.

Fatigue: Many people with Parkinson's disease lose energy and experience fatigue, and the cause is not always known. 

Pain: Many people with Parkinson's disease experience pain, either in specific areas of their bodies or throughout their bodies.

Sexual dysfunction: Some people with Parkinson's disease notice a decrease in sexual desire or performance. 

In addition, a wide range of other symptoms may often be seen, some beginning earlier than others: Depression, problems with sleep, including restlessness and nightmares. Emotional changes including fear, irritability and insecurity. 

Tests and Diagnosis 

The diagnosis of Parkinson disease involves a careful medical history and a neurological exam to look for characteristic symptoms.

There are no definitive tests for Parkinson's disease, although a variety of lab tests may be done to rule out other causes of symptoms, especially if only some of the identifying symptoms are present.

Test for other causes of Parkinsonism may include brain scans, blood tests, lumbar puncture and X-rays.

Treatment and Drugs 

No known treatment can stop or reverse the breakdown of nerve cells that causes Parkinson's disease. But there are many treatments that can help your symptoms and improve your quality of life. Treatments for Parkinson's include:

Medicines: Medicines, such as levodopa and dopamine agonists. The goal is to correct the shortage of the brain chemical dopamine, which causes the symptoms of Parkinson's. Several medicines may be used at different stages of the disease are:

Levodopa and carbidopa: Levodopa is precursor of dopamine. Levodopa is combined with carbidopa, which protects levodopa from premature conversion to dopamine outside brain, which prevents or lessens side effects such as nausea. L-dopa therapy usually remains effective for five years, as disease progresses, many patients develop motor fluctuations including dyskinesias (abnormal movements such as twisting, restlessness), rapid loss of response after dosing (“on-off phenomenon) even after taking of high doses of levodopa.

Dopamine agonists (for example, pramipexole or ropinirole): Dopamine agonists may be used before L-dopa therapy or added on to avoid requirements for higher L-dopa doses late in the disease.

COMT inhibitors: Entacapone and tolcapone are inhibitors of another enzyme system called catechol-o-methyl transferase are effectively treating Parkinson’s disease. This medication mildly prolongs the effect of levodopa therapy by blocking an enzyme that breaks down dopamine.

MAO-B inhibitors (rasagiline, selegiline):MAO-B inhibitors (rasagiline, selegiline): These can prevent the breakdown of brain dopamine by inhibiting the brain enzyme monoamine oxidase B (MAO-B) and prolong the effects of dopamine. This enzyme metabolizes brain dopamine.

Amantadine: Amantadine is sometimes used alone to provide short-term relief of symptoms of mild, early-stage Parkinson's disease. It may also be given with carbidopa-levodopa therapy during the later stages of Parkinson's disease to control involuntary movements (dyskinesia's) induced by carbidopa levodopa. 

Anticholinergic agents: These medications were used for many years to help control the tremor associated with Parkinson's disease. Example: Benztropine or Trihexyphenidyl.

Apomorphine: A short-acting injectable dopamine agonist, apomorphine is used for quick relief. 

Home treatment: There are many steps can be taken at home to make dealing with the symptoms of Parkinson's disease easier, such as getting regular exercise and eating a healthy diet including plenty of fruits, vegetables, grains, cereals, legumes, poultry, fish, lean meats, and low-fat dairy products.

Surgery: Brain surgery, for example deep brain stimulation (DBS), may be considered when medicine fails to control symptoms of Parkinson's disease or causes severe or disabling side effects.

Speech therapy: Speech therapists use breathing and speech exercises to help overcome the soft, imprecise speech and monotone voice that develop in advanced Parkinson's disease.

Physical therapy and Occupational therapy: Therapists may help improve walking and reduce risk of falling.

Alternative Treatment: 

Alternative therapies, including acupuncture, massage and yoga can help relieve some symptoms of the disease and loosen tight muscles. Alternative treatment also include herbal and dietary therapies, including amino acid supplementation, antioxidant (vitamins A, C, E, selenium and zinc) therapy, B vitamin supplementation and calcium and magnesium supplementation to treat Parkinson’s disease.

 Prevention 

Because the cause of Parkinson's is unknown, there is no known way to prevent Parkinson’s disease. However, some research has shown that caffeine found in coffee, tea and cola may reduce the risk of developing Parkinson's disease. Green tea also may reduce the risk of developing Parkinson's disease. Some research has shown that regular aerobic exercise may reduce the risk of Parkinson's disease.

Stroke 

A stroke is a "brain attack". It occurs when blood flow to an area of brain is cut off. When this happens, brain cells are deprived of oxygen and begin to die. When brain cells die during a stroke, abilities controlled by that area of the brain such as memory and muscle control are lost. Stroke also known as cerebrovascular accident (CVA). The effect of stroke depends on where the stroke occurs in the brain and how much the brain is damaged. For example, someone who had a small stroke may only have minor problems such as temporary weakness of an arm or leg. People who have larger strokes may be permanently paralyzed on one side of their body or lose their ability to speak. Some people recover completely from strokes, but more than 2/3 of survivors will have some type of disability.

 Types of Stroke 

There are three main kinds of stroke:

• Ischemic strokes, 
• Hemorrhagic strokes, 
• Transient ischemic attacks (TIAs), also referred to as mini-strokes. 

Causes 

The different forms of stroke have different specific causes.

Causes of Ischemic Stroke: Ischemic stroke is the most common form, accounting for around 85 % of strokes. This type of stroke is caused by blockages or narrowing of the arteries that provide blood to the brain, resulting in ischemia - severely reduced blood flow that damages brain cells. These blockages are often caused by blood clots, which can form either in the arteries within the brain, or in other blood vessels in the body before being swept through the bloodstream and into narrower arteries within the brain. Fatty deposits within the arteries called plaque can cause clots that result in ischemia.

Causes of Hemorrhagic Stroke:

Hemorrhagic strokes are caused by arteries in the brain either leaking blood or bursting open. The leaked blood puts pressure on brain cells and damages them. It also reduces the blood supply reaching the brain tissue after the hemorrhage point. Blood vessels can burst and spill blood within the brain or near the surface of the brain, sending blood into the space between the brain and the skull. The ruptures can be caused by conditions such as hypertension, trauma, blood-thinning medications, and aneurysms (weaknesses in blood vessel walls). Intracerebral hemorrhage is the most common type of hemorrhagic stroke and occurs when brain tissue is flooded with blood after an artery in the brain bursts. Subarachnoid hemorrhage is the second type of hemorrhagic stroke and is less common. In this type of stroke, bleeding occurs in an artery in the subarachnoid space - the area between the brain and the thin tissues that cover it.

Causes of Transient Ischemic Attack (TIA):

TIAs are different from the kinds above because the flow of blood to the brain is only briefly interrupted. TIAs are similar to ischemic strokes. In that, they are often caused by blood clots or other clots. TIAs should be regarded as medical emergencies just like the other kinds of stroke, even if the blockage of the artery and symptoms are temporary. They serve as warning signs for future strokes and indicate that there is a partially blocked artery or clot source in the heart.

Risk Factors 

Uncontrolled hypertension, 

• Diabetes mellitus, 
• Smoking, 
• Cardiac disease, 
• Hyperlipidemia, 
• Excessive alcohol intake

Epidemiology

Stroke is one of the leading causes of death and disability in India. The estimated adjusted prevalence rate of stroke range, 84-262/100,000 in rural and 334-424/ 100,000 in urban areas. The incidence rate is 119-145/100,000 based on the recent population based studies. There is also a wide variation in case of fatality rates with the highest being 42% in Kolkata. Stroke units are predominantly available in urban areas that too in private hospitals. Intravenous (IV) and intra-arterial thrombolysis (IA) are commonly used in India.

 Pathophysiology 

The pathophysiology of stroke is complex and involves numerous processes, including: energy failure, loss of cell ion homeostasis, acidosis, increased intracellular calcium levels, excitotoxicity, free radical

mediated toxicity, generation of arachidonic acid products, cytokine mediated cytotoxicity, complement activation, disruption of the blood-brain barrier (BBB), activation of glial cells, and infiltration of leukocytes. 

Symptoms 

Strokes occur quickly, so symptoms often appear suddenly and without warning. The main symptoms of stroke are:

Muscular: Difficulty walking, paralysis with weak muscles, problems with coordination, stiff muscles, overactive reflexes, or paralysis of one side of the body.

Whole body: Balance disorder, fatigue, light-headedness, or vertigo.   

Visual: Blurred vision, double vision, sudden visual loss, or temporary loss of vision in one eye. 

Speech: Difficulty in speaking, slurred speech, or speech loss. 

Sensory: Reduced sensation of touch, even by applying pins and needles.

Facial: Muscle weakness or numbness.

Limbs: Numbness or weakness.

Common: Difficulty in swallowing, headache, inability to understand, mental confusion, or rapid involuntary eye movement.

Facts on Stroke 

During a stroke, the brain does not receive enough oxygen or nutrients, causing brain cells to die. 

• Ischemic strokes are caused by a narrowing or blocking of arteries to the brain. 
• Hemorrhagic strokes are caused by blood vessels in and around the brain bursting or leaking. 
• Strokes need to be diagnosed and treated as quickly as possible to minimize brain damage. 
• Treatment depends on the type of stroke. 
• The most effective way to prevent strokes is through maintaining a healthy lifestyle and treating underlying conditions that are a risk factor. 

Diagnosis 

There are several different types of diagnostic tests that can be used to determine which type of stroke has occurred:

Physical examination: It consists of measurement of blood pressure, listen to the carotid arteries in the neck, and examine the blood vessels at the back of the eyes, all to check for indications of clotting.

Blood tests: A doctor may perform blood tests to find out how quickly the patient's blood clots. The levels of particular substances (including clotting factors) in the blood, and whether or not the patient has an infection.

CT scan: A series of X-rays that can show haemorrhages, strokes, tumors, and other conditions within the brain.

MRI scan: Radio waves and magnets create an image of the brain to detect damaged brain tissue.

Carotid ultrasound: An ultrasound scan to check the blood flow in the carotid arteries and to see if there is any plaque present. 

Cerebral angiogram: Dyes are injected into the brain's blood vessels to make them visible under X-ray, to give a detailed view of the brain and neck blood vessels. 

Echocardiogram: A detailed image of the heart is created to check for any sources of clots that could have travelled to the brain to cause a stroke. 

Prevention 

• Eating a healthy diet. 
• Maintaining a healthy weight. 
• Exercise regularly. 
• Do not smoke. 
• Avoiding alcohol or drink moderately. 
• Keeping blood pressure under control. 
• Managing diabetes. 
• Treating obstructive sleep apnea (if present). 

Treatment 

Drug Treatment: There is only one Food and Drug Administration (FDA) approved drug treatment for acute ischemic stroke. Tissue plasminogen activator (tPA) is given via intravenous therapy (IV) and works by dissolving the clot and improving blood flow to the part of the brain being deprived of blood flow. tPA should be given within three hours (and upto 4.5 hours in certain eligible patients) of the time symptoms first started.

Mechanical Devices: Some ischemic strokes are treated with small mechanical devices that remove or break up blood clots. If clot-busting drugs are ruled out, another option one of the many FDA approved mechanical devices. A surgeon inserts a small mechanical device into the blocked artery using a thin tube. Once inside, the tool traps the clot, and either breaks it up or the surgeon pulls it out of the brain, reopening the blocked blood vessel in the process. 

Depression

Depression is a common mental disorder, characterized by sadness, loss of interest or pleasure, feelings of guilt or low self-worth, disturbed sleep or appetite, feelings of tiredness and poor concentration. It can be long lasting or recurrent, substantially impairing a person’s ability to function at work or school, or cope with daily life. There are many different types of depression caused by certain events in life and chemical changes in brain.

 Major depression: Major depression is the presence of depressed mood or loss of pleasure for at least two consecutive weeks along with changes in appetite or weight, changes in sleep pattern, retardation, fatigue, feeling of worthlessness, excessive guilt, difficulty concentrating, and thoughts of suicide and can lead to a variety of emotional and physical problems.

Catatonia: Include motor activity that involves either uncontrollable and purposeless movement or fixed and inflexible posture

Peripartum onset: It occurs during pregnancy or in the weeks or months after delivery.  

Epidemiology 

Depression is a major cause of morbidity worldwide. Lifetime prevalence varies widely, from 3% in Japan to 17% in the US. In most countries the number of people who would suffer from depression during their lives falls within 8–12% range.

 Causes

• Genetics  
• Biological: Changes in neurotransmitter levels 
• Environmental 
• Psychological and social (psychosocial)

The causes of depression are not fully understood and may not be down to a single source. Depression is likely to be due to a complex combination of factors that include:

Pathophysiology

• No specific, standard criteria exist for the neuropathologic diagnosis of Parkinson disease, as the specificity and sensitivity of its characteristic findings have not been clearly established. However, the following are the 2 major neuropathologic findings in Parkinson disease:

• Loss of pigmented dopaminergic neurons of the substantia nigra pars compacta.

• The presence of Lewy bodies and Lewy neurites. 

• The loss of dopamine neurons occurs most prominently in the ventral lateral substantia nigari. Approximately 60-80% of dopaminergic neurons are lost before the motor signs of Parkinson's disease emerge. 

• Some individuals who were thought to be normal neurologically at the time of their deaths are found to have Lewy bodies on autopsy examination. These incidental Lewy bodies have been hypothesized to represent the PR symptomatic phase of Parkinson disease. The prevalence of incidental Lewy bodies increases with age. Nonetheless, they are a characteristic pathology finding of Parkinson disease.

Symptoms 

• Parkinson's disease symptoms and signs may vary from person to person. Early signs may be mild and may go unnoticed. Symptoms often begin on one side of body and usually remain worse on that side, even after symptoms begin to affect both sides. Parkinson's signs and symptoms may include:

Tremors:

• Usually begins in a limb, often hand or fingers. The classic tremor of Parkinson's disease is called as “Pill-rolling tremor”, because the movement resembles rolling a pill between the thumb and fore finger. This tremor occurs at a frequency of about three per second.

Slowed movement (Bradykinesia):

•  It may involve slowing down or stopping in the middle of familiar tasks such as walking, eating or shaving, this may include freezing in place during movements (akinesia).

Rigid muscle:

• Muscle rigidity or stiffness, occurring with jerky movements replacing smooth motion. The stiff muscles can limit range of motion and cause pain.  

impaired posture and balance:

• Postural instability or balance difficulty occurs. This may lead to a rapid, shuffling gait (festination) to prevent falling.

Loss of automatic movements:

• In Parkinson's disease, ability to perform unconscious movements, including blinking, smiling or swinging arms when walking may decrease. In most cases, there is a “masked face”, with little facial expression and decreased eye blinking. 

Speech changes:

• Speech may be more of a monotone rather than with the usual inflections. Patient may speak softly, quickly, slur or hesitate before talking. 

Writing changes:

• Handwriting changes, with letters becoming smaller across the page (micrographia) and become difficult. Progressive problems with intellectual function (dementia).

• Bladder problems: Parkinson's disease may cause bladder problems, including being unable to control urine or having difficulty urinating. 

Bladder problems:

• Parkinson's disease may cause bladder problems, including being unable to control urine or having difficulty urinating.

Constipation:

• Many people with Parkinson's disease develop constipation, mainly due to a slower digestive tract. Smell dysfunction: 

• Problems with sense of smell, may have difficulty identifying certain odors or the difference between odors. Parkinson's disease may cause bladder problems, including being unable to control urine or having difficulty urinating. 

Fatigue:

• Many people with Parkinson's disease lose energy and experience fatigue, and the cause is not always known. Pain: 

• Many people with Parkinson's disease experience pain, either in specific areas of their bodies or throughout their bodies.

Sexual dysfunction:

• Some people with Parkinson's disease notice a decrease in sexual desire or performance. 

Complications 

• Depression is a serious disorder that can take a terrible toll on individuals and families. 

• Untreated depression can result in emotional, behavioral and health problems that affect every area of life. Complications associated with depression may include: 

• Excess weight or obesity, which can lead to heart disease and diabetes. 

• Alcohol or substance abuse. 

• Anxiety, panic disorder or social phobia. 

• Family conflicts, relationship difficulties, and work or school problems. 

• Social isolation. 

• Suicidal feelings, suicide attempts or suicide.

• Premature death from other medical conditions.

Tests and Diagnosis

• The diagnosis of Parkinson disease involves a careful medical history and a neurological exam to look for characteristic symptoms. 

• There are no definitive tests for Parkinson's disease, although a variety of lab tests may be done to rule out other causes of symptoms, especially if only some of the identifying symptoms are present. 

• Test for other causes of Parkinsonism may include brain scans, blood tests, lumbar puncture and X-rays. 

Treatments and Drugs 

• No known treatment can stop or reverse the breakdown of nerve cells that causes Parkinson's disease. But there are many treatments that can help your symptoms and improve your quality of life. Treatments for Parkinson's include: 

Medicines:

• Medicines, such as levodopa and dopamine agonists. The goal is to correct the shortage of the brain chemical dopamine, which causes the symptoms of Parkinson's. Several medicines may be used at different stages of the disease are: 

Levodopa and carbidopa:

• Levodopa is precursor of dopamine. Levodopa is combined with carbidopa, which protects levodopa from premature conversion to dopamine outside brain, which prevents or lessens side effects such as nausea. L-dopa therapy usually remains effective for five years, as disease progresses, many patients develop motor fluctuations including dyskinesia's (abnormal movements such as twisting, restlessness), rapid loss of response after dosing (“on-off phenomenon) even after taking of high doses of levodopa.

Dopamine agonists (for example, pramipexole or ropinirole):

• Dopamine agonists may be used before L-dopa therapy or added on to avoid requirements for higher L-dopa doses late in the disease.

COMT inhibitors:

• Entacapone and tolcapone are inhibitors of another enzyme system called catechol-o-methyl transferase are effectively treating Parkinson’s disease. This medication mildly prolongs the effect of levodopa therapy by blocking an enzyme that breaks down dopamine.

MAO-B inhibitors (retailing, selegiline):

• These can prevent the breakdown of brain dopamine by inhibiting the brain enzyme monoamine oxidase B (MAO-B) and prolong the effects of dopamine. This enzyme metabolizes brain dopamine.

Amantadine:

• Amantadine is sometimes used alone to provide short-term relief of symptoms of mild, early-stage Parkinson's disease. It may also be given with carbidopa-levodopa therapy during the later stages of Parkinson's disease to control involuntary movements (dyskinesia's) induced by carbidopa levodopa.

Anticholinergic agents:

• These medications were used for many years to help control the tremor associated with Parkinson's disease. Example: Benztropine or Trihexyphenidyl.

Apomorphine:

•  A short-acting injectable dopamine agonist, apomorphine is used for quick relief.

Home treatment:

• There are many steps can be taken at home to make dealing with the symptoms of Parkinson's disease easier, such as getting regular exercise and eating a healthy diet including plenty of fruits, vegetables, grains, cereals, legumes, poultry, fish, lean meats, and low-fat dairy products.

Surgery:

• Brain surgery, for example deep brain stimulation (DBS), may be considered when medicine fails to control symptoms of Parkinson's disease or causes severe or disabling side effects. 

Speech therapy:

• Speech therapists use breathing and speech exercises to help overcome the soft, imprecise speech and monotone voice that develop in advanced Parkinson's disease. 

Physical therapy and Occupational therapy:

• Therapists may help improve walking and reduce risk of falling.

Prevention

• Because the cause of Parkinson's is unknown, there is no known way to prevent Parkinson’s disease. However, some research has shown that caffeine found in coffee, tea and cola may reduce the risk of developing Parkinson's disease. Green tea also may reduce the risk of developing Parkinson's disease. Some research has shown that regular aerobic exercise may reduce the risk of Parkinson's disease.

Schizophrenia 

• Schizophrenia is a severe mental disorder, characterized by profound disruptions in thinking, affecting language, perception, and the sense of self. It often includes psychotic experiences, such as hearing voices or delusions. It can impair functioning through the loss of an acquired capability to earn a livelihood, or the disruption of studies. Schizophrenia typically begins in late adolescence or early adulthood. Schizophrenia is a serious brain disorder that distorts the way a person thinks, acts, expresses emotions, perceives reality, and relates to others. Schizophrenia can leave its sufferer frightened and withdrawn. It is a lifelong disorder that cannot be cured, but usually can be controlled with proper treatment. Contrary to popular belief, schizophrenia is not a split personality or multiple personality. The word “schizophrenia” does mean “split mind,” but it refers to a disruption of the usual balance of emotions and thinking. The behavior of people with schizophrenia may be very strange and even shocking. A sudden change in personality and behavior, which occurs when schizophrenia sufferers lose touch with reality, is called a psychotic episode. Schizophrenia varies in severity from person to person. Some people have only one psychotic episode while others have many episodes during a lifetime but lead relatively normal lives between episodes. Schizophrenia symptoms seem to worsen and improve in cycles known as relapses and remissions.

Epidemiology 

• Stroke is one of the leading causes of death and disability in India. The estimated adjusted prevalence rate of stroke range, 84-262/100,000 in rural and 334-424/ 100,000 in urban areas. The incidence rate is 119-145/100,000 based on the recent population-based studies. There is also a wide variation in case of fatality rates with the highest being 42% in Kolkata. Stroke units are predominantly available in urban areas that too in private hospitals. Intravenous (IV) and intra-arterial thrombolysis (IA) are commonly used in India.

Types of Schizophrenia 

• Schizophrenia is a term given to a complex group of mental disorders. However, different types of schizophrenia may have some of the same symptoms. There are several subtypes of schizophrenia based on symptoms:

• Paranoid schizophrenia:

•  People with this type, are preoccupied with false beliefs (delusions) about being persecuted or being punished by someone. Their thinking, speech and emotions, however, remain fairly normal. 

•  Disorganized schizophrenia: 

• People with this type often are confused and incoherent and have jumbled speech. Their outward behavior may be emotionless or flat or inappropriate, even silly or childlike. Often they have disorganized behavior that may disrupt their ability to perform normal daily activities such as showering or preparing meals. 

•  Catatonic schizophrenia: 

• The most striking symptoms of this type are physical. People with catatonic schizophrenia are.

• Undifferentiated schizophrenia:

•  This subtype is diagnosed when the person’s symptoms do not clearly represent one of the other three subtypes.

•  Residual Schizophrenia:

•  In this type of schizophrenia, the severity of schizophrenia symptoms has decreased. Hallucinations, delusions, or other symptoms may still be present but are considerably less than when the schizophrenia was originally diagnosed. In addition, there must still be evidence of the disturbance as indicated by the presence of some negative symptoms (for example, inexpressive faces, blank looks, monotone speech, seeming lack of interest in the world and other people, inability to feel pleasure).  

Causes

• The different forms of stroke have different specific causes

• Causes of Ischemic Stroke:

• Ischemic stroke is the most common form, accounting for around 85 % of strokes. This type of stroke is caused by blockages or narrowing of the arteries that provide blood to the brain, resulting in ischemia - severely reduced blood flow that damages brain cells. These blockages are often caused by blood clots, which can form either in the arteries within the brain, or in other blood vessels in the body before being swept through the bloodstream and into narrower arteries within the brain. Fatty deposits within the arteries called plaque can cause clots that result in ischemia.

• Causes of Hemorrhagic Stroke:

• Hemorrhagic strokes are caused by arteries in the brain either leaking blood or bursting open. The leaked blood puts pressure on brain cells and damages them. It also reduces the blood supply reaching the brain tissue after the hemorrhage point. Blood vessels can burst and spill blood within the brain or near the surface of the brain, sending blood into the space between the brain and the skull.

• Causes of Transient Ischemic Attack (TIA):

• TIAs are different from the kinds above because the flow of blood to the brain is only briefly interrupted. TIAs are similar to ischemic strokes. In that, they are often caused by blood clots or other clots. TIAs should be regarded as medical emergencies just like the other kinds of stroke, even if the blockage of the artery and symptoms are temporary. They serve as warning signs for future strokes and indicate that there is a partially blocked artery or clot source in the heart. 

Risk Factors 

• Uncontrolled hypertension, 

• Diabetes mellitus, 

• Smoking, 

• Cardiac disease, 

• Hyperlipidemia, 

• Excessive alcohol intake

Symptoms 

• Strokes occur quickly, so symptoms often appear suddenly and without warning. The main symptoms of stroke are:

•  Muscular: 

• Difficulty walking, paralysis with weak muscles, problems with coordination, stiff muscles, overactive reflexes, or paralysis of one side of the body. Whole body: Balance disorder, fatigue, light-headedness, or vertigo. 

•  Visual: 

• Blurred vision, double vision, sudden visual loss, or temporary loss of vision in one eye. 

•  Speech: 

• Difficulty in speaking, slurred speech, or speech loss. Sensory: Reduced sensation of touch, even by applying pins and needles. 

•  Facial:

•  Muscle weakness or numbness.

•  Limbs: 

• Numbness or weakness. Common: Difficulty in swallowing, headache, inability to understand, mental confusion, or rapid involuntary eye movement.

Tests and Diagnosis 

• There are several different types of diagnostic tests that can be used to determine which type of stroke has occurred: 

• Physical examination: 

• It consists of measurement of blood pressure, listen to the carotid arteries in the neck, and examine the blood vessels at the back of the eyes, all to check for indications of clotting. 

• Blood tests:

•  A doctor may perform blood tests to find out how quickly the patient's blood clots. The levels of particular substances (including clotting factors) in the blood, and whether or not the patient has an infection.

• CT scan: 

• A series of X-rays that can show hemorrhage's, strokes, tumors, and other conditions within the brain. 

• MRI scan: 

• Radio waves and magnets create an image of the brain to detect damaged brain tissue.

• Carotid ultrasound: 

• An ultrasound scan to check the blood flow in the carotid arteries and to see if there is any plaque present.

•  Cerebral angiogram: 

• Dyes are injected into the brain's blood vessels to make them visible under X-ray, to give a detailed view of the brain and neck blood vessels.

• Echocardiogram: 

• A detailed image of the heart is created to check for any sources of clots that could have travelled.

Treatment 

• Drug Treatment: 

• There is only one Food and Drug Administration (FDA) approved drug treatment for acute ischemic stroke. Tissue plasminogen activator (tPA) is given via intravenous therapy (IV) and works by dissolving the clot and improving blood flow to the part of the brain being deprived of blood flow. tPA should be given within three hours (and up to 4.5 hours in certain eligible patients) of the time symptoms first started.

•  Mechanical Devices: 

• Some ischemic strokes are treated with small mechanical devices that remove or break up blood clots. If clot-busting drugs are ruled out, another option one of the many FDA approved mechanical devices. 

• A surgeon inserts a small mechanical device into the blocked artery using a thin tube. Once inside, the tool traps the clot, and either breaks it up or the surgeon pulls it out of the brain, reopening the blocked blood vessel in the process.

Complications

• Left untreated, schizophrenia can result in severe emotional, behavioral and health problems, as well as legal and financial problems that affect every area of life. Complications that schizophrenia may cause or be associated with include: • Suicide, 

• Any type of self-injury,

• Anxiety and phobias, 

• Depression, 

• Abuse of alcohol, drugs or prescription medications, 

• Poverty, 

• Homelessness, 

• Family conflicts, 

• Inability to work or attend school,

• Social isolation, 

Prevention 

• Eating a healthy diet. 

• Maintaining a healthy weight. 

• Exercise regularly. 

• Do not smoke. 

• Avoiding alcohol or drink moderately.

• Keeping blood pressure under control.

• Managing diabetes. 

• Treating obstructive sleep apnea (if present). 

Alzheimer's Disease

• Alzheimer’s disease (AD) is a progressive, degenerative disorder that attacks the brain’s nerve cells, or neurons especially in the cerebral cortex, resulting in loss of memory, thinking and language skills, and behavioural changes. A degenerative brain disease of unknown cause that is the most common form of dementia or loss of intellectual function, is generally found among people aged 65 and older. A common form of dementia of unknown cause, begin in late middle age, characterized by progressive memory loss and mental deterioration associated with brain damage. A disease marked by the loss of cognitive ability, generally over a period of 10 to 15 years and associated with the development of abnormal tissues and protein deposits in the cerebral cortex. Alzheimer's disease is a condition in which nerve cells in the brain die, making it difficult for the brain's signals to be transmitted properly. Alzheimer’s symptoms may be hard to distinguish early on. A person with Alzheimer's disease has problems with memory, judgment, and thinking, which makes it hard for the person to work or take part in day-to-day life. The death of the nerve cells occurs gradually over a period of years. 

Causes 

• The causes of depression are not fully understood and may not be down to a single source. Depression is likely to be due to a complex combination of factors that include:

• Genetics 

Biological:

• Changes in neurotransmitter levels 

• Environmental 

• Psychological and social (psychosocial) Some people are at higher risk of depression than others; risk factors include:

Life events:

• Including bereavement, divorce, work issues, relationships with friends and family, financial problems, medical concerns, or acute stress.

Personality:

• Those with less successful coping strategies, or previous life trauma. 

• Genetic factors: 

• First-degree relatives of depressed patients are at higher risk. 

• Childhood trauma. 

• Some prescription drugs:

•  Including corticosteroids, some β-blockers, interferon, and other prescription drugs. 

• Abuse of recreational drugs (including alcohol and amphetamines): 

• Can accompany depression or result in it. There are strong links between drug abuse and depression. 

• A past head injury.

• People who have had an episode of major depression are at higher risk of a subsequent one. 

• Chronic pain syndromes in particular, but also other chronic conditions, such as diabetes, chronic obstructive pulmonary disease, and cardiovascular disease.

Types of AD 

• Early onset AD: 

• Symptoms appear before age 60. This type is much less common than late onset. However, it tends to get worse quickly. Early onset disease can run in families. Several genes have been identified.

•  Late onset AD: 

• This is the most common type. It occurs in people after age 60 and older. It may run in some families, but the role of genes is less clear.
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Symptoms

• People with depressive illnesses do not all experience the same symptoms. The severity, frequency and duration of depression depending on the individual’s particular illness. Although depression may occur only one time during life, usually people have multiple episodes of depression. During these episodes, symptoms occur most of the day, nearly every day and may include:

• Feelings of sadness, emptiness or unhappiness. Angry outbursts, irritability or frustration, even over small matters. 

• Loss of interest or pleasure in normal activities, such as sex.

• Sleep disturbances, including insomnia or sleeping too much. 

• Tiredness and lack of energy, so that even small tasks take extra effort  

Risk Factors

• Increasing age is the greatest known risk factor for Alzheimer's. Alzheimer's is not a part of normal aging, but risk increases greatly after age 65. Nearly half of those older than age 85 have Alzheimer's

• Family history and genetics:

•  Risk of developing Alzheimer's appears to be somewhat higher if a first-degree relative (parent or sibling) has the disease. Scientists have identified rare changes (mutations) in three genes that virtually guarantee a person who inherits them will develop Alzheimer's. But these mutations account for less than 5 % of Alzheimer's disease.

•  Sex: 

• Women may be more likely than are men to develop Alzheimer's disease. Mild cognitive impairment have an increased risk. 

•  Past head trauma: 

• People who have had a severe head trauma or repeated headframe appear to have a greater risk of Alzheimer's disease. 

•  Lifestyle and heart health: 

• Some evidence suggests that the same factors that put at risk of heart disease also may increase the chance to develop Alzheimer's. Examples include: Lack of exercise, Smoking, High blood pressure, High blood cholesterol, Elevated homocysteine levels, poorly controlled diabetes and a diet lacking in fruits and vegetables.   

Diagnosis

• There is no specific test that confirms Alzheimer's disease. Alzheimer's disease can be diagnosed with complete accuracy only after death, when microscopic examination of the brain reveals the characteristic plaques and tangles. To help distinguish Alzheimer's disease from other causes of memory loss, doctors now typically rely on the following types of tests. A skilled health care provider can often diagnose Alzheimer's disease with the following steps: 

•  Complete physical exam:

•  It includes neurological exam, medical history and symptoms which includes, reflexes, muscle tone and strength, ability to get up from a chair and walk across the room, sense of sight and hearing, co-ordination and balance. 

•  A mental status examination: 

• A brief mental status test to assess memory and other thinking skills. A diagnosis of Alzheimer's disease is made when certain symptoms are present, and by making sure other causes of dementia are not present. Tests may be done to rule out other possible causes of dementia, including

Treatment 

• Although there is no cure, Alzheimer's medications can temporarily slow the worsening of symptoms and improve quality of life for those with Alzheimer's and their caregivers. The U.S. Food and Drug Administration (FDA) has approved five medications (listed below) to treat the symptoms of Alzheimer's disease. 

•  Exercise: 

• Regular exercise has known benefits for heart health and may also help prevent cognitive decline. Exercise may also help improve mood. 

•  Nutrition: 

• People with Alzheimer's may forget to eat, lose interest in preparing 

• Prevention  meals or not eat a healthy combination of foods. They may also forget to drink enough water, leading to dehydration and constipation.

 Prevention 

• Although there is no proven way to prevent Alzheimer's disease, there are some practices that may be worth incorporating into daily routine, particularly with family history of dementia. Consume a low-fat diet, eat Coldwater fish (like tuna, salmon and mackerel) rich in ω-3 fatty acids, at least 2 to 3 times per week, reduce intake of linoleic acid found in margarine, butter, and dairy products, increase antioxidants like carotenoids, vitamin E and vitamin C by eating plenty of darkly closured fruits and vegetables, maintain a normal blood pressure and stay mentally and socially active throughout life.