Central Nervous System Health Article

Alzheimer's disease

Alzheimer's disease (AD), a progressive, neurodegenerative disease, is the most common cause of dementia in later life. The course of the disease varies from person to person. Although the cause of AD is not yet known, researchers have found a familial tendency for AD. They have also implicated several possibilities including genetics, environmental factors, and biochemical changes in the brain caused by low levels of certain neurotransmitters. AD usually begins after age 65, however, it may have an early onset as early as age 40.

SYMPTOMS. The severity and progression of symptoms vary from person to person. Some of the early symptoms of AD, such as forgetfulness or loss of concentration, can easily be overlooked because they resemble signs of aging or could result from fatigue, depression, or the use of certain medications. Symptoms of AD include:

• memory loss, confusion, loss of concentration
• difficulty recognizing family and friends
• poor judgment, indifference
• changes in behavior and personality
• disorientation, wandering, sleep disturbance
• agitation, anxiety, depression

There is no specific test to confirm a diagnosis of AD. A combination of tools including brain imaging technologies, patient and family history, physical and neurological examination, and neuropsychological testing are utilized to definitively diagnose AD. There is no cure for AD and no clinically proven way to slow the progression of the disease. For some patients, medication may alleviate some of the symptoms. Treatments are intended to make the patient more comfortable.

Stroke

Stroke, also called cerebral vascular accident (CVA), occurs when the blood flow to part of the brain is disrupted. There are primarily two categories of stroke, ischemic and hemorrhagic. The most frequent cause of stroke is a blockage (ischemic) of a blood vessel in the brain. The blockage can have several causes but all with the same result, brain cell damage or death. Brain cells cannot survive without a blood supply of oxygen and nutrients. Blockage of blood flow in the brain can be caused by a clot in a blood vessel (thrombosis) of the brain, the movement of a clot from another part of the body (embolism) to the brain, or a severe narrowing of an artery in the brain (stenosis). In a hemorrhagic stroke, a blood vessel in the brain bursts, bleeding into the brain (intracerebral hemorrhage) or into the spaces surrounding the brain.

SYMPTOMS. The signs and symptoms of stroke depend on the areas of the brain affected and the functions they control. The right cerebral hemisphere controls the left side of the body and the left cerebral hemisphere controls the right side of the body. The symptoms of stroke may be:

• sudden numbness or weakness, especially on one side of the body
• sudden confusion, difficulty speaking, or understanding speech
• sudden difficulty seeing in one or both eyes
• sudden trouble walking
• sudden dizziness, loss of balance or coordination
• sudden severe headache
• paralysis, pain

Risk factors for stroke are either changeable or not. For example, a person cannot change their age or family history, but they can change behaviors, like smoking, that put them at risk for a stroke. Risk factors for stroke include:

• high blood pressure
• heart disease
• diabetes
• smoking
• heavy alcohol consumption
• drug abuse
• high blood cholesterol levels
• family history of stroke or TIA
• age over 55

According to the National Center for Health Statistics, stroke is the third leading cause of death in the United States. In order to improve this statistic, patients need prompt interventions. The public education campaign, "Know Stroke: Know the Signs. Act in Time," promoted by the National Institute of Neurological Disorders and Stroke (NINDS) teaches people how to recognize the signs and symptoms of stroke and the importance of prompt medical treatment to improve recovery. Tissue plasminogen activator (t-PA), the first Food and Drug Administration (FDA) approved acute ischemic stroke treatment, needs to be given within a three-hour window of the onset of symptoms to dissolve the clot. Stroke is diagnosed by a neurological examination, blood tests, brain imaging scans, Doppler ultra-sound, or arteriography.