Nervous system diseases and cerebrovascular disease

Because the CNS and PNS are so complex, diseases and conditions that affect them can produce a wide range of signs and symptoms. Causes include trauma, infection, congenital anomalies, degeneration, tumors, and vascular disorders. The medical assistant needs to listen carefully when a patient describes his or her neurologic symptoms. Many different types of symptoms can indicate a serious condition of the nervous system.

Common diseases and conditions of the nervous system

Disease	Signs, symptoms, and etiology
Alzheimer’s disease	Short-term memory loss, irreversible confusion, disorientation; cause unknown, familial link
Brain tumor	Depends on location, generally caused by increased ICP, can be a primary tumor, but typically metastasis
CVA	Depends on severity; speech difficulties, hemiplegia, confusion, loss of muscle coordination; caused by thrombus, embolus, hemorrhage
Encephalitis	Increased ICP, cerebral edema; caused by virus
Epilepsy	Grand mal: Tonic-clonic muscle contractions, petit-mal: momentary absence, stare, amnesia; cause unknown
Closed head Injury; Trauma	Depends on location and severity of injury; headache, increased ICP; caused by trauma
Meningitis	Headache, flu-like symptoms, nuchal rigidity, seizures
Migraine	Unilateral throbbing headache, nausea, vomiting, blurred vision; individual triggers, caused by a combination of trigeminal nerve abnormality and imbalance or neurotransmitter serotonin
Multiple sclerosis	Vision problems, sensation, motor function; autoimmune disease, progressive inflammation and deterioration of the myelin sheath
Parkinson’s disease	Resting tremor, shuffling gait, masklike face; combination of genetic and environmental factors, deficiency of neurotransmitter dopamine

Cerebrovascular disease

Cerebrovascular disease (CVD) is the fourth leading cause of death and the most frequent cause of crippling disease in the United States. Generally, CVD is related to arteriosclerosis or atherosclerosis of the cerebral arteries, but it can also be caused by untreated or uncontrolled hypertension, cerebral hemorrhage, thrombi, or emboli. Arteriosclerosis causes progressive loss of elasticity of the arterial wall and is seen in elderly individuals with CVD. Atherosclerosis, the deposit of fatty plaque on the inside of the arterial wall, can involve any of the major arteries supplying the brain or any of their branches. Sudden narrowing, or occlusion, may occur when an artery becomes blocked by a thrombus or an embolus.

CVD is usually diagnosed through cerebral arterial angiography, in which a radiopaque dye is injected into the suspect vessel, and an X-ray film is immediately taken. Other confirming tests include magnetic resonance imaging (MRI), computed tomography (CT), and electroencephalography.

Signs and symptoms suggesting possible neurologic problems:

• Recurrent headache
• Periodic memory loss
• Change in sleeping patterns
• Frequently dropping items
• Difficulty with particular speech patterns
• Numbness in a specific body area
• Visual disturbances or abrupt changes in vision
• Loss of consciousness
• Confusion or disorientation as to date, time, and place

Transient ischemic attacks (TIAs)

Transient Ischemic Attacks (TIAs), also called ministrokes, occur when the blood supply to a particular part of the brain is inadequate for a limited time, and symptoms typically disappear within an hour. TIAs occur when brain tissue becomes ischemic for a short time, causing the same symptoms as a stroke. Because the cause of the ischemia is limited, the symptoms dissipate quickly. Symptoms can include numbness or weakness in the face, arm, or leg or on one side of the body; confusion or difficulty talking or understanding speech; vision abnormalities, including diplopia; difficulty walking; and vertigo or loss of balance and coordination.

These episodes may occur in the days, weeks, or months before a stroke. Patients and their families should understand that any stroke-like symptom should be taken seriously. Approximately one-third of individuals experiencing TIAs have an acute stroke sometime in the future. Therefore, those experiencing TIAs should be seen within 1 hour of the onset of symptoms so that they can be evaluated carefully and treated to prevent a possible stroke. Depending on the person’s health history and the results of a medical examination, the provider will recommend medications or surgery to reduce the risk of stroke. Individuals with atrial fibrillation (an irregular, rapid firing of electrical activity in the atria of the heart) may be prescribed anticoagulants (e.g., heparin or warfarin [Coumadin]), or they may be put on daily low-dose aspirin or clopidogrel (Plavix), because these individuals are at increased risk of embolism formation. When TIAs occur, it is time for preventive treatment and patient education, including altering and/or treating such factors as hypertension, smoking, heart disease, diabetes, carotid artery disease (carotid artery occlusion with atherosclerotic plaques), and heavy alcohol abuse.

Cerebrovascular accident

A cerebrovascular accident (CVA) is the most important clinical manifestation of CVD. A CVA, commonly referred to as a stroke, occurs when a vessel in the brain either ruptures or becomes occluded, and brain cells on the other side of the damaged vessel become oxygen-deprived. Cerebral artery ruptures are caused by uncontrolled hypertension or hemorrhaging of a weakened section of an artery in the brain. As a result of the rupture, the surrounding brain tissue fills with blood, damaging and possibly destroying the affected tissue. An occlusion occurs when an embolus or thrombus becomes wedged in an artery and obstructs the flow of blood to an area of the brain.

The patient’s symptoms depend on the location of the arterial occlusion or rupture. Some of the more common symptoms include slurred speech, unexplained confusion, sudden, severe headache, difficulty swallowing, vertigo, diplopia, loss of consciousness, personality change, loss of bowel or bladder control, and paralysis on one side of the body. The diagnosis of a CVA begins with a physical examination to assess the patient for the signs and symptoms of a stroke. The exam is repeated over time to see whether symptoms are getting worse or improving. The medical assistant should immediately check the patient’s blood pressure to determine whether the cause of the CVA is hypertension. The physician will also listen to the carotid arteries with a stethoscope for a bruit. If a bruit is present, it indicates atherosclerotic buildup in the carotid arteries. The CVA may have been caused by a piece of the plaque that broke off and became lodged in a cerebral blood vessel.

The type of CVA must be determined as soon as possible so that the best treatment can be provided. The following diagnostic studies are ordered immediately:

• Angiogram of the head to look for a blood vessel that is blocked or bleeding
• Carotid duplex (ultrasound) to see whether the carotid arteries are blocked or narrowed
• Echocardiogram to see whether the stroke was caused by a blood clot from the heart (this frequently occurs with atrial fibrillation)
• Magnetic resonance angiography (MRA) or CT angiography to check for abnormal blood vessels in the brain; this confirms the presence of a vessel bleed

Treatment of a stroke requires immediate emergency transport to the hospital. The initial emphasis is on minimizing the long-term disabilities often seen with strokes by providing immediate treatment to prevent additional brain tissue damage. Thrombolytic drugs to dissolve the clot and anticoagulants may be given if the cause of the stroke was a thrombus or an embolus. However, thrombolytic medication can effectively treat resulting ischemia only if they are given within the first 3 to hours of when the symptoms first started. The sooner this treatment begins, the better the chance of a good outcome. If cerebral edema is present, the patient is treated with corticosteroids and diuretics to reverse the swelling. Hyperbaric oxygen also can be used to increase oxygenation of the brain. An important part of recovery is extensive treatment in a stroke rehabilitation program that includes physical, occupational, swallowing, and speech therapies.

Treatment of a stroke requires immediate emergency transport to the hospital. The initial emphasis is on minimizing the long-term disabilities often seen with strokes by providing immediate treatment to prevent additional brain tissue damage. Thrombolytic drugs to dissolve the clot and anticoagulants may be given if the cause of the stroke was a thrombus or an embolus. However, thrombolytic medication can effectively treat resulting ischemia only if it are given within the first 3 to hours of when the symptoms first started. The sooner this treatment begins, the better the chance of a good outcome. If cerebral edema is present, the patient is treated with corticosteroids and diuretics to reverse the swelling. Hyperbaric oxygen can also be used to increase oxygenation of the brain. An important part of recovery is extensive treatment in a stroke rehabilitation program that includes physical, occupational, swallowing, and speech therapies.