Neurologic Disorders



Neurologic Disorders





ACCELERATION-DECELERATION INJURIES

Acceleration-deceleration cervical injuries (commonly known as whiplash) result from sharp hyperextension and flexion of the neck that damages muscles, ligaments, disks, and nerve tissue. The prognosis for this type of injury is usually excellent; symptoms usually subside with treatment of symptoms.


Causes



  • Motor vehicle and other transportation accidents


  • Falls


  • Sports-related accidents


  • Crimes and assaults







ALZHEIMER’S DISEASE

Alzheimer’s disease is a progressive degenerative disorder of the cerebral cortex, especially the frontal lobe. It affects approximately 5 million Americans; by 2030, that figure may reach 7.7 million. It’s the seventh-leading cause of death in the United states.


The disease has a poor prognosis. Typically, the duration of illness is 8 years, and patients die 2 to 5 years after the onset of debilitating brain symptoms.


Causes



  • Exact cause unknown


Possible Contributing Factors



  • Genetic patterns


  • Beta-amyloid plaque development


  • Inflammatory and oxidative stress processes


  • The role of estrogen in the brain







AMYOTROPHIC LATERAL SCLEROSIS

Commonly called Lou Gehrig’s disease, after the New York Yankees first baseman who died of this disorder, amyotrophic lateral sclerosis (ALS) is the most common of the motor neuron diseases causing muscular atrophy. A chronic, progressively debilitating disease, ALS may be fatal in less than 1 year or continue for 10 years or more, depending on the muscles affected. More than 30,000 Americans have ALS; the disease affects three times as many men as women.



Causes

The exact cause is unknown. A genetic (familial ALS “FALS”) link is seen in 10% of all ALS cases. A specific gene mutation in an enzyme known as superoxide dismutase 1 has been identified in about 20% of FALS cases. Over 90% of cases of ALS occur randomly with no identifiable cause and no risk factors and are referred to as sporadic ALS. Several theories have been proposed that explain why motor neurons die, including:



  • glutamate excitotoxicity


  • oxidative injury


  • protein aggregates


  • axonal strangulation


  • autoimmune-induced calcium influx


  • viral infections


  • deficiency of nerve growth factor


  • apoptosis (programmed cell death)


  • trauma


  • environmental toxins.







ARTERIOVENOUS MALFORMATION

Arteriovenous malformations (AVMs) are tangled masses of thin-walled, dilated blood vessels between arteries and veins that aren’t connected by capillaries. AVMs are common in the brain, primarily in the posterior portion of the cerebral hemispheres. Abnormal channels between the arterial and venous system mix oxygenated and unoxygenated blood and thereby prevent adequate perfusion of brain tissue.

AVMs range in size from a few millimeters to large malformations extending from the cerebral cortex to the ventricles. Usually, more than one AVM is present. Males and females are equally affected. Some evidence exists that AVMs occur run in families.



Causes



  • Congenital: hereditary defect


  • Acquired: trauma such as penetrating injuries







BELL’S PALSY

Bell’s palsy is a disease of the facial nerve (cranial nerve VII) that produces unilateral or bilateral facial weakness. Onset is rapid. In 80% to 90% of patients, it subsides spontaneously and recovery is complete in 1 to 8 weeks. If recovery is partial, contractures may develop on the paralyzed side of the face. Bell’s palsy may recur on the same or opposite side of the face.



Causes



  • Infection such as herpes simplex virus


  • Tumor


  • Meningitis


  • Local trauma


  • Lyme disease


  • Hypertension


  • Sarcoidosis







BRAIN TUMORS

Brain tumors are abnormal growths that develop after transformation of cells within the brain, cerebral vasculature, or meninges. They’re usually referred to as benign or malignant. Malignancy in the brain is graded on the degree of cellularity, endothelial proliferation, nuclear atypia, and necrosis. Highly malignant brain tumors are aggressive tumors that grow and multiply rapidly. Survival and prognosis are directly related to tumor grade. However, even though benign tumors lack aggressiveness, they can be as devastating neurologically depending on their size and location. The most common types of primary brain tumors are gliomas, meningiomas, and pituitary adenomas.



Causes



  • Unknown in most cases


  • A genetic loss or mutation


  • Prior cranial radiation exposure







CEREBRAL ANEURYSM

In an intracranial, or cerebral, aneurysm, a weakness in the wall of a cerebral artery causes localized dilation. Cerebral aneurysms usually arise at an arterial junction in the circle of Willis, the circular anastomosis connecting the major cerebral arteries at the base of the brain. Many cerebral aneurysms rupture and cause subarachnoid hemorrhage.



Causes



  • Congenital defect


  • Degenerative process such as atherosclerosis


  • Hypertension


  • Trauma


  • Infection







DEPRESSION

Depression is a chronic and recurrent mood disorder. Although many people may feel depressed at one time or another, clinical depression is defined when the symptoms interfere with everyday life for an extended period. It affects women twice as often as men, and it’s reported to be significantly underdiagnosed and usually inadequately treated.

Forms of depression include major depression, dysthymia, postpartum depression, premenstrual dysphoric disorder, and seasonal affective disorder.



Causes

Some people may have a genetic predisposition to developing depression.


Possible Contributing Factors



  • Disappointment at home, work, or school


  • Death of a friend or relative


  • Prolonged pain or having a major illness


  • Medical conditions, such as hypothyroidism, cancer, or hepatitis


  • Drugs, such as sedatives and antihypertensives


  • Alcohol or drug abuse


  • Chronic stress


  • Abuse or neglect


  • Social isolation


  • Nutritional deficiencies (such as folate and omega-3 fatty acids)


  • Sleeping problems

Sep 22, 2018 | Posted by in ANATOMY | Comments Off on Neurologic Disorders
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