Encephalopathies

Encephalopathy literally means disease of the brain. It refers to the central nervous system, or parts of it. Pathologists are more likely to use this term. Descriptions of the living usually refer to dementia. Medical Imaging has made physiopathology more practical on the living, however.

Types
There are several types of encephalopathy: -


 * Glycine encephalopathy
 * Hepatic encephalopathy
 * Hypoxic encephalopathy
 * Static encephalopathy - Unchanging, or permanent, brain damage
 * Uremic encephalopathy
 * Wernicke's encephalopathy
 * Hashimoto's encephalopathy

Symptoms and causes
Encephalopathy alters brain function and/or structure. It may be caused by an infectious agent (bacteria, virus, or prion), metabolic or mitochondrial dysfunction, brain tumor or increased intracranial pressure, prolonged exposure to toxic elements (including solvents, drugs, alcohol, radiation, paints, industrial chemicals, and certain metals), chronic progressive trauma, poor nutrition, or lack of oxygen or blood flow to the brain. It is also known that concomitant use of lithium with other neuroleptics may, in rare cases, cause encephalopathy.

The hallmark of encephalopathy is an altered mental state. Depending on the type and severity of encephalopathy, common neurological symptoms are progressive loss of memory and cognitive ability, subtle personality changes, inability to concentrate, lethargy, and progressive loss of consciousness. Other neurological symptoms may include myoclonus (involuntary twitching of a muscle or group of muscles), nystagmus (rapid, involuntary eye movement), tremor, muscle atrophy and weakness, dementia, seizures, and loss of ability to swallow or speak.

Diagnosis
Blood tests, spinal fluid examination by lumbar puncture, imaging studies, electroencephalograms and similar diagnostic studies may be used to differentiate the various causes of encephalopathy.

Encephalopathy due to acute liver failure is vitally important to define because emergency liver transplantation and/or artificial liver support can save a life. The diagnosis is given by low level of factors of coagubility (V), intense jaundice and brain edema. Electroencephalogram can be useful. Encephalopathy due to chronic liver failure is also easy to recognize and is frequently triggered by protein intake or gastrointestinal bleeding.

Therapy
Treatment is symptomatic and varies, according to the type and severity of the encephalopathy. Anticonvulsants may be prescribed to reduce or halt any seizures. Changes to diet and nutritional supplements may help some patients. In severe cases, dialysis or organ replacement surgery may be needed.

Prognosis
Treating the underlying cause of the disorder may improve or reverse symptoms. However, in some cases, the encephalopathy may cause permanent structural changes and irreversible damage to the brain. Some encephalopathies can be fatal.

Reference

 * Adapted from http://www.ninds.nih.gov/disorders/encephalopathy/encephalopathy.htm