Wernicke, Carl
(ver'nĭk-ĕ 
)
Ger. neurologist, 1848–1905.
W. aphasia An injury to the Wernicke area in the temporal lobe of the dominant hemisphere of the brain, resulting in an inability to comprehend the spoken or written word. Visual and auditory pathways are unaffected, but patients are unable to differentiate between words or interpret their meaning. Although patients speak fluently, they are unable to function socially because their ability to communicate effectively is impaired by paraphasia. They also may be unable to repeat spoken words. If the condition is due to a stroke, the aphasia may improve with time. The disorder is often caused by impairment of blood flow through the lower division of the left middle cerebral artery.
SEE: paraphasic speech.
W. area An area in the dominant hemisphere of the brain that recalls, recognizes, and interprets words and other sounds in the process of using language. SYN: Wernicke center.
W. encephalopathy Encephalopathy associated with thiamine (vitamin B1) deficiency.
The disease is less common than formerly because thiamine is routinely given to patients with a history of alcohol use; the disease, however, may be found in more than 10% of chronic alcoholics. It may also develop in patients with severe malnutrition, anorexia nervosa, or hyperemesis gravidarum.
The disease is usually associated with chronic alcoholism or other causes of severe malnutrition, e.g., carcinoid syndrome, chronic gastritis, or Crohn disease.
The patient may present with some or all of the following: ataxia, nystagmus, confusion, impairment of short-term memory, and ophthalmoplegia (paralysis of the ocular muscles).
The disease is diagnosed by its clinical signs and symptoms in an alcoholic patient.
Alcoholics who maintain appropriate nutritional intake can prevent the disease with a diet rich in fruits and vegetables.
Thiamine is given parenterally and /or orally to all patients with a history of alcohol use before the administration of glucose.
Because patients with Wernicke encephalopathy may be confused or delirious and lack the ability to track normally or walk safely, they are at high risk for falling. They frequently lack the ability to participate effectively in their own care. One-to-one supervision, frequent reorientation, and other patient safety measures should be instituted to prevent injuries and misunderstand ings. Any patient who presents to the hospital with a history suggestive of malnutrition should be treated with thiamine urgently. Folate and other multivitamins are also provided to fragile alcoholics, homeless patients, and others at risk. Patients who are not rescued with timely administration of thiamine develop Korsakoffs psychosis, a disease in which the ability to form new memories and learn or incorporate new information is permanently compromised.
Prognosis depends upon severity of the encephalopathy. When treated early, the patient usually recovers from Wernicke encephalopathy rapidly and completely. Advanced encephalopathy, however, may cause serious long-term consequences, with patients requiring long-term or permanent in-patient care.
SYN: amnestic syndrome; Wernicke syndrome.