Familial dysautonomia is a rare genetic disorder of the autonomic nervous system (ANS) that primarily affects people of Eastern European Jewish heritage. It is characterized by diminished sensitivity to pain, lack of overflow tearing in the eyes, a decrease in the number of knob-like projections that cover the tongue (fungiform papillae), unusual fluctuations of body temperature, and unstable blood pressure.
Dysautonomia refers to a disorder of autonomic nervous system (ANS) function. Several common conditions such as diabetes and alcoholism can include dysautonomia. Dysautonomia also can occur as a primary condition or in association with degenerative neurological diseases such as Parkinson’s disease. Other diseases with generalized, primary dysautonomia include multiple system atrophy and familial dysautonomia. Hallmarks of generalized dysautonomia due to sympathetic failure are impotence (in men) and a fall in blood pressure during standing (orthostatic hypotension). Excessive sympathetic activity can present as hypertension or a rapid pulse rate.
The symptoms of familial dysautonomia include indifference to pain, diminished tearing, poor vasomotor control, motor incoordination, labile cardiovascular reactions, decreased reflexes, frequent attacks of pneumonia, increased salivation with aspiration, difficulty in swallowing, increased vomiting, emotional instability, and an intolerance for anesthetic medications. There is no cure for dysautonomia. Secondary forms may improve with treatment of the underlying disease. In many cases treatment of primary dysautonomia is symptomatic and supportive. Measures to combat orthostatic hypotension include elevation of the head of the bed, frequent small meals, a high-salt diet, and drugs such as fludrocortisone, midodrine, and ephedrine.