Abstract: As so often in uncommon syndromes difficulties in diagnosis are a
problem, especially when symptoms are strange and suggest a psychiatric
disorder. Such an example is the Kleine-Levin syndrome. It occurs mainly during
adolescence, and may last for a number of years, but the prognosis for most
patients is excellent. The symptoms are described, especially the triad of
episodes of hypersomnia, compulsive food intake and abnormal behavior; and also
the signs of autonomic dysfunction. The unusual symptoms can lead to social
withdrawal and inter-episodic morbidity. In addition there may be evidence of
long-term effects such as impaired recent memory. Investigations are likely to
be negative, except for the electroencephalogram, which can be abnormal;
especially during sleep. The differential diagnosis is discussed, particularly
from other sleep disorders, and from psychiatric conditions. The definite cause
of the syndrome is not known, but a disturbance of diencephalic function can
explain the symptoms, and they have been recorded after injury to this part of
the brain. There may well be a primary disturbance in the balance of
neurotransmitters. Treatment with a variety of drugs has been tried, and the
response to lithium has been the most encouraging.
