LETHARGY. - A hypnoid state that can be observed in the course of organic diseases of the nervous system (epidemic encephalitis, sleeping sickness), in hysteria (v.) in the forms of neurosis (v.), and in hysteria in particular; in the latter it is sometimes related to convulsive crises, but often independent of them.
In the spontaneous forms, after an initial phase of headache — not constant, however — the patient suddenly falls into a deep sleep (hysterical apoplexy of Debove and Achard) or else develops drowsiness and apathy that progressively increase in intensity up to the lethargic state. On superficial examination, the individual seems simply to be asleep; in reality, muscular relaxation is not complete, the muscles of mastication are slightly but distinctly contracted, and a fine palpebral tremor is frequent; in some cases, schizophrenic catatonic states have been mistaken for l. The face may be pale or even livid; there is generally slow pulse and respiration, and respiratory arrest may occur for entire minutes (the apparent death of hysterics); in a case of Pfendler, cited by Binswanger, respiration stopped for 48 hours, with the disappearance of every sign of life: in such cases, tragic errors may occur (v. MORTE). Examination of sensation shows complete anesthesia; sometimes, however, stimulation of hyperesthetic zones provokes reflex defensive movements, which can interrupt the crisis; moreover, during the lethargy, spontaneous movements are also observed, probably automatic; the cutaneous and corneal reflexes may be abolished, while the tendon reflexes are habitually preserved.
The individual usually swallows food placed in the mouth; at times, instead, the pharyngeal and esophageal reflexes are absent, making feeding difficult. Awakening is sudden or gradual, with laughter, weeping, disconnected phrases; amnesia for everything that happened in the environment during the lethargic period is frequent, but not rarely patients report with exactness what took place around them. The duration of l. can vary from hours to days; in Krauss's case it reached 32 days; Jolly speaks of hysterical sleep prolonged for months, Pfendler for years. The authors of the second half of the last century (Briquet, Charcot, Richer) distinguished three hypnoid states (catalepsy, l., somnambulism) and several varieties of l.: today such subdivisions seem too artificial, and there is a tendency toward a unified framing within hypothalamic vegetopathies. L. occurs classically in the oculo-lethargic form of von Economo's epidemic encephalitis, in which the patient is in the grip of marked drowsiness, from which, however, he can be awakened with relative ease; on awakening he appears oriented, but, left to himself, he falls back into the lethargic state; often he falls asleep again as soon as his position is changed, sometimes while he is eating. Sometimes, in this disease, l. can alternate with states of agrypnia (stubborn insomnia), with notable restlessness especially during the night. In the second stage of sleeping sickness (African trypanosomiasis, caused by Trypanosoma gambiense transmitted by the bite of the tsetse fly), a lethargic state is very frequent, generally intense, often irreversible and resistant to treatment.