LETARGIA. – A hypnoid state that may be observed in the course of organic diseases of the nervous system (epidemic encephalitis, sleeping sickness), in hysteria (v.) and in forms of neurosis (v.), particularly in hysteria; in the latter it is sometimes associated with convulsive crises, but is often independent of them.
In spontaneous forms, after an initial phase of headache, which is not invariable, the patient suddenly falls into a deep sleep (hysterical apoplexy of Debove and Achard), or develops drowsiness and apathy that progressively increase in intensity until the lethargic state is reached. On superficial examination, the individual appears simply 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; the pulse and respiration are generally slow, and respiratory arrest may last for entire minutes (apparent death of hysterics); in a case of Pfendler, cited by Binswanger, respiration ceased for 48 hours, with the disappearance of every sign of life: in such cases, tragic errors may occur (v. MORTE). Examination of sensibility shows complete anaesthesia; sometimes, however, stimulation of the hyperaesthetic areas produces reflex defensive movements, which may interrupt the crisis; moreover, spontaneous, probably automatic movements are also observed during the lethargic state; the cutaneous and corneal reflexes may be abolished, while the tendon reflexes are usually preserved.
The individual generally swallows food placed in the mouth; at times, however, the pharyngeal and oesophageal reflexes are absent, making feeding difficult. Awakening is sudden or gradual, accompanied by laughter, crying, and disconnected phrases; amnesia for everything that occurred in the surroundings during the lethargic period is frequent, but patients not rarely report with accuracy what took place around them. The duration of l. may vary from hours to days; in Krauss’s case it reached 32 days; Jolly speaks of hysterical sleep lasting for months, and Pfendler for years. Authors of the second half of the last century (Briquet, Charcot, Richer) distinguished three hypnoid states (catalepsy, l., somnambulism) and various types of l.; today these subdivisions seem excessively artificial, and there is a tendency toward a unified classification among the hypothalamic vegetopathies. L. occurs classically in the oculolethargic form of von Economo’s epidemic encephalitis, in which the patient is overcome by marked drowsiness, from which, however, he can be awakened with relative ease; on awakening he appears oriented, but, when left to himself, falls again into the lethargic state; he often falls asleep again as soon as his position is changed, sometimes while eating. At times, in this disease, l. may alternate with states of agripia (obstinate insomnia), with considerable 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 extremely frequent, generally intense, often irreversible, and resistant to treatment.