[Lethargic encephalitis. Report of one case].

Lethargic encephalitis (LE) is a Central Nervous System disorder following an upper respiratory tract infection, characterized by sleep disturbances, clinical symptoms corresponding to basal ganglia involvement and in some cases, neuropsychiatric sequelae. We report a 18-year-old mole with a history of sinusitis treated with azithromycin, two weeks before, presenting with fever, headache, confusion and myoclonus. Urine analysis was positive for cannabis. Cerebro spinal fluid analysis showed mononuclear pleiocytosis (109xmm³) and an increase in protein concentration of l.6 g/dl. Forty eight hours after admission, the patient required mechanical ventilation and subsequently a status epilepticus appeared. Ten days later, fever, rigidity and resting tremor appeared. A magnetic resonance imaging showed hyperintensities in FLALR sequence in the right insular cortex. The patient continued with extreme rigidity, catatonia and mutism. Considering the possibility ofa LE, methyl prednisolone 1 g/day was administered for five consecutive days followed by prednisone 40 mg l day, observing a dramatic improvement of rigidity and tremors.