Acute basal ganglia necrosis with favorable course during Mycoplasma encepahlitis

Background: Acute bilateral striatal necrosis complicating the course of a post-infectious encephalitis is rare.

Methods: A previously healthy 5-year-old boy presented with an atypical pneumonia; he rapidly developed, encephalitis revealed by a generalized status epilepticus. After transient improvement, he became confused and mutic, with dystonic postures of his limbs. Painful stimulation resulted in prolonged facial grimacing and doleful cry. CT scan and MRI showed abnormal signals in the whole basal ganglia, typical of bilateral striatal necrosis. Serologic tests for Mycoplasma pneumoniae were positive. The child recovered almost completely.

Conclusions: A parainfectious process is probably responsible for the transient bilateral striatal necrosis seen in this patient who had Mycoplasma pneumoniae infection several days before the onset of neurologic symptoms. MRI seemed more reliable than CT-scan for the diagnosis of this condition.