[Empyema and subdural effusion after meningitis. 2 cases of unusual location].

A 12-year old child and a 2-month old infant developed, in the wane of a purulent meningitis, the former, an infratentorial subdural empyema, the latter, a large, encapsulated, haemoorhagic, aseptic subdural effusion, in the right parieto-temporo-occipital region. In both cases, signs of intracranial hypertension dominated the clinical picture. Neuroradiological investigations permitted diagnosis and localisation of the expansive processes, whose subdural position was recognized at operation and confirmed by histopathological examination. According to the literature, purulent meningitis is a rare cause of subdural empyema, except in infants; the solely infratentorial location is also unusual. Sterile subdural effusion is a more common complication of purulent meningitis in infancy, but the unilateral posterior supratentorial location is also a peculiar feature. Subdural collections after memingitis may be aseptic and possibly haemorrhagic, or septic and purulent; these different modes of presentation correspond perhaps to different degrees or stages of subdural pathological changes in the neighbourhood of leptomeningeal infection.