Basal ganglia infarction complicating basilar meningitis: visualization by serial magnetic resonance imaging.

signs. The temperature remained between 39 and 39.5 ° C until the 10th day of the therapy and the patient was discharged home after 23 days of parenteral antimicrobial therapy. No surgical intervention was required. Neurologic examination on discharge was normal. The diagnosis on discharge was: basilar meningitis with cerebral vasculitis and stroke following sphenoid sinusitis. A follow-up MRI 39 days after hospital admission demonstrated regression of the temporal empyema and resolution of the sphenoid abnormality. Subacute left basal ganglia infarction was visualized ( fi g. 2 a, b). The patient was no longer lethargic. MRI visualizes the location, extent and intensity of intracranial infl ammatory processes. After the initiation of antimicrobial therapy, a temporary increase in infl ammatory signs is often demonstrated by MRI. This is not disease progression, but probably represents the infl ammatory host reaction mediated by antigen release induced by the antimicrobial therapy. The infl ammatory stimulus leads to an increase in the water content, mediated by disruption of the blood-brain barrier and direct toxic effects. Even though the increase in the water content rarely exceeds 10–20%, it allows the visualization of infl ammation by MRI [1] . Dear Sir, We report a 10-year-old with a 10-day history of headache and photophobia. Four days prior to admission to the Children’s Hospital, fever above 39 ° C persisted. There was marked neck stiffness. Neurologic examination was otherwise normal. There was no postnasal drip. Laboratory evaluation showed a peripheral white blood cell count of 17 ! 10 9 /l, 18.0% band forms, 63% segmented neutrophils. The erythrocyte sedimentation rate was 72 mm/h. Cerebrospinal fl uid (CSF) analysis revealed a white blood cell count of 4,567/mm 3 with 4,050 polymorphonuclear and 517 mononuclear cells. CSF glucose was 0.3 mmol/l (1.6–3.9 mmol/l), CSF protein was 1.51 g/l ( ! 0.44 g/l), CSF pressure was normal. No organisms were identifi ed on gram stain. Antimicrobial therapy with fl ucloxacillin, ceftriaxone and ornidazole was initiated. Despite the therapy, fever persisted and MRI showed left-sided sphenoid sinusitis and a temporal subdural empyema with meningeal enhancement ( fi g. 1 a). In the left basal ganglia, enhancement was noted ( fi g. 1 b). Further imaging showed progressive evolution. During hospitalization, the patient became lethargic and sleepy but was responsive, never comatose; there were never any focal neurological defi cits and Received: July 20, 2005 Accepted: October 12, 2005 Published online: January 6, 2006