Subdural effusion in type B Haemophilus influenzae meningitis. A study of 38 cases

OBJECTIVE: Studying clinical, laboratory and radiologic findings, as well as outcome, observed in patients with meningitis caused by Hib, and its relationship with subdural effusion. MATERIAL AND METHODS: Retrospective study of 38 meningitis caused by Hib. Patients were aged between 3 months and 5 years. Imaging was performed in 26 cases (68%): CT in 21 children (55%) and cranial sonography in 11 cases (29%). EEG was made in 29 patients (76%) and auditory-evoked potentials in 13 (34%). The mean follow-up period after discharge was 24 months. RESULTS: Sixty-six per cent were male and 34% female. Eight cases had subdural effusion. These patients showed higher white cell counts in blood and CSF, higher levels of proteins in CSF, and lower levels of glucose in the same medium. They also had seizures before or during hospitalization, with higher frequency than those without subdural effusion (50% vs 26%) as well as more prolonged fever (127 vs 73 hours). No specific treatment was required in any case. CONCLUSIONS: Subdural effusion is one of the most frequent complications observed in meningitis. Patients frequently present more important clinical and laboratory alterations. This finding is not related with neurologic sequelae and they resolve spontaneously with time.