Pneumococcal meningitis with normal cerebrospinal biochemistry and no pneumococci at microscopy, mimicking a stroke:...

Bacterial meningitis commonly presents with symptoms such as headache, impaired consciousness, neck stiffness, and fever. In most cases, cerebrospinal fluid analysis will yield white cell counts >100/mm³. Atypical presentations occur, especially in the very young or very elderly and the immunocompromised. We report an unusual case of pneumococcal meningitis in a healthy 78-year-old Danish woman who presented with clinical features mimicking a stroke with normal cerebrospinal fluid parameters and without microscopic evidence of bacteria.

The patient was admitted after being found unconscious on her bed. Upon admittance, she was considered confused, with a temperature of 39.4 °C and slight neutrophilic leukocytosis, but no neck stiffness. A neurological examination revealed bilateral horizontal nystagmus, unstable eye movements, and suspected right-sided gaze paralysis. Cerebrospinal fluid analysis revealed normal parameters, and the microscopy result was negative for bacteria. The most likely diagnosis was considered to be stroke with concomitant infection. However, cerebrospinal fluid and blood cultures subsequently were rapidly positive for pneumococci. Neither immunodeficiency nor blood contamination was considered a likely cause of this discrepancy.

This case emphasizes the need to consider a multidisciplinary approach and empirical meningitis treatment until diagnostic results from microbiological cultures are obtained.