Case-Based Modules > Case 34 > Stage 2

Sorry! You're on the right track. If you chose this, that means you probably sensed something fishy here. This patient had a suspicious finding on MRI with the right-sided hemispheric (mainly temporal, occipital, insular) cortical diffusion restriction, along with right frontal-maximal LPDs on cEEG. (What organism could be responsible for this constellation of findings?) If your pre-test probability of infection was high and you didn't expect to find anything on the initial culture, it makes sense to repeat an LP and continue his current antimicrobials as-is. However, we could perhaps narrow things slightly. There haven't been any findings suggestive of Listeria, in terms of CSF profile or culture (though cultures are often negative-- it's an intracellular organism), so it'd be reasonable to stop the ampicillin. With the pretty unimpressive WBC, something like pneumococcal or meningococcal meningitis is probably less likely, so it'd be reasonable to stop IV vancomycin and ceftriaxone (latter also helps cover GNRs). What about HSV though? His HSV PCR was negative...

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