Great job! This patient's case was particularly challenging because there weren't any clear imaging findings for a very bad exam finding (fixed and dilated pupils with obtundation). This highlights how you can't totally rely on the presence of neuroimaging abnormalities to rule out dangerous etiologies such as fungal meningitis. In retrospect, as we recommended the usual acute workup of EEG and LP, we could've paused to ask ourselves: could one of the things for which we're looking-- say, infectious meningoencephalitis from an atypical organism-- cause a dangerous process that should be empirically treated, such as intracranial hypertension? We think a lot about TIAs, seizures, and migraines being the only causes of episodic neurologic dysfunction. However, plateau waves should also make that list, at least in a patient like this who is at high risk. Even though it was great that the patient [briefly] regained her mental status and pupillary function, that was another chance to re-evaluate what was happening.
We really had to challenge ourselves to avoid anchoring bias and to re-formulate the patient's presentation to come up with the correct diagnosis and management. Plateau waves are under-recognized, yet missing the diagnosis can be fatal. We also had to recall that therapeutic CSF drainage, even from LPs, is actually very much indicated BECAUSE of the elevated ICPs in this patient, contrary to standard convention.
When called to evaluate a patient for episodic neurologic signs/symptoms, it makes sense to think of common etiologies such as seizures and strokes. However, plateau waves are underappreciated and probably more common than we realize. Don't anchor and fall for the trap of evaluating only for seizure vs. stroke and then walking away. Consider whether something like intracranial hypertension could be the etiology, and whether anything in the patient's presentation could suggest a more ultimate cause for it.
When called to evaluate a patient for episodic neurologic signs/symptoms, it makes sense to think of common etiologies such as seizures and strokes. However, plateau waves are underappreciated and probably more common than we realize. It's easy to only think of big things like cerebral herniation from masses when you encounter findings like fixed and dilated pupils. However, when neuroimaging is unrevealing for this, don't forget to consider whether something like intracranial hypertension could be the etiology. Neuroimaging can also be normal even in Cryptococcal meningitis.
Again, part of what is unique about managing Cryptococcal meningitis is that it is an edge case of when you can actually drain CSF via LPs despite the high ICPs. If you can't do this via LPs, then going from above-- via an EVD-- should be pursued.
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