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. There aren't many causes of episodic neurologic dysfunction, especially with profound dysfunction such as hers. Normal imaging should not completely reassure us. In retrospect, as we followed along with the testing that was recommended, 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? 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 avoid tunnel vision on interventions that would usually be dictated by radiographic changes alone. Plateau waves are under-recognized, yet missing the diagnosis can be fatal. Of course, whether surgery can be offered is complicated, dictated by the clinical circumstances and personal intuition and experience. If the interval between the decline and recognition is short, however, intervention for even palliative purposes is reasonable as long as there are no other disqualifying factors. 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.
Copyright © 2024-2026 Andrew M. Nguyen, M.D. For educational use only.
This work is licensed under
CC BY-NC-SA 4.0.
