Speaking pathophysiologically, increased ICP can be present in Meningitis, but whether that's enough to warrant a CT scan? Almost never. There are some indications where you might need to do a CT scan before going for LP in patients with Meningitis, like immunocompromised patient, new-onset seizures, hx of previous CNS disease, papilledema, focal deficits, etc. If these are present, you need to go for a CT scan. A mild mass effect may be seen in only a handful of patients with meningitis, but even those patients undergo LP without any brain herniation risk.
