Diagnosis:
Rare, A diagnosis by exclusion
Note: Pachymeningitis is a radiologic pattern
Clinical features:
Severe headache, cranial nerve palsies, ataxia, loss of vision (optic nerve involvement)
Pathology:
Biopsy: Meningeal Polymorphonuclear infiltration
Findings on Investigations:
MRI:
- T1 +contrast: enhancement of the meninges without enhancement of the sulci. Involves the tentorium, falx, calvarium
- T2: hypointense dura
Investigations to consider:
LP, CSF analysis:
- Opening pressure: low in spontaneous intracranial hypotension
- Routine analysis: infectious meningitis
- Cytology to rule out leptomeningeal carcinomatosis (carcinomatous meningitis)
Biopsy: sarcoidosis, plasmacytic tumors