Ophthalmoplegia and vision loss in extrapulmonary tuberculosis with bilateral cavernous sinus involvement

We report the case of a 41-year-old woman who initially presented with headache, right hemifacial hypoesthesia, and a right abducens palsy. Initial external investigations failed to identify an etiology, and cerebral MRI was considered normal, although later review revealed subtle meningeal thickening. Approximately two months later, she developed a right pupil-involving oculomotor nerve palsy, followed by progressive visual loss in the right eye, a right inferior quadrantanopia, and a left abducens palsy. Repeat MRI demonstrated a new contrast-enhancing lesion in the right cavernous sinus, vasculitis involving the intracavernous segment of the left internal carotid artery, FLAIR hyperintensity involving the optic chiasm and left optic tract, and dural thickening with contrast enhancement consistent with pachymeningitis. Tuberculosis was suspected based on a positive QuantiFERON-TB Gold test. Cerebrospinal fluid analysis showed mild lymphocytic pleocytosis but was negative for <i>Mycobacterium tuberculosis</i> (<i>M. tuberculosis</i>) by staining, culture, and PCR. Chest imaging was normal; however, 18F-FDG PET-CT identified a hypermetabolic iliac lymph node. Excision revealed epithelioid cell granulomas with caseous necrosis, and PCR testing (Xpert MTB/RIF Ultra) detected <i>M. tuberculosis</i>, confirmed by culture as drug-sensitive. The patient was treated with a four-drug antitubercular regimen combined with corticosteroids, leading to clinical improvement. She experienced neurological worsening during corticosteroid tapering, which resolved after dose escalation. Cavernous sinus involvement is a rare manifestation of tuberculosis, typically occurring without pulmonary disease and with nonspecific imaging or CSF findings. High clinical suspicion is essential, and identification of an accessible extracranial biopsy site may enable definitive diagnosis while avoiding invasive neurosurgical procedures.