Meningeal sarcoidosis causing intracranial hypertension secondary to dural sinus thrombosis

Up to 5% of cases of sarcoidosis involve the central nervous system and may present with neurological features alone (Delaney, 1977). The characteristic granulomata are usually found in the basal meninges and cause multiple cranial nerve palsies or hydrocephalus. The latter is caused by outflow obstruction to the basal cisterns or the fourth ventricle (Kendall & Tatler, 1978). Space-occupying lesions are less common but may also cause raised intracranial pressure. This report describes a patient with meningeal sarcoidosis presenting with the syndrome of pseudo tumour cerebi, namely with intracranial hypertension without either hydrocephalus or a mass lesion. Sequential CT scans demonstrated meningeal granulomata surrounding and obstructing the major dural sinuses. A 32-year-old West Indian woman presented in 1976 with a 15-month history of headaches and vomiting. Several amblyotic episodes, lasting up to five minutes, occurred in the two months before she was seen and she had noticed a general deterioration in her vision. On examination she had gross bilateral papilloedema with exudates and her visual acuity was 6/60, J20, in the right eye and 6/18, J6, in the left. Visual field loss was present in both upper nasal fields and the blind spots were enlarged. Skull radiographs showed an enlarged pituitary fossa with erosion of the dorsum sellae.