Cranial nerve lesions and abnormal visually evoked potentials associated with the M694V mutation in familial Mediterranean fever.

A 52-year-old Turkish man with familial Mediterranean fever (FMF) due to the homozygous M694V mutation in the MEFV-gene on chromosome 16p13.3, newly developed hemicrania, blurred and double vision, ptosis, ophthalmoparesis and peripheral facial nerve palsy. Except for double vision, all the other abnormalities disappeared spontaneously within 10 days after onset. Markedly prolonged latencies of the visually evoked potentials were also found. At follow-up, 8 months after onset of the neurological abnormalities, right-sided bradydiadochokinesia, right-sided discrete weakness and right-sided hypaesthesia were found. After the exclusion of other hereditary fever syndromes, migraine, stroke, Molaret's meningitis, Behçet's syndrome and mitochondriopathy by clinical, serological, CSF investigations, funduscopy, electroencephalography, and cerebral MRI and MRI angiography, the described neurological abnormalities were regarded as CNS and PNS manifestation of vasculitis or amyloidosis in FMF.