Case report

A 33-year-old man presented in 2002 with an acute, severe, occipital headache associated with nausea and photophobia, causing him to collapse to the pavement; there was no persisting neurological impairment. He had mild hypertension, hypercholesterolaemia and asthma, but took no regular medication. His initial neurological examination was normal. A CT scan of head was normal but cerebrospinal fluid (CSF) showed xanthochromia, but was otherwise normal. A four-vessel digital subtraction cerebral angiogram was normal. He took nimodipine for 3 weeks and was discharged.

He subsequently developed recurrent left-sided headaches, each lasting hours to days, with backache and dizziness, nausea and photophobia. These varied in frequency and severity but progressed over time, eventually having more days with headache than without. Following a more severe episode, he required hospital admission, with a diagnosis of migraine. In 2008, he developed neck pain with tingling in his left middle finger. An MR scan of cervical spine showed a posterior osteophytic bar with root impingement at C5/6 and C6/7. He obtained temporary relief from a nerve root blockade at both levels but eventually underwent a C5/6/7 anterior cervical decompression and fusion.

In 2014, he became progressively unsteady and developed a subtle right-hand tremor. One day he woke with severe headache with nausea, vomiting and photophobia, with worsened unsteadiness. On examination there was mild ataxia on tandem gait with scanning dysarthria. CT scan of …