A 34 year- old right-handed eccentric woman presented with thunderclap headache and collapse. Her had bipolar disorder diagnosed 1-year prior and was treated with citalopram. She consumed cannabis. Investigations for subarachnoid haemorrhage were negative and she was discharged from Emergency Department. She represented with recurrent severe headache and transient left lower limb weakness. MRI showed small posterior parafalcine subarachnoid haemorrhage; MRA revealed no aneurysm but widespread distal segmental narrowing of the middle cerebral arteries. She deteriorated suddenly and developed left homonymous hemianopia and dense left hemiparesis. Urgent MR showed acute right occipitoparietal infarct; and worsening of her intracerebral arterial narrowing. Cerebral vasculitis was diagnosed and high dose immunosuppression therapy was instituted. She developed cortical blindness and progressed to involve her right limbs resulting in tetraparesis. Progress MR revealed posterior infarct bilaterally; with further involvement of her all her intracranial vessels, including basilar and vertebral arteries. Autoimmune screen was unremarkable. Nimodipine was added for alternative diagnosis of reversible cerebral vasoconstriction syndrome (RCVS). Citalopram (SSRI) was ceased. Her neurological recovery was slow and she required prolonged rehabilitation; with persistent weakness of all her limbs. Follow-up MRI/MRA in 1 month and 3- month respectively revealed marked improvement of her cerebral vasculature with near-normal calibre of Circle of Willis at 3-month; despite established infarct.
MR findings with subsequent normalisation of Circle of Willis are typical of RCVS. As in our case, the condition is often misdiagnosed as vasculitis, resulting in inappropriate use of powerful immunosuppression.