Diffuse cerebrovascular dilation: Case report of amezinium metilsulfate-induced reversible cerebral vasoconstriction syndrome.

Background: Reversible cerebral vasoconstriction syndrome (RCVS) is characterized by recurrent thunderclap headaches with reversible cerebral vasoconstriction, and often precipitated by the postpartum state and vasoactive medications. We describe a case of a patient with RCVS induced by amezinium metilsulfate, a sympathomimetic drug, in whom magnetic resonance angiography (MRA) initially revealed diffusely dilated cerebral arteries.

Methods: A 34-year-old woman was prescribed amezinium metilsulfate for hypotension. Twelve days later, she suffered from abrupt severe headaches and was referred to our department. She had no neurological deficits; however, MRA revealed diffusely dilated anterior, middle, and posterior cerebral arteries with vasoconstriction. She was tentatively diagnosed with RCVS and successfully treated with verapamil for headache. Nevertheless, follow-up MRAs disclosed widespread segmental vasoconstriction that resolved in two months.

Conclusions: Diffuse cerebrovascular dilation has not been addressed but may be associated with RCVS pathophysiology. In addition, physicians should bear in mind that amezinium metilsulfate can potentially induce RCVS.