title: The reversible cerebral vasoconstriction syndrome in association with venlafaxine and methenamine.
abstract: The reversible cerebral vasoconstriction syndrome (RCVS) is characterised by thunderclap headache and multifocal vasoconstriction of cerebral arteries on angiography. It is often drug induced, but it can occur postpartum, and as a result of a number of other precipitants. To make the diagnosis, it is necessary to exclude other causes of severe headache (such as aneurysmal subarachnoid haemorrhage, carotid dissection and primary angiitis of the central nervous system). However, it is also important to show that the vasoconstriction has resolved with repeat angiography at the 3-month stage. Here we report two cases of RCVS in association with venlafaxine and the urinary antiseptic, methenamine. Serotonin-norepinephrine reuptake inhibitors have recently been reported as a possible precipitant, but this is the first report to implicate methenamine. Although RCVS is relatively uncommon, it should be considered in the differential of those presenting with thunderclap headache.
authors.affiliation: Department of Neurology, The Royal Free London NHS Foundation Trust, London, UK. gerard.davies@nhs.net
authors.forename: G
authors.initials: G
authors.lastname: Davies
authors.forename: H
authors.initials: H
authors.lastname: Wilson
authors.forename: T
authors.initials: T
authors.lastname: Wilhelm
authors.forename: J
authors.initials: J
authors.lastname: Bowler
mesh_terms: D002536:Cerebral Arteries / Q000187:drug effects* / Q000503:physiopathology; D003511:Cyclohexanols / Q000008:administration & dosage / Q000009:adverse effects*; D004359:Drug Therapy, Combination; D005260:Female; D051270:Headache Disorders, Primary / Q000139:chemically induced; D006801:Humans; D008279:Magnetic Resonance Imaging; D008709:Methenamine / Q000008:administration & dosage / Q000009:adverse effects*; D008875:Middle Aged; D014057:Tomography, X-Ray Computed; D014661:Vasoconstriction / Q000187:drug effects*; D000069470:Venlafaxine Hydrochloride
chemical_list: D003511:Cyclohexanols; D000069470:Venlafaxine Hydrochloride; D008709:Methenamine