Reversible Cerebral Vasoconstriction Syndromes Another Cause of Thunderclap Headache
By Daniel M. Keller, PhD
Medscape Medical News
September 23, 2009 (Philadelphia, Pennsylvania) — Reversible cerebral vasoconstriction syndromes (RCVS) are a cause of thunderclap headache and should be considered in the differential diagnosis of these acute-onset headaches.
To better define the triggers, symptoms, and diagnostic findings associated with RCVS, Todd Schwedt, MD, assistant professor of neurology, and colleagues at Washington University School of Medicine in St. Louis, Missouri, reviewed RCVS cases in the literature and presented their findings here at the 14th International Headache Congress.
The researchers report that RCVS primarily affects women and is associated with transient neurological deficits in about one third of cases, but that these deficits may persist in 10% of cases. The syndromes commonly occur in the postpartum period or may be brought on by certain drugs. Patients are at risk for intracranial bleeds, ischemic stroke, and cerebral edema. Vasoconstriction usually reverses within 12 weeks of onset.
Randolph Evans, MD, clinical professor of neurology at Baylor College of Medicine in Houston, Texas, and a member of the Medscape Neurology scientific advisory board, who was not involved in the study, said RCVS is a rare condition and that many neurologists have never heard of it. It has been referred to as Call-Fleming syndrome after the authors who described it in Stroke in 1988. As the syndrome is still underrecognized, however, "it may not be as rare as we think," Dr. Evans told Medscape Neurology.
"The first thing is for us to start recognizing it, particularly when people have thunderclap headaches — when they have sudden, severe headaches," he advised.
Systematic Review on RCVS
In the systematic review presented here, cases were included if they had new-onset headache or multifocal intracranial artery vasoconstriction, if the vasoconstriction resolved within 12 weeks of onset and if there was no aneurysmal subarachnoid hemorrhage.
Eighty publications containing 250 patients who had RCVS met these criteria. Women outnumbered men by 6 to1. Patients ranged in age from 13 to 70 years (mean, 43 years). Predisposing conditions included being postpartum (18% of cases) or having a history of migraine (27%), and activities included bathing, physical exertion/Valsalva, and vascular trauma. Exposure to various medications or illicit drugs occurred in 44% of patients with RCVS. Almost all patients with RCVS (92%) presented with a thunderclap headache. Cerebrospinal fluid parameters were normal or nearly so, with mildly elevated protein in 27% of patients with RCVS and white blood cell count greater than 5 cells/mm3 in 19% of patients with RCVS.
Transient neurologic deficits occurred in 29% of patients with RCVS, and 10% experienced persistent deficits. Cortical subarachnoid hemorrhage, intraparenchymal hemorrhage, ischemic stroke, and cerebral edema occurred in 17%, 9%, 24%, and 22% of patients with RCVS, respectively.
The researchers write in their abstract that "vasoconstriction is most commonly identified in the anterior circulation, specifically the middle cerebral artery." They found in their literature search vasoconstriction of the middle cerebral artery in 91% of patients with RCVS, anterior cerebral artery in 60%, posterior cerebral artery in 56%, basilar artery in 19%, and internal carotid in 10%.
A Rare Condition
Dr. Evans said that neurologists' suspicions should be raised for patients in late pregnancy, during postpartum, or with hypertension. RCVS can be triggered by drugs such as cocaine or ecstasy or some prescription drugs such as selective serotonin reuptake inhibitors, or there may be no trigger at all.
"It's usually a disease of young women who may have a history of migraine," Dr. Evans noted. He said imaging may reveal constriction of affected arteries, but added that "there is no single test to confirm the diagnosis." Other diseases that can also cause vasoconstriction, such as vasculitis, need to be ruled out.
More research into treatments is needed, but some clinicians have been using nimodipine for prevention and acute treatment, and other calcium channel blockers such as verapamil may also work.
In addition to the triggers mentioned by Dr. Schwedt and colleagues, Dr. Evans added sexual intercourse, bowel movement, sudden emotion, urination, coughing, sneezing, or bending over. About 20% of people have a thunderclap headache at rest with no predisposing activities.
Dr. Evans said that patients may have a hemorrhage 1 week and go on to have an ischemic event the next. A normal arteriogram showing no vasoconstriction cannot rule out RCVS. Furthermore, some patients go on to recover completely.
Many RCVS patients will be seen initially in the emergency department, but if they have additional thunderclap headaches, they will probably see a neurologist. Dr. Evans' advice is for neurologists to consider RCVS as part of the differential diagnosis of recurrent thunderclap headaches.
Dr. Schwedt has disclosed receiving payments for conducting clinical research, honoraria, research grants (from GlaxoSmithKline, AGA, and Allergan), and compensation as a consultant or advisory board member for VersusMed. Dr. Evans has disclosed that he has served as an advisor or consultant to, received clinical research support from, or received honoraria from Merck, Ortho-McNeil, Pfizer, GlaxoSmithKline, Lilly, Teva, and UCB. He is also an uncompensated advisory board member for Medscape Neurology.
14th International Headache Congress: Poster PO373. Displayed September 11 and 12, 2009.
