Transcranial Color Doppler Study for Reversible Cerebral Vasoconstriction Syndromes Shih-Pin Chen, MD, 1–3 Jong-Ling Fuh, MD, 2,4 Feng-Chi Chang, MD, 2,5 Jiing-Feng Lirng, MD, 2,5 Ben-Chang Shia, PhD, 6 and Shuu-Jiun Wang, MD 2,4 Objective: Reversible cerebral vasoconstriction syndromes (RCVS) are characterized by thunderclap headaches and reversible cerebral vasoconstrictions. No systematic studies on cerebral hemodynamics have been published. Methods: Patients with RCVS were consecutively recruited. Sequential transcranial color-coded sonography studies were per- formed on the middle cerebral artery (MCA) for 3 months. Mean flow velocities (V MCA ) and Lindegaard Index (LI) were recorded and compared with those of controls. Results: Thirty-two patients (all female; average age, 49.7  6.8 years) were enrolled. Four developed reversible posterior leukoencephalopathy syndrome, and two of them, ischemic strokes. One hundred and twenty-six sonography studies were performed on 57 eligible MCAs. The mean maximum V MCA (109.5  30.8cm/sec) and LI (2.2  0.7) of RCVS patients exceeded those of controls (V MCA : 66.3  9.5cm/sec, p  0.001; LI: 1.4  0.3, p  0.001). The V MCA and LI levels were still at their plateau at the mean time (day 22 after headache onset) of headache resolution. Fifteen (46.9%) patients had V MCA exceeding 120cm/sec, and 5 (16%) had LI exceeding 3. Patients fulfilling the criteria of subarachnoid hemorrhage mild vaso- spasm (n = 4; 13%), that is, both V MCA greater than 120cm/sec and LI greater than 3, had a greater risk of posterior leukoencephalopathy (75 vs 4%; p = 0.003) and ischemic strokes (50 vs 0%; p = 0.01) than those without. Interpretation: Patients with RCVS experienced prolonged vasoconstriction, making the risk for posterior leukoencephalopathy and ischemic strokes outlast headache resolution. Patients fulfilling mild vasospasm criteria for subarachnoid hemorrhage carry a high risk. Ann Neurol 2008;63:751–757 Reversible cerebral vasoconstriction syndromes (RCVS) has recently been proposed as a unifying term for a variety of eponymic syndromes, 1 including the Call– Fleming syndrome, 2 thunderclap headache with revers- ible vasospasm, 3 benign angiopathy of the central ner- vous system, 4 postpartum angiopathy, 5 migrainous vasospasm or migraine angiitis, 6 and drug-induced ce- rebral arteritis or angiopathy. 7 These clinicoradiological syndromes are usually self-limited to 3 months, and are characterized by recurrent acute and severe headaches, as well as reversible multifocal cerebral vasoconstric- tions (or vasospasm). 1 Some patients’ conditions are complicated by reversible posterior leukoencephalopa- thy syndrome (RPLS) or ischemic strokes over water- shed zones. 8 Recent studies have demonstrated that RCVS is not uncommon but require it be differenti- ated from subarachnoid hemorrhage (SAH) in patients presenting with thunderclap headaches at emergency departments. 1,9,10 A myriad of causative factors for RCVS has been identified 1,7 ; the most frequently in- ferred ones are exposure to vasoconstrictive drugs, such as sympathomimetics, serotonergic drugs, cannabi- noids, immunosuppressives or chemotherapeutic drugs, and so forth, or pregnancy and puerperium state. In certain patients, however, there are no identifiable causes. 10 Patients with RCVS tend to be middle-aged women who frequently have identifiable triggers for their thunderclap headaches and generally have a good response to calcium-channel blockers. 1,10,11 The clinical presentations of RCVS are being grad- ually delineated; however, little is known regarding the temporal evolution and clinical significance of associ- ated cerebral vasoconstriction. Transcranial color-coded sonography (TCCS) has been widely applied and vali- From the 1 Institute of Clinical Medicine and 2 Faculty of Medicine, National Yang-Ming University School of Medicine, Taipei; 3 De- partment of Neurology, Taoyuan Veterans Hospital, Taoyuan; 4 The Neurological Institute and 5 Department of Radiology, Taipei Vet- erans General Hospital; and 6 Department of Statistics and Informa- tion Science, Fu-Jen Catholic University, Taipei, Taiwan. Received Nov 20, 2007, and in revised form Feb 4, 2008. Accepted for publication Feb 15, 2008. Published online May 21, 2008, in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/ana.21384 Address correspondence to Dr Wang, Neurological Institute, Taipei Veterans General Hospital, No. 201, Shi-Pai Road, Section 2, Tai- pei, Taiwan, 112. E-mail: sjwang@vghtpe.gov.tw © 2008 American Neurological Association 751 Published by Wiley-Liss, Inc., through Wiley Subscription Services