Acta zyxwv Neurol Scand., zyx 1986:74:460-466 zy Key words: cerebral angiitis; cerebral blood flow; cerebral infarct; contralateral hemiparesis. herpes zoster ophthalmicus. zyxw Herpes zoster ophthalmicus with cerebral angiitis and reduced cerebral blood flow L. Gjerstad', R. Nyberg-Hansen', 0. Bj@rland4, P. Nakstad', D. Russell', K. Rootwelt3 Departments of 'Neurology, 2Radiology, 3Clinical Chemistry, The National Hospital, University of Oslo, 4Departrnent of Medicine, Baerurn Hospital, Sandvika, Norway ABSTRACI - Two patients with herpes zoster ophthalmicus (HZO) who experienced a de- layed contralateral hemiparesis, the so-called crossed zoster syndrome, are described. Parti- cular emphasis is paid to the cerebral blood flow (CBF) findings studied with the Xenon-133 inhalation technique using single photon emission computed tomography (SPECT). In a 40- year-old female with right-sided hemiparesis, angiography showed multiple segmental nar- rowings of the intracerebral arteries. Cerebral computer tomography zyxwv (CT) scans were nor- mal. The CBF studied 11 months after the HZO showed a generalized reduction of flow which, however, was more pronounced in the left hemisphere. On re-examination 8 months later both the mean hemispheric flow and regional CBF (rCBF) had increased to normal va- lues. In a 66-year-old male with dysphasia and right-sided hemiparesis, cerebral (3' scans demonstrated two small deep left-sided infarcts. CBF examination showed a generalized re- duction of flow in the left hemisphere. The flow was slightly increased on re-examination zyxw 12 months later. These findings suggest that the Xenon-133 inhalation method represents a use- ful way to demonstrate the CBF pattern in this group of patients. zyxwv Accepted for publication August 4, 1986. Since the first description in 1896 (1) there have been more than 50 reported cases of contralateral hemiparesis following herpes zoster ophthalmicus (HZO), the so-called crossed zoster syndrome. The cause of the hemiparesis is believed to be viral-in- duced angiitis of cerebral arteries, probably result- ing from direct viral invasion of the vessels (2). Au- topsies have demonstratred necrotizing vasculitis of major branches of the carotid and basilar artery sys- tems (2-4). However, thrombotic vasculopathy with occlusions of large vessels without inflammatory changes have recently also been reported zyxwvuts (5). Angiography in some affected patients has shown segmental narrowing of ipsilateral cerebral arteries (6), and computerized tomography of the head (CT scan) has shown changes consistent with cerebral infarction (5, 7, 8). We report two cases il- lustrating different aspects of this syndrome with particular emphasis on cerebral blood flow (CBF) studied with the Xenon- 133 inhalation technique using single photon emission computed tomogra- phy (SPECT). CBF method CBF was measured with Xenon-133 inhalation us- ing a rapidly rotating single photon emission com- puter tomograph (Tomomatic 64)*. This method has been described in detail elsewhere (9). Using high-sensitivity collimators, 3 slices of the brain are studied simultaneously. The slices are 2 * Tomomatic 64 manufactured by Medimatic, Inc., Copenhagen, Denmark.