Vertigo andupside downvision duetoan infarct intheterritory ofthemedialbranchofthe posterior inferior cerebellar arterycausedby dissection ofavertebral artery

A 48yearoldwoman developed anacute vestibular syndromeassociated with upsidedown visiona fewhoursafter minorcervical trauma.Magnetic resonanceimagingshowedanischaemic lesion intheterritory ofthemedialbranchof theposterior inferior cerebellar artery. An arteriogram showeda dissection of theleft extracranial vertebral artery. Since theadvent ofCTsmall cerebellar strokes areknowntopresent asisolated vestibular, syndromes."5 The pathophysiology of these labyrinthine-lik e syndromes hasrecently been clarified fromtheresults ofmagnetic resonance imaging (MRI)andpathological studies.'7 In most casestheyresultfrominfarction associated withthemedial branch oftheposterior inferior cerebellar artery.67 We report a caseofsuchastroke duetodissection ofa vertebral artery after aclosed headinjury.