PROBABLE BILATERAL POSTERIOR CEREBRAL ARTERY DISSECTION

Abstract

Isolated dissection of the posterior cerebral artery (PCA) is rare. A 68 year old male golf enthusiast developed moderately severe occipital headaches followed two weeks later by transient right sided weakness and speech disturbance. Six weeks later he developed difficulty reading and was found to have left upper quadrantanopia. Blood inflammatory and immunological markers were all normal as was CSF analysis. Initial CT brain showed a small, established left occipital lobe infarct. MR brain showed new right occipital, right thalamic and small left hippocampal infarcts. Transthoracic echocardiogram and arrhythmia recording identified no embolic source. CT and catheter angiography showed occlusion of the right PCA and stenosis of the left PCA. Other intracranial and extracranial vessels were normal. Conventional stroke secondary prevention strategies and steroid therapy was initiated due to initial concern of vasculitis. Follow up MR angiography showed no change in vessel status but interval right PCA infarct. We present the clinical features of this highly unusual case and discuss the radiological findings. In the absence of another identified cause and given the proximity to tentorium, we presume the cause is bilateral PCA dissection.