[Vertebral artery dissection without subarachnoid hemorrhage studied by serial angiography]

We presented six cases we have encountered of vertebral artery dissection without subarachnoid hemorrhage followed by serial angiography. All six patients suffered from severe headache and/or nuchal pain at onset. Pain was acute at onset, with severe intensity and sharp quality and was located unilaterally on the dissection side. Only two patients showed neurological deficits. CT scan disclosed no abnormalities in any of the cases and angiography performed at the acute stage showed varied findings. The so-called pearl and string sign, which has been considered the most common finding of this disorder, was observed in only two cases. The definite diagnosis was able to be finally made by serial angiography. During the first few months after onset, dynamic changes of angiographical findings were demonstrated in all cases. During these periods, although transient deterioration of the angiographical findings was shown in four cases, spontaneous healing or improvement was finally recognized in all cases except one which progressed to total occlusion. In contrast to this, in the chronic stage, no changes of angiographical findings occurred in any of the cases. All six patients were treated non-surgically. All showed almost total recovery from symptoms and returned to their previous life styles. There were no cases of recurrent deterioration of symptoms in spite of the changes indicated by the angiographical findings. Our experience with these patients suggests that the actual incidence of vertebral artery dissection without subarachnoid hemorrhage may be much higher than is usually thought, and that the natural course of this disorder seems to be usually favorable. However, longer follow-up study and an analysis of a larger number of cases are required to identify the true incidence and the natural course of this disorder. In addition, we would like to emphasize that accurate diagnosis is most important. If it is clinically suspected, careful investigations including serial angiography should be carried out for the diagnosis of this disorder.