Brainstem Infarction in Patients with Basilar Artery Dolichosis

ABSTRACT

BACKGROUND: Basilar arterial dolichosis (BD) has chracteristics of tortuosity and elongation. BD can cause obstructive hydrocephalus, direct compression of brainstem and cranial nerves, and cerebral ischemia or infarction. It has been reported that brainstem infarction is usually located contralateral to the side of lateral displacement. This study was aimed to reveal the relation between the location of the infarction and the some characteristics of BD. METHODS: Among the 143 patients who had brainstem infarction from January, 2003 to July, 2004, 40 patients with BD were analyzed retrospectively. Characteristics of BD and infarct site were analysed with special respect via MRI and MRA. We surveyed the relation between the location of the infarction and the lateral displacement of BD. Subjects were divided into two groups by the degree of the lateral displacement of basilar artery (BA). We made a comparison between the two in clinical characteristics and risk factors. Height of the infarct site and the maximal point of lateral displacement from arbitrarily defined standard level (lower pons) were measured. We surveyed the lesional laterality associated with relative height of the infarct site. RESULTS: Infarct lesions located to the contralateral side of the laterally displaced BA were more prevalent (25 cases, 62.5%). There was significant correlation between the lesional laterality and the lateral displacement of the BA in group B (p=0.039) and between the lesion-height and the maximal dolichosis-height (r=0.639, p<0.001). CONCLUSIONS: Patients with BD are more likely to have brainstem infarction at the contralateral side of the laterally displaced BA.