Basilar artery atherosclerotic disease is related to subacute lesion volume increase in pontine base infarction

Background - Although basilar artery atherosclerotic disease (BAD) is frequent in patients with pontine base infarction, it remains unknown whether BAD is related to the lesion size or clinical outcome. Methods - We studied 56 patients with unilateral pontine base infarction who underwent (i) diffusion-weighted MRI within 48 h after stroke onset and (ii) follow-up MRI and MR angiography in the subacute stage. Neurologic progression was defined as increased National Institutes of Health Stroke Scale score by >= 2 during admission. Clinical outcome was dichotomized as good and poor (>= 3) according to the modified Rankin Scale at 1 month after stroke onset. Results - Twenty-two patients (39%) had BAD and 15 patients (27%) had neurologic progression. Follow-up MRI performed at median 3.5 +/- 1.1 days after the initial MRI showed the lesion volume significantly increased (P < 0.001). The BAD was not significantly related to demographic characteristics, risk factors, initial and follow-up lesion volume, neurologic progression and clinical outcome, but was closely related to the subacute increase in lesion volume (P = 0.004 for 20% increase, P = 0.029 for 50% increase). Conclusions - BAD is related to subacute increase in lesion volume, but not to ultimate poor clinical outcome in patients with pontine base infarction.