Isolated pontine infarcts: etiopathogenic mechanisms

Abstract

Although there are several clinico-topographical studies of pontine infarcts, few include vascular studies. To clarify the etiopathogenic mechanisms of pontine infarcts we analyzed the vascular findings and their association with MRI lesions. The clinical features and vascular findings on transcranial Doppler (TCD) or MR angiography (MRA) of 67 patients with acute infarcts involving the pons were studied. Functional outcome was assessed by modified Rankin Scale (mRS) scores on admission and 2 months later. Two groups of isolated pontine infarcts were found on the basis of lesion location on MRI, according to the extent or not to the anterior surface of the pons: paramedian pontine infarcts (PPI, n = 36) and lacunar pontine infarcts (LPI, n = 31). Hypertension was the most common vascular risk factor and pure motor syndrome was the most frequent clinical profile in both groups. Basilar artery stenosis found on TCD or MRA was significantly more frequent amongst the PPI group (P < 0.05). On admission and 2 months later, the mRS scores of the PPI group were significantly worse (P < 0.0001) than those of the LPI group. Patients with PPI have a significantly higher frequency of basilar artery stenosis and they have a worse prognosis than patients with LPI.