Clinical spectrum of pontine infarction. Clinical-MRI correlations

We sought clinical and radiological findings of 150 consecutive patients with acute isolated pontine infarct who were admitted to our Stroke Unit over 6 years. In all patients CT, MRI and magnetic resonance angiography (MRA) were performed during the hospitalization. On clinico-radiological analysis regarding the pontine lesion boundaries there were five main clinical patterns that depended on the constant territories of intrinsic pontine arteries: (1). anteromedial pontine syndrome (58%) presented with motor deficit with dysarthria, ataxia, and mild tegmental signs in one third of patients; (2). anterolateral pontine syndrome (17%) developed with motor and sensory deficits in half of the patients, and were associated with tegmental signs (56%) more frequently than the anteromedial infarct syndrome; (3). tegmental pontine syndrome (10%) presented with mild motor deficits and associated with sensory syndromes, eye movement disorders and vestibular system symptoms including vertigo, dizziness and ataxia; (4). bilateral pontine syndrome (11%) consisted with transient consciousness loss, tetraparesis and acute pseudobulbar palsy; (5). unilateral multiple pontine infarcts (4%) were rarely observed, and were always associated with severe sensory-motor deficits and tegmental signs. In our series, there was no infarct in the extreme dorsal and lateral tegmental pontine territories which have been mostly associated with cerebellar infarctions. The main etiology of stroke was basilar artery branch disease (BABD) in 59 patients (39%), followed by small-artery disease (SAD) in 31 (21%), large-artery disease of vertebrobasilar arteries in 27 patients (18%), cardioembolism in 12 (8%) and in 16 patients (11%) no cause of stroke was found. Our findings suggest that it is possible to identify clinical subgroups of pontine infarction, in which BABD and SAD were the most common causes of stroke. After an acute onset, outcome is in general excellent except in those with bilateral pontine lesions.