Magnetic resonance imaging in Wallenberg's lateral medullary syndrome.

Four patients with a clinical diagnosis of Wallenberg's lateral medullary syndrome were studied with both Magnetic Resonance Imaging (MRI) and cranial Computed Tomography (CT). Using transverse images and both T1 and T2--weighted sequences, MRI demonstrated a medullary infarction not seen on CT in all four cases. MRI also demonstrated a coexisting cerebellar infarction in three cases which was unsuspected clinically and undetected by CT.