A man in his 60s with a long-term history of smoking and severe hypertension presented with acute speech disturbances and gait instability on awakening. A clinical examination revealed bilateral tremor, dysarthria, decreased verbal fluency, and ataxia with shuffling gait. Classic disconnection syndrome was not seen in this patient. Computed tomography angiography performed 12 hours after detection of symptoms revealed occlusion of a single pericallosal artery derived from a left anterior cerebral artery (Figure 1). Cerebral magnetic resonance imaging, performed 24 hours after admission, revealed infarction confined to the corpus callosum (Figure 2). The splenium of the corpus callosum was preserved, which explains why the patient did not have classic disconnection syndrome (the posterior pericallosal artery, a branch of the posterior cerebral artery, supplies this region of the corpus callosum).1,2 The arteries within the region showed many variations that led, in this patient, to an atypical presentation with nonlocalizing signs of acute stroke. Large artery atherosclerosis was the probable cause in this case. Two months after discharge, the patient was able to walk alone, and speech disturbances partially improved (modified Rankin score, 2).