Transient vertical diplopia and nystagmus associated with acute thalamic infarction.

We describe a patient who presented with a 1-h history of vertical diplopia and nystagmus and was found to have acute left ventrolateral thalamic infarction on the diffusion-weighted magnetic resonance imaging (DWI MRI). This is the first case report demonstrating that vertical diplopia and nystagmus, which typically suggest a lesion in the brainstem or cerebellum, may also occur in acute thalamic infarction. DWI MRI can detect thalamic infarction as early as 1 h after its clinical manifestations.