Bilateral thalamic infarction associated with selective downward gaze paralysis.

A 34-year-old man presented with transient downward gaze paralysis and impairment of convergence together with prominent psychic disturbances. Cranial CT and MRI clearly demonstrated a symmetric infarction extending from the bilateral thalamus to the rostral medial midbrain. The existence of downward gaze paralysis following ischemic stroke is contributory to the diagnosis of not only the location of but also the responsible artery for the infarction.