Thalamic infarction disrupts spinothalamocortical projection to the mid-cingulate cortex and supplementary motor area.

Thalamic infarction presenting with heat anesthesia is rare. A 62-year-old man developed acute heat anesthesia and deep sensory disturbance in the right half of his body, but sensation for cold and pain was preserved. The resolution of these symptoms was accompanied by the gradual development of central dysesthesia. Magnetic resonance imaging (MRI) and computed tomography (CT) findings showed a small infarction in the left thalamic principal somatosensory nucleus (ventral caudal) and pulvinar. Single-photon emission CT showed hypoperfusion in the mid-cingulate cortex (mid-CC) and supplementary motor area (SMA), however, the primary and secondary somatosensory cortices were spared. Somatosensory-evoked potential findings were normal. The disruption of spinothalamocortical projection to the mid-CC and SMA is attributable to the development of central dysesthesia in the present case.