Virtually all of the thalamus is supplied with blood by deep branches of the posterior cerebral artery. The exception is two tiny regions of each lateral geniculate body that are supplied by the anterior choroidal artery instead. Lesions in the thalamus produced by infarction can and do replicate the results of lesions elsewhere in these supersystems. Thalamic lesions can and do produce cerebellar or extrapyamidal types of motor deficits. For reasons which remain profoundly mysterious, lesions deliberately placed in the motor thalamus often afford dramatic relief from some of these same motor deficits.
Thalamic lesions can and do produce primary sensory deficits.
Finally, thalamic lesions of sufficient magnitude may produce total loss of all mental life and awareness of surroundings. Most of the thalamus is supplied by deep branches of the posterior cerebral artery. The organization of the internal capsule reflects the locations of thalamic nuclei and their cortical partners. The corticospinal and corticobulbular tracts are located in a specific region of the internal capsule. The anterior limb contains the fibers linking the dorsomedial nucleus with their territory in the frontal lobes, and also the frontopontine projections, i.e. from frontal cortex to griseum pontis.