Proprioception more impaired distally than proximally in subjects with hemispheric dysfunction.

Holmes noted that with hemispheric injuries proprioceptive disturbances were more marked in the distal than proximal limb segments and proposed that this difference was related to the size of cortical sensory representations. An alternative hypothesis is that sensation from distal segments projects to the contralateral hemisphere and sensation from proximal segments projects to both hemispheres. Selective hemispheric anesthesia was used to test these alternative hypotheses and revealed a decrement in distal but not proximal proprioception with hemispheric anesthesia, thereby supporting the bilateral projection hypothesis.