The crossed upgoing toe sign: a clinical study.

We compared the crossed upgoing toe sign with the plantar response as an indicator of pyramidal tract dysfunction in 125 normal subjects and 192 patients with neurological disorders. A positive crossed upgoing toe sign was associated significantly with a partial pyramidal tract lesion in the contralateral cerebral hemisphere with a frequency similar to that of Babinski's sign. Unlike Babinski's sign, however, the positive crossed upgoing toe sign was lost when pyramidal weakness was severe enough to produce paralysis of voluntary dorsiflexion of the great toe, and it was found only rarely with pyramidal tract lesions of the spinal cord. The crossed upgoing toe sign has little value as a sensitive indicator of a pyramidal tract lesion. It is potentially of limited value as an aid in determining the level of a pyramidal tract lesion (cerebral hemisphere versus spinal cord), but its usefulness is seriously impaired by the high frequency of false positive signs in normal subjects and patients with other neurological disorders.