Babinski sign

Abstract

Despite all of the medical advances, Babinski sign has proved reliable in precise localization of central nervous system dysfunction. It is well accepted that Babinski sign is indicative of dysfunction of fibers within the pyramidal tract. Joseph François Félix Babinski first described the clinical significance of the reflex in 1896. He showed that the extensor plantar response was indicative of pyramidal dysfunction and that it was absent in hysteria. He also illustrated that it was present in infancy and transiently appeared in epilepsy and strychnine poisoning. Babinski also pointed to the existence of "formes frustes" of his reflex and recognized its occasional absence in patients with other clinical signs of pyramidal lesions. The sign emerges when the dysfunction of the pyramidal tract involves the fibers that project on motoneurons of foot muscles and is mediated by extensor hallucis longus. Babinski sign may not be present acutely after transverse lesions of the spinal cord or acute brain lesions because of temporary inexcitability of spinal motoneurons.