Cortical versus non-cortical lesions affect expression of Babinski sign.

This study was conducted to investigate the relationship between the pattern of pathological plantar response (Babinski sign), and the focus of the lesions of pyramidal tract. We examined 107 subjects with definite lesions of the pyramidal tract recruited from inpatients at the Neurology Department of the Xuanwu Hospital of Capital Medical University (Beijing, China). We found that patients with sub-cortical lesions (corona radiata to spinal cord) showed different patterns of Babinski sign than those with lesions within the primary motor cortex. Specifically, dorsiflexion of the big toe without recruitment of the other toes was seen in 71.4 % of patients with cortical pyramidal tract lesions, while 93 patients with lesions lower than cortex (corona radiata to spinal cord) showed movement of other toes in addition to the big toe, which showed movement due to contraction of the extensor hallucis longus tendon in all patients. There were no differences in patterns of Babinski sign between the different sub-cortical lesion foci. We conclude that the patterns of Babinski sign can be used to predict cortical lesions of the pyramidal tract.