The Babinski toe sign is regarded by many clinicians as the most important superficial reflex used in neurologic diagnosis because it is thought to be indicative of destruction of the pyramidal tract. There is difference of opinion as to whether irritation of the bundle can also produce the reflex. Many physicians believe that there is scarcely a neurologic sign with less possibility of error. No matter how transient the Babinski sign, it is thought by some clinicians that it is evidence of a lesion involving the pyramidal tract and that even an equivocal sign may be regarded as of as great significance as an actual positive response.
If both irritation and destruction produce a Babinski sign, there must be diametrically opposite nervous phenomena which act on the anterior horn cells of the first sacral segment of the cord, namely, hyperactivity and hypoactivity of the pyramidal tract. According to this concept,
LASSEK AM. THE HUMAN PYRAMIDAL TRACTX. THE BABINSKI SIGN AND DESTRUCTION OF THE PYRAMIDAL TRACT. Arch NeurPsych. 1944;52(6):484-494. doi:10.1001/archneurpsyc.1944.02290360056003