The Corticospinal Tract and the Plantar Response
The Plantar response is an integral part of any routine neurological exam. First introduced as the Babinski reflex by Joseph Francois Felix Babinski in 1896. He observed that pricking the affected side in hemiplegic patients affected by a pyramidal tract lesion would cause big toe extension even in patients who could not extend their toes voluntarily, and in later puplications Babinski described that the response was best elicited with a firm stroke of the lateral sole of the foot.
In 1904, an American neurologist by the name of Alfred Gordon, described a similar response in patients with pyramial tract lesions, when firmly pressing the middle or lower portion of the calf muscles, even producing an extensor response in patients who exhibited an absent Babinski reflex.
In 1911, Charles Gilbert Chaddock who had worked under Babinski in France, published his own version of the Babinski reflex in which the lateral inframalleolar skin was stroked, rather the sole of the foot.
Hermann Oppenheim who was celebrated in Germany in a similar regard to Babinski in France, described another version of the response achieved by firmly stroking the medial tibia.
While the Babinski is by far the most popular test used by clinicians worldwide, these other variations have their advantages and are worth knowing to increase the accuracy of the neurological examination.
A study Puplished in 2015 was conducted to compare between the Babinski, Chaddock, and Oppenheim reflexes found that the Babinski was of higher sensitivity, and that the Babinski and the Chaddock demonstrated similar sensitivity and PPV.
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- Babinski J. Relachement des muscles dans l'hémiplégie organique. 1896.
- Gordon A. A new reflex: paradoxic flexor reflex. Its diagnostic value. Am Med. 1904;8:971.
- Chaddock CG. A preliminary communication concerning a new diagnostic nervous sign. Interstate Med J. 1911;18:742-6.
- Chaddock CG. An explanation of the external malleolar sign made with a view to incite study of it to determine its place in semiology. J Mo State Med Assoc. 1911;8:138-44.
- Chaddock CG. The external malleolar sign. Interstate Med J. 1911;13:1026-38.
- Oppenheim H. Zur Pathologie der Hautreflexe an den unteren Extremitäten. European Neurology. 1902;12(6):518-30.
- Singerman J, Lee L. Consistency of the Babinski reflex and its variants. European journal of neurology. 2008 Sep;15(9):960-4.
- Araújo R, Firmino-Machado J, Correia P, Leitão-Marques M, Carvalho J, Silva M, Nogueira A, Nunes C. The plantar reflex: A study of observer agreement, sensitivity, and observer bias. Neurology: Clinical Practice. 2015 Aug 1;5(4):309-16.