Book Review

The Babinski Sign: A centenary

N Engl J Med 1996; 335:1075October 3, 1996

Article

The Babinski Sign: A centenary
By J. van Gijn. 176 pp. Utrecht, Heidelberglaan, the Netherlands, Universiteit Utrecht, 1996. $49.95. ISBN: 90-9008908-X

Have you ever seen a crowd of medical students and house officers watching intently as the professor repeatedly strokes the sole of a patient's foot, trying to decide whether the great toe goes up, down, or nowhere? Is the Babinski sign present? If not, should we flick the toes, squeeze the gastrocnemius muscles, scratch the dorsum of the foot, massage the anterior surface of the tibia, or do something else to evoke one of the myriad variations of the Babinski sign? My own teacher, Houston Merritt, dismissed the mutants with a simple response: “I have a hard enough time telling whether there is a Babinski. I don't waste time with the 20 ways of evoking it.”

How can a simple reflex be so important? Examples: Is the diagnosis multiple sclerosis? A psychogenic disorder? Amyotrophic lateral sclerosis or peripheral neuropathy? Guillain–Barré syndrome or transverse myelitis? A lot may be riding on the movement of that toe.

But the clinical importance of the sign is only one of its attractions. What is the physiologic basis of the normal response, and why does the toe go up after there are lesions of the corticospinal tract? Is it really a reliable marker of something wrong in the pyramidal tract? How did Babinski find it in the first place? There is a rich literature on these subjects, summed up judiciously in this book by J. van Gijn to celebrate the centennial of Babinski's first paper.

Van Gijn himself has studied patients with the sign, using electromyography to analyze whether the extensor hallucis longus is activated; he found that the response is widespread, involving many muscles. (I myself watch for contraction of the tensor fascia lata in the thigh. I once thought this might be a new observation, but van Gijn notes that it was also recognized in 1896.) He comes down in favor of Babinski in disputes about priority for the eponym. He analyzes the controversies generated by reports of patients with corticospinal lesions and no Babinski signs, or the reverse — no lesion in the pyramidal tract in a patient with the sign. He recognizes that the varying degree of intraobserver reliability leaves room for uncertainty. Nevertheless, as custom surely dictates, he concludes that it is a useful clinical sign.

The human story is of interest. Charcot is recognized as the “father of modern neurology,” and Babinski was one of his outstanding students. In a famous painting by André Brouillet of Charcot's teaching conference, Babinski is a central figure, holding up a swooning woman. That picture provides the background for this book. Charcot was criticized for a major error; he attributed “hysteria” to permanent physical changes in the central nervous system. He came to that view because he was immersed in the studies that made him the pioneer in relating clinical signs to tissue disease in other conditions. His name is immortalized in the eponyms for multiple sclerosis, amyotrophic lateral sclerosis, hereditary peripheral neuropathy, and the joint changes of tabes dorsalis.

Babinski did not follow Charcot in an academic position because he failed a key examination. Van Gijn tells the story of a clash between Charcot and Bouchard, another of his pupils and one who rose to a position of ruthless power. All of Bouchard's candidates in that examination passed and all of Charcot's failed, including the renowned Gilles de la Tourette (who passed it a few years later). Babinski, however, was disheartened and never tried again. Instead, he committed himself to clinical studies and helped develop the modern neurologic examination. Babinski identified the localizing importance of a level of sensory loss after spinal cord injury; he diagnosed the patient who had the first spinal cord operation in France. Babinski was therefore important in the evolution of the physical examination in medical diagnosis.

Babinski was determined to prove that hysteria is not “organic.” He became fascinated with the challenge of finding physical signs seen in patients with organic hemiplegia or paraplegia, but not in those with psychogenic disorders. The toe sign is only one.

Neurologists and historians will find this book of interest. It is rich in historical detail and involves several famous figures. But general medical readers are likely to find more details than they ever want to know, including a wild discussion of the misnaming of the “extensor” sign. (Flexion shortens a limb; extension lengthens it. It is therefore more appropriate to note that the toe goes up or down, instead of using the word “flexion” or “extension” alone; “plantar flexion” and “dorsiflexion” are equally clear. But the key muscle is the extensor hallucis longus.) The writing is straightforward and clear, pointing to the importance of simple clinical contributions that are still important, even in the age of molecular medicine.

Lewis P. Rowland, M.D.
Neurological Institute at Columbia–Presbyterian Medical Center, New York, NY 10032