Babinski's reflex - Overview

Alternative Names

Reflex - Babinski's; Extensor plantar reflex; Babinski's sign

Definition of Babinski's reflex:

Babinski's reflex occurs when the big toe moves toward the top of the foot and the other toes fan out after the sole of the foot has been firmly stroked.

This reflex, or sign, is normal in younger children, but abnormal after the age of 2.

Considerations:

Reflexes are specific, predictable, involuntary responses to a particular type of stimulation.

Babinski's reflex is one of the infantile reflexes. It is normal in children up to 2 years old, but it disappears as the child ages and the nervous system becomes more developed. It may disappear as early as 12 months.

The presence of a Babinski's reflex after age 2 is a sign of damage to the nerve paths connecting the spinal cord and the brain (the corticospinal tract). This tract runs down both sides of the spinal cord, therefore a Babinski's reflex can occur on one side or on both sides.

An abnormal Babinski's reflex can be temporary or permanent.

Common Causes:

Generalized tonic-clonic seizure (there may be a temporary Babinski's reflex for a short time after a seizure)
Amyotrophic lateral sclerosis (Lou Gehrig's disease)
Brain tumor (if it injures or puts pressure on the corticospinal tract)
Familial periodic paralysis
Friedreich's ataxia
Head injury
Hepatic encephalopathy
Meningitis
Multiple sclerosis
Pernicious anemia
Poliomyelitis (some forms)
Rabies
Spinal cord injury
Spinal cord tumor
Stroke
Syringomyelia
Tuberculosis (when it affects the spine)

Reviewed last on: 3/26/2009
David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; Daniel B. Hoch, PhD, MD, Assistant Professor of Neurology, Harvard Medical School, Department of Neurology, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

References

Griggs R, Jozefowicz R, Aminoff M. Approach to the patient with neurologic disease. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 418.

Hammerstad J. Strength and reflexes. In: Goetz, CG, ed. Textbook of Clinical Neurology. 3rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 15.

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