A Babinski reflex is an involuntary response of the nervous system that may be tested during a physical exam. This reflex is normal in small children, but should not occur in a person over 2 years old unless he or she has some type of damage to the brain or spinal cord.
A healthcare professional tests for the Babinski reflex when he or she suspects head injury, brain disease, spinal cord injury, or spinal cord disease. The test may be performed as part of a routine physical exam.
The person is usually asked to lie on his or her back with legs resting flat on the bed or table. The test is performed on the sole, or bottom, of the foot. The examiner takes the foot or leg in his or her hand and the person is asked to relax. The bottom of the foot is stroked, usually with a special tool. The examiner observes the toes to see how they react to the foot stroking.
No preparation is required for this test, other than the removal of shoes and socks.
In a healthy person over the age of 2 years old, the toes curl downward when the bottom of the foot is stroked. This is considered a normal reflex. If the big toe curls upward, and the other toes curl upward and fan apart, this is considered an abnormal response.
An abnormal Babinski reflex may indicate brain or spinal cord damage from many causes. For example, an abnormal reflex may result from: a stroke a brain tumor a head, neck, or back injury affecting the brain or spinal cordmultiple sclerosis, a degenerative disease affecting the nerve linings
The Babinski reflex is not, in and of itself, diagnostic for a particular condition. If the disease process causing the abnormality is not already obvious from the history and the rest of the physical exam, other tests may be performed to determine the reason for brain or spinal cord damage.
Cecil Textbook of Medicine, 1996, Bennett et al.