An unusual curling upwards of the big toe when a finger is lightly run across the sole of the foot, while the others turn down and spread out, a sign of hemiplegia and pyramidal tract disease.
The Babinski reflex is a phenomenon observed when the sole of the foot is stroked from below the heel toward the toes on the lateral (outside) side resulting in the big toe flexing toward the top of the foot and the other toes fanning out. The Babinski reflex is considered one of the infantile reflexes. It is normal in children under the age of 2 or 3 years but typically disappears as the child matures and the nervous system develops. In individuals older than 2 or 3, the presence of a Babinski reflex indicates damage to the pyramidal tract (the nerve paths connecting the spinal cord and the brain; American Heritage Stedman’s Medical Dictionary, 1995; Royal College of Physicians of London, 1996). Even though the Babinski reflex is considered to be a normal response before children reach a certain age, medical researchers have not reached consensus as to the age at which the sign becomes abnormal suggested that it is abnormal after 6 months of age consider it abnormal after 3 years of age; and the majority of medical professionals consider it abnormal after age 2.
Upward flexion of the big toe and fanning of the other toes, when a child’s foot is firmly stroked on the outside of the sole. Babinski’s reflex is normal in newborns, but its presence in children and adults can indicate brain or spinal-cord disorders. The normal post-newborn response to such stroking is to curl the toes, called the plantar response.
Extension or moving of the big toe upward or toward the head, with the other toes fanned out and extended, when the sole of the foot is stroked from below the heel toward the toes on its lateral side (outside). The reflex is normal in infants, but in others usually indicates brain or spinal cord disease. Also called Babinski sign.
An abnormal reflex response to stimulation of the plantar (bottom) surface of the foot indicating upper motor neuron disease (damage to the brain or spinal cord). During a neurological examination, people demonstrating a Babinski reflex will extend and point their great toe up in response to irritating stimulation along the bottom of the foot, which indicates an abnormality in the brain or spinal cord (central nervous system).
This is said to be present if, when a sharp body, such as a key, is drawn along the sole of the foot, instead of the toes bending down towards the sole as usual, the big toe turns upwards and the other toes spread apart. After the age of about two years, the presence of this reflex means that there may be a severe disturbance in the brain. The Babinski reflex may occur transiently during coma or after an epileptic fit and need not indicate permanent damage.
Dorsiflexion of the great toe when the sole of the foot is stimulated. Normally, when the lateral aspect of the sole of the relaxed foot is stroked, the great toe flexes. If the toe extends instead of flexes and the outer toes spread out, Babinski’s reflex is present. It is a normal reflex in infants under the age of 6 months but indicates a lesion of the pyramidal (corticospinal) tract in older individuals. Care must be taken to avoid interpreting voluntary extension of the toe as Babinski’s reflex.
A pathologic sign in MS in which stroking the outside sole of the foot with a pointed object causes an upward (extensor) movement of the big toe rather than the normal (flexor) bunching and downward movement of the toes.
A reflexive movement of the big toe in response to tickling the sole of the foot. In infancy, an upward response is considered normal. However, in older children and adults, an upward response suggests damage to the central nervous system.
Elevation of the big toe in response to stimulation on the sole of the foot. In adults, this indicates damage to motor pathways in the brain or spinal cord.