Babinski's reflex occurs when the big toe moves toward the top surface 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 very young children. It is not normal after age 2.

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

Reflexes are predictable, uncontrollable responses to a certain type of stimulation.

Babinski's reflex is one of the reflexes that occurs in infants. It is normal in children up to 2 years old, but it disappears as the child gets older 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. A Babinski's reflex can occur on one side or on both sides of the body.

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

• Amyotrophic lateral sclerosis (Lou Gehrig's disease)
• Brain tumor
• 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)

A person older than an infant who has a Babinski's reflex will often also have incoordination, weakness, and difficulty with muscle control.

Safety is important to prevent injury. The person may need help with activity. The environment should be kept free of hazards.

People do not usually know they have Babinski's reflex. It is often found by the health care provider.

The health care provider will perform a physical exam and ask questions about the patient's symptoms and medical history.

The physical examination will include a complete nervous system (neurological) examination.

Tests may include:

• Angiography of the head
• Blood tests
• CT scan of the head
• Lumbar puncture and analysis of the cerebrospinal fluid
• MRI scan of the head or spine
• Somatosensory evoked potentials

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.

Murray B, Mitsumoto H. Disorders of the upper and lower motor neurons. In: Bradley WG, Daroff RB, Fenichel GM, Jankovic J, eds. Bradley: Neurology in Clinical Practice. 5th ed. Philadelphia, Pa: Butterworth-Heinemann Elsevier; 2008:chap 78.