Babinski sign This reflex is normal in children up to 2 years old. It disappears as the child gets older. It may disappear as early as 12 months. When the Babinski reflex is present in a child older than 2 years or in an adult, it is often a sign of a brain or nervous system disorder. Disorders may include: Amyotrophic lateral sclerosis (Lou Gehrig disease) Brain tumor or injury Meningitis Multiple sclerosis Spinal cord injury, defect, or tumor Stroke | Dr. Amr Arafa psychiatrist