Babinski sign is an up-turning or extensor plantar response.

Pyramidal: extensor plantar responses, and distal weakness are commonly found.

This can occur when there is no movement of the toes, and is part of the extensor plantar response.

A complication of severe chronic PA is subacute combined degeneration of spinal cord, which leads to distal sensory loss (posterior column), absent ankle reflex, increased knee reflex response, and extensor plantar response.

A few days after the injury to the upper motor neurons, a pattern of motor signs and symptoms appears, including spasticity, the decreased vigor (and increased threshold) of superficial reflexes, a loss of the ability to perform fine movements, and an extensor plantar response known as the Babinski sign.