What is spasticity and neuropathic pain?
Spinal cord injury disconnects the brain from the spinal cord below the injury site. The spinal cord below the injury site does not die unless it has been damaged by loss of blood flow (ischemia). The lower spinal cord becomes hyperactive because spinal cord injury interrupts not only excitatory but also inhibitory connections to the cord. The spinal cord above the injury site also may become hyperactive, producing abnormal sensations. • Spasticity and spasms. Reflexes may be hyperexcitable in the lower spinal cord isolated from the brain by injury. Such reflex hyperexcitability is called spasticity, including neurons that mediate muscle reflexes for feedback control, more complex reflexes such as the withdrawal reflex, anti-gravity reflexes for standing and postural control, and locomotor programs that mediate walking and running. Hyperactive reflexes may be present even when there is voluntary control of the muscle. Spasms are spontaneous or evoked movements of multiple muscles. Spas
