This chapter discusses phantom pain, defined as an unpleasant or painful sensation in the distribution of the lost or deafferentiated body part. It is more commonly reported in the limbs but also has been reported in other body parts such as the tongue, teeth, nose, breast, part of the gastrointestinal tract, and the penis. The incidence varies from 42.2% to 78.8%. Perception of non-painful sensations from the amputated body part is known as phantom sensation. The severity and frequency of attacks slowly decrease with time during the first 6 months, after which they remain constant. Patients with significant preoperative pain, stump pain, and infection are at increased risk of developing phantom pain. The mechanism of origin is not known; it is thought to be due to peripheral nerve damage, which contributes to neural sensitization at peripheral, spinal, and supraspinal levels. Both chemical mediators and psychological factors are involved. Phantom pain improves with time and responds to conservative medical management, mirror therapy, and psychological counseling. A small percentage of cases are resistant to treatment and may require invasive neuromodulatory treatment options such as spinal cord stimulation and peripheral nerve stimulation.
Neural sensitization improves encoding fidelity in the primate retina
