Phantom Limb Pain

Written by Staff | 30 October 2011

Phantom limb pain (PLP) is the sensation of pain perceived from a limb that is no longer attached to the body; a phenomenon experienced by patients having lost an upper or lower extremity due to trauma or surgical amputation¹. PLP is common following limb removal, affecting between 49–88% of amputees². Onset of PLP typically occurs shortly after limb loss, although in some cases it sets on months or years later¹.

While continuous pain may occur, intermittent episodes of pain tend to be more common, with episodes lasting anywhere from seconds to days¹. Patients often qualify PLP in a variety of ways, including stabbing, throbbing, tingling, cramping, spasms and more. Episodes of PLP can be triggered or exacerbated by physical, psychological or emotional stress¹.

The exact cause of PLP is unknown, although it is thought to arise from changes in the motor and sensory portions of the brain^{2, 4}. What is known, however, is that PLP can have serious negative consequences that including difficulty sleeping, challenges with training and use of prosthetics, dissatisfaction with self-image, loss of interest in social activities, symptoms of depression and despair, and a diminished quality of life¹. Because of these challenges, many patients with PLP become permanently disabled.

Diagnosis and Treatment

Diagnosis of PLP is performed by a doctor via a thorough history and comprehensive physical exam. The physical exam and supplemental imaging can help doctors exclude other possible physical causes of pain such as cysts, masses or bony spurs¹. Additionally, a physician may perform a complete neurological examination as PLP can be complicated by, or confused with, other nerve-related pain.

Effective treatments for PLP can be broken down into three categories, including pharmacological, psychological, and rehabilitation^{1, 3, 4}:

• Pharmacological
  • Anticonvulsant medications such as gabapentin are the drugs of choice for PLP. Tri-cyclic antidepressants may also be beneficial for pain control
  • Prescription opioid medications also have a demonstrated effect on reducing PLP, and may help re-organize the disrupted pain pathways in the brain. Tramadol is an opioid analgesic shown to be effective for long-term relief of PLP
• Rehabilitation
  • Electrical nerve stimulation has been shown to have some benefit in controlling PLP early after loss of a limb
  • Muscle relaxation and biofeedback, or having patients learn to become aware of how their body responds to the PLP and control those responses, has shown some effectiveness
• Psychological
  • Training in mental imagery and feedback with mirrors, while attempting movements with the lost limb, has shown promise for pain relief
  • Relaxation, stress management, distraction and hypnosis may also provide relief

Anesthesia and nerve blocks can be performed for intractable pain unaffected by medications¹. Surgery is generally not indicated for PLP, except in severe, intractable cases of pain.

PLP cannot be prevented; it is not a complication, but rather a typical side effect of limb loss¹. Given that stress can induce episodes of PLP, understanding this fact may be beneficial in reducing anxiety about the condition, helping pain control.

References

1. Bang, M.; Jung, S. (2008). Phantom Limb Pain. Frontera: Essentials of Physical Medicine and Rehabilitation, 2nd Ed.. MD Consult Web site, Core Collection.
2. Mishra, S.; et al. (2007) High-dose Morphine for Intractable Phantom Limb Pain. Clin J Pain. Vol 23(1), 99-101.
3. Portenoy, R.; Dhingra, L. (2011). Overview of cancer pain syndromes. In: UpToDate, Basow, DS (Ed), UpToDate, Waltham, MA.
4. MacIver, K.; et al. (2008) Phantom limb pain, cortical reorganization and the therapeutic effect of mental imagery. Brain. Vol 131(8), 2181-2191.