The Basics of Phantom Limb Pain

Phantom limb pain is severe pain felt in the area where a limb has been removed by amputation. These sensations usually decrease gradually and disappear over time. However, some patients continue to havePhantom Limb Pain phantom limb pain for the duration of their lives.

Although the body part is no longer there, the nerve endings continue to send pain signals to the brain, causing the perception of a limb that is still present. Sometimes, the brain retains a memory of pain, regardless of sensing signals from nerves.

Most patients who have a limb amputation experience phantom sensations. Also, approximately 75% of these patients experience phantom limb pain. Following the amputation, the phantom limb is perceived as the pre-amputation limb in regards to shape, volume, and length. The phantom sensations includes feelings of movement and posture, as well as hot and cold sensations.

Risk Factors for Phantom Limb Pain

Doctors do not know why some patients develop phantom limb pain after amputation while others do not. However, some factors increase the risk of this phenomenon:

  • Pain prior to the amputation – Patients who had pain before the limb removal are more likelphantom-limb-syndromey to have it afterwards. Experts believe this is because the brain holds the memory of pain.
  • Stump pain – Patients who have stump pain after the amputation are more likely to develop phantom pain. The stump pain is related to an abnormal growth on damaged nerve endings.
  • Poor-fitting prosthesis – If the artificial limb does not fit properly, it can result in pain.

Symptoms associated with Phantom Limb Pain

The patient will often experience other symptoms along with the phantom limb pain. These symptoms include:

  • Tingling
  • Cramping
  • Sensations of heat and/or cold in the area where the limb was removed

Treatment Options

  • Transcutaneuos electrical nerve stimulation (TENS) – A device is worn on the body that sends weak electrical current via adhesive patches on the skin. This interrupts the pain signals, which prevents them from reaching the brain.

 

  • Spinal cord stimulation – The doctor surgically implants a small device near the spinal cord. The unit delivers electrical current via a wire, which interrupts pain signals.Spinal Cord Stimulator3

 

  • Acupuncture – The doctor inserts extremely small sterilized needles into the skin, which stimulate the central nervous system to release endorphins (feel-good chemicals).

 

  • Injections – The doctor injects a long-acting anesthetic and a corticosteroid into the stump.

 

  • Intrathecal pain pump – The surgically implanted unit delivers pain medication directly into the spinal fluid to avoid unpleasant side effects.

 

Medications for Phantom Limb Pain

No single medication works for every patient, but there are several drugs that have proved useful for patients with phantom limb pain. These include:

  • Antidepressants – Tricyclic antidepressants relieve the pain caused by damaged nerves, including amitriptyline and nortriptyline. These agents work by modifying chemical messengers that detect pain.
  • Anticonvulsants – Drugs that quieten damaged nerves to prevent or slow pain signals, including Neurontin, Tegretol, and Lyrica.
  • Opioids – Often called narcotics, these agents, when taken appropriately, decrease pain perception.

 

Resources

Nikolajsen L & Jensen TS (2001). Phantom limb pain. British Journal of Anesthesia, 87, 107-116.