Phantom limb pain

Of particular interest among the neurological causes of chronic pain is phantom limb pain, in which amputation or deafferentation of the limb (or other parts of the body) is regularly associated with persistence of the body image of the affected part. The phantom may be painless or painful and tends to shrink and eventually disappear over time. However, in about 50% of patients a painful phantom persists. The pain may be perceived in discrete parts of the phantom which may seem to move or feel as if fixed in a distorted position. 

Unlabeled Uses Relief of neuropathic pain, such as that experienced by patients with diabetic neuropathy or postherpetic neuralgia treatment of anxiety, bulimia nervosa, migraine, nocturnal enuresis, panic disorder, peptic ulcer, phantom limb pain... 

Rogers, A.G. (1989) Use of amitriptyline (Elavil) for phantom limb pain in younger children. J Pain Symptom Manage 4 96. 

Rusy, L.M., Troshynski, T.J., and Weisman, J. (2001) Gabapentin in phantom limb pain management in children and young adults report of seven cases. / Pain Symptom Manage 21 78—82. 

In 1997 Brose et al. published the result of a single case study. SNX-111, administered i.t. by continuous, constant-rate infusion, produced dose-dependent pain relief in a 43-year-old male patient with a 23-year history of intractable deafferentation and phantom limb pain secondary to brachial plexus avulsion and subsequent amputation. Dizziness, blurred vision, and lateral-gaze nystagmus... 

Pain occurs in various degrees, from dull and aching to piercing and intense. Acute pain is usually associated with tissue injury and, for the most part, occurs for only a short amount of time. Chronic pain, however, persists for long periods of time, even years after the injury that originally caused the pain has gone away. For example, severe bums can create scar tissue that can continue to cause excmciating discomfort. Certain disorders, such as arthritis or cancer, may also cause persistent pain. In the case of phantom limb pain, an individual may continue to perceive pain in an arm or leg that has been ampu-... 

These include postherpetic neuralgia, phantom limb pain, peripheral neuropathies of various causes, central pain, e.g. following a stroke, compression neuropathies, and the complex regional pain syndromes (comprising causalgia, when there is nerve damage, and reflex sympathetic dystrophy, when there is tissue but no nerve injury) they present the most challenging problems. 

In a double-blind, placebo-controlled, crossover pilot study in three patients with cancer-associated postamputation phantom limb pain, oral dextromethorphan 60-90 mg bd or placebo were given for 1 week each, followed by dextromethorphan or placebo again (10). Dextromethorphan satisfactorily improved phantom Umb pain at a dosage of 60 mg bd in two patients and 90 mg bd in the third. Even though a relatively high total dose of dextromethorphan was used, there were no adverse effects. 

New onset, severe lightning pain after repeated subarachnoid blockade occurred in a 48-year-old man with pre-existing neuropathic pain after incomplete spinal cord injury, similar to previous reports in patients with phantom limb pain (202). 

Weinstein, S. Phantom limb pain and related disorders. Neurol. Clinic 1998, 16 (4), 919 935. 

Neuropathic pain is severe chronic pain due to damage to sensory nerves. This is not because of tissue injury and can occur as a consequence of central nervous system disorders, such as stroke or multiple sclerosis, or because of malignancy, amputation (phantom limb pain) diabetic neuropathy or following infection with Herpes zoster (as shingles). Mechanisms underlying neuropathic pain are poorly understood. The pain is described as... 

A general study of the clinical effectiveness of massage by Ernst (1994) used numerous trials, with and without control groups. A variety of control interventions were used in the controlled studies including placebo, analgesics, transcutaneous electrical nerve stimulation, and so on. There were some positive effects of vibrational or manual massage, assessed as improvements in mobility, Doppler ow, expiratory volume, and reduced lymphedema in controlled studies. Improvements in musculoskeletal and phantom limb pain, but not cancer pain, were recorded in controlled studies. Uncontrolled studies were invariably positive. Adverse effects included thrombophlebitis and local in ammation or ulceration of the skin. 

While persistent post-operative pain was believed to be low following amputation (2%), phantom limb pain occurs in anywhere from 50 to 80% of amputees. It is suggested to be independent of age, but it is more prevalent if the amputation is conducted in adulthood vs. childhood. It is also independent of gender or site of amputation. Most studies show no relationship with health status and this condition exists whether the amputation is for trauma or medical... 

Flor H, Nikolajsen L, Jensen TS. Phantom limb pain a case of maladaptive CNS plasticity. Nature Rev Neurosci 2006 7 873-881. 

Gabapentin monotherapy was better than placebo in post-amputation phantom limb pain after 6 weeks. There were no significant differences in mood, sleep interference, or activities of daily living. 

Schley M, Topfer S, Weich K, et al. Continuous brachial plexus blockade in combination with NMDA receptor antagonist memantine prevents phantom limb pain in acute traumatic upper limb amputees. 

Ketamine may play a role in the prevention of post-amputation pain and development of phantom limb pain if given epidurally over a period of 48 hours at a dose of 0.03 mg/kg per h. Ketamine can be used as second-line treatment in refractory status asthmaticus in both adults and children should conventional treatment have failed. 

Ketamine may be used to decrease the duration of a migraine with aura in patients with familial hemiplegic migraine, and can be used to decrease opioid withdrawal symptoms. It can decrease phantom limb pain if given IV. 

Wiech K, Kiefer RT, Topfner S, et al. A placebo-controUed randomized crossover trial of the N-methyl-D-aspartic acid receptor antagonist, memantine, in patients with chronic phantom limb pain. Anesth Analg 2004 98(2) 408-413. 

Hackworth RJ, Tokarz BCA, Fowler lA, Wallace SC, Stedje-Larsen ET. Profound pain reduction after induction of memantine treatment in two patients with severe phantom limb pain. Anesth Analg 2008 107 1377-1379. 

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