Phantom limb syndrome

What is Phantom limb syndrome?

After amputation, paralysis or other neuronal damage of limb or limbs, the sensation of pain is termed as Phantom limb syndrome. However, in some cases Phantom limb syndrome is non-painful.

Non-painful symptoms can be related to the perception of movement or the perception related to the external sensations including temperature, pressure, vibration, itching and touch. Whereas, pain sensation can be burning, shooting and pin pricking feeling in the affected limb or limbs.

Ambrose Pare, a French military surgeon first described the symptoms of Phantom limb syndrome in 1552. But in the nineteenth century, Silas Weir Mitchell, a Civil War surgeon first using the term ‘ Phantom limb syndrome’.

It has been identified from different case studies the symptoms of Phantom limb syndrome is usually occurring immediately after amputation, means within the first month of the amputation or a year after amputation.

These two time periods are considered as peak periods of onset of symptoms of Phantom limb syndrome^1,2,3

Risk Factors

Certain risk factors increase the Phantom limb syndrome occurrence:

• Female gender has higher tendency than male
• Amputation of upper extremity has more risk to build Phantom limb syndrome
• Prior to amputation severe pain in the affected limb
• Remaining limb has a residual pain
• Time- duration after amputation, immediately after amputation risk is more³.

Causes

Earlier, it is considered that Phantom limb syndrome may relate to psychiatric illness. But recent research studies suspected that altered neural axis, especially at the cortex is responsible for this syndrome. Both central neural mechanisms and peripheral neural mechanisms have the chance of involvement in case Phantom limb syndrome.

In central neural mechanisms, alteration of the spinal cord and related modification sensitization or cortical region modification and neuromatrix alteration may associate.

Hyperactivity of peripheral nervous system may also involve. However psychogenic involvement is also a considerable factor. But all these propose mechanisms are only explained theoretically, but no practical evidence able to provide a proper explanation. Experts believe multiple mechanisms are responsible for the onset of Phantom limb syndrome⁴.

Symptoms

Phantom limb syndrome affected patients feel that there is a limb with proper functioning even after amputation of the limb. Patients can experience different sensations based on the amputated limb. The included sensations are:

• Feeling of irritation
• Limb cramps
• A stabbing, piercing or shooting pain
• Numbness

Some affected individuals also explained that they have warmth, cold, itchiness and tightness on the amputated limb. This sensation may be mild or severe. In the case of the severe feeling of the symptoms hampers daily activities¹.

Treatment

A number of the management plan is applied in the treatment of Phantom limb syndrome. However, no specific treatment guidelines are set to treat Phantom limb syndrome affected patients. Following are some of the treatment plan applied for Phantom limb syndrome treatment and rehabilitation.

Medicinal approaches

To prevent the noxious stimulation preemptive use of analgesics and anesthetics are administered prior to amputation. Mostly ketamine and bupivacaine are the drugs used for preemptive analgesia and anesthesia purposes^3,5.

Analgesic medications also prescribe to control pain symptoms. Acetaminophen and Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) are considered as first-line drugs to treat Phantom limb syndrome pain3,6.

Opioid analgesics can control the pain symptoms by acting on the central nervous system. But this drugs does not cause unconsciousness, loss of touch sensation etc. But research studies showed that Opioid analgesic does not efficiently control symptoms associated with Phantom limb syndrome.

But combination therapy like opioid analgesics, tricyclic antidepressants or anticonvulsants are effective choice to control Phantom limb syndrome. Some experts also suggested Tramadol, (a weak opioid) combined with mixed serotonin-noradrenalin reuptake inhibitor to treat Phantom limb syndrome^3,7.

Tricyclic antidepressant drugs like duloxetine can also use to treat neuropathic pain, associated with Phantom limb syndrome^3,8.

Gabapentin, Carbamazepine, Oxcarbazepine are different anti-convulsive drugs, but able to reduce lancinating and stabbing pain^3,7.

The N-Methyl-D-aspartate receptor antagonist (NMDA) like Memantine may provide a positive effect in the treatment of Phantom limb syndrome^3,9.

Non- pharmacological Treatment

Transcutaneous Electrical Nerve Stimulation (TENS) is a medical device and it has been expected that in the treatment of Phantom limb syndrome, which can TENS is effective and provide the low side effect. The handling of this device is easy^3,10.

Mirror therapy is also applied in some cases, where mirror reflection on of their intact limb by placing it properly, so that patient can observe the movement of the limbs. When a patient sees the reality then they may stop feeling of symptoms^3,11.

Guided imagery, hypnosis, and relaxation techniques are applied in biofeedback process, integrative, and behavioral methods. Though the effectiveness of these technique does not provide any evidential prove for improvement of the patient condition.

Electroconvulsive therapy is a novel therapeutic approach to treat Phantom limb syndrome affected patients, though the detailed mechanism of this therapy is unknown^3,12.

References

1. Michael Rugnetta. Phantom limb syndrome. Encyclopedia Britannica; https://www.britannica.com/topic/phantom-limb-syndrome
2. Phantom Limb Pain; Web MD; http://www.webmd.com/pain-management/guide/phantom-limb-pain
3. Bishnu Subedi, George T. Grossberg. Phantom Limb Pain: Mechanisms and Treatment Approaches. Pain Res Treat. 2011; 2011: 864605. Published online 2011 Aug 14. doi: 10.1155/2011/864605
4. Flor H, Nikolajsen L, Jensen TS. Phantom limb pain: a case of maladaptive CNS plasticity? Nature Reviews Neuroscience. 2006;7(11):873–881
5. Wilson JA, Nimmo AF, Fleetwood-Walker SM, Colvin LA. A randomised double blind trial of the effect of pre-emptive epidural ketamine on persistent pain after lower limb amputation. Pain. 2008;135(1-2):108–118.
6. Hanley MA, Ehde DM, Campbell KM, Osborn B, Smith DG. Self-reported treatments used for lower-limb phantom pain: descriptive findings. Archives of Physical Medicine and Rehabilitation. 2006;87(2):270–277.
7. Weeks SR, Anderson-Barnes VC, Tsao JW. Phantom limb pain: theories and therapies. Neurologist. 2010;16(5):277–286.
8. Spiegel DR, Lappinen E, Gottlieb M. A presumed case of phantom limb pain treated successfully with duloxetine and pregabalin. General Hospital Psychiatry. 2010;32(2):3 pages.
9. Hackworth RJ, Tokarz KA, Fowler IM, Wallace SC, Stedje-Larsen ET. Profound pain reduction after induction of memantine treatment in two patients with severe phantom limb pain. Anesthesia and Analgesia. 2008;107(4):1377–1379.
10. Black LM, Persons RK, Jamieson B. What is the best way to manage phantom limb pain? Journal of Family Practice. 2009;58(3):155–158.
11. Rizzolatti G, Fogassi L, Gallese V. Mirrors in the mind. Scientific American. 2006;295(5):54–61.
12. Rasmussen KG, Rummans TA. Electroconvulsive therapy for phantom limb pain. Pain. 2000;85(1-2):297–299.