Post-Amputation Pain and Phantom Limb PainWhat is Post-Amputation Pain? Post-amputation pain is a poorly understood, yet common, condition that causes significant disability and can be difficult to treat. Amputation pain occurs in approximately 60 to 70% of patients, often arising weeks or months after a limb has been removed due to accident, injury, or disease. (1-2) Pain following an amputation may develop as either residual limb pain, phantom limb pain, or phantom limb sensation. (3) Post-amputation pain is a broad “catch-all” term, often used to refer to any of the aforementioned (without distinction) or even simply the general pain from the trauma of the amputation itself. The pain is often described as aching, throbbing, shooting, cramping, or burning. Non-painful sensations may include feelings of numbness, itching, paresthesias, twisting, pressure or even the perception of involuntary muscle movements in the residual limb at the amputation site. (4) These sensations may be generalized to the entire missing limb or localized to specific anatomical regions such as the fingers or toes. What is Phantom Limb Pain? Phantom limb pain is a type of post-amputation pain that can occur in any part of the body that no longer exists. Phantom pain has been described after mastectomy (phantom breast syndrome), eye removal and even after teeth extraction. Phantom sensations may be mild at first and decline over time, yet remain to some degree indefinitely. Occasionally the discomfort will progress to severe pain that includes intermittent tremors and muscle spasms. With time the sensation of a phantom body part can fade away. However in 50% of cases, especially upper limb phantoms, the missing arm seems to get progressively shorter until the patient is left with a sensation of the phantom hand alone, dangling from the stump. This symptom change is referred to as telescoping. What Causes Post-Amputation Pain? This type of pain is believed to stem from mixed signals that arise from the residual limb or brain. At the end of the stump, nerve fibers may grow a mass, or neuroma, that sends disordered signals to the brain. Meanwhile, in the brain, as other functions gradually take over the part of the brain that had been linked to the limb, painful sensations may arise. Risk Factors for Developing Post-Amputation Pain Relative risks are indicated as: Greater risks (top) > lesser risks (bottom) What is Stump Pain? Stump pain is common in the early post-amputation period but diminishes as healing occurs. In 5 to 10% of patients, stump pain persists and can even get worse over time. What Treatments are Available for Post-Amputation Pain? Providers should remember to look for causes of stump pain and treat these since addressing the cause may reduce the incidence or severity of phantom pain. Medications (5) Physical Therapy and Behavioral Interventions (6) Interventional Pain Management Treatments Neurostimulation Spinal cord and peripheral nerve stimulation have been performed with varying results. For selected patients who have not obtained adequate relief with medical management, i.e. those who have intractable pain, spinal cord stimulation (SCS) can prove an effective intervention and should be considered. (7) In 2015, dorsal root ganglion (DRG) stimulation in eight patients with amputation pain was reported to reduce phantom limb and residual limb pain by 53%; one individual reported a complete resolution of pain at 9 months. (8) Potential newer neurostimulation treatments have been studied in recent years. For example, in 2015, pilot-study results were reported for high-frequency electrical nerve block in post-amputation pain. (9) A randomized clinical trial of repetitive transcranial magnetic stimulation in phantom limb pain was reported in 2016. (10) Post-Amputation Pain and Neuromodulation
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| Last Updated on Sunday, November 21, 2021 08:12 PM |