Phantom Limb Pain Rehabilitation Management

Original Editor - Jess Bell based on the course by Inger Brueckner
Top Contributors - Jess Bell and Stacy Schiurring

Introduction

Phantom limb pain (PLP) is a painful sensation that occurs in a part of the body that has been amputated. It is distinct from residual limb pain and non-painful phantom sensations. PLP is common after amputation, but despite its prevalence, we still don’t fully understand its underlying mechanisms. Nor do we have strong evidence for any one treatment approach.

If you would like to learn more about the features of PLP, residual limb pain and non-painful phantom sensations, please see: Distinguishing Phantom Limb Pain from Residual Limb Pain and Non-painful Phantom Limb Sensations.

Proposed Phantom Limb Pain Mechanisms

Our understanding of PLP has shifted significantly over time. Early 20th-century theories that relied on psychopathology or other psychogenic mechanisms to explain PLP have been “conclusively debunked”.

While maladaptive brain plasticity (or cortical reorganisation) has been the dominant theory since the late 20th century, recent research has challenged this view.

Current theories suggest that PLP may be caused by sensory-motor incongruence, where there is a mismatch between what the brain experiences and what it expects to experience after amputation.

When considering PLP research, mechanisms and treatment, it's important to remember that there is little level 1 evidence for PLP treatments and that most studies have small sample sizes with short follow-up periods.

There is also insufficient evidence to support the theory that maladaptive cortical reorganisation is responsible for PLP, but many of the most commonly recommended pharmacological and non-pharmacological treatments for PLP continue to focus on reversing maladaptive plasticity (e.g. mirror therapy, motor imagery, and virtual reality).

Most recommended PLP treatments have been described as “marginally effective at best and no more effective than placebo”; this suggests that current interventions aren’t effectively targeting the mechanisms or causes of PLP.

If you would like to recap the proposed mechanisms of PLP in more detail, please see: Clinical Features and Mechanisms of Phantom Limb Pain.

The following optional video from Professor Makin also highlights recent shifts in our understanding of PLP mechanisms:

Evidence-Supported Phantom Limb Pain Interventions

Six PLP treatments have been endorsed in a 2021 expert consensus Delphi study of 37 interventions:

• graded motor imagery, mirror therapy, amitriptyline (a tricyclic antidepressant), sensory discrimination training, and the use of a functional prosthesis are endorsed by experts because of available scientific evidence and reported clinical efficacy
• cognitive behavioural therapy and virtual reality training are endorsed by experts because of their reported clinical efficacy despite a lack of scientific evidence

Graded Motor Imagery

Graded motor imagery (GMI) is a graded, three-phase intervention that has been used to treat various pain conditions, including PLP.

The first phase is left / right discrimination (or implicit motor imagery). During this phase, the individual aims to distinguish between left and right body parts in an image. This activates the somatosensory, premotor and supplementary motor areas contralateral to the phantom limb.

The second phase involves explicit motor imagery (or imagined movements). During this phase, the individual imagines moving their phantom limb into a range of postures. This activates the somatosensory, premotor and primary motor cortices contralateral to the phantom limb.

The final phase is mirror therapy. During this phase, the individual conceals their amputated limb behind a mirror and moves both their phantom limb (i.e. a movement intention) and their intact limb while looking at the reflection of their intact limb in the mirror. The reflection provides visual feedback that the phantom limb moved (i.e., that the movement intention was successful). It is believed that this helps address the visual-motor mismatch that may contribute to PLP.

If you would like to learn more about GMI generally, including typical response times for laterality training, precautions, and some tips on what to do and what not to do, please see: Graded Motor Imagery. You can also find out more about GMI from the NOI group here.

The following table describes a GMI protocol for individuals with phantom limb pain based on a randomised controlled trial (RCT) by Limakatso et al. Please note that prior to treatment, each individual received education on phantom limb pain and GMI. The intervention consisted of two 30-minute treatment sessions held at least one day apart during the first week of each phase.

Table 1. Graded motor imagery treatment protocol

Time	Intervention	Home exercise programme
Weeks 1-2	Left / right discrimination The individual is shown 50 photographs that represent the individual’s intact and amputated limb in different positions on a tablet (Limakatso et al. used the Neuro Orthopaedic Institute’s (NOI) Recognise™ app) Each photograph is shown for five seconds and the individual is asked to identify if the image shows a right or left limb This left / right judgement task is looped for 30 minutes per treatment session, with less than one minute between loops	The individual is given a number of magazines (or cards, Recognise™ app, etc.) and is asked to identify and circle photos of limbs that match the side of their amputated limb Performed for 10 minutes every hour from 9 am to 9 pm each day (12 sessions per day)
Weeks 3-4	Explicit motor imagery (imagined movements) The individual is shown an image of a limb that matches the side of their amputated limb They are asked to imagine moving their amputated limb slowly and smoothly from the position they feel it is in, to the position shown in the photograph and back to the original position Three images are shown during a 30-minute treatment session and the task should be performed repeatedly	The individual is given three printed images or three images on their phone or tablet They are asked to perform the imagined movement activity at home for 10 minutes every hour from 9 am to 9 pm each day (12 sessions daily)
Weeks 5-6	Mirror therapy The individual places their amputated limb behind a mirror with the intact limb positioned in front of the mirror The individual is shown an image of their unaffected limb in an easily achieved position They are asked to move both their intact and phantom limb to the position shown while watching their intact limb’s reflection in the mirror   Three images are shown during a 30-minute session and the task is performed repeatedly	The individual is asked to perform this activity with the same photos for 10 minutes every hour from 9 am to 9 pm each day (12 sessions per day)

Using this protocol, Limakatso et al. found that patients receiving GMI had improved health-related quality of life and pain interference with function at six weeks, three months and six months. They were also more likely to experience clinically meaningful reductions in pain compared to patients who received routine physiotherapy alone. Routine physiotherapy in this study assumed a patient received ongoing treatment from their current physiotherapy provider and continued with their preferred / clinician-prescribed home programmes.

Please note the recommended frequency of sessions is high for GMI. You may see different dosages and frequencies in different trials, but regular practice is important.

Mirror Therapy

Mirror therapy has also been proposed as an effective standalone treatment for PLP. However, responses vary among individuals and it isn’t beneficial for everyone who has PLP.

When considering mirror therapy, it is essential to remember that this intervention requires an intact, functional limb and you are limited to symmetrical movements. While strong initial responses may predict better outcomes, some patients may experience increased pain severity after mirror therapy. If done correctly, this activity can be mentally fatiguing and you might find that some individuals experience an emotional response to seeing two whole limbs.

Treatment suggestions:

• 10-15 minute sessions, 5 times per week or as indicated
• general set-up matches that described in the GMI table above
• patients must be given feedback
• patients should not look at their residual limb but at the reflection of their intact limb

The following video shows the AmputeeOT demonstrate mirror box therapy. The demonstration starts at around 2:25:

Virtual Reality (VR) Training

The use of virtual reality for individuals with PLP is relatively new, and there is currently only low-level evidence. However, it has shown promise, particularly for individuals with bilateral amputations.

Virtual reality training uses visuo-proprioceptive feedback from a VR headset to help manage PLP. Some evidence suggests that it may be preferable to traditional mirror therapy “because of its utility during functional tasks”, like walking. And unlike mirror therapy, it allows individuals to perform unsynchronised, realistic limb movements.

Cognitive Behavioural Therapy (CBT)

There is a high level of expert support for CBT, but limited evidence for its use for PLP. It is, however, well supported in the management of other persistent pain conditions. It is proposed that CBT can reduce PLP because it targets common risk factors for PLP, such as depression, feelings of helplessness, and passive coping strategies.  

Functional Prosthesis Use

While there is a lack of evidence for using functional prostheses to manage PLP, their use is endorsed by experts. They can have various benefits as they provide proprioceptive feedback to the residual limb during functional activities (e.g., walking, lifting a cup). They are also considered more effective than cosmetic prostheses for improving pain and function.

Sensory Discrimination Training

In sensory discrimination training, patients touch the distal part of their residual limb with different fabrics (soft, rough, etc). While expert consensus for sensory discrimination training is low, it may be a useful adjunct to other therapies like GMI and mirror therapy.

Exercise Interventions for Phantom Limb Pain

Phantom Motor Execution / Phantom Exercise

Phantom motor execution (or phantom exercise) requires the individual to imagine their phantom limb is moving while they perform other physical movements. It is distinct from imaginary or visualised activity as it follows a different neurophysiological pathway.

While this strategy hasn’t been investigated as much as other interventions for PLP, reductions in pain have been reported by Zaheer et al. In their study, participants performed 15 minutes of phantom motor execution alongside 15 minutes of mirror therapy and 20 minutes of routine physical therapy.

The phantom exercises were structured as follows: (1) participants were asked about the position of their phantom limb and asked to place their intact limb in this position, (2) they were then asked to move both limbs in the opposite direction and back to the starting position, and (3) the phantom exercises were repeated until the participant felt their PLP had subsided completely, with a maximum of 15 repetitions per session.

To see the full protocol, please see: Effects of phantom exercises on pain, mobility, and quality of life among lower limb amputees; a randomized controlled trial.

General Exercise and Movement

While specific evidence for PLP is limited, general principles of exercise and lifestyle management for neuropathic pain may apply. For instance, general exercise is considered beneficial for neuropathic pain. Specific lifestyle factors, such as reducing stress, getting adequate sleep, having an appropriate diet, etc. are also important.

Remember that pain, guarding and emotion can impact pain, so it is useful to focus on how people move, rather than how much they move. Moreover, because PLP is associated with residual limb pain, it is important to maximise prosthetic comfort before increasing exercise or movement.

The following table lists some additional interventions used for PLP.

Table 2. Additional phantom limb pain interventions

Intervention	Considerations
Local injections	A study by Casale et al. found that myofascial injection of the contralateral limb with local anaesthetic can relieve PLP
Pulsed radiofrequency ablation of residual limb neuromas	Small studies show improvement
Neurostimulation techniques, including spinal cord stimulation, peripheral nerve stimulation, and deep brain stimulation	Some success in small studies
Acupuncture	Evidence is limited to case reports and case series
Associative awareness technique (AAT)	A low-risk technique created specifically for patients with trauma
Transcutaneous electrical nerve stimulation (TENS)	Evidence supporting its use is limited, but it is recommended as an adjunct treatment
Biofeedback	Preliminary studies show some improvement, but further studies are required
Eye movement desensitisation and reprocessing (EMDR)	An integrative psychological treatment initially used for individuals with psychological trauma; it is currently unclear who may benefit from EMDR, but it may be beneficial for individuals with PLP and post-traumatic stress disorder (PTSD)

Pharmacology

“Overall, there is a paucity of well-conducted clinical studies on the pharmacologic management of PLP with most studies limited by small sample sizes.”

Non-opioid medications are a first-line option for PLP as they tend to be safe with fewer long-term adverse effects. Antidepressants (e.g., amitriptyline) are often used because they are effective in treating other types of neuropathic pain. There is, however, a lack of evidence for their use in PLP. Similarly, anticonvulsants are often used to treat neuropathic pain, including PLP. The use of opioids for individuals with PLP is controversial. While they may have some benefits, they are associated with significant side effects and limited functional improvements. Thus, "the risks may outweigh the benefit”. There is conflicting results for botox in the research, but it may be used for PLP. Ketamine infusions may have some potential in acute PLP but not in chronic PLP (i.e., lasting more than one year).

If you would like to learn more about the pharmacological management of PLP, please see: An algorithm approach to phantom limb pain.

Phantom Limb Pain Surgery

“Surgical interventions have been attempted in the treatment of PLP, largely without overwhelming success”

One surgical treatment you might come across is residual limb revision, which may help with intractable residual limb pain. Some patients will also have neuroma revision. While neuroma revision is not typically thought of as helpful for PLP, it may lessen residual limb pain and indirectly help PLP. If you would like to read a summary of surgical interventions for PLP, please see: An algorithm approach to phantom limb pain.