Phantom limb pain, phantom sensation, and residual limb pain

By Luke Kung’u

The feeling of wholesomeness is the aspiration of any living thing and more so for human beings who can express their feelings more elaborately.

Pain is the unpleasant but unavoidable circumstance that is brought by the loss of someone or something that one has an attachment with, and it affects the way we act and think.

To someone else, pain may not be perceived to be a bother, but it is everything to the bearer.

Now come to think of losing a body part that one has had for the greatest part of their lives. This is what amputees face as some of their body parts are taken away.

It is nightmarish, to say the least. The fact that real pain can be experienced while the body part is missing is food for thought. It is a reality shrouded in mystery.

Newsline engaged Senior Assistant Orthopedic Technologist, Mr. Damiano M. Mwangi, to unravel the secrecy that is ‘phantom pain’; and this is what he had to say. Read on:

Q. Kindly differentiate between Phantom limb pain, Phantom sensation, and residual limb pain.

A phantom limb is a vivid perception that a limb that has been removed or amputated is still present in the body and performing its normal functions. Amputees usually experience sensations including pain in the absent limb.

Phantom sensation: Resembles the somatosensory experience of the physical limb before amputation, including warmth, itching, sense of position, and mild squeezing. That is, the patient perceives sensation in a severed body part. Changes occur in both the central nervous system and peripheral nervous system after an amputation that depends on the subsequent reorganization of the primary somatosensory and motor cortices of the brain.

Residual limb pain: this is when the phantom sensations become intense enough for the amputee to define them as pain. It is a complex poorly understood pain syndrome that is described as burning, aching or electric type pain in the amputated limb.

Q. What symptoms are exhibited in such pain?

Patients suffering from phantom limb pain perceive that the amputated limb is still present and functioning as usual. In many cases, these patients will experience a wide range of sensations in the phantom limb, some of which include: • A tickling feeling • Cramps • A shooting, piercing or stabbing pain • Numbness • Cold • Warmth • Tightness • Itchiness Q. What causes the pain?

There are numerous theories about the causes of phantom limb pain including peripheral, central, and spinal theories:

Peripheral Theories: Remaining nerves in the stump grow to form neuromas, which generate impulses. These impulses are perceived as pain in the limb that has been removed.

Central nervous system: Melzack proposed that the body is represented in the brain by a matrix of neurons. Sensory experiences create a unique neuromatrix, which is imprinted on the brain. When the limb is removed, the neuromatrix tries to reorganize, but the neuro signature remains due to the chronic pain experienced before the amputation. This causes phantom limb pain after amputation.

PHOTO|COURTESY:

Pain pathway in the dorsal horn

Spinal theories: When peripheral nerves are cut during amputation, there is a loss of sensory input from the area below the level of amputation. This reduction in neurochemicals alters the pain pathway in the dorsal horn.

Other related causes:

Residual limb pain is believed to be caused by Ischemia, infections before amputation, neuroma, and pressurerelated wounds.

Psychological factors such as stress and depression also influence the development of chronic phantom limb pain.

Q. How is the pain diagnosed and managed in a hospital as well as at a home set-up?

The residual limb pain is diagnosed through carrying out clinical examination (patient assessment) procedures that include; patient history, clinical examination, clinical investigations, and differential diagnosis among others. Various pain management strategies have been used including: • Peripheral Sensitization: Irritant management with attention to excluding differential diagnosis, poor wound dressings, stump oedema. • Pharmacology (Follow the pain

PHOTO | neurosciencenews

Individual experiencing Phantom

ladder), Application of Stump sock, Education, Prosthetic (IPOP; immediate post-operative prosthesis), Scar management,

Acupuncture, physiotherapy, Selfmassage, Sleep hygiene. • Psychological and Social Factors:

Education, Sleep hygiene, Physical exercise Relaxation techniques,

Referral for formal mental health/ social support. • Musculoskeletal (MSK) Factors:

Enhancing on Joint range of motion, muscle power, managing

Trigger points/myofascial release, and Neural mobilization • Combining: Orthopaedic, prosthetics, physical and occupational therapy with a cognitive understanding of the condition will amplify the effects of treatment.

Q. How common is the pain?

The incidence of phantom pain widely varies in the literature ranging from 50 to 85 percent depending on the criteria used to define the syndrome. Inadequate control of preoperative and postoperative pain may increase the risk of chronic amputation pain.

Q. How often is the pain reported to health care providers?

The onset is mostly immediate after amputation, some at a few weeks, rarely months later. In most cases, the reporting of the pain is immediately after recovery from anesthesia, or during a patient assessment session. Residual limb pain is a poorly understood clinical phenomenon that remains the subject of intense research due to the acute and chronic nature of the condition. The incidence is reported to be as high as 60-80% in patients’ postamputation

Q. How can the pain be prevented and when is one supposed to call a doctor?

The phantom pain can be prevented through the application of the right surgical technics, the use of effective painkillers during the procedure and after it, and optimal stump care and rehabilitation.

The patient should report the pain immediately. The management of phantom pain leads to indirect management resolution of other anomalies.

Q. Who is vulnerable to such pain?

Phantom pain is independent of age in adults, gender, level, or side of amputation. The phantom limb pain phenomenon is seen more commonly in adults than in children. This is likely due to the brain as the brain of children has typically not finished consolidating images of their external organs.

Q. What are the treatment options? (therapies)

Coping techniques such as muscle relaxation, meditation, biofeedback, massage, and hypnosis have been shown to help some patients deal with phantom pain or related symptoms. Additionally, certain drugs such as analgesics, muscle relaxants, sedative-hypnotics, antidepressants, antipsychotics, and anticonvulsants are commonly used in treating phantom pain.

In some cases, shock therapy and acupuncture have been used to relieve symptoms. When non-invasive treatments fail to work, invasive approaches such as stimulation of the spinal cord, intrathecal drug delivery, and deep brain stimulation have been used to treat phantom limb pain.

Electrical nerve stimulation techniques such as transcutaneous electrical nerve stimulation and transcranial magnetic stimulation are beneficial in some patients. Mirror therapy is a therapeutic intervention, which has been shown to affect motor and sensory processes through the relative dominance of the visual input it provides. The effect is created by viewing a reflection of the intact limb, through a mirror placed where the amputated limb would have existed.

Q. Could there be any complications from this kind of pain?

Risk factors include chronic pre-amputation pain, post-operative surgical pain, and psychological distress. The risk factor for phantom pain includes the hypersensitivity of the distal part of the residuum. This hinders the distal weight-bearing of the residuum and problems during donning and doffing of prosthesis

PHOTO | COURTESY

Senior Assistant Orthopedic Technologist Mr. Damiano M. Mwangi

Q. What information is at the disposal of the person undergoing amputation and the family/relatives?

The patient and family must be made aware of the psychosocial repercussions of amputation. The rehabilitation team plays a greater role in ensuring that after the treatment, the patient is reintegrated back into society.

Q. Are there myths related to such pain and what does society say about it?

Early theories on the underlying cause of phantom pain were based around it being imagined or “in the head”. An apparent similarity to phantom illusions experienced in a psychotic state-led professional is to believe phantom pain was purely psychological or imaginary. The reason someone with an amputated limb felt pain was because they weren’t dealing with the loss very well, and it manifested as physical pain. Dr. G. Riddoch reported that many patients were reluctant to discuss their phantom pain for fear they would be thought insane.

Q. What is your parting shot?

The success of rehabilitation of an amputee dwells on the teamwork between the rehabilitation team and the patient. There is limited research carried out in Kenya on the life of amputees in the broad spectrum of their rehabilitation, service transition, psychosocial support, patient reintegration back to society/ occupation, and societal perception, among others. This calls for intensive study in this field to optimize service provision through innovativeness, and the generation of evidence-based data through research.