Complications with Peripheral Nerve Injury

Original Editors - Naomi O'Reilly

Top Contributors - Naomi O'Reilly, Tarina van der Stockt, Kim Jackson and Manisha Shrestha      

Introduction[edit | edit source]

Peripheral nerve injuries are common conditions with broad ranging symptoms depending on the severity of the nerve injury and what nerves are involved. Peripheral nerves convey signals between the spinal cord and the rest of the body. Nerves are comprised of various combinations of motor, sensory, and autonomic neurons with symptoms and complications depending on which nerve fibres are involved .[1] Thus injury to peripheral nerves can have various secondary complications, which can be significant and have long term effects depending upon the classification of nerve injury.

Table.1 Types of Peripheral Nerves
Motor Nerves Sensory Nerves Autonomic Nerves
Damage to these nerves is typically associated with muscle weakness, muscle cramps and uncontrollable muscle twitching. Damage to sensory nerves is typically associated with altered touch, temperature or pain. Damage to autonomic nerves can be associated with activities that are not controlled consciously, such as breathing, the heart, thyroid function, and digestion, which can result in secondary complications secondary to excessive sweating, changes in blood pressure and inability to tolerate heat and gastrointestinal symptoms.

Pain and Hypersensitivity[edit | edit source]

Significant pain can occur with peripheral nerve injury, particularly with nerve root avulsions, causing neuropathic pain. Severe pain can also potentially lead to complex regional pain syndrome, all of which can impact rehabilitation.

Adequate pain control for rehabilitation is of paramount importance.[2]

Altered Sensation[edit | edit source]

Peripheral nerve injury is often associated with significant changes in sensation, with numbness, burning sensation, tingling or total loss of sensation in the part of the body affected by the damaged nerve, which can increase the incidence of further secondary injuries as a result of this altered reduced sensation such as pressure ulcers, burns, and lacerations.[3]

Pressure Ulcers[edit | edit source]

Pressure sore in patient with foot drop

Patients with decreased sensation as a result of a peripheral nerve injury are at increased risk of developing pressure ulcers, which can be harder to see on dark skin. A pressure ulcer is a localised injury to the skin and/or underlying tissue usually over a bony prominence, as a result of pressure, or pressure in combination with shear.  A pressure sore can develop in a few hours, but the results can last for many months and can cause significant loss of function and impairment. A number of contributing or confounding factors are associated with pressure ulcers, but the significance of these factors is yet to be elucidated. Tissue injury is related to both extrinsic and intrinsic factors.

  • Extrinsic factors include pressure, shear, friction, immobility, and moisture.
  • Intrinsic factors relate to the condition of the patient such as local infection, sepsis, decreased autonomic control, altered level of consciousness, increased age, vascular occlusive disease, anaemia, malnutrition, sensory loss, and contracture.

Keeping the skin dry, regular position changes and regular skin checks (use a mirror if necessary) will help.

Read more here about the prevention and management of Pressure Ulcers

Burns and Lacerations[edit | edit source]

Burns and skin lacerations as a result of contact with hot surfaces or water, sharp surfaces or not using protective clothing, e.g. shoes are common with altered sensation following peripheral nerve injury.

Test water with the opposite, or sensate limb, and always wear covered supportive shoes if foot sensation is reduced.

Delayed Healing[edit | edit source]

Peripheral nerve injury can have an impact on healing, and slow down the healing mechanisms of soft tissue. This can be further exacerbated by muscle weakness, which can impact on the circulation of blood in distal limbs causing swelling and thus poor healing. Other factors that may impair healing include;

  • Smoking, which significantly reduces blood flow to the injured nerve and soft tissue
  • Diabetes,
  • Nutrition, which can delay healing if inadequate protein and nutritional intake.

Swelling[edit | edit source]

As peripheral nerve injury causes motor impairment in extremities, it affects the muscle pump from the distal aspect of limbs, particularly in a sciatic nerve injury, which may lead to blood pooling in distal limbs when limbs are in a gravity-dependent position. This may cause further neuropraxia as a result of increased compression of the nerve and increased pain.

Limb elevation and range of movement (passive, active-assisted or active) can encourage the movement of fluid and help with swelling.

Contracture and Deformity[edit | edit source]

Contractures result from a loss in the extensibility of the soft tissue structures-skin, ligaments, muscles, and joint capsules crossing joints, leading to restriction in joint mobility, causing joint stiffness, and later on the deformity.[4] Contractures reduce joint mobility and restrict activities of daily living. They are also associated with pain, spasticity, sleep disturbances, and skin breakdown. Most often contractures affect the joints important to daily living: hips, knees, ankles, wrists, and shoulder, causing problems with dressing, eating, transferring, sleeping comfortably, using a wheelchair, or doing any tasks that require full joint movement. Problems in any of these areas can reduce a person's independence[5]. If the joints of the affected muscles are not moved passively on a daily basis, the muscles shorten and joints can become stiff causing contracture and deformities. Positions or postures in which the patient spends most of each day in bed or wheelchair increase the susceptibility to contracture, as can pain, which increases the likelihood of contracture as a result of increased tendency to contract the non-paralyzed muscles, which increases the time soft tissues spend in shortened positions.

Stretching, range of motion and strengthening exercise, splinting, serial casting, and positioning should all be used to prevent and manage contractures.

Neuroma[edit | edit source]

A neuroma is a common complication of a peripheral nerve injury or amputation, and it can cause tremendous pain that is often resistant to most analgesics. Neuromas are a non-cancerous thickening of nerve fibres made of non-conducting tissue that stops the signal from being sent along the nerve. Neuromas are thought to be formed when nerve regeneration is blocked by scar tissue, preventing further regeneration. Neuromas are a potential, limiting complication of nerve recovery which can cause pain or hypersensitivity; they usually do not develop until at least six weeks post-injury. Movement of adjacent tissues or direct application of pressure on neuromas often causes pain by stimulating the nerve enclosed by the neuroma.

Muscle Weakness[edit | edit source]

Involvement of motor nerve causes weakness of muscles supplied by that nerve. A consequence of denervation is muscle atrophy and functional deficits. A healthy neuromuscular junction is critical for nervous control of muscles. TENS has been seen in numerous studies to have a positive effect on maintaining neuromuscular junction health and preventing muscle atrophy.[5] A 2018 study found the use of TENS was most beneficial if delayed to one-week post-trauma, the use of 100hz being most beneficial.[6]

Muscle care is of utmost importance to prevent damage to muscle units, in particular, preventing: heat or cold trauma; overstretching by gravity or incorrect lifting/transfer techniques; contractures of muscles. When muscle strengthening exercises can commence it is important not to damage the healing nervous tissue:  if pins and needles, numbness or increased pain occurs if the exercise is too hard and progressed too quickly and can have a negative effect on healing.

Psychological Stress[edit | edit source]

Muscle weakness, contractures, deformity and pain can impact mental health following peripheral nerve injury. Chronic neuropathic pain has a life-debilitating effect causing emotional stress and reduced quality of life, and increased risk of post traumatic stress disorder, depression, or anxiety. The ultimate goal is not simply to reduce pain but to achieve an improved quality of life, which can only be achieved if depression, anxiety, and sleep disorders are also addressed.[7]

References [edit | edit source]

  1. Menorca RM, Fussell TS, Elfar JC. Peripheral nerve trauma: mechanisms of injury and recovery. Hand clinics. 2013 Aug;29(3):317.
  2. Michael D Robinson, Steven Shannon.Rehabilitation of peripheral nerve injuries.PMID: 11878078.DOI: 10.1016/s1047-9651(03) National Library of Medicine. National Centre for Biotechnology Information.
  3. Ginny, G, Chapter 18 - Peripheral Nerve Injuries. In Editors: Cameron, MH and Monroe, LG. Physical Rehabilitation, W.B. Saunders, 2007, Pages 473-513,
  4. Harvey LA, Glinsky JA, Katalinic OM, Ben M. Contracture management for people with spinal cord injuries. NeuroRehabilitation. 2011 Jan 1;28(1):17-20.
  5. 5.0 5.1 SCI joint Contractures. Research and Training Center on Independent Living, University of Kansas. (1996). Contractures. Lawrence, KS. Available from Accessed on 16/12/20
  6. Su HL, Chiang CY, Lu ZH, Cheng FC, Chen CJ, Sheu ML, Sheehan J, Pan HC. Late administration of high-frequency electrical stimulation increases nerve regeneration without aggravating neuropathic pain in a nerve crush injury. BMC neuroscience. 2018 Dec;19(1):37.(last accessed 25.3.2019)
  7. Torta R, Ieraci V, Zizzi F. A Review of the Emotional Aspects of Neuropathic Pain: From Comorbidity to Co-Pathogenesis. Pain and therapy. 2017 Dec 1;6(1):11-7. Available from: (last accessed 27.3.2019)