Neuropathies

Original Editor - Lucinda hampton

Top Contributors - Lucinda hampton, Kim Jackson, Candace Goh, Melissa Coetsee, Uchechukwu Chukwuemeka, Merinda Rodseth, Ahmed M Diab, Sehriban Ozmen and Manisha Shrestha

Clinically Relevant Anatomy

Neuropathy is a dysfunction of one or more peripheral nerves or peripheral nervous system.

Neuropathy can involve damage of only one nerve (called mononeuropathy); two or more nerves in different areas, called mononeuropathy multiplex; or most commonly, many nerves are affected (called polyneuropathy).

Mechanism of Injury / Pathological Process

The causes of neuropathies are manyfold and include:

• Physical injury eg pressure from disc herniation , pressure from a cast, trauma, arthritis.
• Systemic autoimmune diseases eg diabetes, Sjogren's syndrome, RA
• Autoimmune diseases that attack nerves eg Guillain-Barre syndrome, Multifocal motor neuropathy.
• Toxins eg from toxic amounts of substances in the blood associated with kidney and liver disorders, alcoholism, chemotherapy drugs
• Infections eg Varicella zoster virus (shingles), White Nile virus, AIDS, Lyme disease ( carried by ticks)

Neuropathies may primarily affect sensory nerves, motor nerves, autonomic nerves, or multiple types. Anything that damages nerves can interfere with their ability to transmit accurate signals, which can lead to a number of signs and symptoms.

Clinical Presentation

Neuropathies may primarily affect sensory nerves, motor nerves, autonomic nerves, or multiple types. Anything that damages nerves can interfere with their ability to transmit accurate signals, which can lead to a number of signs and symptoms.

Dependant on the type of nerves affected

• Motor nerve damage will cause muscle weakness, painful cramps, fasciculations (uncontrolled muscle twitching visible under the skin) and muscle shrinking.

• Sensory nerve damage causes various symptoms because sensory nerves have a broad range of functions. Damage to large sensory fibers affects the ability to feel vibrations and touch. The client may feel as if you are wearing gloves and stockings. This damage may contribute to the loss of reflexes (along with motor nerve damage). Loss of position sense presenting with eg balance problems. The “small fibers”( without myelin sheaths ) damage affects the transmission of pain and temperature sensations which interferes with the ability to feel pain or changes in temperature. This causes neuropathic pain, which can erode a person's quality of life.

• Autonomic nerve damage affects the axons in small-fiber neuropathies. Common symptoms include excess sweating, heat intolerance, inability to expand and contract the small blood vessels that regulate blood pressure, and gastrointestinal symptoms.

An example of foot damage due to sensory loss, bottom R

Diagnostic Procedures

A full Medical History (including client symptoms, lifestyle, exposure to toxins, drinking habits and a family history of nervous system (neurological) diseases).

Neurological examination

Other tests ordered include

• Blood tests, checking for eg toxins, vitamin deficiencies, diabetes
• Imaging test eg CT MRI for eg tumours, disc herniation.
• Nerve function tests, checking nerve conduction.
• Nerve biopsy, looking for abnormalities
• Skin biopsy, looking for reduction in nerve endings
  

Outcome Measures

The many different presentations of neuropathies lead to a need to client specific outcome measures. Usually related to muscle strength, pain, QOL, and activity limitations. They include

The SF-36 is a measure of health status and an abbreviated variant of it, the SF-6D, is commonly used in health economics as a variable in the quality-adjusted life year calculation to determine the cost-effectiveness of a health treatment.

INCAT (inflammatory cause and treatment) score is a measure of activity limitation

TUG; 10 metre walk test; grip strength; FSS; PSFS; oxford muscle strength scale; Romberg test.

Management / Interventions

Besides medications used to treat conditions associated with peripheral neuropathy, medications used to relieve peripheral neuropathy signs and symptoms include:

Anticonvulsants: Gabapentin; Pregabalin; Valproate

Antidepressants:Amitriptyline; Duloxetine; Venlafaxine

Opioids: Dextromethorphan; Morphine sustained release; Oxycodene; Tapentadol; Tramadol.

Others: Topical nitrate sprays; Capsaicin cream

Physiotherapy

The main role of physiotherapy is to

• Restore, or maintain muscle strength, and prevent muscle shortening and deformity
• Balance, co-ordination and functional training.
• Pain relief eg provision of TENS, massage
• Splints as needed, prevent deformity and contractures
• Education re managing conditions, preventing damage and emotional support.

For a comprehensive guide see individual neuropathies below

• AIDS
• Diabetic Neuropathy
• Brachial plexus injuries
• Sciatic nerve injuries
• Cyclists Palsy
• Axillary nerve damage