HIV-related Neuropathy

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Original Editor - Melissa Coetsee
Top Contributors - Melissa Coetsee, Kim Jackson and Pacifique Dusabeyezu

Epidemiology

The prevalence of HIV-associated neuropathy varies from 1.73% tot 69.4% among people living with HIV (PLWH). This variation could be attributed to the introduction of anti-retroviral treatment (ART), with its benefits and adverse effects varying with evolving drug-combinations. Diagnostic criteria and geographical region also influence the he prevalence of HIV-associated neuropathy. The estimated pooled frequency of DSN in Africa, prior to ART, was 27%. This increased to 52% in the post-ART era, and was mainly attributed to the widespread use of dideoxynucleoside reverse transcriptase inhibitors (like Stavudine).

It is however important to note that although the frequency appears to have increased since the introduction of ART, some studies indicate a significant reduction in pain associated with neuropathy - i.e. although patients test positive for neuropathy (based on signs), it is often asymptomatic.

Clinically Relevant Anatomy

add text here relating to clinically relevant anatomy of the condition

Patholophysiology

Neuropathy typically develops 5-6 months after initiating ART.

DSN: distal axonal neuropathy secondary to activated dorsal root inflammation, likely due to viral proteins.

ART drugs associated with peripheral neuropathy: Didanosine, Zalcitabine, Stavudine

Clinical Presentation

Clinical presentation varies depending on the type of neuropathy (discussed below)

Diagnostic Procedures

Based on medical history, clinical examination and laboratory tests

EMG

A clinical tool

Differential Diagnosis

Also see Neurological Complications of HIV and Neuropathies

• Myelopathy - including Vacuolar Myelopathy and Pott's Disease
• Opportunistic infections affecting the CNS - TB Meningitis, Neurosyphilis, Toxoplasmosis Encephalitis, Cryptococcal Meningitis
• Other CNS conditions - Stroke, Lymphoma, Aseptic Meningitis
• Vitamin B deficiency - Vit B12 deficient or excess of vit B6
• Alcoholic neuropathy
• Diabetic Neuropathy
• Neuropathy related to isolated nerve damage (eg. surgery, compression, traction injury)
• Claudication associated with Peripheral Vascular Disease
• Pain and weakness caused by Central Sensitisation
• Schwannoma
• Morton's Neuroma

Outcome Measures

add links to outcome measures here (see Outcome Measures Database)

Types

Neuropathy can occur at all stage of HIV, and various types of neuropathy have been documented. The neuropathies present in PLWH include:

1. Distal sensory neuropathy
2. Inflammatory neuropathies
3. Radiculopathies
4. Mononeuropathies

1. Distal Sensory Neuropathy (DSN)

DSN is the most common type of neuropathy in PLWH.It affects the distal extremities (more commonly the feet) and is caused by axonal damage secondary to dorsal root inflammation. It is more common in the advanced stages of HIV infection (WHO stages 3 and 4). Some patients with DSN (about 25%) do not experiences any sensory symptoms (asymptomatic DSN).

Signs and symptoms include:

• Burning, stabbing pain and numbness in the soles of the feet/palms of the hands - this ascends symmetrically
• Sensitivity is most pronounced one the soles and palms
• Reduced or absent ankle reflexes
• Impaired light touch sensation
• Impaired proprioception of the affected region

Risk factors for developing DSN:

• Advanced HIV disease

• Lower CD4 count and high viral load
• A history of prior TB or alcohol abuse
• ART regime that includes Dideoxynucleoside revers transcriptase inhibitors (NRTIs), especially Stavudine

3. Radiculopathy

Radiculopathy in less common and when present usually affects the lumbosacral nerve roots, mostly caused by TB or Cytomegalovirus (CMV).

4. Mononeuropathy

The most common mononeuropathies are:

• Facial nerve palsy (Bell's palsy): Usually occurs during the early, asymptomatic stages of HIV (at seroconversion). It may present as part of an acute inflammatory demyelinating neuropathy, but this is less common.
• Herpes zoster reactivation: One of the earliest signs of HIV, and affects the thoracic and trigeminal nerve. Complications include myelitis and post herpetic neuralgia.

Management / Interventions

• HIV infection control - early diagnosis and treatment with ART
• Drug regime alteration if associated with ART - Avoiding dideoxynucleoside reverse transcriptase inhibitors
• Pain control - With neuropathic medication (amitriptyline, gabapentin, pregabalin)- see the page on Neuropathic Pain and Pain in PLWH
• Education - On possible other causes of neuropathy (alcohol, diabetes and Vit B6 deficiency secondary to isoniazid)
• Treatment of other infections - in the case of Herpes reactivation, treatment with acyclovir is indicated
  

Resources

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