What is the management of polyneuropathy?

Management of Polyneuropathy

The management of polyneuropathy should focus on treating the underlying cause when identifiable, and providing symptomatic relief with medications such as pregabalin, duloxetine, or tricyclic antidepressants for neuropathic pain. 1, 2

Diagnostic Approach

• Polyneuropathy presents with distal, symmetric sensory or sensorimotor deficits including numbness, paresthesia, pain, and sometimes weakness 1
• Physical examination typically reveals distal sensory loss, reduced or absent reflexes, and sometimes distal muscle weakness 1
• Initial diagnostic workup should include:
  • Screening for reversible causes: diabetic screen, B12, folate, TSH, HIV, serum protein electrophoresis, and vasculitic/autoimmune screen 3, 1
  • Nerve conduction studies to document large fiber involvement 1
  • For small fiber polyneuropathy, skin biopsy with intraepidermal nerve fiber density assessment may be necessary 1
  • MRI of spine with or without contrast when indicated 3

Treatment of Underlying Causes

• Identify and treat the underlying cause whenever possible 4:
  • Diabetes mellitus (most common cause in Europe and North America) 4
  • Alcohol abuse (prevalence 22-66% among persons with chronic alcoholism) 4
  • Chemotherapy-induced neuropathies (prevalence 30-40%) 4
  • Vitamin deficiencies or toxicities 4
  • Exposure to toxic substances and drugs 4
  • Immune-mediated processes 4
  • Hereditary causes 4

Pharmacological Management of Neuropathic Pain

• First-line medications for neuropathic pain 3, 5:

  • Pregabalin: FDA-approved for diabetic peripheral neuropathy, postherpetic neuralgia, and neuropathic pain associated with spinal cord injury 2
  • Duloxetine: FDA-approved for diabetic peripheral neuropathy 6
  • Tricyclic antidepressants (TCAs): Number needed to treat (NNT) of 2.6 for pain relief 5

• Second-line medications 3, 5:

  • Gabapentin: Similar mechanism to pregabalin with NNT of 4.1 5
  • Tramadol: Mixed opioid and monoaminergic drug with NNT of 3.4 5
  • Selective serotonin reuptake inhibitors (SSRIs): Less effective than TCAs with NNT of 6.7 5

• Dosing considerations 3:

  • Start with low doses and titrate based on efficacy and tolerability
  • Consider safety, tolerability, drug interactions, and cost when selecting medications
  • Different mechanism of action may be beneficial when switching treatments

Management of Autonomic Symptoms

• For orthostatic hypotension: increased salt/fluid intake, fludrocortisone, midodrine, or droxidopa 1
• For gastrointestinal symptoms (early satiety, nausea, vomiting, gastroparesis): dietary modifications, prokinetic agents 1
• For urinary symptoms: anticholinergics for urinary frequency, intermittent catheterization for retention 1
• For sexual dysfunction: phosphodiesterase inhibitors for erectile dysfunction 1

Non-Pharmacological Approaches

• Physical therapy to improve strength, balance, and mobility 7, 4
• Occupational therapy for adaptive strategies and assistive devices 1
• Proper foot care to prevent ulcers and injuries, especially in patients with sensory loss 7
• Orthopedic shoes or braces for stability and prevention of falls 7

Special Considerations for Specific Types of Polyneuropathy

• Immune-mediated polyneuropathies 3:

  • Guillain-Barré syndrome: Intravenous immunoglobulin (IVIG) 2 g/kg over 5 days or plasmapheresis for 5 days 3
  • Corticosteroids may be beneficial in immune checkpoint inhibitor-related polyneuropathy 3

• Diabetic polyneuropathy:

  • Strict glycemic control to prevent progression 1
  • Pain management with approved medications (pregabalin, duloxetine) 2, 6

• Small fiber polyneuropathy:

  • May have normal conventional nerve conduction studies 1
  • Skin biopsy to detect decreased epidermal nerve fiber density 1
  • Treatment focuses on pain management 1

Monitoring and Follow-up

• Regular assessment of symptom progression or improvement 8
• Monitoring for medication side effects and adjusting treatment accordingly 3
• Ongoing surveillance for development of systemic disease in idiopathic cases 8
• Patient education about self-care, injury prevention, and symptom management 8

Common Pitfalls and Caveats

• About half of all polyneuropathy cases are associated with pain, requiring specific management 4
• Patients with severe neuropathy of unidentified cause should be referred to specialized centers 4
• Avoid medications that can worsen neuropathy in patients with certain conditions (e.g., avoiding medications that can worsen myasthenia gravis in patients with that condition) 3
• Recognition that some polyneuropathies may be progressive despite treatment, requiring ongoing adaptation of management strategies 8