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Management of Peripheral Neuropathy

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Step 1 - Diagnosis and Etiology-Directed Workup

• Fasting blood glucose / HbA1c (diabetes)
• Serum B12 with methylmalonic acid ± homocysteine
• Serum protein electrophoresis + immunofixation (monoclonal gammopathy)
• CBC, CMP, TSH, ESR, ANA (depending on clinical suspicion)

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Step 2 - Disease-Modifying (Etiology-Specific) Treatment

Diabetic Neuropathy

• Optimize glycemic control - the single most important intervention to slow progression
• ACE inhibitors / ARBs for associated nephropathy
• No disease-modifying drug has proven reversal of established neuropathy, though aldose reductase inhibitors and alpha-lipoic acid (antioxidant) are studied

GBS (Guillain-Barre Syndrome)

• IV immunoglobulin (IVIg): 2 g/kg over 5 days - equivalent to plasma exchange
• Plasma exchange (PE): 5 exchanges over 2 weeks - equally effective
• Glucocorticoids alone are NOT effective in GBS
• ICU monitoring for respiratory compromise (intubate if FVC < 15–20 mL/kg)

CIDP (Chronic Inflammatory Demyelinating Polyneuropathy)

• IVIg (first-line): 2 g/kg loading, then 1 g/kg every 3–4 weeks as maintenance
• Plasma exchange: effective, especially in refractory cases
• Prednisone: effective but long-term side effects limit use; used when IVIg/PE unavailable
• Efgartigimod alfa (anti-FcRn) - newer approved option for IgG-mediated CIDP

Vasculitic Neuropathy

• High-dose glucocorticoids (prednisone 1 mg/kg/day)
• Add cyclophosphamide for systemic vasculitis or refractory cases
• Azathioprine or methotrexate for maintenance

B12 Deficiency Neuropathy

• IM cyanocobalamin 1000 mcg daily x 1 week, then weekly x 4 weeks, then monthly
• Oral B12 supplementation in milder cases

Toxic/Drug-Induced Neuropathy

• Remove the offending agent (e.g., chemotherapy, alcohol, amiodarone, metronidazole, thalidomide, isoniazid)
• Pyridoxine (B6) supplementation for INH-induced neuropathy

MGUS-Associated Neuropathy

• For IgM anti-MAG neuropathy: rituximab (anti-CD20) or chlorambucil
• For myeloma: treat the underlying plasma cell dyscrasia

Hereditary Neuropathy (CMT)

• No proven disease-modifying therapy currently available
• Ascorbic acid (vitamin C) studied in CMT1A - no significant benefit in large trials
• Management is supportive (see below)

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Step 3 - Symptomatic Management of Neuropathic Pain

First-Line Medications

Second-Line Medications

Third-Line / Selective Use

Combination therapy (e.g., gabapentin + opioid) may be superior to either drug alone for postherpetic neuralgia and diabetic neuropathy. - Adams and Victor's Principles of Neurology, 12th Ed.

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Step 4 - Non-Pharmacological Management

Physical and Occupational Therapy

• Exercise reduces pain sensitivity and improves function; especially beneficial for musculoskeletal components
• Gait correction, balance training (important for fall prevention)
• Orthoses and foot care: custom insoles, ankle-foot orthoses (AFOs) for foot drop
• Physical therapists address gait abnormalities and provide TENS, heat/cold therapy

Topical Agents (Self-applied)

• Capsaicin cream (lower-dose OTC preparations) applied to feet morning and evening
• EMLA (eutectic mixture of local anesthetics) or lidocaine gel with/without gabapentin compounded topically

Psychological / Behavioral

• Cognitive-behavioral therapy (CBT): enhances inhibitory pain signaling; targets catastrophization and fear-avoidance; especially useful when anxiety or depression co-exist
• Biofeedback and guided imagery: effective for anxiety-associated pain amplification
• Relaxation techniques

Spinal and Interventional

• Epidural corticosteroid injections for radicular pain (limited long-term benefit)
• Nerve root blocks (lidocaine or long-acting local anesthetics): useful for thoracic radiculitis from shingles, diabetic radiculopathy
• Radiofrequency ablation: controversial but used in selected cases of facet-mediated pain
• Spinal cord stimulation (SCS): for refractory neuropathic pain (e.g., CRPS, painful DPN)
• Sympathetic nerve blocks (stellate ganglion, lumbar ganglia): for sympathetically maintained pain (CRPS/causalgia)
• IV lidocaine infusion: brief effect in many neuropathic pain types

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Step 5 - Management of Motor and Autonomic Complications

Motor Weakness

• Physical therapy and strengthening exercises
• AFOs for foot drop
• Surgical decompression for nerve entrapment (carpal tunnel, ulnar neuropathy at elbow)

Autonomic Neuropathy

• Orthostatic hypotension: compression stockings, fludrocortisone, midodrine, droxidopa
• Gastroparesis: dietary modifications (small frequent meals), metoclopramide, erythromycin
• Erectile dysfunction: PDE5 inhibitors (sildenafil)
• Bladder dysfunction: timed voiding, alpha-blockers, anticholinergics, or intermittent catheterization

Foot Care

• Podiatric review - crucial in DM neuropathy to prevent ulceration and amputation
• Protective footwear, daily foot inspection

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Summary Table - First-Line Drug Selection by Context

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Key Takeaways

1. Treat the cause first - glycemic control, remove toxins, replace deficiencies, immunotherapy for inflammatory neuropathies
2. First-line pain drugs: gabapentin/pregabalin, duloxetine, TCAs (amitriptyline/nortriptyline)
3. Combination therapy may be superior to monotherapy for refractory pain
4. Complete nerve damage reversal is uncommon even when a treatable cause is found - set realistic expectations
5. Multidisciplinary approach (neurology, pain medicine, PT/OT, podiatry, psychology) yields best outcomes

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• Harrison's Principles of Internal Medicine, 22nd Ed. (2025) - Ch. 457, Peripheral Neuropathy
• Goldman-Cecil Medicine, International Ed. - Table 26-5, Pharmacologic Treatment of Chronic Neuropathic Pain
• Adams and Victor's Principles of Neurology, 12th Ed. - Treatment of Neuropathic Pain
• Bradley and Daroff's Neurology in Clinical Practice - Inflammatory Neuropathies, CIDP/MGUS
• Mauermann ML, Staff NP. "Peripheral Neuropathy: A Review." JAMA 2026 Jan 20. [PMID: 41247746]