Residency · Residency · Physical Medicine Rehabilitation
Chemotherapy-Induced Peripheral Neuropathy
Introduction
Chemotherapy-induced peripheral neuropathy (CIPN) is one of the most common and debilitating side effects of cancer treatment, affecting 30-70% of patients receiving neurotoxic chemotherapy agents. CIPN can lead to dose reductions or treatment discontinuation, impair functional independence, and persist long after treatment completion.
Pathophysiology
Mechanisms of Neurotoxicity
Axonal degeneration: Primary mechanism; distal dying-back pattern. Dorsal root ganglion (DRG) neuronopathy. Mitochondrial dysfunction and oxidative stress. Disruption of axonal transport (microtubule damage). Ion channel dysfunction. Neuroinflammation.
Agent-Specific Mechanisms
Platinum compounds (cisplatin, oxaliplatin): DRG accumulation; DNA crosslinking in sensory neurons. Taxanes (paclitaxel, docetaxel): Microtubule stabilization; disrupted axonal transport. Vinca alkaloids (vincristine): Microtubule destabilization; motor involvement more common. Proteasome inhibitors (bortezomib): Small fiber and autonomic neuropathy. Thalidomide/lenalidomide: Antiangiogenic mechanism; axonal degeneration.
| Agent Class | Examples | Mechanism of Neurotoxicity | Fiber Type | Unique Features |
|---|---|---|---|---|
| Platinum compounds | Cisplatin, oxaliplatin | DRG accumulation, DNA crosslinking | Sensory (large fiber) | Coasting; cold-triggered (oxaliplatin) |
| Taxanes | Paclitaxel, docetaxel | Microtubule stabilization | Sensory > motor | Dose-dependent; coasting |
| Vinca alkaloids | Vincristine | Microtubule destabilization | Motor > sensory | Most motor involvement |
| Proteasome inhibitors | Bortezomib | Small fiber/autonomic | Small fiber | Autonomic symptoms |
| Thalidomide/lenalidomide | Thalidomide | Antiangiogenic, axonal | Sensory | Cumulative, irreversible |
Clinical Presentation
Sensory Symptoms (Most Common)
Length-dependent stocking-glove distribution. Numbness, tingling, paresthesias in distal extremities. Neuropathic pain: Burning, shooting, electric-shock quality. Loss of proprioception and vibration sense. Coasting: Worsening symptoms weeks to months after chemotherapy cessation.
Motor Symptoms
Distal weakness (more common with vinca alkaloids). Difficulty with fine motor tasks (buttoning, writing). Foot drop in severe cases. Proximal weakness rare but reported with taxanes.
Autonomic Symptoms
Orthostatic hypotension. Constipation or gastroparesis. Urinary retention. Most common with bortezomib and vinca alkaloids.
Oxaliplatin-Specific Acute Neurotoxicity
Cold-triggered paresthesias in hands, feet, and perioral region. Occurs within hours of infusion; resolves within days. Pharyngolaryngeal dysesthesia. Distinct from chronic cumulative neuropathy.
Assessment and Grading
Clinical Scales
NCI Common Terminology Criteria for Adverse Events (CTCAE): Grade 1-4; widely used but limited sensitivity. Total Neuropathy Score (TNS): Composite of symptoms, signs, and electrodiagnostics. Patient-reported outcome measures: EORTC QLQ-CIPN20, FACT/GOG-Ntx. Quantitative sensory testing (QST) for research.
Electrodiagnostic Findings
Reduced sensory nerve action potential (SNAP) amplitudes (axonal pattern). Nerve conduction velocities relatively preserved. Sural nerve most commonly affected. Motor studies may show reduced CMAP amplitudes with vinca alkaloids. EMG: Fibrillation potentials in distal muscles if motor involvement.
Functional Assessment
Timed Up and Go (TUG) test. Berg Balance Scale. Grip and pinch strength. 6-Minute Walk Test. Assessment of fall risk.
Prevention
Dose Modification
Primary prevention strategy: Dose reduction or treatment delay. Risk-benefit analysis with oncology team. Cumulative dose thresholds vary by agent.
Pharmacological Prevention
No agent has strong evidence for CIPN prevention (ASCO guidelines). Duloxetine has the most evidence but only for treatment, not prevention. Cryotherapy (frozen gloves/socks) during infusion: Emerging evidence for taxanes. Compression therapy during infusion: Under investigation. Calcium/magnesium infusions for oxaliplatin: Inconclusive evidence.
Treatment
Pharmacological Management
Duloxetine 60 mg/day: Only agent with moderate evidence for CIPN-related pain (ASCO recommendation). Gabapentin/pregabalin: Commonly used despite limited CIPN-specific evidence. Tricyclic antidepressants (nortriptyline, amitriptyline): Low-dose for neuropathic pain. Topical agents: Lidocaine patches, capsaicin cream, compounded topicals. Opioids: Reserved for severe refractory pain; use with caution.
Rehabilitation Interventions
Balance and proprioceptive training: Reduces fall risk. Gait training with assistive devices as needed. Strengthening programs for distal weakness. Occupational therapy for hand function and adaptive strategies.
Desensitization techniques for hypersensitivity. Exercise training: Emerging evidence for neuroprotective effects during chemotherapy.
Orthotic and Adaptive Solutions
AFOs for foot drop. Compression gloves for hand symptoms. Adaptive equipment for fine motor difficulties. Home safety modifications to reduce fall risk.
Complementary Approaches
Acupuncture: Limited but growing evidence. Scrambler therapy: Electroanalgesia for refractory pain. Neuromuscular electrical stimulation (NMES).
Prognosis
Partial or complete recovery occurs in many patients months to years after treatment. Platinum-based neuropathy: Slowest to recover; may be permanent. Taxane-induced: Often improves but may persist in 30-40%. Vincristine: Generally good recovery after discontinuation. Predictors of poor recovery: Older age, pre-existing neuropathy, higher cumulative dose, diabetes. 
Key Clinical Pearls
- Duloxetine is the only pharmacological agent with moderate evidence supporting its use for CIPN-related pain per ASCO guidelines. 2. Coasting, the worsening of neuropathy symptoms after chemotherapy cessation, is particularly common with platinum agents and should be anticipated. 3. Balance and fall prevention training are critical rehabilitation interventions, as CIPN patients have significantly elevated fall risk. 4. No agent has been proven effective for CIPN prevention; dose modification remains the primary preventive strategy.
References
- Hershman DL, Lacchetti C, Dworkin RH, et al. Prevention and management of chemotherapy-induced peripheral neuropathy in survivors of adult cancers: American Society of Clinical Oncology clinical practice guideline. Journal of Clinical Oncology. 2014;32(18):1941-1967.
- Staff NP, Grisold A, Grisold W, Windebank AJ. Chemotherapy-induced peripheral neuropathy: a current review. Annals of Neurology. 2017;81(6):772-781.
- Smith EML, Pang H, Cirrincione C, et al. Effect of duloxetine on pain, function, and quality of life among patients with chemotherapy-induced painful peripheral neuropathy. JAMA. 2013;309(13):1359-1367.
- Kleckner IR, Kamen C, Gewandter JS, et al. Effects of exercise during chemotherapy on chemotherapy-induced peripheral neuropathy. Supportive Care in Cancer. 2018;26(4):1019-1028.