Peripheral Neuropathy — Nerve Damage Side Effect

Chemotherapy-induced peripheral neuropathy (CIPN) occurs when neurotoxic antineoplastic agents disrupt axonal transport, damage microtubules, or impair mitochondrial function within sensory and motor neurons. Sensory fibres are especially vulnerable due to their high metabolic rate and absence of a robust blood-nerve barrier.

Patients typically experience symmetrical, distal sensory deficits presenting in a characteristic 'glove-and-stocking' distribution across hands and feet. Symptoms include paraesthesia (pins and needles), numbness, burning dysaesthesia, altered temperature perception, mechanical allodynia, and occasionally motor weakness or loss of deep tendon reflexes.

Recognising peripheral neuropathy early is crucial because untreated or severe nerve damage can become permanent, impairing balance, increasing fall risks, and eroding quality of life. Because there are limited ways to reverse established structural nerve damage, oncologists rely on early detection to modify chemotherapy dosages, space out treatment cycles, or switch drugs before deficits progress from temporary irritation to chronic disability.

Neuropathy is not diagnosed with routine blood biomarkers. Clinicians assess it via focused neurological examinations testing sensation (monofilament, pinprick, vibration tuning fork), deep tendon reflexes, and gait. Standardised grading scales, such as the NCI Common Terminology Criteria for Adverse Events (CTCAE), quantify severity. Nerve conduction studies (NCS) or electromyography (EMG) are reserved for ambiguous or atypical cases.

CIPN is common in cancers treated with neurotoxic regimens: colorectal cancer (oxaliplatin-based regimens), breast and ovarian cancers (taxanes like paclitaxel and docetaxel), lung cancer (platinum compounds, taxanes), and multiple myeloma (proteasome inhibitors such as bortezomib and immunomodulatory agents such as thalidomide).

Onset of moderate to severe neuropathy frequently necessitates chemotherapy dose reductions, temporary treatment delays, or discontinuation of the offending agent to prevent long-term disability. Symptomatic pain relief may be managed with medications like duloxetine, gabapentin, or pregabalin. Non-pharmacological approaches, including occupational therapy, physical therapy, and cold therapy (cryotherapy) during infusions, are also utilised.