Peripheral Neuropathy, Sciatica, and Nerve Pain in OPD: Clinical Guide for Indian Doctors

Nerve pain is among the most undertreated conditions in Indian OPD. Patients often suffer for years before receiving appropriate diagnosis and analgesia. Understanding the common patterns of peripheral neuropathy allows effective diagnosis and management at the clinic level.

Approach to Peripheral Neuropathy in OPD

Neuropathy presents as: numbness, tingling, burning, pain (often worse at night), weakness, or loss of reflexes. The clinical pattern narrows the differential rapidly:

• Distal symmetrical ("glove and stocking"): Starts in toes/feet, gradually ascends. Commonest pattern — diabetic, B12 deficiency, alcohol, drugs
• Mononeuropathy (single nerve): Carpal tunnel (median), ulnar neuropathy at elbow, foot drop (common peroneal), Bell's palsy (facial nerve)
• Radiculopathy (nerve root): Band-like pain in dermatomal distribution — sciatica (L4/L5/S1), cervical radiculopathy (C5–C7)
• Asymmetric/multi-focal: Mononeuritis multiplex — think vasculitis, leprosy (very important in India), diabetes

Essential workup for new peripheral neuropathy:

• FBS/HbA1c (diabetes most common cause)
• Serum B12, folate
• CBC (anaemia from B12 deficiency — macrocytic)
• TFTs (hypothyroidism causes neuropathy)
• RFTs (uraemic neuropathy)
• Skin smear for AFB if patchy sensory loss + thickened nerves (leprosy)

Diabetic Peripheral Neuropathy

The most common neuropathy in Indian OPD. Distal symmetrical sensorimotor neuropathy — starts as numbness/tingling in toes, progresses proximally. Burning pain worse at night is classic.

Screening at Every Diabetic Visit

• 10g monofilament — loss on plantar surface of big toe = impaired protective sensation
• 128 Hz tuning fork — vibration sense on first metatarsal head
• Ankle jerk reflexes
• Visual inspection of feet for ulcers, callus, deformity

Management

Glucose control is the only disease-modifying treatment — intensifying glycaemic control slows progression. Symptomatic pain management:

First-line: Pregabalin 75mg BD (titrate to 150mg BD if tolerated) OR Duloxetine 30mg OD (titrate to 60mg OD). Both have similar efficacy — choose based on comorbidities. Duloxetine preferred if comorbid depression; Pregabalin if anxiety or poor sleep.

Second-line: Amitriptyline 10–75mg nocte (cheap, effective, but anticholinergic side effects — avoid in elderly, urinary retention, glaucoma). Tramadol 50–100mg TDS for moderate-severe pain not responding to first-line.

Sciatica and Lumbar Radiculopathy

Sciatica is pain radiating from the lower back into the buttock and down the leg, typically below the knee. It is caused by compression of L4, L5, or S1 nerve roots — most commonly by a prolapsed intervertebral disc (PIVD).

Clinical Diagnosis

• L4 root: Inner calf numbness, weak knee extension, reduced knee jerk
• L5 root: Dorsum of foot numbness, weak ankle/big toe dorsiflexion, no reflex change
• S1 root: Lateral foot + sole numbness, weak plantar flexion, reduced ankle jerk

Straight leg raise (SLR) test: Positive (pain below knee at <60° elevation) has 91% sensitivity for disc herniation with nerve root compression.

Management (80% resolve in 12 weeks)

Carpal Tunnel Syndrome

Most common nerve entrapment. Median nerve compressed at wrist — tingling/numbness in thumb, index, middle, and radial half of ring finger. Worse at night and with prolonged grip (phone use, cooking). Thenar wasting in severe cases.

Diagnosis: Phalen's test (sustained wrist flexion 60 seconds reproduces symptoms), Tinel's sign (tapping over carpal tunnel). Nerve conduction study confirms and quantifies severity.

Management:

• Mild-moderate: Wrist splint in neutral position at night. Avoid repetitive wrist flexion. NSAIDs for pain
• Moderate: Corticosteroid injection into carpal tunnel (Methylprednisolone 40mg) — 70–80% short-term relief
• Severe (thenar wasting, constant numbness, failed conservative treatment): Surgical decompression — highly effective, day-case procedure

Vitamin B12 Deficiency Neuropathy in India

B12 deficiency is extremely common in India — 47% of vegetarians are deficient. Metformin use further depletes B12. Classic presentation: subacute combined degeneration of spinal cord — peripheral neuropathy + posterior column signs (positive Romberg, impaired vibration) + possible cognitive decline.

Treatment:

• Serum B12 <200 pg/mL with symptoms: Cyanocobalamin 1mg IM daily × 7 days, then weekly × 4, then monthly for life (if pernicious anaemia/malabsorption)
• Dietary deficiency (pure vegetarian, no pernicious anaemia): Oral Methylcobalamin 1500mcg OD is effective and adequate
• All patients on Metformin >1 year: Check B12 annually and supplement

Neuropathic Pain: Pharmacological Management

Neurological Red Flags Requiring Urgent Referral

• Bilateral leg weakness or ascending paralysis (Guillain-Barré syndrome)
• Rapid onset neuropathy over days (GBS, vasculitis, paraneoplastic)
• Cauda equina symptoms (bilateral sciatica + bladder/bowel changes)
• Neuropathy + unexplained weight loss (paraneoplastic syndrome)
• Asymmetric neuropathy + thickened peripheral nerves (leprosy)
• Cranial nerve involvement with peripheral neuropathy

Nerve pain patients need regular follow-up to assess treatment response and side effects. CliniqFlo's appointment scheduling makes chronic pain follow-up efficient →