Makindo Medical Notes

🖐️ Carpal tunnel syndrome (CTS) is the most common mononeuropathy, caused by compression of the median nerve within the carpal tunnel. It typically presents with nocturnal paraesthesia, hand pain, and sometimes thenar muscle weakness or wasting.

📌 About

• Most common entrapment neuropathy
• Median nerve compressed beneath the flexor retinaculum at the wrist
• Classically affects dominant hand, but can be bilateral

🧬 Aetiology

• Median nerve runs with 9 flexor tendons in the carpal tunnel → space-occupying or thickening processes lead to compression
• Can cause thenar wasting and impaired thumb opposition/abduction
• Weakness of abductor pollicis brevis and intrinsic hand muscles supplied by the median nerve

⚠️ Causes / Risk Factors

• Rheumatoid arthritis, pregnancy, acromegaly
• Colles’ fracture, minor trauma, idiopathic
• Amyloidosis (β2-microglobulin in dialysis patients)
• Myxoedema (hypothyroidism), obesity, diabetes

🩺 Clinical Features

• Paraesthesia and pain in radial 3½ fingers (thumb, index, middle, radial half of ring finger); palm sparing due to palmar cutaneous branch
• Nocturnal symptoms common; may radiate to forearm/shoulder
• Motor: thenar weakness, difficulty opposing thumb, thenar wasting late
• Provocative tests:
  • 🔔 Tinel’s sign: percussion over flexor retinaculum → tingling
  • 📐 Phalen’s test: forced wrist flexion 60 sec → symptoms reproduced

🔬 Investigations

• Bloods: FBC/U&E usually normal; TFT (hypothyroidism), B12 (neuropathy screen), ESR/protein studies if myeloma suspected
• Nerve conduction studies → delayed conduction across wrist (gold standard for diagnosis & severity grading)
• Needle EMG can show denervation if severe

🔎 Differentials

• Cervical radiculopathy (C6–C7): often with neck pain and dermatomal distribution
• Peripheral neuropathy (e.g. diabetic, B12 deficiency)

💊 Management

• 🔹 Treat underlying cause (e.g. hypothyroidism, inflammatory arthritis)
• 🔹 Splinting: neutral wrist splints, especially nocturnal
• 🔹 Analgesia ± corticosteroid injection into carpal tunnel (may cause transient worsening)
• 🔹 Surgery: carpal tunnel decompression (division of flexor retinaculum) if intractable symptoms, weakness, or NCS-confirmed severe disease