skip to main content

Severe Bilateral Carpal Tunnel Syndrome — SCE Neurology MCQ

Instant feedback + full explanation. One question, done properly.

EasyPeripheral Neuropathy & NeuromuscularSevere Bilateral Carpal Tunnel SyndromeSCE Neurology

A 45-year-old woman presents with progressive bilateral hand weakness and wasting over 12 months. She has weakness of thumb abduction and opposition bilaterally (APB, opponens pollicis) but interossei and lumbricals are spared. Sensation is reduced in the median nerve distribution bilaterally. NCS show bilateral severely prolonged distal motor latencies of the median nerve at the wrist with absent median sensory responses. What is the diagnosis?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: A — Bilateral carpal tunnel syndrome (severe)

Severe bilateral carpal tunnel syndrome can cause thenar wasting (APB, opponens pollicis) with sparing of the interossei and lumbricals (ulnar-innervated). The key NCS findings are prolonged distal motor latencies and absent sensory responses of the median nerve at the wrist bilaterally. Risk factors for bilateral CTS include pregnancy, hypothyroidism, rheumatoid arthritis, diabetes, obesity, and acromegaly. Given the severity with thenar wasting, surgical decompression is indicated bilaterally. A: Ulnar neuropathy affects interossei and hypothenar muscles. C: C8/T1 radiculopathy affects all hand intrinsic muscles. D: MND would not cause sensory loss. E: Brachial plexopathy would affect multiple nerve distributions.

Reference: AANEM CTS Guidelines; ABN Peripheral Neuropathy Guidelines