MRCS B: Hand examination for Carpal Tunnel Syndrome

Stem: A 54-year-old lady working as cleaner in a hospital came to surgical OPD with the complain of pain, numbness & weakness of her right hand for 4 months. She is a known case of DM- controlled well on treatment, otherwise she is healthy. 
Considering this as clinical examination station, you have been asked to examine her hand. 

  • Read the stem carefully outside
  • Wash your hands
  • Introduce yourself
  • Confirm details of the patient: Name, DOB
  • Explain about examination (Look,Feel, Move etc)
  • Obtain consent
  • Expose the patient’s hands, wrists & elbows (on both sides for comparison)
  • Position the patient with hands on a pillow
  • Ask about any pain at present
  • LOOK:
    • Dorsum
      —Inspection of hand posture- asymmetry, abnormalities
      —Skin colour-
      ~Erythema: e.g. Cellulitis, Palmar erythema
      ~Pallor: e.g. Peripheral vascular disease, Anaemia
      —Skin changes-
      ~Skin thinning/bruising– long term steroid use
      ~Rashes– e.g.psoriatic plaques
      —Muscle wasting–may indicate chronic joint pathology or motor neurone lesions
      —Nail changes-
      ~Nail fold vasculitis–small areas of infarction
      ~Pitting & onycholysis– associated with psoriasis

      1. Bouchard’s nodes (PIP)/Heberden’s nodes (DIP)–OA
      2. Swan Neck deformity- hyperflexion of DIP (distal interphalangeal) joint with hyperextended PIP (proximal interphalangeal) joint– RA
      3. Boutonnières deformity– PIP flexion with DIP hyperextension– RA
      4. Z-thumb deformity– hyperextension of the IP (interphalangeal) joint, in addition to fixed flexion & subluxation of the MCP (metacarpophalangeal) joint of thumb– RA
    • Palms
      Inspect hand posture– asymmetry/abnormalities (e.g.claw hand)
      —Scars– e.g.carpal tunnel release surgery
      —Skin colour-
      ~Erythema- e.g.cellulitis/palmar erythema
      ~Pallor- e.g. peripheral vascular disease/anaemia
      —Deformity- Dupuytren’s contracture
      —Thenar/hypothenar wasting- isolated wasting of the thenar eminence is suggestive of carpal tunnel syndrome
      —Elbows- psoriatic plaques/rheumatoid nodules

  • FEEL:
    1. Assess radial nerve sensation by touching- First dorsal web space- radial nerve
    2. Assess & compare temperature using the back of your hand- Forearm/Wrist/MCP joints
    3. Gently squeeze across the metacarpophalangeal (MCP) joints: observe for non-verbal signs of discomfort- tenderness may indicate inflammatory arthropathy
    4. Bimanually palpate the joints of the hand (MCP/PIP/DIP/CMC)- assess & compare for tenderness/irregularities/warmth
      —Metatarsophalangeal (MCP) joint, Proximal interphalangeal (PIP) joint, Distal interphalangeal (DIP) joint, Carpometacarpal (CMC) joint of the thumb (squaring of the joint is associated with OA)
    5. Palpate the anatomical snuffbox- tenderness may suggest scaphoid fracture
    6. Bimanually palpate the patient’s wrists
    7. Elbows- Palpate the patient’s forearm along the ulnar border to the elbow: Note any rheumatoid nodules/psoriatic plaques (extensor surface)
  • MOVE:
    —Assess each of the following movements actively first (patient does the movements independently). Then assess movements passively, feeling for crepitus & noting any pain.
    • Finger extension– “open your fist & splay your fingers”
    • Finger flexion– “make a fist”
    • Wrist extension– “put palms of your hands together & extend wrists fully”
    • Wrist flexion– “put backs of your hands together & flex wrists fully”
    • Test separately for both sets of flexor tendons
      —FDS (Flexor digitorum profundus): stabilise the PIPJ & ask the patient to flex at the DIPJ
      —FDP (Flexor digitorum superficialis): isolate the finger being examined by holding the other fingers in extension, then ask the patient to flex at the PIPJ
      Assess all movements of the thumb- flexion, extension, abduction, adduction & opposition.
      NB: To simply check for extension of the thumb, ask the patient to place his/her hand palm down on the table & see if he/she is able to raise his/her thumb off the table. Feel for integrity of the EPL (Extensor Pollicis Longus) tendon.
    1. Power grip – “squeeze my fingers with your hands”
    2. Pincer grip – “place your thumb & index finger together & don’t let me separate them”
    3. Pick up small object or undo a shirt button – “can you pick up this small coin out of my hand?”
    • Motor:
      1. Median Nerve
        Test the function of AbPB (abductor pollicis brevis): with patient’s palm facing up, stabilise the rest of patient’s hand on the table & ask them to point with the thumb to the ceiling.
      2. Ulnar Nerve
        Palmar interossei- adduct the fingers
        Dorsal interossei- abduct the fingers
        Froment’s sign– ask the patient to grasp a piece of paper between the index finger & the thumb. Then, you try to pull the paper away. If there is an ulnar nerve lesion, the distal phalanx of the thumb flexes (due to action of the unaffected flexor pollicis longus) to compensate for the weak muscle (adductor pollicis) which is supplied by the ulnar nerve. This is a +ve Froment’s sign.
      3. Radial nerve
        ask the patient to extend the fingers & wrist against resistance
    • Sensory:
      Volar aspect of index finger (median nerve, C6)
      Volar tip of middle finger (C7)
      Volar tip of little finger (ulnar nerve, C8)
      First dorsal web space (radial nerve)
    • Tinel’s sign
      used to identify nerve irritation & therefore can be useful in the diagnosis of carpal tunnel syndrome.
      The test involves the following:
      ~Tap over the carpal tunnel. If the patient develops tingling in the thumb & radial two & a half fingers- this is suggestive of median nerve irritation & compression.
    • Phalen’s test
      ~Ask the patient to hold their wrist in complete &forced flexion (pushing the dorsal surfaces of both hands together) for 60 seconds. If the patient’s symptoms of carpal tunnel syndrome (e.g. burning, tingling or numb sensation over the thumb) are reproduced, then the test is positive.

  • To complete my examination, I would like to do a full neurovascular examination of the upper limb & the examination the elbow joint.

    • Sensory deficit present on the palmar aspect of the first three digits & radial one half of the fourth digit.
    • Motor examination: Wasting & weakness of the median-innervated hand muscles (LOAF muscles) can be detectable.
    • Positive Phalen’s test & Tinel’s sign.
    • Investigations:
      Electrophysiologic studies including EMG (electromyography) & NCV (nerve conduction velocity) studies
      NCV studies are the first-line investigations in suspected CTS.
      MRI scan can exclude underlying causes in the carpal tunnel.
      Laboratory: CBC, blood glucose, thyroid function test
    • Treatment:
      Treatment of underlying disease, if any.
      Conservative management of mild to moderate disease (EMG & NCS) includes: –Splinting the wrist at nighttime for a minimum of three weeks
      Non-steroidal anti-inflammatory drugs (NSAIDs) & / or diuretics
      Steroid injection into the carpal tunnel
      Surgical treatment is indicated for severe disease, or when conservative management fails & includes carpal tunnel release.