<prompt> A 37-year-old obese female presents with pain in her left wrist and abnormal sensations, numbness, burning and tingling in her left thumb, index, and middle fingers and some part of ring finger. The pain is severe and wakes her up at night. She works as a typist and pain increases with typing all day. Nerve conduction studies reveal nerve compression. Which of the following additional clinical findings would be present in this patient?Atrophied adductor pollicis.Inability to oppose the thumb to other digits.Flattened hypothenar eminenceParesthesia of thenar eminence  <response>: Answer: b Inability to oppose the thumb to other digits.Patient is suffering from carpal tunnel syndrome.It is a medical condition in which the median nerve is compressed as it passes through the carpal tunnel deep to the flexor retinaculum at the wrist.The patients occupation as typist may have predisposed the patient to this condition.MEDIAN NERVE labourers nerve C5, C6, C7, C8, T1Formed from the branches of medial and lateral cord of brachial plexus.No branches to axilla arm.Sensory SupplyPalmar aspect:- Lateral half of Palm Lateral 312 fingers with their nail bedsDorsal aspect: - distal part of later 312 fingers Motor SupplyForearm: All flexors except flexor carpi ulnaris and medial half of flexor digitorum profundusHand: Ist two lumbricals 1st 2nd lumbricals, thenar muscles except adductor pollicis Supplied by ulnar nerveInjuries to Median nerve:At elbowPointing Index detected by Oschner clasping testSimianApe thumb deformity Thenar muscles wastedPen testAt wrist: Abduction Opposition of thumb is lost.Median Nerve- Commonly injured in cut injury at flexor retinaculum.Commonly gets involved in entrapment neuropathy carpal tunnel syndromeTests of median nerve lesion:Tinels sign- percussion of flexor retinaculum - tingling sense in the distribution of median N.Phalens test- hyperextension flexion aggravates pain paresthesiaCuff compression test of Gilliatt Wilson- BP cuff is inflated above systolic BP- aggravates pain paresthesia.CARPAL TUNNEL SYNDROMEMost common upper extremity compressive neuropathyNeuropathy caused by compression of the median nerve within the carpal tunnel.The floor of the tunnel is formed by the volar radiocarpal and intercarpal ligaments.The transverse carpal ligament forms the roof of the tunnel.9 long flexors of the wrist and fingers and median nerve run within this spatially limited and relatively rigid tunnel.Etiology: PRAGMATICP-PregnancyR-Rheumatoid arthritisA-Arthritis degenerativeG-Growth hormone abnormalities acromegalyM-Metabolic gout, diabetes myxedema, etcA-AlcoholismT-Tumorsl-ldiopathicC- Connective tissue disorders e.g. amyloidosis.Thus, any increase in pressure within the tunnel compresses the injury-prone median nerve.A decrease in thenar muscle strength occurs, along with a numbness or a decrease in the sensibility of the palmar surface of the radial 3 12 digits, especially the middle and index fingers.Initial stage:Dull pain in the arm at night brachialgia paresthetica nocturnaWakes the patient from sleep and can be relieved by shaking and massaging the armsStiff uncoordinated fingers for a short time after the patient wakes up in the morningAdvanced stage:Abnormal sensations paresthesia developSense of touch is impaired, mainly in the thumb and index finger.The Phalen wrist flexion sign or Phalen maneuver is positive in carpal tunnel syndrome.Inability to oppose the thumbs.Emaciation of thenar eminenceParesthesia, hypoesthesia, or anesthesia of lateral three and a half digits.Sensation in the central palm remains unaffected.TESTS:Provocative testing includes Phalens test, Tinels test at the wrist, or the carpal tunnel compression test Durkans test.The carpal tunnel compression test is generally regarded as the most sensitive.The most predictable sensory test to evaluate carpal tunnel syndrome is the Semmes-Weinstein monofilament test. 