This is the case of median nerve injury; sensation is lost over area supplied by median nerve. Findings: Injury or compression of median nerve at wrist (e.g. Carpal tunnel syndrome) can be tested by 1. Pen test for abductor pollicis brevis there is inability to touch the pen kept above the palm by thumb abduction 2. Ape thumb deformity (In median nerve palsy, the thumb is adducted and laterally rotated and lies in same plane as rest of finger, due to unopposed action of extensor pollicis longus (radial nerve) and adductor pollicis (ulnar nerve). 3. Loss of opposition 4. Sensory loss lateral 3 1/2 of digits and 2/3rd palm (autonomous zone is tip of index and middle finger) 5. Loss of sensation over thenar eminence 6. Anterior dislocation of lunate may cause median nerve compression.