Ratio of the Cross Sectional Area of Median Nerve to Ulnar Nerve in Diagnosing Carpal Tunnel Syndrome

Inclusion Criteria: * CTS patients were required to have subjective symptoms of numbness, tingling pain, or dysesthesia over the median nerve innervated area of the involved hand. * Patients should have positive response in either Tinel's test or Phalen's test during physical examination * Evidence of median neuropathy at wrist level in NCS. * Control subjects should have neither symptoms nor signs of CTS along with no abnormal findings in electrodiagnostic study of the median nerve and the ulnar nerve across the wrist joint. Exclusion Criteria: * Age younger than 20 years old * Electrodiagnostic evidence of ulnar neuropathy at the wrist level * Previous trauma or surgery history of hand * Medical history of hypothyroidism, diabetes mellitus, uremia, rheumatoid arthritis, amyloidosis, and acromegaly * Pregnancy