Summary Carpal Tunnel Syndrome (CTS) is a common acquired compressive neuropathy of the median nerve that presents with symptoms of numbness and tingling in the median nerve distribution of the hand. Diagnosis is made clinically with primary symptoms of night pain, hand weakness/clumsiness, and numbness in median nerve distribution along with positive provocative tests and/or EMG/NCS studies Treatment is usually conservative with night splints and corticosteroid injections. Operative treatment in the form of carpal tunnel release is reserved for refractory cases. Epidemiology Incidence affects 0.1-10% of general population Up to 70% of patients have bilateral carpal tunnel syndrome Demographics age login to view 2 more bullets sex login to view 1 more bullet Location carpal tunnel/canal at the wrist Risk factors female sex obesity pregnancy hypothyroidism rheumatoid arthritis trauma (acute CTS) - distal radius fractures or malunions, dislocation/or subluxation of the carpus repetitive motion activities acromegaly advanced age menopause chronic renal failure space-occupying lesion (e.g. ganglion cyst, neoplasm) use of oral contraceptives congestive heart failure diabetes smoking alcoholism mucopolysaccharidosis (children) mucolipidosis Etiology Pathophysiology increased pressure on the median nerve affects intraneural blood supply login to view 3 more bullets mechanism login to view 6 more bullets pathoanatomy login to view 4 more bullets Associated conditions login to view 5 more bullets Anatomy Carpal tunnel borders scaphoid tubercle and trapezium radially hook of hamate and pisiform ulnarly transverse carpal ligament palmarly (roof) proximal carpal row dorsally (floor) Carpal tunnel contents four flexor digitorum superficialis (FDS) tendons four flexor digitorum profundus (FDP) tendons flexor pollicis longus (FPL) login to view 1 more bullet median nerve Median nerve terminal branch of medial and lateral cords of brachial plexus; receives input from nerve roots of C5-T1 course login to view 2 more bullets branches login to view 17 more bullets Carpal tunnel is narrowest at the level of the hook of the hamate Presentation History hand overuse, particularly with vibrating equipment or frequent computer use Symptoms numbness and tingling in radial 3-1/2 digits clumsiness pain and paresthesias that awaken patient at night Physical exam inspection login to view 4 more bullets palpation login to view 1 more bullet provocative tests login to view 17 more bullets CTS-6 Evaluation Tool: a validated clinical tool for diagnosis of CTS. login to view 2 more bullets CTS-6 Evaluation Tool Numbness predominantly or exclusively in median nerve territory +3.5 Nocturnal Numbness +4 Thenar atrophy and/or weakness 4/5 weakness or less +5 Positive Phalen test +5 Loss of 2-point discrimination Threshhold of 5mm +4.5 Positive Tinel sign +4 Imaging Radiographs not necessary for diagnosis and not routinely indicated MRI or CT scan indicationsConsider for space-occupying lesion. login to view 2 more bullets Ultrasound increased cross-sectional area (CSA) of the median nerve >10mm² at the level of the pisiform/proximal edge of transverse carpal ligament is associated with CTS Studies Diagnostic criteria numbness and tingling in the median nerve distribution nocturnal numbness weakness and/or atrophy of the thenar musculature positive Tinel sign positive Phalen test loss of two-point discrimination EMG and NCV overview login to view 4 more bullets nerve conduction velocity (NCV) login to view 7 more bullets electromyography (EMG) login to view 8 more bullets Electrodiagnostic study (EDS) results are associated with outcomes (prognosis) after carpal tunnel surgery login to view 1 more bullet Histology nerve histology characterized by login to view 3 more bullets Differential AIN compressive neuropathy Pronator syndrome Ulnar tunnel syndrome Cervical radiculopathy Diagnosis Clinical and EMG/NCS diagnosis can be made purely based on history and physical examination and can be confirmed with EMG/NCS and ultrasound login to view 1 more bullet Treatment Nonoperative NSAIDS, night splints, activity modifications login to view 5 more bullets steroid injections login to view 7 more bullets Operative carpal tunnel release login to view 17 more bullets revision CTR for incomplete release login to view 6 more bullets Technique Open carpal tunnel release antibiotics login to view 1 more bullet approach login to view 3 more bullets technique login to view 3 more bullets postoperative care and rehab login to view 7 more bullets Endoscopic carpal tunnel release different systems available, some offering one versus two incisions technique login to view 5 more bullets pros login to view 1 more bullet cons login to view 2 more bullets Ultrasound-guided percutaneous carpal tunnel release technique login to view 5 more bullets Complications Scar tenderness (most common) incidence login to view 1 more bullet treatment login to view 2 more bullets pillar pain deep-seated ache over the thenar or hypothenar region secondary to injury of small sensory branches of the median/ulnar nerves incidence login to view 1 more bullet treatment login to view 2 more bullets recurrence incidence login to view 2 more bullets risk factors login to view 2 more bullets treatment login to view 1 more bullet injury to the recurrent branch of median nerve Incidence login to view 2 more bullets risk factors login to view 1 more bullet treatment login to view 5 more bullets iatrogenic injury to palmar cutaneous branch of the median nerve incidence login to view 2 more bullets treatment login to view 1 more bullet injury to proper palmar digital nerve to the index finger incidence login to view 2 more bullets treatment login to view 2 more bullets arterial arch injury incidence login to view 2 more bullets treatment login to view 1 more bullet Prognosis Good prognostic indicators include night symptoms small incisions relief of symptoms with steroid injections not improved when incomplete release of transverse carpal ligament is discovered