Carpal tunnel syndrome

Mamatha Pasnoor MD (

Dr. Pasnoor of the University of Kansas Medical Center received medical advising fees from Alexion Pharmaceuticals, CSL Behring, and TerumoBCT and a consulting fee from Momenta Pharmaceuticals.

Randolph W Evans MD, editor. (

Dr. Evans of Baylor College of Medicine received honorariums from Allergan, Amgen, Avanir, DepoMed, Lilly, and Novartis for speaking engagements and honorariums from Alder and Promius for advisory board membership.

Originally released February 3, 1998; last updated August 1, 2019; expires August 1, 2022

This article includes discussion of carpal tunnel syndrome and median nerve entrapment at the wrist. The foregoing terms may include synonyms, similar disorders, variations in usage, and abbreviations.


Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy with a prevalence of about 270 per 100,000. The etiology is compression of the median nerve in the carpal tunnel. Clinical manifestations consist of intermittent pain, numbness, and tingling in the fingers that is dependent on the position of the hand and wrist and commonly associated with subjective weakness of grip. Diagnosis is made on the basis of clinical complaints and electrodiagnostic studies. Treatment is conservative or surgical depending on the severity of the symptoms. Data on carpal tunnel syndrome in pregnancy reveal that about half of the patients remain symptomatic at 6 months after delivery. Ultrasound has emerged as a useful and less invasive technique for evaluation of carpal tunnel syndrome. Endoscopic carpal tunnel release supposedly produces less scarring than open release, but is more expensive and precludes visualization of the median nerve proper. Controversy continues about which surgical procedure is the best. Some studies showed increased prevalence of carpal tunnel syndrome in patients with cardiac amyloidosis. In this article, the author discusses updates on diagnosis and management.

Key points


• Carpal tunnel syndrome is the most common entrapment neuropathy.


• Peripheral nerve ultrasound imaging is proposed as a painless rapid screening test for carpal tunnel syndrome.


• Electrodiagnostic studies have a sensitivity of up to 95% for the diagnosis when detailed studies are performed.


• In most patients, including elderly patients and patients with diabetes, surgical carpal tunnel release should be considered if conservative measures fail.

Historical note and terminology

The first description of a chronic median nerve entrapment at the wrist was by Paget (Paget 1865) concerning a patient with a previous distal radius fracture (Rosenbaum and Ochoa 1993). This was a severe entrapment accompanied by ulceration in the first 3 fingers. Paget noted recovery of the ulcerations with rest and an increase of symptoms with use of the hand secondary to nerve compression. Putnam first described the classical clinical symptoms of intermittent nocturnal hand paresthesias with subjective hand swelling and an improvement with shaking of the hand (Putnam 1880). A careful autopsy study by Marie and Foix documents the thinning of the median nerve under the flexor retinaculum in a patient with bilateral isolated thenar atrophy (Marie and Foix 1913). They made the suggestion that transection of this ligament may have been therapeutic. The first surgery for carpal tunnel syndrome was done in 1933 at the Mayo Clinic. Carpal tunnel syndrome received increasing attention in the 1940s and 1950s from both neurologists and surgeons. The development of clinical electrodiagnostic testing with EMG and nerve conduction studies in the 1960s added a valuable diagnostic tool. The use of high resolution ultrasound imaging to study the median nerve in carpal tunnel syndrome was first published in 1992 (Buchberger 1992); however, most studies have appeared since early 2000.

The content you are trying to view is available only to logged in, current MedLink Neurology subscribers.

If you are a subscriber, please log in.

If you are a former subscriber or have registered before, please log in first and then click select a Service Plan or contact Subscriber Services. Site license users, click the Site License Acces link on the Homepage at an authorized computer.

If you have never registered before, click Learn More about MedLink Neurology  or view available Service Plans.