Table 3 Participants’ characteristics table

Borg & Lindblom 1988 [20]

Mean = 48, Range = 20–71/ 86.4% W, 13.6% M/ consecutive

NR/ Mean = 1 year, Range = 2 months to 22 years

Patients referred to either the department of Neurology or the department of Clinical Neurophysiology,

IC: Sensory or motor symptoms from the median nerve territory distal to the wrist; 2) Positive “wrist flexion test” as described by Phalen and/or significant nerve conduction or electromyographic abnormalities consistent with compression of the median nerve at the wrist level.

EC: NR

Buch Jaeger & Foucher 1994 [21]

Mean = 52, Range: 29–81/ 80% W, 20% M/ consecutive

NR/ Mean = 26 months, Range 1–120 months

112 patients presenting with signs of carpal tunnel syndrome, 60 of them bilaterally, were referred for nerve conduction studies.

IC: Paresthesia in the territory of the median nerve in the hand 2) Occasional pain 3) Nocturnal recrudescence of the symptoms 4) Numbness leading to clumsiness of the hand.

EC: NR

Dale et al. 2011 [8]

Mean = 30.3; SD = 10.3/ 35% W

65% M/ consecutive

NR/ NR

Subjects were recruited from eight employers and three construction trade union apprenticeship programs between July 2004 and October 2006.

IC: > 18 years and starting a new full-time job (over 30 h per week) or changing their work benefits status.

EC: 1) If they had a current or previous diagnosis of CTS or peripheral neuropathy 2) contraindication to NCS or pregnant.

Franzblau et al. 1993 [22]

Mean = 34.1, SD = 11/ 56.% W

44% M/ consecutive

NR/ NR

All workers in the plant were invited to participate in the medical survey.

NR

Katz et al. 1990 [23]

Mean = 45.6, SD = 14.4/ 66.4% W 33.6% M/ consecutive

NR/ <  2 months = 21 subjects

2 to 12 months = 42 subjects

>  12 months = 44 subjects

Patients with upper extremity complaints of diverse causes referred to a neurophysiology laboratory for diagnostic studies. Eligible patients were identified by review of the laboratory schedule

IC: Patients referred to the Brigham and Women’s Hospital Neurophysiology Laboratory for electrophysiologic evaluation of upper extremity complaints

EC: Under 18 years old

Kucukakkas & Yurdakul 2019 [7]

Mean = 46.7, SD = 12.7/ 20.7% M79.3% W/ consecutive

Negative = 51.1%

Minimal = 0.9%

Mild = 12.1%

Moderate = 24.8%

Severe = 10.2%

Extreme = 0.9% / 9 ± 6.4 months

Patients who visited an outpatient clinic, with symptoms consistent with CTS

IC: Paresthesia or pain in the median nerve distribution

of the hand, existed for at least 3 months

EC: Pregnancy, prior history of wrist fracture or surgery, cervical radiculopathy, polyneuropathy or mononeuropathies

Kuhlman et al. 1997 [24]

NR /NR / consecutive

NR/ NR

Subjects referred for electrodiagnostic consultation with suspected CTS were evaluated.

IC: Subjects had at least one symptom indicative of possible CTS

EC: 1) generalized peripheral neuropathy, 2) previous carpal tunnel surgery, 3) cervical radiculopathy, or 4) some other neuromuscular disorder that could account for their signs and symptoms.

Subjects with diabetes were not excluded unless their NCSs demonstrated a generalized peripheral neuropathy.

MacDermid et al. 1994 [25]

CTS patients: Mean = 47, SD = 15;

Non-CTS patients: Mean = 31, SD = 13 / NR/ consecutive

Mild = 36%

Moderate = 36%

Severe = 28%/ NR

New patients who had been referred to the hand clinic with complaints of numbness, tingling, and/or pain affecting one or both hands.

IC: New referred patients with complaints of numbness, tingling, and/or pain affecting one or both hands.

EC: 1) Ulnar neuropathies 2) Their small fingers were not considered legitimate comparators 3) Overuse-related diagnoses, such as tendinitis, and nonspecific repetitive strain injury

MacDermid et al. 1997 [26]

Mean = 47, SD = 15/ NR/ consecutive

Mild = 36%

Moderate = 35%

Severe = 28% / NR

Patients referred to the clinic with a history of gradual onset of pain, numbness or tingling

IC: Patients referred to the clinic with a history of gradual onset of pain, numbness or tingling

EC: 1) Acute injuries, 2) previous upper extremity surgery, 3) complaints related to congenital malformations, 4) dupuytren’s disease, 5) tumors, 6) severe hand deformities.

Makanji et al. 2013 [11]

Mean = 56, Range = 21–85 / 62% W 38% M/ consecutive

Mild = 7%

Moderate = 44%

Severe = 23% / NR

Adult patients in the practice of four hand surgeons that were prescribed electrophysiological testing to diagnose suspected CTS were invited to enrol.

IC: Adult patients in the practice of four hand surgeons that were prescribed electrophysiological testing to diagnose suspected CTS were invited to enrol

EC: 1) Prior carpal tunnel release, 2) Prior diagnosis of CTS, 3) Median nerve surgery, 4) Previous electrophysiological testing of the median nerve, 5) Rheumatoid arthritis, and 6) Pregnancy

Naranjo et al. 2007 [9]

Mean = 47, SD = 11/ 56 W

12 M/ consecutive

Mild = 13 hands

Moderate = 30 hands

Severe = 37 hands/ Mean duration = 21 months, Interquartile Range = 8–36

Adult patients with suspected CTS referred to the outpatient Rheumatology clinic at the University Hospital Dr. Negrin in Las Palmas, Spain, between December 2005 and May 2006 were selected for the study.

IC: Sensory symptoms over the distribution of the median nerve regardless of the results of Phalen’s or Tinel’s maneuvers. Also, burning pain or numbness aggravated by sustained positions and relief by shaking or moving the hands, sleep disruption by symptoms, and daily complaints over at least a three-month period

EC: 1) Had undergone surgery, or 2) traumatic injuries at the target wrist, 3) hypothyroidism, acromegaly, 4) polyneuropathy or radiculopathy, 5) pregnancy, 6) fibromyalgia, 7) rheumatoid arthritis or crystal arthritis or 8) had received injections, or 9) presented ganglions, tenosynovitis or arthritis

Pagel et al. 2002 [27]

Mean = 52.8, Range = 23–85, SD = 13.7/ 7.1% W 92.9% M/ consecutive

NR/ NR

Patients were referred to the electrodiagnostic laboratory of the Portland Veterans Affairs Medical Center between August 5, 1999, and June 1, 2000, for evaluation of symptoms suggestive of CTS.

IC: Symptoms of paresthesia inclusive of the median nerve distribution distal to the wrist

EC: 1) Prior carpal tunnel release, 2) Neurologic diseases such as ipsilateral stroke, multiple sclerosis, paresthesia limited to digits four and five, or cervical myelopathy, 3) Patients referred for CTS evaluation who did not have median distribution paresthesia.

Raudino 2000 [28]

Mean = 48.9, SD = 13.9 years, Range = 19–82 / NR/ consecutive

NR/ Mean duration = 26.9 + 38.1 months, Range = 1–180 months

Referred for electrodiagnostic evaluation

IC: According to the diagnostic criteria of the American Academy of Neurology, all patients were complaining of discomfort, paresthesia or weakness in the territory of the median nerve occurring especially at night or after repetitive actions and relieved by changes in posture or shaking hand.

EC: Metabolic diseases, radiculopathies or polyneuropathies were exclusion criteria. If adequate, other electrophysiologic studies or needle electromyography were performed in order to exclude concomitant pathologies.

Sartorio et al. 2017 [10]

Severe CTS: Mean = 56.1, SD = 11.7; Moderate: Mean = 54.51, SD = 8.21; Mild: Mean = 51.6, SD = 7.7; Negative: Mean = 49.1, SD = 8.5/ Severe: 80% W; Moderate: 77.1% W; Mild: 88.2% W; Negative: 55.6% W/ consecutive

Severe (n = 10),

Moderate (n = 35)

Mild (n = 17)

Negative (n = 18)

/ NR

In the period between January and July 2015 at the Laboratory of Ergonomics and Evaluation of Musculoskeletal Disorders of the Clinical Scientific Institutes Maugeri.

IC: All patients between 40 and 70 years of age.

EC: 1) fractures or surgical interventions in the upper limb; 2) cervical whiplash in the last three months; 3) amputations of the 1st, 2nd and 3rd fingertips; 4) pregnancy; 5) polyneuropathies or relapse of STC; 6) hypo/hyperthyroidism; 7) outcomes of treatment with neurotoxic drugs (antineoplastic).

Szabo et al. 1999 [29]

CTS: range = 20–73, Non-CTS: range = 28–72; Healthy: range = 18–59 / CTS: 38 W, 12 M

Non-CTS: 40 W, 10 M

Healthy: 3 W, 17 M/ consecutive

NR/

Group 1: diagnosed CTS: 2 months to 20 years

Group 2: other hand pathologies:

2 weeks to 15 years

Group 3: good general health and lack of upper extremity pathology

Consecutive patients evaluated and treated at an institution for hand, wrist, and forearm problems between 1993 and 1996

Group 3: healthy volunteers recruited from the general population and included university students, medical center employees, and their friends and relatives.

IC: Group 1: a clinical history of numbness and tingling in the median nerve distribution and/or night pain relieved by shaking of the hand; results of physical examination, including sensibility and provocative examinations, consistent with carpal tunnel syndrome; and relief of symptoms after carpal tunnel release

Group 2: Diagnoses included epicondylitis, de Quervain’s and other tendinosis, radiculopathy, and hand pain of unknown etiology.

Group 3: good general health and lack of UE pathology and symptoms.

EC: NR

Yildirim & Gunduz 2015 [6]

Mean = 49.09, SD = 10.5, Range = 20–72 / 8.1% M/ consecutive

Mild CTS = 19, moderate CTS = 18, Severe CTS = 12 / NR

Patients who applied to the outpatient clinic of a university with symptoms suggesting CTS were assessed retrospectively

IC: NR

EC: 1) Presence of a neurologic disease; 2) Prior nerve injuries, trauma, or a surgical procedure in the upper extremities; 3) Thenar atrophy; pregnancy; or acute/ subacute cervical radiculopathy; 4) Patients who had clinical or electrophysiological findings suggesting other pathologies, such as polyneuropathy, ulnar, and/or radial neuropathy.