title: Diurnal variation in clinical and electrophysiologic parameters associated with carpal tunnel syndrome.
abstract: OBJECTIVE
  Patients with carpal tunnel syndrome (CTS) often report aggravated symptoms in the early morning. In this study, we aimed to identify diurnal variations in clinical and electrophysiologic parameters of patients with CTS.
  
  
  METHODS
  A cross-sectional clinical and electrophysiologic study was designed. First, electrophysiologic examinations were performed at 2 p.m. to confirm the diagnosis of patients who had been clinically labeled with CTS. Patients who were electrophysiologically and clinically diagnosed with CTS were included in the study, and electrophysiologic examinations were repeated at 7 p.m. and 7 a.m. A total of 64 hands with CTS (27 bilateral, 10 unilateral) and 40 control hands were studied. Grip and pinch strength of all the patients included in the study were measured using a hand dynamometer. Finally, a CTS clinical symptom severity scale and functional status scale were used to measure the symptoms and functional impairment, respectively.
  
  
  RESULTS
  The median motor nerve distal latency and median F-minimum latency were found to be prolonged in the CTS group in the morning, and the grip strength was also markedly reduced at this time. Similar results were obtained for the median palm mixed nerve conduction velocity and amplitude.
  
  
  CONCLUSIONS
  This study demonstrated that the clinical and electrophysiologic parameters of CTS patients were clearly different in the morning hours, with the symptoms of CTS manifesting at that time.
authors.affiliation: Department of Physical Medicine and Rehabilitation, Başkent University Faculty of Medicine, Ankara, Turkey.
authors.forename: Seyhan
authors.initials: S
authors.lastname: Sozay
authors.forename: Ayşe Banu
authors.initials: AB
authors.lastname: Sarfakoğlu
authors.forename: Sehri
authors.initials: S
authors.lastname: Ayaş
authors.forename: Nuri
authors.initials: N
authors.lastname: Cetin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002349:Carpal Tunnel Syndrome / Q000503:physiopathology*; D016022:Case-Control Studies; D002940:Circadian Rhythm / Q000502:physiology*; D003430:Cross-Sectional Studies; D005260:Female; D018737:Hand Strength / Q000502:physiology; D006801:Humans; D008297:Male; D008475:Median Nerve / Q000503:physiopathology; D008875:Middle Aged; D009431:Neural Conduction / Q000502:physiology*