Tingling/numbness in the hands of computer users: neurophysiological findings from the NUDATA study.
OBJECTIVE
To investigate whether tingling/numbness of the hands and fingers among computer users is associated with elevated vibration threshold as a sign of early nerve compression.


METHODS
Within the Danish NUDATA study, vibratory sensory testing with monitoring of the digital vibration threshold at seven frequencies on the second and fifth fingers of both hands was performed on 20 cases with unilateral tingling/numbness in the hands and fingers, and 20 gender- and age-matched controls. Both cases and controls were identified from questionnaire information about tingling/numbness at least once a week or daily within the last 3 months. Participants with more than slight muscular pain or disorders of the neck and upper extremities, excessive alcohol consumption, previous injuries of the upper extremities, or concurrent medical diseases were excluded. The two groups had a similar amount of work with mouse, keyboard, and computer.


RESULTS
Seven of the 20 cases (35%) had elevated vibration thresholds, compared with 3 of the 20 controls (15%); this difference was not statistically significant (chi2=2.13, P=0.14). Compared with controls, cases had increased perception threshold for all frequencies, but the difference was statistically significant for only 2 out of 14 measurements. Comparison between left and right hand threshold values within the case group did not show any significant difference at any frequency.


CONCLUSIONS
The results indicate that tingling/numbness of the hands and fingers among computer users cannot be explained by nerve compression.
Overgaard
E
E
Department of Occupational Medicine, Herning Hospital, Gl. Landevej 61, 7400, Herning, Denmark, erik.overgaard@dadlnet.dk.
Brandt
L P A
LP
Ellemann
K
K
Mikkelsen
S
S
Andersen
J H
JH
D000328:Adult; D016022:Case-Control Studies; D003201:Computers; D003718:Denmark; D004594:Electrophysiology; D005385:Fingers; D006225:Hand; D006801:Humans; D006987:Hypesthesia / Q000503:physiopathology; D009408:Nerve Compression Syndromes / Q000503:physiopathology; D009784:Occupational Diseases / Q000503:physiopathology*; D011446:Prospective Studies; D012684:Sensory Thresholds; D020886:Somatosensory Disorders / Q000503:physiopathology*; D014732:Vibration