The subclinical incidence of CTS in pregnancy: Assessment of median nerve impairment in asymptomatic pregnant women.
OBJECTIVE
The true incidence of pregnancy related carpal tunnel syndrome (PRCTS) is unknown. Most of the diagnoses of PRCTS are made based only on clinical symptoms. Here, we report a prospective controlled clinical trial assessing the electrophysiological changes in pregnant women to provide objective measure of the median nerve function.


METHODS
Pregnant women in the third trimester (n=69) and age-matched non-pregnant women (n=40) asymptomatic for CTS were included in the study. Nerve conduction studies of the median and ulnar nerves across the carpal tunnel were bilaterally performed with the standard techniques.


RESULTS
All the median sensory nerve conduction studies (amplitude, latency and velocity) performed from the ring finger and palmar region to wrist showed significant prolongation of median nerve conduction in the pregnant women compared with the control group (*p</=0.05). Median sensory nerve latencies from palmar branches to wrist were significantly longer in the pregnant group (**p<0.01). Sensory nerve action potential amplitudes recorded in the palmar region were smaller in the pregnant women (45.1AmicroV) than in the control group (56.5AmicroV). Ulnar motor and sensory conduction studies showed no significant difference between the pregnant women and the control group. According to the mean values of median nerve conduction velocity, 8 (11%) pregnant women were electrophysiologically diagnosed as CTS and four of these cases became symptomatic later during pregnancy or after delivery.


CONCLUSIONS
Median nerve impairment occurs even in asymptomatic pregnant women. The electrophysiological characteristics of this impairment are defined and the pathophysiology of PRCTS is discussed. Electrophysiological evaluation is a tolerable and feasible technique for the early diagnosis of PRCTS.
Baumann
F
F
Haydarpasa Numune Teaching and Research Hospital, Istanbul, Turkey. fusuna@medisin.uio.no
Karlikaya
G
G
Yuksel
G
G
Citci
B
B
Kose
G
G
Tireli
H
H
D000328:Adult; D002349:Carpal Tunnel Syndrome / Q000175:diagnosis* / Q000453:epidemiology* / Q000503:physiopathology; D015897:Comorbidity; D042241:Early Diagnosis; D004558:Electric Stimulation; D004568:Electrodiagnosis / Q000379:methods*; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D015994:Incidence; D008475:Median Nerve / Q000503:physiopathology*; D009431:Neural Conduction / Q000502:physiology; D011237:Predictive Value of Tests; D011247:Pregnancy; D011248:Pregnancy Complications / Q000175:diagnosis* / Q000453:epidemiology* / Q000503:physiopathology; D011446:Prospective Studies; D011930:Reaction Time / Q000502:physiology; D012680:Sensitivity and Specificity; D014459:Ulnar Nerve / Q000503:physiopathology