Short-distance sensory stimulation technique in the early diagnosis of carpal tunnel syndrome

Abstract Aim. Normal results obtained from nerve conduction studies do not exclude the diagnosis of carpal tunnel syndrome (CTS). We intended to increase diagnostic sensitivity of nerve conduction studies in the early stage CTS by stimulating shorter palm-wrist segment, and excluding distal region outside the entrapment site of the median nerve which is unaffected from pathologic changes. Methods. In this prospective study, 41 patients (66 hands) with clinically diagnosed CTS with normal conventional electrophysiologic examinations were stimulated with electrodes placed at 8, 7, 6, 5, 4 cm from the distal wrist crease (DWC) on the palm-wrist segment, and the conduction velocities, latencies, and the differential latencies (conduction delay) were compared with those of 34 patients (68 hands) in the control group. Results. Conduction delay recorded between 4-5, 5-6, 6-7, 7-8 cm. away from DWC of both groups was statistically insignificant (p>0.1), while the conduction velocities and the latencies obtained from the electrodes placed on 4, 5, 6, 7, and 8 cm away from DWC differed statistically significantly between two groups (p 0.1); 4, 5, 6, 7, 8. cm.’lerdeki hiz, latans degerleri her iki grup arasinda istatistiksel olarak anlamli bulunmustur (p<0.001). Sonuc. KTS tanisini dogrulamak icin yapilan elektrofizyolojik incelemede, avucici-bilek segmentinde, mesafenin daha kisa tutulup, uyarimin DBC’nin 4 ve/veya 5 cm distalinden yapilmasi, karpal tuneldeki hafif ve lokalize iletim gecikmesini tespit etmede yeterlidir. Iletim hizi normal olan distal segmentin hafifletici etkisinin ortadan kalkmasiyla duyarlilik %92,4’e yukselmistir. Anahtar sozcukler: Karpal tunel sendromu, sinir ileti calismalari, avucici-bilek iletimi, kisa mesafe stimulasyon