Palm stimulation in carpal tunnel syndrome [La stimolazione palmare nella sindrome del tunnel carpale]

In order to verify the sensory nerve conduction velocity (SNCV) by median nerve palmar stimulation regard to each single finger, we tested 48 patients with typical CTS symptoms, confirmed by neurophysiological examination. The control group consisted of twenty-seven healthy volunteers, of similar mean age. The SNCVs were obtained by stimulating the II finger (M2), III (M3), IV (M4) and II and III intermetacarpo-phalangeal site (respectively P2 and P3) for median nerve; IV finger (U4) and IV intermetacarpophalangeal site (P4) for ulnar nerve. Data show that P2 was normal in 3 cases (6.2%), as was M2; M3 in 2 cases (4.2%) and P3 only in one case (2.1%). No sensory nerve action potential was recorded in 3 case (6.2%) during P3 stimulation, in comparison to 14 cases (29.2%) during M4 stimulation. When each case was examined separately, the behaviour of palmar SNCV resulted similar to the corresponding fingers. Finally, the ratio between SNCV values of P2/P3, with respect to controls, showed a further more severe damage of P3 compared to the P2, generally preferred by other authors.