<p>The purpose of this study was to investigate the difference in amplitude between M-response from m. Abductor pollicis brevis/m. Pronator quadratus and m. Abductor pollicis brevis/m. Abductor digiti minimi on patients with carpal tunnel syndrome, compared with control subjects. We wanted to see if m. Pronator quadratus is a better alternative than m. Abductor digiti minimi as comparison with m. Abductor pollicis brevis on patients with carpal tunnel syndrome.</p><p>Nerve conduction studies were performed on 20 patients with carpal tunnel syndrome and on 31 healthy subjects.</p><p>The test-retest result shows that this method was reproducible. The amplitude difference of m. Abductor pollicis brevis-m. Abductor digiti minimi, for the patients, was 1,5mV lower and the amplitude for m. Abductor pollicis brevis-m. Pronator quadratus was 2mV lower than for healthy subjects. Two of the patients were outside the 2SD for the m. Abductor pollicis brevis-m. Pronator quadratus difference but not on the m. Abductor pollicis brevis-m. Abductor digiti minimi. This may indicate that m. Pronator quadratus was better than m. Abductor digiti minimi in the comparison with the m. Abductor pollicis brevis amplitude.</p>

The purpose of this study was to investigate the difference in amplitude between M-response from m. Abductor pollicis brevis/m. Pronator quadratus and m. Abductor pollicis brevis/m. Abductor digiti minimi on patients with carpal tunnel syndrome, compared with control subjects. We wanted to see if m. Pronator quadratus is a better alternative than m. Abductor digiti minimi as comparison with m. Abductor pollicis brevis on patients with carpal tunnel syndrome. Nerve conduction studies were performed on 20 patients with carpal tunnel syndrome and on 31 healthy subjects. The test-retest result shows that this method was reproducible. The amplitude difference of m. Abductor pollicis brevis-m. Abductor digiti minimi, for the patients, was 1,5mV lower and the amplitude for m. Abductor pollicis brevis-m. Pronator quadratus was 2mV lower than for healthy subjects. Two of the patients were outside the 2SD for the m. Abductor pollicis brevis-m. Pronator quadratus difference but not on the m. Abductor pollicis brevis-m. Abductor digiti minimi. This may indicate that m. Pronator quadratus was better than m. Abductor digiti minimi in the comparison with the m. Abductor pollicis brevis amplitude.

No description available.

Bakgrund: Nervus medianus är armens mittersta nerv med både efferenta och afferenta nervfibrer. För att undersöka perifera nerver används neurografi. N. medianus sensorik går att undersöka både ortodromt och antidromt där den antidroma metoden framförallt används vid karpaltunnelsyndromfrågeställning. Vanligtvis stimuleras nerven då 7 respektive 14 cm från registreringspunkten på digitorum III, men det finns fördelar med att istället för 7 cm-punkten använda sig av proximal stimulering ovanför armvecket. För denna metod finns dock ont om referensvärden. Syftet med denna studie var därför att samla in referensvärden för latenstider och amplituder.  Metod: Försökspersonerna bestod av 34 personer mellan 22 och 65 år. N. medianus undersöktes sensoriskt med proximal stimulering och registrering på dig III med både 0,1 och 0,2 ms impulsduration.  Resultat: Peaklatenstider varierade mellan 5,94 och 8,7 ms (x̄=7,00 ms) och amplituder varierade mellan 7,2 𝜇V och 72,6 𝜇V (x̄=35,6) vid 0,1 ms impulsduration. Det fanns ett signifikant bidrag av både längd och ålder på både latenstider och amplituder och en signifikant könsskillnad mellan män och kvinnor kunde uppmätas. Det fanns en signifikant, men mycket liten, skillnad i latenstid för impulsduration, men inga skillnader i amplituder. Variationskoefficienten för tre upprepade mätningar varierade mellan 0,9 och 5,3 % för peaklatens och 1,0 och 15,6 % för amplitud.  Slutsats: Hos friska försökspersoner ses en viss variation för amplituder medan latenstider ligger mer samlat. Ålder och längd bör tas med i beräkning av individuella normalvärden och en könsaspekt kan inte heller uteslutas. Impulsduration bör inte ha någon klinisk relevans. Reliabiliteten är bättre för latenstider än amplituder. / Background:. Sensory nerves can be examined both orthodromic and antidromic with nerve conduction studies. In the mixed median nerve is the antidromic method mainly used for evaluation of carpal tunnel syndrome. Usually the nerve is stimulated 7 and 14 cm from the recording at digitorum III, but there are some advantages in changing the 7 cm stimulation point to a more proximal one. The purpose of this study was to collect reference values for peak latency times and amplitudes with a proximal stimulation.  Methods: 34 test subjects in the age of 22-65 years were recruited for the study. Sensory nerve conduction studies of the median nerve with proximal stimulation and recording at digitorum III were performed with both 0,1 and 0,2 ms stimulus duration.  Results: Latency times varied between 5,94 and 8,7 ms (x̄=7,00 ms) and amplitudes varied between 7,2 𝜇V and 72,6 𝜇V (x̄=35,6) when 0,1 ms stimulus duration was used. There was a significant contribution by both length and age on latency times and amplitudes and a significant sex difference. There was a small difference in latency times by stimulus duration, but not in amplitudes. The coefficient of variation varied between 0,9 and 5,3 % for peak latency time and 1,0 and 15,6 % for amplitude.  Conclusion: There was some variation in amplitudes, but the latency times were more gathered together. Age and length have to be taken in consideration while individually reference values are calculated and a sex difference cannot be ruled out. Stimulus duration probably does not have a clinically relevant impact. The reliability is better for latency times than for amplitudes.