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Objective To investigate the relationship between the results of preoperative needle electromyography and the recovery of abductor pollicis brevis (APB) function in patients with severe carpal tunnel syndrome. Methods The clinical data of 68 patients (76 hands) with severe carpal tunnel syndrome were retrospectively analyzed. According to the results of preoperative needle electromyography, the patients were divided into the motor unit potential (MUP) positive group (46 cases, 52 hands), and MUP negative group (22 cases, 24 hands). The patients were followed up 1 year after operation, and the manual muscle testing (MMT) grade of abductor pollicis brevis muscle, functional assessment of thumb and patient satisfaction was recorded. Results The MMT grade ≥ 3 rate and satisfaction rate 1 year after operation in MUP positive group were significantly higher than those in MUP negative group: 100.0% (52/52) vs. 75.0% (18/24) and 100.0% (52/52) vs. 66.7% (16/24), and there were statistical differences (P＜0.05). The patient′s thumb function 1 year after operation was evaluated by coin pickup test, button fastening test and sewing needle clamp test. The results showed that the thumb function in MUP positive group was significantly better than that in MUP negative group, and there was statistical difference (P＜0.05). Conclusions The recovery of postoperative thumb function is related with the evocation MUP of postoperative abductor pollicis brevis needle electromyography. For MUP positive patients, there is no need for secondary thumb opponensplasty 1 year after operation. Needle electromyography has a certain reference value for thumb opponensplasty.
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OBJECTIVE: The main aim of the present study is to examine the electrode configurations used to record the muscle motor evoked potential (mMEP) in the upper extremities during surgery with the goal of producing a high and stable mMEP signal, in particular among the abductor pollicis brevis (APB), abductor digiti minimi (ADM), and across the APB-ADM muscles, which have been widely used for the mMEP in the upper extremities. METHODS: Thirty right-handed patients were recruited in this prospective study. No patients showed any adverse events in their mMEP signals of the upper extremities during surgery. The mMEPs were recorded independently from the signals for the APB and ADM and for those across the APB-ADM. RESULTS: The mMEP amplitude from across the APB-ADM was statistically higher than those recorded from the APB and ADM muscles. Moreover, the coefficient of variation of the mMEP amplitude from across the APB-ADM was smaller than those of mMEP amplitude recorded from the APB and ADM muscles. CONCLUSION: The mMEP from across the APB-ADM muscles showed a high yield with high stability compared to those in each case from the APB and ADM muscles. The configuration across the APB-ADM muscles would be best for mMEP recordings from the upper extremities for intraoperative neurophysiological monitoring purposes.
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Humans , Electrodes , Evoked Potentials, Motor , Intraoperative Neurophysiological Monitoring , Muscles , Prospective Studies , Upper ExtremityABSTRACT
Background: Long Latency Reflex (LLR) is one of the late responses occurring after H reflex from a mixed nerve by submaximal stimulation. LLR has been found to be absent in patients with multiple sclerosis, spastic patients and in Huntington’s disease. A change in body temperature affects conduction velocity. It is a known fact that there is a change in body temperature during menstrual cycle. However, no studies are available to indicate changes in latency of LLR during the menstrual cycle. Aim: To determine the effect of menstrual cycle on Long Latency Reflex of Abductor Pollicis Brevis among healthy female volunteers. Material and Methods: A cross sectional study was carried out in 30 healthy female volunteers aged 20-30 yrs. The study was conducted between 9.00 a.m.-11.00 a.m using Digital Nerve Conduction/EMG/EP machine (Recorders Medicare system, India) in a laboratory maintained at 22º±3ºC. LLR was recorded during early follicular and mid-luteal phases by stimulation of median nerve while abducting the thumb and recording the EMG response of Abductor Pollicis Brevis. Body temperature was recorded. Latency of LLR obtained during two phases of menstrual cycle was compared. Result: The mean value of latency for LLR was 45.45±2.95 ms (mean±SD) in the mid luteal phase. It was significantly (Wilcoxon test, p<0.001) shorter than the value in the early follicular phase 47.10±2.51ms (mean±SD). This is possibly due to the higher body temperature in the mid luteal phase. Conclusion: Long Latency Reflex was found to be affected during the phases of the menstrual cycle in healthy female volunteers.
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ObjectiveTo study whether the abductor pollicis brevis been effected by the reinnervation of the Riche-Cannieu anastomosis in the median nerve injury cases.MethodsCollect 43 cases (29male,14 female,mean age 32.6)corresponds with the study needs: (1)The traumatic median nerve injury (proved by the results of electrophysiological examine and the clinic diagnose)on or below the forearm.(2)The existence of RCA was verified by the electrophysiological examine results,and the amplitude of electric potential was under 1mv.(3) Rule out the cases with the other injure of nerve or nervous system disease and cervical vertebra disease,diabetes patient.The analysis base on the results of 43 case's periodical examine,the periodical criteria as following: within 2-4th week,within the 2-4thmonth and 1 year after the injury.Results Forty-three cases had not obvious recovery indication of the median nerve under the clinical and electrophysiological aspect,eight cases of abductor pollicis brevis function improved quickly in 3 months,the relevant CMAP amplitude of Riche-Cannieu anastomosis increased apparently,the EMG (Electromyography)results of abductor pollicis brevis ameliorated accordingly.ConclusionIn the case of RCA combined with the median nerve injury,the abductor pollicis brevis fibra might be dominated by RCA reinnervation when losing domination of median nerve,the reinnervation process will much faster than the regeneration process of the broken nerve.
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Abductor pollicis brevis muscle (APB) belongs to the foreground of the subfascial muscle thenar region, which is of great importance in the movement of the thumb on its two-joint arrangement. In this article, we report the presence of a superficial portion of the APB muscle and its relationship and discuss the available literature and the clinical implications of the presence of this variation.
El músculo abductor corto del pulgar (ACP) pertenece al primer plano muscular subfascial de la región tenar de gran importancia en los movimientos del pulgar por su disposición biarticular. En el presente artículo reportamos la presencia de un fascículo superficial del músculo ACP y sus relaciones, se analiza la literatura disponible y se discuten las implicancias clínicas de la presencia de esta variación.
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Humans , Male , Muscle, Skeletal/anatomy & histology , Muscle, Skeletal/abnormalities , Thumb/anatomy & histology , Thumb/abnormalities , CadaverABSTRACT
Objective To compare the influence of different end-tidal concentrations of sevoflurane on transcranial electrical four-limb muscle motor evoked potential (MEP) monitoring. Methods Twenty ASA Ⅰ-Ⅱpatients aged 23-62 years undergoing craniotomy were enrolled. Triangular muscle, biceps brachii muscle, triceps brachii muscle, brachioradialis muscle, extensor digitorum communis muscle, abductor pollicis brevis abductor digiti minimi muscle, rectus femoris muscle, tibialis anterior muscle, gastrocnemius muscle and abductor hallucis were selected for MEPs recording. Sevoflurane was introduced at 0.5, 0.75, 1.0 and then 1.3 MAC (15 min each), and the effects on MEPs were studied. Results ①Maximum MEP amplitude was observed at abductor pollicis brevis muscle in upper limb and abductor hallucis muscle in lower limb at baseline and 0.5 MAC. Up to 1.0 MAC, there was no significant difference in MEP amplitude among extensor digitorum communis muscle, abductor pollicis brevis and abductor digiti minimi muscle. ②The success rate of MEP recording from abductor pollicis brevis muscle and abductor hallucis muscle was 100% during the administration of 0.5-1.0 MAC sevoflurane. ③The MEP amplitude was decreased and the latency was increased in a sevoflurane dose-dependent manner. Conclusions Abductor pollicis brevis muscle and abductor hallucis muscle were suitable for MEP monitoring during the administration of 0.5-1.0 MAC sevoflurane.
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Objective To explore the optimal electrophysiologieal approach for detecting Riehe-Cannieu anastomosis(RCA),an anomalous anastomosis between the deep branch of ulnar nerve and the recurrent branch of the medial nerve in the palm of the hand,and to estimate its incidence. Methods One hundred subjects(56 male,44 female,mean age 37.8 years)without any hand motor or sensory dysfunction were selected randomly.The ulnar nerve was stimulated at both the elbow and wrist,and recordings were made from the abductor pollicis brevis,which is normally innervated by the medial nerve,to document any compound muscle action potentials(CMAP).CMAP recorded from both points during stimulation is an accepted indicator of RCA.Group A comprised 40 hands of 20 subjects,while group B included 160 hands of 80 subjects.Surface electrode stimulation was used in both groups.Surface and needle electrode recording was used in group A,while only needle electrode recording was used in group B.Results In group A,31 hands of 16 subjects were found to have RCA by means of surface electrode recording,but only 6 hands of 3 subjects were found to have RCA by means of concentric needle electrode recording.There was a difference of up t0 80.6% between results obtained by the 2 recording methods.In group B,35 hands of 20 subjects were found to have RCA.A total of 41 hands of 23 subjects among the 100 were found to have RCA when concentric needle electrode recording was used(20.5%incidence). Conclusion The type of recording electrode influences the accuracy of RCA examination.An accurate and reliable result can be obtained by using a concentric needle electrode.The abductor pollicis brevis can be anomalously innervated by the ulnar nerve because of RCA.When both the medial and ulnar nerve have been injured.RCA might result in anomalous clinical symptoms and electrophysiological findings.Thoroughly understanding this anomaly is of crucial importance in the clinical evaluation and diagnosis of medial or ulnar nerve injury,as well as to avoid mistakenly interpreting the electrophysiological data when Riche-Cannieu anastomosis is present.
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Objective To study the effect of the Riche-Cannieu anastomosis, an anomalous anastomosis between the deep branch of ulnar nerve and the recurrent branch of median nerve in the palm of the hand, on the diagnosis of patients with carpal tunnel syndrome. Methods Twelve patients (2 male, 10 female, mean age 49.8 years) with carpal tunnel syndrome with the presence of Riche-Cannieu anastomosis were tested in this study. Their clinical data including the symptoms and signs, electrophysiological findings and diagnosis were collected and discussed in relation to an anatomical review of these nerves. Results Due to the existence of the Riche-Cannieu anastomosis, the patients with carpal tunnel syndrome spared part or all of the function of the abductor pollicis brevis (APB) muscle. It may result in an unconformity of the patients′lesion degree caused by carpal tunnel syndrome and its clinical symptoms and electrophysiological findings. Conclusion Knowledge of the Riche-Cannieu anastomosis is of crucial importance in the clinical evaluation, diagnosis and treatment of carpal tunnel syndrome, as well as in avoiding errors in interpreting the electrophysiological data of the patients.