Citations
To derive normative values for ulnar nerve conduction study of the active recording electrode on the first dorsal interosseous muscle (FDI) and the reference electrode on the proximal phalanx of the thumb.
Ulnar nerve motor conduction study with FDI and abductor digiti minimi muscle (ADM) recording was performed in 214 hands of 107 healthy subjects. Ulnar NCS was performed with 2 different recording electrode montages (ADM-base of 5th finger; FDI-thumb) and differences in latency and amplitude were compared. Using this technique, the initial positivity of ulnar compound muscle action potential (CMAP) was not observed in any response with FDI recording.
The maximal values for distal motor latency to the ADM and FDI muscle were 3.8 ms and 4.4 ms, respectively. The maximal difference of distal motor latency between the bilateral FDI recordings was 0.6 ms. The maximal ipsilateral latency difference between ADM and FDI was 1.4 ms.
Placement of the reference electrode on the thumb results in a CMAP without an initial positivity and the normative values obtained may be useful in the diagnosis of ulnar neuropathy at the wrist.
Citations
Method: Ulnar motor nerve conduction studies were performed bilaterally in twenty healthy adult volunteers. For each limb, nerve conduction study was carried out in two different positions. In the first position, shoulder were abducted, elbow and wrist flexed to 90o. For the second position, all joints were kept constant except for the wrist where it was extended. Routine conduction study was performed in both wrist positions. All data were statistically analyzed.
Results: The average conduction velocities in the wrist flexed position were 61.6 m/sec for the forearm segment and 62.3 m/sec across elbow. With the wrist extended, the average was 62.6 m/sec and 64.1 m/sec, respectively. The differences in conduction velocities between two different wrist positions were statistically significant (p＜0.05). In the wrist flexed position, the average measured latencies were 2.3 msec with wrist, 5.4 msec below elbow, and 7.4 msec above elbow stimulation, compared to wrist extended which showed 2.4, 5.4 and 7.2 msec, respectively. The difference of latencies at wrist between the two wrist positions was statistically significant (p＜0.05).
Conclusion: The authors conclude that wrist position affect ulnar nerve conduction velocity.
Objective: The previously established method of carpal tunnel syndrome (CTS) diagnosis is relatively troublesome and risk of misleading due to uncertainty of exact distance measurement for stimulation. If we use the wrist crease, an anatomical landmark, there might not be error in length measurement for stimulation at any wrist position. This study was performed to evaluate the wrist stimulation method in the diagnosis of CTS for it's convenience and reducing the errors.
Method: Seventy healthy adults and sixty-five patients with clinical and electrophysiologic evidence of CTS were studied. Sensory nerve action potentials (SNAPs) in second and fifth digit were recorded antidromically with stimulation at a distance of 14 cm from recording electrode and stimulation at wrist crease. The ratio and difference of distal latency and ratio of amplitude between median and ulnar SNAPs were assessed.
Results: The ratio and difference of distal latency and ratio of amplitude in the 14 cm stimulation method were 1.52⁑0.28, 1.59⁑0.91 msec, 1.26⁑0.27 in the right, 1.43⁑0.14, 1.29⁑0.42 msec, 1.18⁑0.20 in the left, respectively in the men patients, and those of women patients were 1.48⁑0.35, 1.43⁑1.04 msec, 1.18⁑0.30 in the right, 1.53⁑0.30, 1.46⁑0.80 msec, 0.75⁑0.36 in the left. In wrist crease stimulation, those of men patients were 1.72⁑0.39, 1.74⁑0.98 msec, 1.22⁑0.24 in the right, 1.53⁑0.21, 1.31⁑0.46 msec, 1.25⁑0.29 in the left, and those of women patients were 1.67⁑0.46, 1.56⁑1.01 msec, 0.63⁑0.32 in the right, 1.68⁑0.37, 1.56⁑0.82 msec, 0.68⁑0.30 in the left. These results showed a significant positive correlation between the patients group and the control group in two stimulation methods (p＜0.001).
Conclusion: Based on the result of this study, wrist crease stimulation method is a quick and easy procedure, which would be recommended in the early diagnosis of CTS.
Objective: To determine whether flexion and extension of the wrist joint produce the change in the conduction study of the median nerve in the normal and diabetic patients, and to compare the susceptibility of median nerve compression injury in two groups.
Method: Thirty healthy adults as control and thirty diabetic patients without carpal tunnel syndrome were studied. The wrist joint was maintained in flexion or extension position for 5 minutes before performing conduction study. The variables used for statistical analysis included the mean difference of amplitude and latency in median motor and sensory responses in neutral, flexion, and extension positions.
Results: The results showed that significant differences in the latency and amplitude of median motor and sensory responses between neutral, extension, and flexion of wrist within each group (p＜0.01). The differences in the median sensory latency (p＜0.01), amplitude (p＜0.05) and the change of wrist-palm segmental conduction velocity (p＜0.01) were statistically significant between the diabetes and the normal control.
Conclusion: The results of this study suggest that median nerves are susceptible to compression pressure in diabetic patients. Therefore, the position of the wrist joint should be considered in the median nerve conduction study.
Objective: To demonstrate a conduction block of the median nerve at the flexor retinaculum (FR) in carpal tunnel syndrome (CTS), comparison of potentials obtained with stimulation of median nerve at the wrist and the palm may be required.
Method: To determine the severity and incidence of conduction block in patients with CTS, seventy hands of neurologically healthy adults (mean age, 48 years) as control, and seventy hands of patients with CTS (mean age, 51 years) were tested. We performed median motor and middle finger recorded antidromic sensory conduction study with stimulation of the wrist and palm of a distance of 5 cm. The negative peak spike duration and baseline to peak amplitude of the compound muscle action potential (CMAP), and sensory nerve action potential (SNAP) with wrist and palm stimulations were measured. From these values, the wrist to palm duration ratio and amplitude ratio were obtained.
Results: The criteria of median motor nerve conduction block were a wrist to palm amplitude ratio of less than 0.7 and a wrist to palm duration ratio of less than 1.13. The criteria of median sensory conduction block were a wrist to palm amplitude ratio of less than 0.61 and a wrist to palm duration ratio of less than 1.33. In the patient group, 10 hands (14.3%) showed motor conduction block and 12 hands (17.1%) showed sensory conduction block and 3 hands (4.3%) showed both. The wrist to palm amplitude ratios of CMAP and SNAP in the patient showing conduction block were 0.6⁑0.1, and 0.4⁑0.2, respectively. There was no correlation between palm CMAP or SNAP amplitude and respective wrist to palm ratios.
Conclusion: Comparison of the amplitude and duration of CMAP or SNAP obtained with stimulation of both wrist and palm may be able to differentiate between conduction block and axonal degeneration. These values may be useful in planning treatment and predicting outcome.
Upper limb amputations usually leave a significant functional limitation in activities of daily living for the amputees despite the use of a conventional prosthesis. New developments in prosthetic design have greatly increased the rehabilitation potential for active individuals with the upper limb amputation. The application of external power to artificial hands and elbow, and elimination of the control cables, the most unpopular feature of body-powered arms, has had a great impact on upper-limb prosthetics in the last two decades. We applied a myoelectric hand to a traumatic amputee with wrist disarticulation. As a result, it was possible to provide a considerable improvement in function and cosmesis with this new device.
Further research will undoubtly improve the appearance, function and durability of the present electrically powered myoelectrical hand, making them even more acceptable and useful to the upper limb amputees.
Partial hand amputation may leave a significant functional limitations for amputee that are difficult to ameliorate by either orthoses or prostheses. Many kinds of devices have been tried to promote the function and cosmesis. Cosmetic hand was the best answer to the person with first and second metacarpophalangeal joint disarticulation and the strength and range of motion of remaining three fingers were not in optimal status till now. We applied a new device of wrist driven prehension prosthesis consist of forearm stabilizer, short opponens, actuator rod, artificial thumb, artificial index and attached 2 rings was designed and fabricated. As a result, it is possible to provide considerable improvement in function and cosmesis with this new device.
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