Citations
To verify the utility of the lateral femoral cutaneous nerve (LFCN) ultrasound-guided conduction technique compared to that of the conventional nerve conduction technique.
Fifty-eight legs of 29 healthy participants (18 males and 11 females; mean age, 42.7±14.9 years) were recruited. The conventional technique was performed bilaterally. The LFCN was localized by ultrasound. Cross-sectional area (CSA) of the LFCN and the distance between the anterior superior iliac spine (ASIS) and the LFCN was measured. The nerve conduction study was repeated with the corrected cathode location. Sensory nerve action potential (SNAP) amplitudes of the LFCN were recorded and compared between the ultrasound-guided and conventional techniques.
Mean body mass index of the participants was 23.7±3.5 kg/m2, CSA was 4.2±1.9 mm2, and the distance between the ASIS and LFCN was 5.6±1.7 mm. The mean amplitude values were 6.07±0.52 µV and 6.66±0.54 µV using the conventional and ultrasound-guided techniques, respectively. The SNAP amplitude of the LFCN using the ultrasound-guided technique was significantly larger than that recorded using the conventional technique.
Correcting the stimulation position using the ultrasound-guided technique helped obtain increased SNAP amplitude.
Citations
To understand various morphologic types and locations of the sural nerve (SN) that are important for nerve conduction studies or nerve grafting procedures. The aim of this study was to describe the course and variations of the SN based on ultrasonographic findings for an adequate nerve conduction study.
A total of 112 SNs in 56 volunteers with no history of trauma or surgery were examined by ultrasonography. The location and formation of the SNs in relation to the medial and lateral sural cutaneous nerve were investigated. We measured the horizontal distance between the SNs and the midline of the calf at the level of 14 cm from the lateral malleolus, and the distance between the SNs and the most prominent part of the lateral malleolus.
SN variants was classified into four types according to the medial and lateral sural cutaneous nerve; type 1 (73.2%), type 2 (17.9%), type 3 (8.0%), and type 4 (0.9%). The mean distance between the SN and the midline of the calf was 1.02±0.63 cm, the SN and the most prominent part of the lateral malleolus was 2.14±0.15 cm.
Variations in the location and formation of the SN was examined by ultrasonography, and the results of this study would increase the accuracy of the SN conduction study.
Citations
To evaluate each digital branch of the median sensory nerve and motor nerves to abductor pollicis brevis (APB) and 2nd lumbrical (2L) according to the severity of carpal tunnel syndrome (CTS).
A prospective study was performed in 67 hands of 41 patients with CTS consisting of mild, 23; moderate, 27; and severe cases, 17. Compound muscle action potentials (CMAPs) were obtained from APB and 2L, and median sensory nerve action potentials (SNAPs) were recorded from the thumb to the 4th digit. Parameters analyzed were latency of the median CMAP, latency difference of 2L and first palmar interosseous (PI), as well as latency and baseline to peak amplitude of the median SNAPs.
The onset and peak latencies of the median SNAPs revealed significant differences only in the 2nd digit, according to the severity of CTS, and abnormal rates of the latencies were significantly lower in the 2nd digit to a mild degree. The amplitude of SNAP and sensory nerve conduction velocities were more preserved in the 2nd digit in mild CTS and more affected in the 4th digit in severe CTS. CMAPs were not evoked with APB recording in 4 patients with severe CTS, but obtained in all patients with 2L recording. 2L-PI showed statistical significance according to the severity of CTS.
The branch to the 4th digit was mostly involved and the branch to the 2nd digit and 2L were less affected in the progress of CTS. The second digit recorded SNAPs and 2L recorded CMAPs would be valuable in the evaluation of severe CTS.
Citations
To understand the neural generator of double-peak potentials and the change of latency and amplitude of double peaks with aging.
In 50 healthy subjects made up of groups of 10 people per decade from the age of 20 to 60, orthodromic sensory nerve conduction studies were performed on the median nerves using submaximal stimulation. Various stimulus durations and interstimulation distances were used to obtain each double peak in the different age groups. The latency and amplitude of the second peak were measured. Statistical analyses included one-way ANOVA and correlation tests. p-values<0.05 were considered significant.
When the cathode moved in a proximal direction, the interpeak intervals increased. Second peak amplitudes decreased, and second peak latencies were delayed with aging (p<0.05). In some older people, second peaks were not obtained.
Our experiments indicate that the double-peak response represented the two stimulation sites under the cathode and anode. The delayed latency and decreased amplitude of the second peak that occurs with aging represented peripheral nerve degeneration in aging, which starts at the distal nerve.
Citations
Method: Subjects were 22 patients with AVF in patients with CRF and 10 controls without AVF in patients with CRF. We studied nerve conductions, and compared the findings in the arms with fistula and without fistula, and the arms in controls.
Results: In ulnar motor nerve conduction study, the amplitude in fistula side was lower than non-fistula side, but the conduction velocity in non-fistula side was lower than fistula side. In radial motor nerve conduction study, the distal latency in non-fistula side was more delayed than that in fistula side. There were no statistical significancies between fistula side and non-fistula side in the other nerve conduction study parameters in arms. And there was no statistically different incidences of carpal tunnel syndrome in both sides. Comparing with controls, conduction velocities of ulnar and radial motor nerves and peak latencies of ulnar and radial sensory nerves were more delayed in both sides.
Conclusion: There were no significant local effects of arteriovenous fistula on nerve conductions in patients with chronic renal failure. (J Korean Acad Rehab Med 2003; 27: 912-916)
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.
Method: The subjects were 50 healthy adults (mean age, 45.6 years) without the clinical signs and symptoms of peripheral neuropathy. All subjects underwent electrodiagnostic evaluation of the following sensory nerves in lower limbs: superficial peroneal, sural, proximal sural, lateral dorsal cutaneous branch of sural nerve (LDSN), and medial plantar. Examined late responses included: tibial F-wave, peroneal F-wave, and H-reflex recorded from the soleus muscle.
Results: No response rates of sensory nerve conduction studies such as superficial peroneal, sural, proximal sural, LDSN, and medial plantar nerves were 2%, 0%, 0%, 24%, and 18%, respectively. No response rates of late responses such as tibial F-wave, peroneal F-wave, and H-reflex were 0%, 2%, and 8%, respectively. And no response rates were significantly correlated with age (p＜0.05).
Conclusion: No response rate of sensory and late responses of lower limbs are relevant to age increments, the results should be considered for an early diagnosis of peripheral neuropathy in the lower limbs of old population. (J Korean Acad Rehab Med 2003; 27: 220-223)
Method: Nerve conduction studies were performed in 23 patients with chronic renal failure. We not only measured distal latencies, amplitudes, and conduction velocities of median and ulnar motor nerves but also measured same parameters of radial sensory nerves at both upper limbs. In case of pateints with suspected peripheral polyneuropathy, we checked peripheral nerves at one lower limb. The results of nerve conduction studies and the frequency of cubital tunnel syndrome or carpal tunnel syndrome were compared between arteiovenous fistula side and non-arteiovenous fistula side.
Results: The amplitudes of median motor, ulnar motor nerves and radial sensory nerve in arteiovenous fisula side are statistically lower than those in non-arteiovenous fisula side (p＜0.05). In the 14 patients with peripheral polyneuropathy, the difference is also statistically significant between two sides (p＜0.05). Compared arteiovenous fisula side with non-arteiovenous fisula side, the frequency of cubital tunnel syndrome or carpal tunnel syndrome was not different between two sides.
Conclusion: Arteiovenous fisula may damage to the peripheral nerve in patients with chronic renal failure. (J Korean Acad Rehab Med 2003; 27: 85-89)
Method: Prospectively, total 40 patients with non-insulin dependent diabetes mellitus were included in the study. NCS was performed on median, ulnar, posterior tibial, deep peroneal, superficial peroneal, and sural nerves. Distal latency and conduction velocity (CV) of compound muscle action potential (CMAP), distal latency and amplitude of sensory nerve action potential (SNAP) were used as parameters of NCS. Multiple linear regression analysis were used to analyze the relations of HbA1c and parameters of NCS, after adjustment for age, height, weight, and disease duration of diabetes mellitus.
Results: HbA1c level had an inverse relation to CV of median motor nerve (β=1.272, p＜0.01), ulnar motor nerve (β=1.287, p＜0.01), posterior tibial nerve (β=0.982, p＜0.05), and deep peroneal nerve (β=1.449, p＜0.05).
Conclusion: This study indicates that HbA1c level was inversely related to motor nerve CV, and that sustained hyperglycemia may be involved in demyelination of motor nerves. Analysis of motor nerve CV related to HbA1c is expected to be useful in the follow-up or efficacy study of diabetes mellitus neuropathy as baseline data. (J Korean Acad Rehab Med 2003; 27: 80-84)
Method: The subjects were 26 patients with asymptomatic diabetic neuropathy and 40 healthy adults as control group. All subjects underwent electrodiagnostic evaluation of the following motor nerves: median, ulnar, tibial, and peroneal. Sensory nerves included: median, ulnar, radial, superficial peroneal, sural, lateral dorsal cutaneous branch of the sural nerve (LDSN) and medial plantar. And other studies were the sural/radial amplitude ratio, LDSN/sural amplitude ratio, peroneal and tibial F-responses, and H-reflex recorded from the soleus muscle. The frequency of abnormal parameters in the patients with asymptomatic diabetic neuropathy was obtained by comparison with the normative limits obtained from the control group.
Results: The most frequent abnormal electrodiagnostic parameters were the LDSN onset latency and the amplitude ratio of LDSN/sural (84.6%, respectively) followed by the LDSN peak latency, LDSN amplitude, and medial plantar onset and peak latency (80.8%, respectively).
Conclusion: We concluded that the LDSN and medial plantar nerve conduction studies are useful for early detection of neuropathy in diabetes mellitus. (J Korean Acad Rehab Med 2003; 27: 75-79)
Objective: Electrophysiologic study and 24 hours urine study were analysed in patients with diabetes mellitus in order to assess the correlation between the severity of the diabetic neuropathy and degree of microalbuminuria.
Method: Two hundreds forty one patients with diabetic neuropathy were included and divided into 3 groups - mild, moderate and severe groups. The latency and amplitude of the peroneal motor nerve, median and sural sensory nerves, F-wave of the peroneal nerve and H-reflexes were measured. Microalbuminuria and creatinine clearance with 24 hours urine were studied. The results of the nerve conduction study and the degree of microalbuminuria were evaluated for the correlation between the two signs.
Results: The degree of microalbuminuria significantly increased in accordance with the electrophysiologic severity of neuropathy (p＜0.05). The latencies and amplitudes of the peroneal motor, median and sural sensory nerves had significant correlation with the degree of microalbuminuria (p＜0.05).
Conclusion: The degree of microalbuminuria was significantly correlated with the electrophysiologic severity of diabetic neuropathy. The results suggest that pathogenesis of the neuropathy and nephropathy in patients with diabetes seem the same as microvascular and biochemical basis. (J Korean Acad Rehab Med 2002; 26: 555-561)
Objective: To compare the degree of change of current perception threshold (CPT) results with the degree of nerve conduction study (NCS) change and evaluate the effectiveness of the CPT in following up patients who went through operation for carpal tunnel syndrome (CTS).
Method: Twenty hands with CTS were examined with CPT and NCS, before, 2 weeks after and 2 months after operation. In the CPT, the threshold of the median nerve was measured, in the NCS, amplitude and latency of the median nerve was measured. Subjects were divided into 3 groups according to the severity by NCS results and into 2 groups according to the subjective perception of improvement.
Results: The subjects mean age was 51.4. Changes of NCS results in amplitude and latency showed no statistical relevance. CPT study result changes demonstrated to be statistically significant. Improvement of CPT results seen in the period of 2 weeks and 2 months and the initial first 2 weeks showed no difference. Change of CPT results showed correlation not in accordance with the severity of the NCS study, but with the symptomatic improvement of the patients.
Conclusion: CPT can be an effective tool in evaluating the improvement of symptoms and may be used as a follow up tool in patients with CTS. (J Korean Acad Rehab Med 2002; 26: 414-419)
Objective: To investigate the character of peripheral neuropathy associated with end-stage liver disease and the effect of liver transplantation on peripheral neuropathy.
Method: Twenty five patients admitted for a liver transplantation were involved in this study. All patients underwent nerve conduction study before liver transplantation and 6 months after liver transplantation. Based on results of this study, motor amplitude (MAS), motor velocity (MVS), sensory amplitude (SAS), and sensory velocity score (SVS) were calculated. Neuropathy symptom score (NSS), and neuropathy disability score (NDS) were estimated. The scores from the nerve conduction study were compared with NSS and NDS to find out the correlation between them. The changes in nerve conduction study, NSS and NDS after liver transplantation were evaluated.
Results: All patients had abnormalities on their nerve conduction study preoperatively, but 10 patients (40%) showed normal findings 6 months after transplantation. Only SAS disclosed significant correlation with NDS preoperatively. SAS, SVS, and MVS showed significant correlation with NDS after transplantation. SAS and MVS substantially increased after transplantation.
Conclusion: Nerve conduction study showed the improvement both in sensory and motor nerve after liver transplantation. The correlation between the nerve conduction study and clinical estimates after liver transplantation was closer than before the transplantation.
Objective: To evaluate the characteristics of peripheral nervous system involvement in patients with mucopolysaccharidoses (MPS).
Method: Electrophysiologic studies were performed in 26 children with MPS confirmed by semiquantitative MPS study, high resolution electrophoresis and enzyme assay. The age distribution of the patients were 2 to 18 year old (mean 8.2 year old).
Results: Of the 26 children, 21 children (80.8%) showed abnormal electrophysiologic finding. Eighteen children had median entrapment neuropathy at wrist level (carpal tunnel syndrome), 3 children had demyelinating peripheral polyneuropathies dominant in motor nerves.
Conclusion: The most prominent features of the peripheral nervous system involvement in MPS patients were entrapment neuropathy at wrist but concomittent peripheral polyneuropathy. Further studies would be necessary to clarify the characteristics of the peripheral polyneuropathy in MPS.
Objective: To evaluate the clinical usefulness of current perception threshold (CPT) test in diagnosing the diabetic neuropathy.
Method: We have recorded the neuropathic symptom score (NSS), CPT and the parameters of nerve conduction study (NCS) in 45 patients with diabetes. NSS was calculated according to the clinical symptom and signs, and the score more than 3 was regarded as abnormal (neuropathic). CPT was measured at the 2nd finger and 1st toe delivering the three different frequencies (2000, 250 and 5 Hz) of current and conventional NCS were performed at the median, peroneal motor and sural nerves. All the patients were assigned to three groups according to the result of NSS and NCS; group A, abnormal NSS and NCS; group B, abnormal NSS only; group C, normal NSS and NCS. CPT was compared between groups, and we investigated the correlation between CPT and NSS, and parameters of NCS. Also the sensitivity and specificity of CPT test were calculated.
Results: The mean CPT was significantly increased in the entire diabetic groups as compared with control group (p＜0.05). CPTs measured by 2000 Hz stimulation at the finger and toe were positively correlated with the most parameters of NCS (p＜0.05), and CPT was more highly correlated with NCS (p＜0.05) than NSS. The sensitivity and specificity of the CPT were 94.1% and 10.7%, respectively.
Conclusion: The CPT test may have added value in diagnosing the diabetic neuropathy as a screening.
Objective: The purpose of this study was to determine whether quantitative sensory test can be used as a screening test of peripheral polyneuropathy in patients with diabetes mellitus, and to evaluate the severity of peripheral polyneuropathy in patients with diabetes mellitus using quantitative sensory test.
Method: We performed nerve conduction study to right upper and left lower extremity of the patients. Quantitative sensory test was performed using TSA-2001 thermal sensory analyser on right thenar and left foot dorsum in both diabetic and control groups.
Results: 1) The warm sense and heat pain threshold were higher, the cold sense and cold pain threshold were lower in diabetic group than age-matched control group (p＜0.05). 2) The warm sense and heat pain threshold were higher, the cold sense and cold pain threshold were lower in diabetic group than young-aged control group (p＜0.05). 3) As nerve conduction study results were severe, the cold sense threshold in right thenar were decreased (p＜0.05).
Conclusion: Quantitative sensory study in patients with diabetes mellitus are sensitive to identify neuropathic change; thus, they would be used as the screening method of diabetic peripheral polyneuropathy.
Objective: To investigate the influence of electronic filter setting change on the parameters of motor and sensory nerve conduction studies.
Method: Median motor and sensory nerve conduction studies were performed in 25 neurologically healthy adult subjects with a mean age of 29 years (range, 20∼50). Compound muscle action potentials (CMAPs) and sensory nerve action potentials (SNAPs) were recorded after fixing the low frequency filter cutoff value of 1 Hz, 10 Hz, 100 Hz and 300 Hz and by changing high frequency filter cutoff level from 10 KHz to 0.5 KHz. Onset and peak latency, amplitude of CMAPs and SNAPs were measured and the area of CMAPs were also recorded. Dantec Counterpoint MK2 machine was used. Skin temperature was maintained at 34oC or above.
Results: As the high frequency filter was changed from 10 KHz to 0.5 KHz, the mean amplitude of SNAPs and CMAPs decreased by 33.5%, 3.3%, respectively. Onset and peak latency prolonged significantly below the high frequency filter level of 2 KHz (p＜0.01). When the low frequency filter was varied form 1 Hz to 300 Hz, large differences were seen in amplitude (69.7%) and area (86.5%) of CMAPs and amplitude of SNAPs (36.6%) (p＜0.01), but onset latency was not changed. Peak latency of CMAPs decreased by 20.8%, however, the peak latency of SNAPs reduced slightly (1.4%) (p＞0.01).
Conclusion: Significant alterations in parameters of CMAPs and SNAPs were produced by modification of filter setting. Optimum filter setting is recommended in nerve conduction study and filter parameters must remain constant when determining normal values and when performing serial studies on patients.
Objective: The purpose of this study was to determine the relationship of abnormal parameters in commonly tested peripheral nerves and clinical findings in diabetic neuropathy.
Method: Parameters in tested peripheral nerves are all 18 as follows; Distal latency and amplitude of median motor, median sensory, ulnar motor, ulnar sensory, tibial motor, peroneal motor, and sural sensory (14) plus conduction velocity of median motor, ulnar motor, peroneal motor, and tibial motor (4). Person who had at least one abnormal parameter out of 18 parameters counted as abnormal group and then it was divided 3 groups depending on numbers of abnormal parameter as follows; one to two abnormal parameters as mild group, three to five as moderate group, and more than 6 as severe group.
Results: The factors which were correlated with number of abnormal parameters on nerve conduction study (NCS) were 1) duration of diabetes mellitus and 2) age of patients but not the level of HbA1c (p＜0.05). The involved nerves in the order of frequency were sural sensory (49.7%), peroneal motor (43.2%), median sensory (32.7%), ulnar sensory (31.2%), median motor (29.6%), and ulnar motor (23.1%). In persons having mild grade on NCS, amplitude of sensory nerve action potential (SNAP) was more frequently involved than distal latency of SNAP. Among the parameters, amplitude of median compound muscle action potential (CMAP), amplitude of ulnar CMAP, distal latency of ulnar SNAP and the amplitude and distal latency of tibial CMAP seemed to be less affected in diabetic neuropathy.
Conclusion: The amplitude of SNAP seemed to be valuable parameter in detection of early diabetic neuropathy.
Objective: To assess the possibility of phrenic neuropathy in diabetic patients, and to define the factors that influence phrenic neuropathy in those patients.
Method: Seventeen diabetic patients and sixteen controls participated in this study. The fasting and postprandial 2 hours blood sugar levels, HbA1c study, motor and sensory nerve conduction study, pulmonary function test, and phrenic nerve conduction study were examined in all subjects. The neuropathic disability score (NDS) was measured for clinical assessment in diabetic patients.
Results: 1) The mean duration of diabetes was 12.3⁑7.7 years, and the mean NDS score was 3.2⁑3.8. 2) In pulmonary function test, FEV1 and FVC of diabetic patients were lower than controls (p＜0.05). 3) The prolonged latency and decreased amplitude of phrenic nerve were shown in diabetic patients compared with controls (p＜0.05). The FEV1 and FVC in the diabetics with phrenic neuropathy were lower than ones without phrenic neuropathy (p＜0.05). 4) The duration of diabetes, NDS are related to prolonged phrenic latency.
Conclusion: The diabetic patients with decreased pulmonary function with might be related phrenic neuropathy. The prolonged latencies of phrenic nerve were related with longer duration of diabetes and higher NDS score.
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