No abstract available.
H-Reflex*

No abstract available.
H-Reflex*

No abstract available.
Electrodes* ; H-Reflex* ; Muscles*

OBJECTIVE: To determine the normal values of flexor carpi radialis (FCR) H-reflex without facilitation, with facilitation and with facilitation & averaging. And to compare the three methods. METHOD: The FCR H-reflex was tested in 60 healthy people. 1) H-reflexes was recorded in the FCR muscle without facilitation. 2) H-reflexes was recorded in the FCR muscle with facilitation and facilitation was carried out by contracting the FCR muscle with 1 kg of weight. 3) FCR H-reflex was tested by repetitive stimulation with facilitation and the multiple responses were averaged. RESULTS: Without facilitation, FCR H-reflexes were elicited only in 24 people out of 60 people and with facilitation, FCR H-reflexes were elicited in all 60 people. The mean latencies and amplitudes of the three methods were measured and normal limits of latency difference and amplitude ratio were calculated. In the FCR H-reflex without facilitation, with facilitation and with facilitation & averaging, the normal limits of latency difference were 1.0 msec, 1.0 msec, 1.1 msec and normal limits of amplitude ration were 0.37, 0.22, 0.57. CONCLUSION: FCR H-reflex with facilitation and with facilitation & averaging might be useful in the clinical diagnosis.
Diagnosis ; H-Reflex* ; Reference Values

The vibratory inhibition index(V.I.I.) of H-reflex, H/M(mean H-reflex amplitude / mean M wave amplitude) and F/M(mean F wave amplitude / mean M wave amplitude) ratios were measured in patients of hyperreflexia with or without spasticity. These data were compared with age-matched control subjects. In comparison to normals, V.I.I. And F/M ratios were increased at statistically significant levels(versus normal : V.I.I. P<0.001, F/M p<0.005) in patient group. And V.I.I.'s were inclined to be correlated with F/M ratios without statistical significance(r=0.27, p=0.21). H /M ratios showed no significant difference between patient and control groups. In these patients, the normal significant correlation between mean F wave amplitude and M wave amplitudes was maintained(p<0.01). F/M ratios were negatively correlated with rnotor nerve conductoion velocity(r= -0.72, p<0.01).These results indicate that V.I.I. And F/M ratios increase in patients with hyperreflexia and/or spasticity. Although mechanisms differ, the data are consistent with a similar physiological responses of H-reflex and F wave to spasticity.
H-Reflex* ; Humans ; Muscle Spasticity* ; Reflex, Abnormal

Since the early discovery of H-reflex by Hoffmann in 1918 there have been a great number of articles in the literature suggesting its clinical used by Magladery in the early 1950. Our experiments about measurement of latent time in H-reflex were performed on 40 normal male adult(composed of medicos and medical officers) and 82 patients(lumbago 40, lumbar disc 42) admitted at CAFGH from January '79. to August '79. The result about normal adult are as follows: 1) The mean value and the standard deviation of the latent time in normal adult(height 171+/-5.14 cm) is 27.74+/-1.86 msec at right leg, 27.77+/-1.64 msec at left one respectively. 2) There may be a linear relationship between latency and the height of normal adult and the difference between right and left is revealed 0.15+/-0.19 msec. We compare the measurementon the 82 patients group with the normal adult experimental groups in addition literatures review.
Adult* ; H-Reflex ; Humans ; Leg ; Male

OBJECTIVE: To find the developing features of H reflex by the gradual increase of stimulation intensity, to evaluate the variability of each H reflex latency, and to verify the consistency of the side-to-side difference of bilateral H reflex latencies in normal population. METHOD: Fifty normal persons (100 limbs) were studied. H reflexes were elicited using standardized technique from Braddom and Johnson. RESULT: H reflex developed in the stimulation intensity at which M response was not evoked in 46 of total 100 limbs. The latency difference between the longest and shortest in each ipsilateral evoked potential was 0~2.1 ms (mean 0.65+/-0.44 ms). In the side-to-side latency difference between the variously evoked H waves, the mean value of maximal one was 1.28+/-0.63 ms (0.4~2.6 ms), and the mean value of the minimal one was 0.24+/-0.35 ms (0~1.5 ms). The mean side-to-side latency difference between the H waves of maximal amplitudes was 0.69+/-0.46 ms (0.1~1.6 ms), and the mean side-to-side difference between the shortest latencies was 0.61+/-0.53 ms (0~2.1 ms). Among these findings the latency difference of the maximal amplitude was observed in 47 cases with 0~1.5 ms, in 3 cases with more than 1.5 ms. CONCLUSION: In diagnosing the S1 radiculopathy with the side-to-side latency difference it will be reasonable to use the latency of maximal amplitude or the shortest latency as diagnostic tool, and reevaluation will be needed with the diagnostic criteria of 1.5 ms latency difference.
Evoked Potentials ; Extremities ; H-Reflex* ; Humans ; Radiculopathy

BACKGROUND AND PURPOSE: Dystonia is not understood and its pathophysiology is uncertain. The fundamental motor abnormality is an abnormality of muscle command signals, in such that the wrong agonists may be activated for too long, there is abnormal co-contraction of agonists and antagonist, and there is excessive and misdirected action of synergists and postural fixators. The reciprocal inhibition of H reflex has been studied for the evaluation of pathophysiology in tonus abnormalities. Lelli et al.(1991) found the similarities in reciprocal inhibition studies between dystonia and Parkinson's disease. He suggested that abnormalities of reciprocal inhibition appear to be a physiologic overlap between two disorders. There is, however, controversy about the results of reciprocal inhibition studies in both disorders. The cutaneous reflex study is another valuable test for the evaluation of the pathophysiology in tonus abnormalities. In an attempt to clarify the pathophysiologic mechanisms of both disorders, we performed cutaneous reflex tests and compared the findings of both disorders with those of the control group. METHODS: 50 normal persons as a control group, 10 patients with dystonia, and 10 patients with Parkinson's disease participated in this study. Cutaneous reflex responses were recorded in the first dorsal interosseous muscle following electrical stimulation of the digital nerves of the index finger. RESULTS: Each mean amplitude of I1 of cutaneous reflex responses in patients with dystonia and in patients with Parkinson's disease is significantly decreased as compared with those of the control group. CONCLUSION: The results from this study lead us to conclude that both dystonia and Parkinson's disease might have abnormalities of inhibitory supraspinal influences on spinal mechanisms.
Dystonia* ; Electric Stimulation ; Fingers ; H-Reflex ; Humans ; Parkinson Disease* ; Reflex*

OBJECTIVE: To evaluate the values of H-reflex from tibialis anterior in the diagnosis of L5 radiculopathy. METHOD: The subjects were 37 patients and 30 normal controls. The patient group was composed of 28 patients with L5 radiculopathy and 9 patients with S1 radiculopathy, which were confirmed by clinical, radiological, and electrodiagnostic studies. Tibialis anterior H-reflex (TA-H reflex) was recorded from maximally contracting tibialis anterior muscle by averaging technique and submaximal stimulation of common peroneal nerve. Sensitivities and specificities were delineated from the several diagnostic criteria. RESULTS: In the normal controls, mean side to side difference in the TA-H reflex latency was 0.66+/-0.48 msec and mean amplitude ratio was 75+/-16%. The diagnostic criteria of abnormal TA-H reflex were latency difference above 1.62 msec and amplitude ratio less than 42.2%. The abnormal TA-H reflexes were shown in 17 out of 28 patients with L5 radiculopathy and 1 out of 9 patients with S1 radiculopathy. Sensitivity and specificity of TA-H reflex as a diagnostic criteria of L5 radiculopathy were 61% and 89%, respectively. CONCLUSION: Tibialis anterior H-reflex might be useful in the diagnosis of L5 radiculopathy.
Diagnosis ; H-Reflex* ; Humans ; Peroneal Nerve ; Radiculopathy* ; Reflex ; Sensitivity and Specificity

OBJECTIVE: To investigate the effects of Jendrassik maneuver on latency and amplitude of the T-reflex and H-reflex of the soleus muscle in normal adults. METHOD: The T-reflex and H-reflex tests were performed on sixty normal adults with standardized technique using the soleus muscle. The shortest latency and the largest peak-to-peak amplitude were chosen for representative values. RESULTS: The results were as follows: 1) There was a significant difference in latency of the T-reflex between with and without Jendrassik maneuver. 2) The increment ratio of the amplitude with Jendrassik maneuver was 88% in the T-reflex and 18% in the H-reflex. There were a significant difference in the amplitude of both reflexes between with and without Jendrassik maneuver. 3) A high correlation was present between the latency of H- & T-reflex and the length. CONCLUSION: According to these results, we suggest that Jendrassik maneuver primarily increases the sensitivity of muscle spindles and decreases the presynaptic inhibition of the Ia terminals at cortical, subcortical and spinal levels. Jendrassik maneuver can be a useful tool in cases of clinically decreased or absent deep tendon reflex.
Adult ; H-Reflex* ; Humans ; Muscle Spindles ; Muscle, Skeletal* ; Reflex ; Reflex, Stretch