Comparative study of soleus H-reflex in normal humans and in patients with neuropathies

Background: The H-reflex derived its name from Hoffman. Hoffmann reflex is an electrically induced reflex analogous to the mechanically induced spinal stretch reflex. This measurement can be used to assess the response of the nervous system to various neurological conditions, musculoskeletal injuries, and application of therapeutic modalities, pain, exercise training, and performance of motor tasks. This simple and reproducible physiological response was studied to evaluate conduction along the course of the whole “final common pathway” from the moto neuron to the terminal axon as well as to gain some information regarding the function of large diameter group la afferent fibers supplying the muscle spindle. Aims and Objectives: The aim of the study was to compare the H-reflex latency between the normal person and in neuropathic patients. The study aimed to see whether there is any difference in H-reflex latency in the right leg of normal person and in neuropathic patients. The study aimed to see whether there is any difference in H-reflex latency in the left leg of normal person and in neuropathic patients. Materials and Methods: The study was conducted among 25 normal subjects and 25 neuropathic patients between 20 and 70 years of age from Nootan Medical College and Research Centre, Visnagar. The normal subjects were evaluated clinically to find their normal condition. The neuropathic patients which are included in study are of diabetic neuropathy, plexopathy, radiculopathy, vitamin deficiency, and Guillain Barre Syndrome. The patients who had bilateral neuropathy were included in the study. The study was conducted using mainly stimulator circuit, stimulating and recording electrodes, preamplifier, and oscilloscope. The software used for this experiment was RMS EMG EPMK II, one of the latest software with facilities for nerve conduction velocity, electromyography, F-wave, and H-reflex recording. Results: Out of the 50 participants, 25 participants who were suffering with any kind of neuropathy evaluated for their H-reflex latency in both leg. Patients with neuropathy showed higher latency in the right leg compared to the 25 participants in the control group in the right leg demonstrated significantly higher latency in the group with neuropathy. The 25 participants who were suffering with any kind of neuropathy evaluated for their H-reflex latency left leg compared to the 25 participants in the control group left leg demonstrated significantly higher latency in the group with neuropathy. Conclusion: The results show that there is an increase in the H-reflex latency in neuropathy patients as compared to normal subjects but it can be not used as a specific test for diagnosis of neuropathies, because the H-reflex latency may also change in normal subjects as the age of the persons is increases or the height of the persons increases but H-reflex latency can be used for the diagnosis of the proximal nerve root injuries as it mainly investigates the proximal nerve reflex arc.

Effects of Extracorporeal Shock Wave Therapy in Different Output Pressures on Triceps Surae Spasticity after Stroke / 中国康复理论与实践

Objective:To evaluate the effects of different output pressures of extracorporeal shock wave therapy (ESWT) on triceps surae spasticity after stroke, and to explore the electrophysiologic mechanism involved. Methods:From January, 2015 to December, 2017, 90 hemiplegic stroke patients with triceps surae spasticity were randomly assigned into control group (n = 30), treatment group 1 (n = 30) and treatment group 2 (n = 30). All the patients accepted routine medicine and rehabilitation, while the treatment groups 1 and 2 received ESWT of 1.5 bar and 2.0 bar in addition, respectively, for four weeks. They were assessed with Composite Spasticity Scale (CSS), passive range of motion (PROM), 10-meter walk test (10MWT), and H reflex latency and the Hmax/Mmax ratio before and after treatment, and the two treatment groups were assessed with Visual Analogue Scale (VAS) immediately after ESWT. Results:All the groups improved in scores of CSS, PROM and 10MWT after treatment (t > 7.261, P < 0.001), and improved more in scores of CSS and 10MWT in the two treatment groups than in the control group (P < 0.05), and the 10MWT was less in the treatment group 2 than in the treatment group 1 (P < 0.05). H reflex latency lengthened (t > 15.025, P < 0.001) and Hmax/Mmax ratio decreased (t > 14.850, P < 0.001) after treatment in the two treatment groups, and the H reflex latency was longer in the two treatment groups than in the control group (P < 0.01). There was no significant difference in VAS between the two treatment groups (t = 0.735, P > 0.05). Conclusion:ESWT of both 2.0 bar and 1.5 bar can improve triceps surae spasticity after stroke, and ESWT of 2.0 bar may more benefit the ability of walking. Further study is needed to explore the involved electrophysiologic mechanism.

Effects of Extracorporeal Shock Wave Therapy in Different Output Pressures on Triceps Surae Spasticity after Stroke / 中国康复理论与实践

Objective:To evaluate the effects of different output pressures of extracorporeal shock wave therapy (ESWT) on triceps surae spasticity after stroke, and to explore the electrophysiologic mechanism involved. Methods:From January, 2015 to December, 2017, 90 hemiplegic stroke patients with triceps surae spasticity were randomly assigned into control group (n = 30), treatment group 1 (n = 30) and treatment group 2 (n = 30). All the patients accepted routine medicine and rehabilitation, while the treatment groups 1 and 2 received ESWT of 1.5 bar and 2.0 bar in addition, respectively, for four weeks. They were assessed with Composite Spasticity Scale (CSS), passive range of motion (PROM), 10-meter walk test (10MWT), and H reflex latency and the Hmax/Mmax ratio before and after treatment, and the two treatment groups were assessed with Visual Analogue Scale (VAS) immediately after ESWT. Results:All the groups improved in scores of CSS, PROM and 10MWT after treatment (t > 7.261, P < 0.001), and improved more in scores of CSS and 10MWT in the two treatment groups than in the control group (P < 0.05), and the 10MWT was less in the treatment group 2 than in the treatment group 1 (P < 0.05). H reflex latency lengthened (t > 15.025, P < 0.001) and Hmax/Mmax ratio decreased (t > 14.850, P < 0.001) after treatment in the two treatment groups, and the H reflex latency was longer in the two treatment groups than in the control group (P < 0.01). There was no significant difference in VAS between the two treatment groups (t = 0.735, P > 0.05). Conclusion:ESWT of both 2.0 bar and 1.5 bar can improve triceps surae spasticity after stroke, and ESWT of 2.0 bar may more benefit the ability of walking. Further study is needed to explore the involved electrophysiologic mechanism.

Extracorporeal shock wave therapy alleviates spasticity in the triceps surae after stroke / 中华物理医学与康复杂志

Objective To evaluate the effect of applying extracorporeal shock wave therapy (ESWT) to alleviate triceps surae spasticity after a stroke and to explore the electrophysiological mechanisms involved.Methods Sixty hemiplegic stroke patients with triceps surae spasticity were recruited and randomly assigned to either an ESWT group or a control group,each of 30.Both groups were given routine medication and rehabilitation training.The ESWT group additionally received 3000 shots of ESWT at 0.089 mJ/mm2,1.5 bars and 8 Hz applied once a week for 4 weeks.Before the treatment,immediately afterward,and then 1 and 4 weeks later the subjects were assessed using the composite spasticity scale (CSS),passive range of motion (PROM) measurements,the 10-meter walk test (10MWT),H reflex latency and the Hmax/Mmax ratio.Results The ESWT group showed significant improvement in their average CSS,PROM and 10MWT results at t1,t2 and t3 compared with t0,while the control group had significant improvement in their average CSS and 10MWT scores,but their average PROM score improved significantly only at t1 and t2.The ESWT group showed significantly better progress in terms of their average CSS score at t1 and t2.The groups' average PROM scores were not significantly different,but the ESWT group had faster 10MWT times at t1,t2 and t3.In the ESWT group H reflex latency had lengthened significantly by t1 and the Hmax/Mmax ratio had decreased significantly,but the only significant difference from the controls was in the average H reflex latency at t1.The ESWT was well tolerated and did not cause any severe adverse effects.Conclusions ESWT improves triceps surae spasticity effectively after stroke quite safely.

The features of nerve electrophysiology in children with Miller-Fisher syndrome / 临床儿科杂志

Objective To explore the features of nerve electrophysiology in Miller-Fisher syndrome (MFS) in children.Methods Thirty-four children with MFS were selected.The examinations of routine motor sensory nerve conduction,H reflexes of soleus muscle and F wave of median and tibial nerevs were performed.At the same time,33 healthy children of the same age were selected as control group and 30 children with typical Guillain-Barre syndrome (GBS) selected as GBS group,which were compared with children with MFS.Results In children with MFS,routine motor nerve conduction velocity and amplitude,and sensory nerve conduction velocity were in normal range.Twelve cases (35.29％) showed a decrease in sensory nerve amplitude potential (SNAP),5 cases (14.71％) showed sural sparing phenomena (the decline degrees of SNAP in median or ulnar nerve greater than in sural nerve),22 cases (64.71％) showed abnormality of H reflex,and 12 cases (35.29％) showed the decline of SNAE Compared with control group,there was no difference in sensory nerve conduction velocity and SNAP in sural nerve in children with MFS (P＜0.05);While there were significant decreases in SNAP in both median nerve and ulnar nerve (P＜0.05).Compared with GBS group,children with MFS had significantly higher sensory conduction amplitude and faster velocity (P＜0.01).Conclusion A decrease of terminal sensory nerve conduction amplitude could be found in children with MFS,but,the SNAP had limited impact on it.H reflex abnormality is the most common electrophysiologic abnormalities in MFS.

The practical value of H-reflex to nerve root stimulation on postoperative evaluation of the effects on patient with lum-ber disc herniation / 中华骨科杂志

Objective To explore the role of S1 root stimulation H-reflex in evaluating the efficacy of lumbar disc hernia-tion (LDH). Methods 95 LDH patients (55 males, 40 females) who had underwent discectomy for the lumber herniated discs were recruited in this research from January 2014 to January 2016. The average was (40.5±6.7) years, ranged 17-60 years. The vi-sual analogue scale (VAS) scores and the MOS item short from health survey (SF-36) scale was evaluated in preoperative, day 7, 3 month and 1 year after operation, respectively. Meanwhile, the S1 H-reflex and routine H-reflex were taken before operation and 1 year of postoperation. Results The subjects were divided into two groups according to the results of the preoperative S1 H-reflex:①60 patients with S1 present group, the H-M interval was significantly longer (8.1±1.2) ms, 47 of those with routine H-reflex and the latency was prolonged (31.8 ± 2.5) ms, 13 of those with absent routine H-reflex. 32 among 60 patients H-M interval was short-en before operation (7.8 ± 1.0) ms in 1 year follow-up, and there was statistically significant (P=0.001);the latency of conventional H-reflex was shorter than that of preoperation (28.5 ± 2.3) ms in 20 patients, there was statistical difference (P=0.023);the H-re-flexes were detected in the 6 patients from that 13 with absent routine H-reflex.②35 patients absent group, of which 30 cases of conventional H reflex disappeared, only 5 had normal routine H-reflex and the latency was prolonged (31.2 ± 3.0) ms. There were no H-wave patterns detected in 18 patients with H-reflexed one year later, and there was no significant difference in the H-reflex latency (31.0 ± 3.1) ms. All patient's VAS scores and SF-36 were significantly improved from preoperation to postoperation. Both scores were no difference between two groups in 7 d of post surgery. The mean VAS score of two groups: 3 months (1.7 ± 1.0) points, (2.1 ± 1.2) points (t=2.618, P=0.010), and 1 year (1.3 ± 0.9) points, (1.8 ± 1.1)( t=3.311, P=0.002). SF-36 in two groups:3 months (28.9 ± 5.6) points, (33.2 ± 5.5) points ( t=-2.670, P=0.008), 1 year (23.2 ± 6.2), (30.2 ± 5.6) (t=-3.012, P=0.001). Conclusion The patients with LDH had detected S1 H-reflex before surgery which indicated the minor leisure in intravertebral nerves, so that nerve can get better recovery and functional score of postoperation, it could objectively evaluate the efficacy of LDH surgery.

The practical value of H-reflex to nerve root stimulation on postoperative evaluation of the effects on patient with lum-ber disc herniation / 中华骨科杂志

Objective To explore the role of S1 root stimulation H-reflex in evaluating the efficacy of lumbar disc hernia-tion (LDH). Methods 95 LDH patients (55 males, 40 females) who had underwent discectomy for the lumber herniated discs were recruited in this research from January 2014 to January 2016. The average was (40.5±6.7) years, ranged 17-60 years. The vi-sual analogue scale (VAS) scores and the MOS item short from health survey (SF-36) scale was evaluated in preoperative, day 7, 3 month and 1 year after operation, respectively. Meanwhile, the S1 H-reflex and routine H-reflex were taken before operation and 1 year of postoperation. Results The subjects were divided into two groups according to the results of the preoperative S1 H-reflex:①60 patients with S1 present group, the H-M interval was significantly longer (8.1±1.2) ms, 47 of those with routine H-reflex and the latency was prolonged (31.8 ± 2.5) ms, 13 of those with absent routine H-reflex. 32 among 60 patients H-M interval was short-en before operation (7.8 ± 1.0) ms in 1 year follow-up, and there was statistically significant (P=0.001);the latency of conventional H-reflex was shorter than that of preoperation (28.5 ± 2.3) ms in 20 patients, there was statistical difference (P=0.023);the H-re-flexes were detected in the 6 patients from that 13 with absent routine H-reflex.②35 patients absent group, of which 30 cases of conventional H reflex disappeared, only 5 had normal routine H-reflex and the latency was prolonged (31.2 ± 3.0) ms. There were no H-wave patterns detected in 18 patients with H-reflexed one year later, and there was no significant difference in the H-reflex latency (31.0 ± 3.1) ms. All patient's VAS scores and SF-36 were significantly improved from preoperation to postoperation. Both scores were no difference between two groups in 7 d of post surgery. The mean VAS score of two groups: 3 months (1.7 ± 1.0) points, (2.1 ± 1.2) points (t=2.618, P=0.010), and 1 year (1.3 ± 0.9) points, (1.8 ± 1.1)( t=3.311, P=0.002). SF-36 in two groups:3 months (28.9 ± 5.6) points, (33.2 ± 5.5) points ( t=-2.670, P=0.008), 1 year (23.2 ± 6.2), (30.2 ± 5.6) (t=-3.012, P=0.001). Conclusion The patients with LDH had detected S1 H-reflex before surgery which indicated the minor leisure in intravertebral nerves, so that nerve can get better recovery and functional score of postoperation, it could objectively evaluate the efficacy of LDH surgery.

Efecto inmediato de la crioterapia sobre la excitabilidad refleja en personas con espasticidad post-ECV / Immediate effect of cryotherapy on the spastic reflex excitability in people with spasticity post-stroke

Introducción: Existe controversia sobre los efectos terapéuticos de la crioterapia en el músculo espástico y las implicaciones clínicas que fundamentan su uso como coadyuvante en el proceso de rehabilitación. Objetivo: Evaluar el efecto inmediato de la aplicación del paquete de hielo sobre la excitabilidad refleja en la musculatura plantiflexora espástica en personas post-ECV. Métodolos: Estudio experimental de mediciones repetidas con asignación aleatoria a dos grupos de intervención: Grupo Experimental (n=10) y Grupo Control (n=5). Se registró latencia (ms), duración (ms) y amplitud (mV) de las ondas M y H y el índice de amplitud Hmáximo/Mmáximo (%) antes y después de la crioterapia o reposo. Los participantes fueron quince individuos de ambos géneros con hemiparesia espástica post-ECV, edad media de 60,7±10,7años, mediana tiempo de evolución 36 meses (RIC17-49). No hubo diferencias significativas en las características basales entre los grupos de intervención. Resultados: La crioterapia induce un aumento estadísticamente significativo en la latencia de la onda H (32,9±3,3 vs. 34,9±3,6ms, p<0,001) y M (8,0±1,9 vs. 9,4±2,4ms, p<0,05) y en la duración de la onda M (6,3±1,3 vs. 9,8±2,2ms, p<0,001) y H (7,2±1,6 vs. 9,9± 2,0ms, p<0,001). No se determinaron cambios significativos en la amplitud, ni en el índice Hmáx/Mmáx. Conclusiones: Nuestros hallazgos sugieren que el enfriamiento puede ser útil para el tratamiento de la espasticidad, pues retrasa la respuesta muscular evocada por estimulación eléctrica directa y refleja. A su vez, prolonga el período refractario del potencial de acción, por lo cual se requeriría más tiempo para activar las fibras musculares.

Introduction: There is controversy about the therapeutic effects of cryotherapy on spasticity and clinical implications underlying its use as an adjunct in the rehabilitation process. Objective: To evaluate the immediate effect of the application of ice pack on the H-reflex excitability in spastic muscles post-stroke people. Methods: A randomized experimental study of repeated measurements, with two intervention groups, was performed: Experimental group (n=10) and control group (n=5). Latency (ms) duration (ms) and amplitude (mV) of M and H waves and the amplitude index Hmáximo / Mmáximo (%) were recorded before and after cryotherapy or rest. The participants were fifteen subjects with spastic hemiparesis post-stroke were screened, mean age 60.7±10.7 years, median of injury duration 36 months (IQR17-49). There were no significant differences in baseline characteristics between the intervention groups. Results: Cryotherapy induces a statistically significant increase in the H wave latency (32.9±3.3 vs. 34.9± 3.6ms, p<0,001) and M wave (8.0±1.9 vs. 2.4ms±9.4, p<0.05); as well as, increase was observed in the duration of the M wave (6.3±1.3 vs. 9.8±2.2ms, p<0.001) and H (7.2±1.6 vs. 9.9±2.0ms, p<0.001). No significant changes in the amplitude or the Hmax/Mmax ratio were determined. There were no differences between the H-reflex or the M-wave variables recorded before and after in the control group. Conclusions: Our findings suggest that cooling may be useful for the treatment of spasticity, due to it delays muscle response evoked by direct and reflects electrical stimulation. Simultaneously, cooling prolongs the refractory period of the action potential, whereby more time is required to activate the muscle fibers.

Unilateral photothrombotic motor cortex lesion-induced hindlimb spastic hemiplegia model in rats / 第二军医大学学报

Objective To examine the feasibility of using photothrombotic unilateral motor cortex lesion for establishing hindlimb spastic hemiplegia model in rats. Methods Twenty SD rats were randomized into 2 groups: rats in group A received erythrosine B injection followed by laser iiradiation, and those in group B received sham operation. Then the rate dependent depression (RDD) of H reflex was employed to measure the spasticity of the plantaris before and 3, 7, 14, 28 days postoperation. H-E staining was used to observed the lesions in the motor cortex. Cholera toxin B subunit was used to retrogradely labll motoneurons in the spinal cord. The number of vesicular glutamine transporter 1 (VGLUT1) boutons on motoneuron soma and dendrite was quantified by immunofluorescence staining and laser confocal microscope scanning. Results Hreflex RDD in the right plantaris muscle was significantly decreased in group A compared with that in group B at 3, 7,14, and 28 days postoperation (P0. 05). The number of VGLUT1 boutons on soma and dendrite in group A was significantly increased compared with that in group B (P<0. 01). H-E staining showed specific lesion in the motor cortex of the brain tissue in group A, but not in group B. Conclusion Unilateral photothrombotic motor cortex lesion is feasible to generate contralateral hindlimb spastic hemiplegia in rats.

<b>Effect of Epidermal Penetration by Needle Stimulation to Make an Insertion in the Achilles Tendon of the Soleus H-reflex : A Two-minute Examination</b> / 日本東洋医学雑誌

<b>[Background]</b> Although we have demonstrated the clinical effect of acupuncture therapy with epidermal stimulation by needle penetration, its neurophysiological mechanisms are unclear. To investigate the clinical effects of epidermal stimulation by needle penetration on muscle tone, we tested the Hoffmann's reflex (Hreflex) of the soleus muscle during epidermal needle stimulation. <br><b>[Methods]</b> Eighteen healthy participants were recruited. We tested the soleus H-reflex elicited by tibial nerve stimulation before and after epidermal stimulation by needle penetration. Epidermal stimulation was performed at several points on the Achilles tendon by needle penetration. We analyzed the amplitude ratio of H/M obtained from the waveforms of the soleus muscle before and after epidermal stimulation. <br><b>[Results]</b> The amplitude ratio of H/M was significantly decreased during stimulation when compared with ratio during rest (p < 0.05). Each participant demonstrated a decrease in soleus muscle amplitude ratio of H/M during epidermal stimulation by needle penetration as compared with the ratio during rest. <br><b>[Discussion]</b> Epidermal stimulation of the muscle by needle penetration activated the inhibitory interneurons of the dermatome at the stimulation site. Therefore, epidermal stimulation by needle penetration was considered as a possible method to induce muscle relaxation. <br><b>[Conclusion]</b> It is suggested that epidermal stimulation by needle penetration for 2 minutes for the insertion of the Achilles tendon results in an inhibitory effect by stimulating the spinal cord neural mechanisms that correspond to the soleus muscle.

Time-series relationship to achieve performance on rebound drop jump / 体力科学

<p>The aim of this study was to demonstrate a time-series relationship in drop jump (DJ) from a pre-set state with improved performance. Twelve male college athletes performed a DJ from a height of 0.60 m. DJ performance was assessed with a DJ-index (jump height/contact time). Short-interval intracortical inhibition (SICI) was assessed as intracortical inhibitory circuit excitability in a pre-set state, calculated by using paired-pulse transcranial magnetic stimulation for the medial gastrocnemius muscle (MG). The H-reflex of the left MG and the ankle joint torque were calculated in the early phase of take-off. A significant correlation was shown between ⊿SICI during the pre-set state and the DJ index. Thus, we examined the relationships between phases, focusing on time-series relationships throughout the jump period. The results showed a significant correlation between ⊿SICI during the pre-set state and %H-reflex during the early phase of take-off, and peak ankle joint torque during take-off was also significantly correlated with %H-reflex during the early phase of take-off. A significant correlation was also demonstrated between ankle joint torque during take-off and the DJ-index. In conclusion, we observed a time-series relationship between DJ from a pre-set state and improved performance. A decrease of intracortical inhibitory circuit excitability in the pre-set state affects stretch-reflex facilitation during the early phase of take-off; stretch-reflex facilitation results in the development of a large force in the ankle joint during take-off, and this force develops ankle joint torque. These findings may be used to improve jump performance.</p>

Evaluating the Differential Electrophysiological Effects of the Focal Vibrator on the Tendon and Muscle Belly in Healthy People

OBJECTIVE: To investigate the electrophysiological effects of focal vibration on the tendon and muscle belly in healthy people. METHODS: The miniaturized focal vibrator consisted of an unbalanced mass rotating offset and wireless controller. The parameters of vibratory stimulation were adjusted on a flat rigid surface as 65 microm at 70 Hz. Two consecutive tests on the different vibration sites were conducted in 10 healthy volunteers (test 1, the Achilles tendon; test 2, the muscle belly on the medial head of the gastrocnemius). The Hoffman (H)-reflex was measured 7 times during each test. The minimal H-reflex latency, maximal amplitude of H-reflex (Hmax), and maximal amplitude of the M-response (Mmax) were acquired. The ratio of Hmax and Mmax (HMR) and the vibratory inhibition index (VII: the ratio of the Hmax after vibration and Hmax before vibration) were calculated. The changes in parameters according to the time and site of stimulation were analyzed using the generalized estimating equation methods. RESULTS: All subjects completed the two tests without serious adverse effects. The minimal H-reflex latency did not show significant changes over time (Wald test: chi2=11.62, p=0.07), and between the two sites (chi2=0.42, p=0.52). The changes in Hmax (chi2=53.74, p<0.01), HMR (chi2=20.49, p<0.01), and VII (chi2=13.16, p=0.02) were significant over time with the adjustment of sites. These parameters were reduced at all time points compared to the baseline, but the decrements reverted instantly after the cessation of stimulation. When adjusted over time, a 1.99-mV decrease in the Hmax (chi2=4.02, p=0.04) and a 9.02% decrease in the VII (chi2=4.54, p=0.03) were observed when the muscle belly was vibrated compared to the tendon. CONCLUSION: The differential electrophysiological effects of focal vibration were verified. The muscle belly may be the more effective site for reducing the H-reflex compared to the tendon. This study provides the neurophysiological basis for a selective and safe rehabilitation program for spasticity management with focal vibration.

Post-activation Depression in Spasticity (review) / 中国康复理论与实践

Recent studies show that post-activation depression is highly correlated with the severity of spasticity in patients with stroke or cerebral palsy, which may be potentially used in the evaluation of spasticity. This article reviewed the concept, mechanism and related fac-tors of post-activation depression.

Post- activation Depression in Spasticity (review) / 中国康复理论与实践

@#Recent studies show that post-activation depression is highly correlated with the severity of spasticity in patients with stroke or cerebral palsy, which may be potentially used in the evaluation of spasticity. This article reviewed the concept, mechanism and related factors of post-activation depression.

Comparação de inibições medulares entre indivíduos com doença de Parkinson e saudáveis / Comparison of spinal inhibitions between parkisonian and helathy individuals

O objetivo do presente estudo foi comparar os níveis de inibição pré-sináptica (IPS) e inibição recíproca (IR) entre indivíduos com Doença de Parkinson e saudáveis e, a correlação entre essas inibições e a rigidez muscular e a severidade clínica de indivíduos com Doença de Parkinson (avaliadas através da Escala Unificada de Avaliação da Doença de Parkinson). Foram avaliados 11 indivíduos nos estágios 2 e 3 da doença e 13 indivíduos saudáveis pareados pela idade. A IPS foi menor em indivíduos com Doença de Parkinson (31,6%) do que em saudáveis (67,1%) (p = 0,02). A IR não diferiu entre indivíduos com Doença de Parkinson (26,9%) e saudáveis (27,6%) (p = 0,91). Adicionalmente, não foram detectadas correlações entre os níveis de IPS com a rigidez e a severidade clínica (p > 0,05). Portanto, mecanismos inibitórios não explicam totalmente a rigidez muscular e a severidade clinica da doença. Alterações entre ativação de músculos agonistas e antagonistas parecem estar relacionadas a influências supraespinhais anormais nos mecanismos espinhais decorrentes da doença...

The purposes of the present study were to compare presynaptic inhibition (PI) and disynaptic reciprocal inhibition (DRI) levels between parkinsonians and healthy individuals and to verify the correlation of such inhibitions with muscle rigidity and clinical severity (assessed by the Unified Parkinson Disease Rating Scale). We evaluated 11 parkinsonians in stages 2 and 3 of the disease and 13 healthy individuals matched for age. The PI was significant lower in parkinsonians (31.6%) than in healthy individuals (67.1%) (p = 0.02). The DRI did not differ between parkinsonians (26.9%) and healthy individuals (27.6%) (p = 0.91). Furthermore, no significant correlation was observed between PI with muscle rigidity and clinical severity (p > 0.05). Therefore, inhibitory mechanisms do not fully explain the cause of muscle rigidity and clinical severity of parkinsonians. Changes between the activation of agonist and antagonist muscles seem to be caused by abnormal supraspinal influence on spinal mechanisms...

Immediate effects of TENS and cryotherapy in the reflex excitability and voluntary activity in hemiparetic subjects: a randomized crossover trial / Efeitos imediatos da TENS e crioterapia na excitabilidade reflexa e atividade voluntária de sujeitos hemiparéticos: um estudo controlado aleatorizado cruzado

BACKGROUND: The disorder of reflex and motor function in patients affected by stroke causes negative impact on the performance of movement patterns and affects the functional activities. OBJECTIVES: To investigate the immediate effects of transcutaneous electrical nerve stimulation (TENS) and cryotherapy interventions on the spinal reflex excitability and in the voluntary electromyography (EMG) activity in people with chronic stroke. METHOD: Randomized crossover trial. The maximum H-reflex (Hmax), the H-reflex latency and the maximum motor response (Mmax) of the soleus muscle and also the EMG of the tibialis muscle where evaluated before and after the application of TENS, cryotherapy and control conditions. RESULTS: The Hmax/Mmax ratio was statistically significant higher (p=0.0245) and the H-reflex latency was statistically significant lower (p=0.0375) in the soleus muscle of the affected limb. The EMG amplitude of the tibialis anterior was reduced in the compromised limb (p<0.0001). After the use of the TENS, a reduction in the Hmax/Mmax ratio (p=0.0006) was observed leading to lower reflex excitability. However, after the cryotherapy intervention an increase of the Hmax/Mmax ratio was observed, which was accompanied by an increase in the H-reflex latency (p=0.0001). The EMG amplitude has not changed by any of the interventions. CONCLUSIONS: Our findings suggest that TENS may be a choice for immediate reduction of reflex excitability, whereas cryotherapy intervention may increase reflex excitability in hemiparetic subjects. However, none of the changes mediated by either intervention were able to modify the electrical activity in the antagonist muscle of the spastic muscle.

CONTEXTUALIZAÇÃO: O distúrbio da função motora e reflexa em pacientes acometidos por acidente vascular encefálico (AVE) causa impactos negativos na realização de padrões motores, comprometendo as atividades funcionais. OBJETIVOS: Investigar os efeitos imediatos da estimulação elétrica nervosa transcutânea (TENS) e da crioterapia na excitabilidade reflexa e na atividade voluntária de sujeitos vítimas de AVE. MÉTODO: Estudo Crossover. O reflexo H máximo (Hmáx), a latência do reflexo H e a resposta motora máxima (Mmáx) do músculo solear e a eletromiografia (EMG) do músculo tibial anterior foram avaliados antes e após a aplicação de TENS, crioterapia e em condições de controle. RESULTADOS: A razão Hmáx/Mmáx estava significativamente aumentada (p=0,0245) e a latência do reflexo H significativamente diminuída (p=0,0375) no músculo solear do membro afetado. A amplitude do sinal EMG do músculo estava significativamente reduzida no membro comprometido (p<0,0001). Depois da TENS, houve uma diminuição da razão Hmáx/Mmáx (p=0,0006). Porém, após a aplicação do gelo, houve um aumento da razão Hmáx/Mmáx, acompanhado por um aumento da latência do reflexo H (p=0,0001). A amplitude do sinal EMG não foi alterada por nenhuma das intervenções. CONCLUSÕES: Nossos achados indicam que a TENS pode ser uma escolha para redução imediata da excitabilidade reflexa, enquanto a crioterapia pode aumentar a excitabilidade reflexa de sujeitos hemiparéticos. No entanto, nenhuma das alterações mediadas por qualquer um dos tratamentos foi capaz de alterar a atividade elétrica do músculo antagonista ao espástico.

Transcranial magnetic stimulation combined with body-weight-supported treadmill treating after incomplete spinal cord injury / 中华物理医学与康复杂志

Objective To investigate the clinical effects of repetitive transcranial magnetic stimulation (rTMS) combined with body-weight-supported treadmill training (BWSTT) on patients with incomplete spinal cord injury (SCI).Methods Four patients with chronic incomplete SCI participated in this study.They were first treated with rTMS and then BWSTT training.They were assessed with clinical measures of function.Two of the four patients were assessed in terms of their H reflex,and using functional magnetic resonance imaging (fMRI) and a balance performance monitor (BPM).Results In two of the four patients,American spinal injury association (ASIA) clinical measures of motor and sensory function improved,as did 10 m walking speed and their sense of effort.In static balance tests,the sway path and sway area of the two patients both decreased.These improvements lasted for 3 weeks after the intervention.The two patients' maximum H reflex amplitude and the H/M amplitude ratio decreased.The fMRI results showed progressive enlargement of the activation volume of the movement-related M1 region after treatment.Conclusion High-frequency rTMS combined with BWSTT may improve motor function,elevate excitability of spinal motor neurons and improve the plasticity of the cerebral cortex in chronic incomplete SCI patients.

Spasticity and Electrophysiologic Changes after Extracorporeal Shock Wave Therapy on Gastrocnemius

OBJECTIVE: To evaluate the spasticity and electrophysiologic effects of applying extracorporeal shock wave therapy (ESWT) to the gastrocnemius by studying F wave and H-reflex. METHOD: Ten healthy adults and 10 hemiplegic stroke patients with ankle plantarflexor spasticity received one session of ESWT on the medial head of the gastrocnemius. The modified Ashworth scale (MAS), tibial nerve conduction, F wave, and H-reflex results were measured before and immediately after the treatment. The Visual Analogue Scale (VAS) was used during ESWT to measure the side effects, such as pain. RESULTS: There were no significant effects of ESWT on the conduction velocity, distal latency and amplitude of tibial nerve conduction, minimal latency of tibial nerve F wave, latency, or H-M ratio of H-reflex in either the healthy or stroke group. However, the MAS of plantarflexor was significantly reduced from 2.67+/-1.15 to 1.22+/-1.03 (p<0.05) after applying ESWT in the stroke group. CONCLUSION: After applying ESWT on the gastrocnemius in stroke patients, the spasticity of the ankle plantarflexor was significantly improved, with no changes of F wave or H-reflex parameters. Further studies are needed to evaluate the mechanisms of the antispastic effect of ESWT.

Value of the H reflex elicited by magnetic stimulation and the F wave in the diagnosis of S1 radiculopathy / 中华物理医学与康复杂志

Objective To explore a new electrodiagnostic approach using the H reflex elicited by magnetic stimulation of the S1 nerve root and F waves to evaluate sensory nerve root function in patients with S1 radiculopathy.Methods Thirty normal subjects and 30 patients with unilateral S1 radiculopathy were recruited in this study.H reflex and M response were recorded from the bilateral soleus of all the subjects by magnetic stimulation of S1 nerve roots.F and M wave responses elicited by electrical stimulation of bilateral tibial nerves at the popliteal fossa were also recorded.The sensory root conduction time (SRCT) was calculated.Correlations of age and body height with SRCT in the healthy subjects,and between SRCT and pain in the patients with S1 radiculopathy were analyzed.Results The mean values of normal subjects were 3.10 ± 0.44 ms for SRCT,and 0.13 ± 0.19 ms for inter-side SRCT differences.In the 30 patients with S1 radiculopathy,H reflex could not be elicited from 4 patients.Among the remaining patients,the SRCT of the affected side was prolonged significantly (3.90 ±0.65 ms),and the mean value of the inter-side difference increased significantly (0.90 ±0.50 ms).A regression equation correlating SRCT with height was developed,but no significant correlation between SRCT and age in the normal subjects was revealed.There was positive correlation between SRCT and the severity of pain among the patients.Conclusion SRCT can be used as a new electrodiagnostic index in estimating sensory nerve root function in patients with S1 radiculopathy.

Electrophysiological characteristics in patients with early Guillain-Barré syndrome / 中华神经科杂志

Objective To analyze the characteristics of the F waves,H-reflex and nerve conductions and its diagnostic value in the patients with Guillain-Barré syndrome(GBS)onset within 4 weeks.Methods The electrophysiological data of the 40 patients with GBS were analyzed retrospectively.These patients were divided into 2 groups according to the duration of illness including in 2 week' s group and over 2 week' s group.The results of the F waves,H-reflex,the motor nerve conduction velocity (MCV),and the sensory nerve conduction velocity(SCV)of these patients were analyzed.Results The abnormality rate of the F waves was 17/20 and 7/18 respectively in less 2 week' s group and over 2 week' s.The H-reflexes were 13/20 and 12/19.The MCV was 28.4％(25/88)and 32.9％(26/79).The distal motor latency was 40.9％(36/88)and 36.7％(29/79).The compound muscle action potential amplitude was 35.2％(31/88)and 32.9％(26/79)respectively in these two groups.The abnormality rate of the SCV was 11.2％(10/89)and 25.2％(24/95)respectively in the two groups.The higher abnormality rate of these tests was the F waves and H-reflex in both the groups.The abnormality rates of the F waves(x2 =8.657,P =0.003)and SCV(x2 =6.002,P =0.014)were significantly different between the two groups.There were no significant differences in the other tests.Conclusion The electrophysiological tests are valuable in the diagnosis of GBS.The F waves and H-reflex are more significant for early diagnosis of GBS.