This study aimed to investigate changes in the H-reflex recruitment curve in compressive radiculopathy, specifically assessing differences between symptomatic and asymptomatic limbs in patients with unilateral S1 radiculopathy through derived parameters. A total of 24 volunteers (15 male and 9 female, aged between 22 and 60 years) with confirmed nerve root compression in the L5/S1 segment participated. Nerve root compression was verified through clinical MRI examination and attributed to disc protrusion, spinal canal stenosis, or isthmic spondylolisthesis of L5/S1. Analysis revealed no difference in M-wave threshold intensity between symptomatic and non-symptomatic limbs. However, the H-reflex exhibited a trend toward increased threshold intensity in the symptomatic limb. Notably, a significant decrease in the slope of the H-reflex was observed on the symptomatic side, and the maximal H-reflex amplitude proved to be markedly different between the two limbs. The Hmax/Mmax ratio demonstrated a significant decrease in the symptomatic limb, indicating reduced effectiveness of signal translation. In conclusion, our findings emphasize the importance of H-reflex parameters in evaluating altered recruitment curves, offering valuable insights for neurological examinations. The observed differences in maximal values of M-wave, H-reflex, and their ratio in affected and unaffected limbs can enhance the diagnostic process for lumbosacral unilateral radiculopathy and contribute to a standardized approach in clinical assessments.

• MeSH
• dospělí MeSH
• elektromyografie MeSH
• H-reflex * fyziologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• radikulopatie * patofyziologie   diagnóza   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Deep brain stimulation (DBS) of the globus pallidus interna is an effective tool for the treatment of dystonia with possible distant effects reaching beyond the basal ganglia network. AIM: We analyzed the cortical silent period (CoSP) to test inhibitory circuits at the cortical level, and the cutaneous silent period (CuSP) and the H-reflex to test inhibitory circuits at the spinal level. METHODS: The upper limb muscles of 16 patients (9F, aged 54±(SD)16years) with generalized (N=9) and cervical (N=7) dystonia treated with DBS bilaterally were examined by the CoSP, CuSP and H-reflex in two states with random order: (i) in DBS ON and (ii) in DBS OFF condition two hours later, and compared with healthy controls. RESULTS: While the CuSP and H-Reflex did not differ between groups and remained unaffected by DBS, the CoSP was influenced significantly in dystonia. The CoSP onset latency was shortened (p<0.05 corrected) and the CoSP duration prolonged (p<0.01 corrected) in ON versus OFF condition. This effect was especially larger in generalized or phasic type of dystonia. Compared to healthy controls, the CoSP latency and duration became shorter in patients during the OFF condition only. CONCLUSION: The pallidal DBS did not affect the spinal inhibitory circuitry in dystonia. However, the abnormally low cortical inhibition was normalized after DBS possibly offering more efficient suppression of aberrant dystonic movements.

• Klíčová slova
• Cortical inhibition, Cortical silent period, Cutaneous silent period, Deep brain stimulation, Dystonia, Globus pallidus, H-reflex, Spinal inhibition,
• MeSH
• dospělí MeSH
• dystonie terapie   MeSH
• globus pallidus fyziologie   MeSH
• H-reflex fyziologie   MeSH
• hluboká mozková stimulace metody   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mícha patofyziologie   MeSH
• mladý dospělý MeSH
• motorické evokované potenciály fyziologie   MeSH
• mozková kůra patofyziologie   MeSH
• nervový útlum fyziologie   MeSH
• senioři MeSH
• šířící se kortikální deprese fyziologie   MeSH
• stupeň závažnosti nemoci MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

OBJECTIVE: The cutaneous silent period (SP) is a spinal inhibitory reflex, which suppresses activity in spinal motor nuclei. Transcranial magnetic stimulation (TMS) elicits a cortical SP, which represents GABA(B) receptor-mediated inhibition of cortical excitability. Baclofen as a strong GABA(B) agonist effectively reduces muscle hypertonia, however, it is not known whether intrathecal baclofen (ITB) may modulate spinal inhibitory circuits. METHODS: We evaluated clinical and neurophysiological effects of ITB in ten patients with severe spasticity due to spinal cord injury (n = 9) and chronic progressive multiple sclerosis (n = 1). Neurophysiological assessment included H reflex and cutaneous and cortical SPs, before and 15, 30, 60, 90, 120, and 180 min after ITB bolus administration. RESULTS: ITB suppressed soleus H reflex as early as 15 min after lumbar bolus injection; MAS scores declined after 1 h. Cortical SP end latency and duration increased progressively with a significant maximum 3h following ITB bolus, whereas cutaneous SP latency and duration did not change significantly. CONCLUSION: The present findings suggest that baclofen does not affect the cutaneous SP, but prolongs the cortical SP. SIGNIFICANCE: The spinal inhibitory circuitry of the cutaneous SP is not modulated by GABA(B) receptor-mediated activity, in contrast to the cortical inhibitory circuitry of the cortical SP, which is subject to powerful GABA(B) control.

• MeSH
• agonisté receptorů GABA-B aplikace a dávkování   farmakologie   MeSH
• baklofen aplikace a dávkování   farmakologie   MeSH
• časové faktory MeSH
• dospělí MeSH
• H-reflex účinky léků   fyziologie   MeSH
• kosterní svaly inervace   MeSH
• lidé středního věku MeSH
• lidé MeSH
• míšní nervy účinky léků   patofyziologie   MeSH
• mozková kůra účinky léků   patofyziologie   MeSH
• poranění páteře komplikace   MeSH
• reakční čas účinky léků   fyziologie   MeSH
• reflex účinky léků   fyziologie   MeSH
• roztroušená skleróza komplikace   MeSH
• spinální injekce MeSH
• svalová spasticita etiologie   patofyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• klinické zkoušky MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• agonisté receptorů GABA-B MeSH
• baklofen MeSH

PURPOSE: The natural course of lumbar spinal stenosis (LSS) fluctuates and is not necessarily progressive. The aim of this study was to explore the predictors of clinical outcome in patients with LSS that might eventually help to optimise the therapeutic choices. METHODS: A group of 56 patients (27 men, 29 women, median age 55; range 31-72 years) with clinically symptomatic mild-to-moderate LSS were re-examined after a median period of 88 months and their clinical outcomes classified as satisfactory (34 patients, 60.7 % with stable or improved clinical status) or unsatisfactory (22 patients, 39.3 % for whom clinical status deteriorated). A wide range of demographical, clinical, imaging and electrophysiological entry parameters were evaluated as possible predictors of clinical outcome. RESULTS: Unlike the demographical, clinical and imaging variables, certain electrophysiological parameters were significantly associated with unsatisfactory outcomes. There was a significantly higher prevalence of pluriradicular involvement detected by EMG in patients with unsatisfactory outcome than those with satisfactory outcome (68.2 vs. 32.3 %; p = 0.035). Patients with unsatisfactory outcome had more frequent bilateral abnormalities of the soleus H-reflex (50.0 vs. 14.7 %; p = 0.015) and lower mean H-reflex amplitude. Multivariate logistic regression proposed two variables as mutually independent predictors of unsatisfactory outcome: EMG signs of pluriradicular involvement (OR = 3.72) and averaged soleus H-reflex amplitude ≤ 2.8 mV (OR = 2.87). CONCLUSIONS: Satisfactory outcomes were disclosed in about 61 % of the patients with mild-to-moderate LSS in a 7-year follow-up. Electrophysiological abnormalities, namely the presence of pluriradicular involvement and abnormalities of the soleus H-reflex, were predictive of deterioration of clinical status in these patients.

• MeSH
• bederní obratle MeSH
• dospělí MeSH
• elektromyografie MeSH
• H-reflex fyziologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• odds ratio MeSH
• progrese nemoci MeSH
• ROC křivka MeSH
• senioři MeSH
• spinální stenóza komplikace   patofyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Increased excitability of the spinal motor system has been observed after loud and unexpected acoustic stimuli (AS) preceding H-reflexes. The paradigm has been proposed as an electrophysiological marker of reticulospinal tract activity in humans. The brainstem reticular formation also maintains dense anatomical interconnections with the cortical motor system. When a startling AS is delivered, prior to transcranial magnetic stimulation (TMS), the AS produces a suppression of motor evoked potential (MEP) amplitude in hand and arm muscles of healthy subjects. Here we analyzed the conditioning effect of a startling AS on MEP amplitude evoked by TMS to the primary motor leg area. Ten healthy volunteers participated in two experiments that used a conditioning-test paradigm. In the first experiment, a startling AS preceded a suprathreshold transcranial test stimulus. The interstimulus interval (ISI) varied between 20 to 160 ms. When given alone, the test stimulus evoked a MEP amplitude of approximately 0.5 mV in the slightly preinervated soleus muscle (SOL). In the second experiment, the startling AS was used to condition the size of the H-reflex in SOL muscle. Mean MEP amplitude was calculated for each ISI. The conditioning AS suppressed MEP amplitude at ISIs of 30-80 ms. By contrast, H-reflex amplitude was augmented at ISIs of 100-200 ms. In conclusions, acoustic stimulation exerts opposite and ISI-specific effects on the amplitude of MEPs and H-reflex in the SOL muscle, indicating different mechanism of auditory-to-motor interactions at cortical and spinal level of motor system.

• MeSH
• akustická stimulace MeSH
• analýza rozptylu MeSH
• časové faktory MeSH
• dolní končetina MeSH
• dospělí MeSH
• elektromyografie MeSH
• H-reflex MeSH
• kosterní svaly inervace   MeSH
• lidé MeSH
• míšní nervy fyziologie   MeSH
• motorické evokované potenciály MeSH
• motorické neurony fyziologie   MeSH
• mozková kůra fyziologie   MeSH
• nervový útlum MeSH
• transkraniální magnetická stimulace MeSH
• úleková reakce * MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• randomizované kontrolované studie MeSH
• Geografické názvy
• Německo MeSH

Central motor conduction time (CMCT) is usually abnormally prolonged in leg muscles of patients with pure hereditary spastic paraparesis (PHSP). One consequence of such abnormality should be an abnormal timing in the modulation of segmental reflexes, which might be more relevant for the pathophysiology of spasticity-related gait disturbances than just the CMCT delay. We examined the effects of transcranial magnetic stimulation (TMS) on the soleus H reflex in 13 control subjects and 11 PHSP patients using a conditioning (TMS) and test (H reflex) paradigm. Interstimulus interval (ISI) was 0-100 ms in steps of 10 ms. The amplitude of the H reflex at each interval was expressed as percentage of the control H reflex and the conditioned curves were compared between control subjects and patients. In control subjects, TMS-induced facilitation of the H reflex with two well-defined phases: early (ISIs 10 and 20 ms) and late (ISIs 70-90 ms). In patients, the early phase of facilitation was significantly reduced, while there was facilitation at 40 ms that was not present in control subjects. However, neither the characteristics of the MEP nor the differential modulation of the H reflex correlated significantly with clinical measures of motor dysfunction. Our results indicate an abnormal effect of TMS on the H reflex in PHSP patients. This suggests that the excitability of interneurons and soleus motoneurons is not modified in tune with the arrival of descending inputs. Desynchronization of the descending volley may contribute to both the lack of early facilitation and the presence of abnormal facilitatory phases.

• MeSH
• chůze (způsob) fyziologie   MeSH
• dospělí MeSH
• elektrická stimulace MeSH
• elektrofyziologie MeSH
• H-reflex fyziologie   MeSH
• kosterní svaly patofyziologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• nervus tibialis fyziologie   MeSH
• pyramidové dráhy patofyziologie   MeSH
• spastická paraparéza patofyziologie   MeSH
• transkraniální magnetická stimulace MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

UNLABELLED: Neurogenic claudication (NC) is typical of lumbar spinal stenosis (LSS). One suspected pathophysiological mechanism underlying NC is intermittent hypoxia of cauda equina fibres resulting from venous pooling, which may lead to ischaemic nerve conduction failure and to transient clinical and electrophysiological changes after exercise. The aim of this study was to evaluate the appearance of significant transient electrophysiological abnormalities after walking exercise in patients with LSS and to establish the contribution of dynamic electrophysiological examination in the differential diagnostics of patients with LSS. The study participants were 36 consecutive patients with LSS demonstrated by computed tomography (CT). The control groups included, respectively, 28 patients with diabetes mellitus and clinically manifested polyneuropathy, and 32 healthy volunteers. The LSS patients were divided into four subgroups based on the clinical severity of the disease (with respect to the presence or absence of NC in the history and pareses on neurological examination). Soleus H-reflex, tibial F-wave and motor evoked potentials (MEPs) to abductor hallucis muscle were examined in all groups, before and after quantified walking on a treadmill. The electrophysiological parameters measured after an exercise treadmill test (ETT) in LSS patients and in both control groups were compared with the same parameters obtained before ETT. The study shows that the electrophysiological parameters reveal minimal but statistically significant changes after walk loading in patients with LSS (a prolongation of the minimal latency of the tibial F-wave and of the latency of the soleus H-reflex). The changes in these parameters were demonstrated not only in patients with NC but also in patients without NC. More pronounced changes were found in LSS patients exhibiting chronic lower extremity pareses. CONCLUSIONS: From among a large battery of electrophysiological tests, only the minimal latency of the tibial F-wave and the latency of the soleus H-reflex exhibit changes after walk loading in patients with LSS. These are minimal but statistically significant. Dynamic electrophysiological examination can illustrate the pathophysiology of NC in LSS, but from a practical point of view its contribution to the differential diagnostics of LSS or diabetic polyneuropathy is limited by an absence of established cut-off values.

• MeSH
• bederní obratle patofyziologie   MeSH
• diagnostické zobrazování metody   MeSH
• dospělí MeSH
• elektrofyziologie metody   MeSH
• elektromyografie metody   MeSH
• fyzikální vyšetření metody   MeSH
• H-reflex fyziologie   MeSH
• kohortové studie MeSH
• lidé středního věku MeSH
• lidé MeSH
• nervové vedení fyziologie   MeSH
• senzitivita a specificita MeSH
• spinální stenóza diagnóza   MeSH
• studie případů a kontrol MeSH
• stupeň závažnosti nemoci MeSH
• zátěžový test MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH

Lumbar spinal stenosis (LSS) and diabetic polyneuropathy are common ailments of older age. Many people suffer from both at the same time. In such patients it may sometimes be difficult to separate signs and symptoms that could be attributed to either disease. This study evaluates the contributions and limits of various tests, especially the exercise treadmill test (ETT) and electrophysiological examination, in the diagnostics of patients with mild LSS. Twenty-nine patients with mild LSS documented by computed tomography (CT) participated in this study. Sixteen of the patients had neurogenic claudication (LSS NC+), and 13 patients did not (LSS NC-). Patients with LSS were compared with a group of 24 patients with diabetic polyneuropathy and 25 healthy volunteers. The distance covered, the time spent walking and the reasons for preliminary termination of the ETT were evaluated in all groups. Initial electrophysiological examination included electromyography (EMG) from the upper and lower extremities and motor evoked potentials (MEPs) to the lower extremities. LSS NC+ patients covered a significantly shorter distance and the time spent walking was significantly shorter than in LSS NC- patients and in the two control groups. The main reason for preliminary termination of the ETT was the development of NC in 67% of the LSS NC+ patients. In contrast, no LSS NC- patient and none from the control groups revealed NC, but 31% of LSS NC- patients were not able to finish the ETT for other reasons (e.g. dyspnoea). Electrophysiological parameters evaluated from the upper extremities distinguished diabetic patients from LSS patients. The latencies of the tibial F-wave, soleus H-reflex and spinal MEP response reliably distinguished healthy volunteers from diabetic patients and LSS patients, and particularly LSS patients from diabetic patients. The chronodispersion of the tibial F-wave distinguished LSS NC+ patients from the other groups. The results of the study show that electrophysiological examination contributes to the differential diagnostics between mild lumbar spinal stenosis and diabetic polyneuropathy. The contribution of electrophysiological methods in verification of NC in LSS patients is limited (chronodispersion of the tibial F-wave only). The ETT is useful in confirmation of NC and walking capacity verification, but restriction of walking capacity should be carefully analysed.

• MeSH
• diabetické neuropatie patologie   patofyziologie   MeSH
• diferenciální diagnóza MeSH
• elektrofyziologie MeSH
• elektromyografie MeSH
• H-reflex fyziologie   MeSH
• horní končetina patofyziologie   MeSH
• intermitentní klaudikace etiologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• lumbosakrální krajina diagnostické zobrazování   patologie   MeSH
• motorické evokované potenciály MeSH
• prospektivní studie MeSH
• radiografie MeSH
• spinální stenóza komplikace   diagnostické zobrazování   patologie   patofyziologie   MeSH
• zátěžový test MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH

It is well known that the training level of a muscle belongs to the parameters that affect the H-reflex response amplitude. The aim of this study was to investigate the effects of training type on H- and T-reflex response parameters. For this purpose, 20 long-distance athletes (group I, test group), 18 short-distance athletes (group II, test group) and 20 non-trained subjects (group III, control group) were involved in this study in which the H- and T-reflex amplitude and latency values were measured. The H-reflex amplitude and latency values found in groups I, II and III were 3.64 +/- 0.28 mV and 26.88 +/- 1.45 ms, 3.17 +/- 0.26 mV and 26.19 +/- 1.89 ms, and 6.07 +/- 0.34 mV and 26.77 +/- 1.32 ms, respectively. The T-reflex amplitude and latency values of the groups I, II and III were 3.30 +/- 0.18 mV and 32.01 +/- 1.02 ms, 3.11 +/- 0.20 mV and 31.47 +/- 1.16 ms, 4.24 +/- 0.21 mV and 31.47 +/- 1.16 ms, respectively. There was no statistically significant difference between the groups with respect to latencies of H- and T-reflexes (p>0.05). In both test groups, the amplitudes of the H-reflex and T-reflex were significantly smaller than the control group (p<0.05). The results of this study suggest that training of muscles affect the H- and T-reflex response parameters.

• MeSH
• Achillova šlacha fyziologie   MeSH
• běh fyziologie   MeSH
• časové faktory MeSH
• dospělí MeSH
• elektrofyziologie MeSH
• fyzická vytrvalost * MeSH
• H-reflex * fyziologie   MeSH
• lidé MeSH
• reakční čas MeSH
• reflex fyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

In a set of 25 normal subjects the probable site of activation of the motor pathway was looked for using transcutaneous cervical spinal stimulation. The motor conduction time in the fastest fibres between the "spinal cord" and the wrist reached 10.79 (SD 1.17) ms when using this technique and this value was compared to the same parameter obtained with other methods: F wave mean conduction time in the established distance was 11.0 (SD 0.96) ms; the conversion of sensory to motor conduction showed 11.0 (SD 1.1) ms and H wave 10.97 (SD 1.03) ms. The conduction time through the fastest motor fibres with the spinal stimulation corresponds to the activation of the alpha-motoneuron axons near their bodies. When interpreting the results of the cortical and spinal stimulation, it is necessary to take this fact into account.

• MeSH
• dospělí MeSH
• elektrická stimulace MeSH
• elektromyografie MeSH
• evokované potenciály fyziologie   MeSH
• H-reflex fyziologie   MeSH
• lidé MeSH
• mícha fyziologie   MeSH
• motorické neurony fyziologie   MeSH
• mozková kůra fyziologie   MeSH
• nervové dráhy fyziologie   MeSH
• nervové vedení fyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH