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1.
Acta Chir Orthop Traumatol Cech ; 87(1): 39-47, 2020.
Artigo em Eslovaco | MEDLINE | ID: mdl-32131970

RESUMO

PURPOSE OF THE STUDY This retrospective study investigated the significance of a combination of peak latency of waveform amplitude and waveform amplitude in association with spinal deformities. The correlation with postoperative neurologic deficit was evaluated too. MATERIAL AND METHODS Between January 2007 and January 2018, a group of 113 patients was evaluated in the study who underwent spine surgery using intraoperative neurophysiological monitoring (IONM) focusing on transcranial motor evoked potential (tc-MEP) monitoring. The average age of the patients was 30 years. Tc-MEPs were recorded bilaterally from tibialis anterior muscle and the abductor hallucis muscle in 88 patients without neurological deficit and in 25 patients with neurological deficit. The peak latency of waveform amplitude was defined as the period from stimulation until the waveform amplitude reached its peak. The correlation with postoperative neurological deficit was examined separately for latency delays of 5% and 10% or more and in combination with a decrease in amplitude of 70% or more. We used the presence-absence paradigm to evaluate the disappearance of previously present tc-MEPs and amplitude latency delays. The correlation with the deterioration of amplitudes from baseline or the elevation of thresholds was not used. Statistical tests were used to investigate the changes. The cases in our study with significant tc-MEP alerts were reviewed against the evidence-based response checklist. RESULTS Of 113 patients, the decrease in amplitude of 70% or more was identified in the neurological deficit group in 64% vs. 36% in the normal neurological group (p < 0.001). The neurological deficit was observed in 7.96% of patients postoperatively. A decrease in intraoperative amplitude of 70% or more from previously present tc-MEP occurred in 40 cases, with 89% sensitivity, 64% specificity, 36% false positive rate (FPR), and 20% positive predictive value (PPV) for prediction of postoperative neurological deficit. The amplitude latency peak delay of 10% or more was observed in 41 cases from the group of patients with postoperative neurological deficit, with 100% sensitivity, 64% specificity, 36% FPR and 22% PPV. A combination of a decrease in amplitude of 70% or more from the previously present tc-MEP and a delay in amplitude latency peak of 10% or more resulted in 100% sensitivity, 49% specificity, 51% FPR and 10% PPV in the group of postoperative neurological deficit patients. DISCUSSION Intraoperative tc-MEP alarm points have previously focused mainly on waveform amplitude. In our series, a criterion of an amplitude decrease of 70% or more from previously present tc-MEP was set as the alarm point. No alarm criterion for delay of peak latency of waveform amplitude was set before. We set a latency peak delay of 5% or more and 10% or more of waveform amplitude compared with the previously present tc-MEP as alarm criteria. This is the first study exploring the issue. We demonstrated the efficacy of latency peak of waveform amplitude together with the decrease of waveform amplitude. Another study found similarities in the decrease of amplitude of 70 % or more from baseline and the delay in amplitude latency of 10% or more from baseline; with 86% sensitivity, 98% specificity, 2% FPR and 86% PPV (1). CONCLUSIONS In conclusion, we investigated the efficacy of a change of peak latency delay of waveform amplitude in tc-MEP monitoring. The utilizing of the peak latency delay of waveform amplitude value resulted in high sensitivity up to 100 % and allows reduction of the FPR and an increase of the PPV. Further studies should set the alarm criteria more precisely for the waveform amplitude latency peak delay to achieve more effective spinal cord tc-MEP monitoring. Our concept of findings supports the neurophysiological monitoring findings in other studies. Key words: monitoring, IONM, intraoperative neurophysiological monitoring, tc-MEP, motor evoked potential, transcranial, amplitude, latency, peak.


Assuntos
Potencial Evocado Motor , Monitorização Neurofisiológica Intraoperatória , Procedimentos Neurocirúrgicos , Adulto , Humanos , Incidência , Estudos Retrospectivos
3.
Ann Vasc Surg ; 62: 275-286, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31445091

RESUMO

BACKGROUND: Venous percutaneous transluminal angioplasty (vPTA) in patients with multiple sclerosis (MS) and chronic cerebrospinal venous insufficiency (CCSVI) have shown contradictory results. The aim of the study is to evaluate the efficacy of the procedure in a randomized wait list control study. METHODS: 66 adults with neurologist-confirmed diagnosis of MS and sonographic diagnosis of CCSVI were allocated into vPTA-yes group (n = 31) or vPTA-not group (n = 35, control group). vPTA was performed immediately 15 days after randomization in the PTA-yes group and 6 months later in the control group. Evoked potentials (EPs), clinical-functional measures (CFMs), and upper limb kinematic measures (ULKMs) were measured at baseline (T0) and six months after in both groups, just before the venous angioplasty in the vPTA-not group (T1). RESULTS: Comparing the vPTA-yes and vPTA-not group, the CFM-derived composite functional outcome showed 11 (37%) versus 7 (20%) improved, 1 (3%) versus 3 (8%) stable, 0 versus 7 (20%) worsened, and 19 (61%) versus 18 (51%) mixed patients (χ2 = 8.71, df = 3, P = 0.03). Unadjusted and adjusted (for baseline confounding variables) odds ratio at 95% confidence interval were, respectively, 1.93 (1.3-2.8), P value 0.0007, and 1.85 (1.2-1.7), P value 0.002. EP- and ULKM-derived composite functional outcome showed no significant difference between the two groups. CONCLUSIONS: Venous angioplasty can positively impact a few CFMs especially for the quality of life but achieving disability improvement is unlikely.


Assuntos
Angioplastia , Veias Cerebrais , Transtornos Cerebrovasculares/terapia , Esclerose Múltipla Crônica Progressiva/terapia , Esclerose Múltipla Recidivante-Remitente/terapia , Extremidade Superior/inervação , Insuficiência Venosa/terapia , Adolescente , Adulto , Idoso , Angioplastia/efeitos adversos , Fenômenos Biomecânicos , Veias Cerebrais/diagnóstico por imagem , Veias Cerebrais/fisiopatologia , Transtornos Cerebrovasculares/diagnóstico por imagem , Transtornos Cerebrovasculares/fisiopatologia , Doença Crônica , Potencial Evocado Motor , Humanos , Itália , Pessoa de Meia-Idade , Esclerose Múltipla Crônica Progressiva/diagnóstico , Esclerose Múltipla Crônica Progressiva/fisiopatologia , Esclerose Múltipla Recidivante-Remitente/diagnóstico , Esclerose Múltipla Recidivante-Remitente/fisiopatologia , Qualidade de Vida , Recuperação de Função Fisiológica , Fatores de Tempo , Resultado do Tratamento , Insuficiência Venosa/diagnóstico por imagem , Insuficiência Venosa/fisiopatologia , Adulto Jovem
4.
Top Spinal Cord Inj Rehabil ; 25(4): 340-354, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31844386

RESUMO

Background: Electrophysiological measures are being increasingly utilized due to their ability to provide objective measurements with minimal bias and to detect subtle changes with quantitative data on neural function. Heterogeneous reporting of trial outcomes limits effective interstudy comparison and optimization of treatment. Objective: The objective of this systematic review is to describe the reporting of electrophysiological outcome measures in spinal cord injury (SCI) clinical trials in order to inform a subsequent consensus study. Methods: A systematic search of PubMed and EMBASE databases was conducted according to PRISMA guidelines. Adult human SCI clinical trials published in English between January 1, 2008 and September 15, 2018 with at least one electrophysiological outcome measure were eligible. Findings were reviewed by all authors to create a synthesis narrative describing each outcome measure. Results: Sixty-four SCI clinical trials were included in this review. Identified electrophysiological outcomes included electromyography activity (44%), motor evoked potentials (33%), somatosensory evoked potentials (33%), H-reflex (20%), reflex electromyography activity (11%), nerve conduction studies (9%), silent period (3%), contact heat evoked potentials (2%), and sympathetic skin response (2%). Heterogeneity was present in regard to both methods of measurement and reporting of electrophysiological outcome measures. Conclusion: This review demonstrates need for the development of a standardized reporting set for electrophysiological outcome measures. Limitations of this review include exclusion of non-English publications, studies more than 10 years old, and an inability to assess methodological quality of primary studies due to a lack of guidelines on reporting of systematic reviews of outcome measures.


Assuntos
Fenômenos Eletrofisiológicos , Traumatismos da Medula Espinal/fisiopatologia , Eletromiografia , Potencial Evocado Motor , Potenciais Somatossensoriais Evocados , Humanos , Reflexo Anormal
5.
PLoS One ; 14(12): e0217886, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31851669

RESUMO

BACKGROUND AND OBJECTIVES: Respiratory muscles dysfunction has been reported in COPD. Transcranial magnetic stimulation (TMS) has been used for assessing the respiratory corticospinal pathways particularly of diaphragm. We aimed to study the cortico-diaphragmatic motor system changes in COPD using TMS and to correlate the findings with the pulmonary function. METHODS: A case control study recruited 30 stable COPD from the out-patient respiratory clinic of Main Alexandria University hospital- Egypt and 17 healthy control subjects who were subjected to spirometry. Cortical conduction of the diaphragm was performed by TMS to all participants followed by cervical magnetic stimulation of the phrenic nerve roots. Diaphragmatic resting motor threshold (DRMT), cortical motor evoked potential latency (CMEPL), CMEP amplitude (CMEPA), peripheral motor evoked potential latency (PMEPL), PMEP amplitude (PMEPA) and central motor conduction time (CMCT) were measured. RESULTS: 66.7% of COPD patients had severe and very severe COPD with median age of 59 (55-63) years. There was statistically significant bilateral decrease in DRMT, CMEPA and PMEPA in COPD group versus healthy subjects and significant increase in CMEPL and PMEPL (p <0.01). Left CMCT was significantly prolonged in COPD group versus healthy subjects (p <0.0001) but not right CMCT. Further, there was significant increase in CMEPL and CMCT of left versus right diaphragm in COPD group (p = 0.003 and 0.001 respectively) that inversely correlated with FEV1% and FVC% predicted. Right and left DRMT were insignificantly different in COPD group (p >0.05) but positively correlated with FEV1/FVC, FEV1% and FVC% predicted. CONCLUSION: Central cortico-diaphragmatic motor system is affected in COPD patients with heterogeneity of both sides that is correlated with pulmonary function. SIGNIFICANCE: Coticospinal pathway affection could be a factor for development of diaphragmatic dysfunction in COPD patients accordingly its evaluation could help in personalization of COPD management especially pulmonary rehabilitation programs.


Assuntos
Diafragma/fisiopatologia , Potencial Evocado Motor , Córtex Motor/fisiopatologia , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Estudos de Casos e Controles , Diafragma/efeitos da radiação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Córtex Motor/efeitos da radiação , Estimulação Magnética Transcraniana
6.
J Stroke Cerebrovasc Dis ; 28(12): 104452, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31635964

RESUMO

BACKGROUND: Motor evoked potentials obtained with transcranial magnetic stimulation (TMS) can provide valuable information to inform stroke neurophysiology and recovery but are difficult to obtain in all stroke survivors due to high stimulation thresholds. OBJECTIVE: To determine whether transcranial magnetic stimulation evoked potentials (TEPs) evoked using a lower stimulus intensity, below that necessary for recording motor evoked potentials, could serve as a marker of poststroke upper-limb motor function and were different compared to healthy adults. METHODS: Eight chronic stroke survivors (66 ± 21 years) and 15 healthy adults (53 ± 10 years) performed a motor function task using a customized grip-lift manipulandum. TMS was applied to the lesioned motor cortex, with TEPs recorded using simultaneous high-definition electroencephalography (EEG). RESULTS: Stroke participants demonstrated greater hold ratio with the manipulandum. Cluster-based statistics revealed larger P30 amplitude in stroke participants, with significant clusters over frontal (P = .016) and parietal-occipital electrodes (P = .023). There was a negative correlation between the N45 peak amplitude and hold ratio in stroke participants (r = -.83, P = .02), but not controls. CONCLUSIONS: TEPs can be recorded using lower stimulus intensities in chronic stroke. The global P30 TEP response differed between stroke participants and healthy controls, with results suggesting that the TEP can be used as a biomarker of upper-limb behavior.


Assuntos
Eletroencefalografia , Potencial Evocado Motor , Atividade Motora , Acidente Vascular Cerebral/diagnóstico , Estimulação Magnética Transcraniana , Extremidade Superior/inervação , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Feminino , Força da Mão , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudo de Prova de Conceito , Tempo de Reação , Reprodutibilidade dos Testes , Acidente Vascular Cerebral/fisiopatologia
7.
Bratisl Lek Listy ; 120(10): 794-801, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31663357

RESUMO

BACKGROUND: Intraoperative neuromonitoring using tc-MEPs satisfactorily detects motor tract integrity changes during spinal surgery. However, tc-MEP is affected by anesthesia and other factors, in which the stimulation threshold increases because the waveform amplitude decreases over time with the accumulation and boluses of anesthetics. METHODS: We conducted a retrospective study of 139 patients. The average age was 30 years. Tc-MEPs were recorded bilaterally from the tibialis anterior muscle and the abductor hallucis muscle. Statistical tests were used to investigate the changes to evaluate anesthetic effects. RESULTS: There were no significant differences in tc-MEP amplitude change (%) between the groups of propofol (13 %), remifentanil (22 %) and sufentanil (26 %, p < 0.01). Significant differences were found between the groups of propofol, remifentanil, and sufentanil (20 %) and bolus sufentanil (‒30 %), and bolus ketamine (730 %, p < 0.008). Major differences were observed between bolus sufentanil (‒30 %) and bolus ketamine (730 %, p < 0.001). When comparing tc-MEPs with no amplitude, no significant difference was found between the groups of propofol (26 %), remifentanil (24 %), and sufentanil (28 %, p < 0.007). Substantial difference was found between the groups of propofol, remifentanil, and sufentanil (mean 26 %) and the group where ketamine boluses were administered. We didn't observe any loss of amplitude (0 %, p < 0.0002). CONCLUSION: IONM may be useless in patients where boluses of sufentanil are administered and also with Medical Research Council grades 3 and below. Consider applying IONM in patients with severe spinal deformity along with a higher age of over 50 and neurological deficit. Increasing stimulus intensity or facilitation techniques may be considered to improve the usefulness of tc-MEP. Our concept of findings supports the neurophysiological monitoring findings in other studies (Tab. 10, Ref. 45).


Assuntos
Anestesia , Monitorização Neurofisiológica Intraoperatória , Coluna Vertebral/cirurgia , Adulto , Anestésicos Intravenosos , Potencial Evocado Motor , Humanos , Ketamina/administração & dosagem , Propofol/administração & dosagem , Remifentanil/administração & dosagem , Estudos Retrospectivos , Sufentanil/administração & dosagem
8.
Spine (Phila Pa 1976) ; 44(21): 1492-1498, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31609917

RESUMO

STUDY DESIGN: A prospective, within-subject study was conducted. OBJECTIVE: We aimed to compare the influence of anesthetic fade under maximum stimulation conditions between constant-current and constant-voltage stimulation techniques. SUMMARY OF BACKGROUND DATA: The monitoring of muscle-evoked potentials after electrical stimulation to the brain [Br(E)-MSEP)] is useful for assessing the integrity of spinal cord motor tracts during major spine surgery. Nonetheless, Br(E)-MSEP responses are known to deteriorate over the duration of surgeries performed under general anesthesia. This phenomenon is known as anesthetic fade. METHODS: We recruited 117 patients undergoing various spinal surgeries from the cervical to the lumbar level. We excluded 29 cases with insufficient data. The decrease rate of the Br(E)-MSEP amplitude for each muscle was examined. Br(E)-MSEP monitoring with constant-current and constant-voltage stimulations at the C3 and C4 electrode positions was applied. Compound muscle action potentials (CMAPs) were bilaterally recorded from the abductor pollicis brevis, deltoid, abductor hallucis, tibialis anterior, gastrocnemius, and quadriceps muscles. We defined the decrease rate as follows: (initial CMAPs-final CMAPs)/initial CMAPs × 100. Differences in the decrease rate were evaluated between stimulators, limbs (upper vs. lower), and operative time group (lowest quartile vs. highest quartile). RESULTS: The overall decrease rate (across all muscles) increased as the operative time increased, and the rate was higher in the lower limbs than in the upper limbs. In addition, the overall decrease rate was lower with constant-voltage stimulation than with constant-current stimulation. Furthermore, the decrease rate for constant-current stimulation was significantly higher than that for constant-voltage stimulation, regardless of the operative time. CONCLUSION: The CMAP waveform with constant-voltage stimulation is less susceptible to anesthetic fade than that with constant-current stimulation, even during long surgeries. LEVEL OF EVIDENCE: 3.


Assuntos
Anestésicos/farmacologia , Encéfalo/efeitos dos fármacos , Potencial Evocado Motor/fisiologia , Músculo Esquelético/fisiologia , Procedimentos Neurocirúrgicos/métodos , Coluna Vertebral/cirurgia , Adulto , Anestesia Geral , Estimulação Elétrica , Eletrodos , Potenciais Evocados , Feminino , Humanos , Extremidade Inferior , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
9.
J Electromyogr Kinesiol ; 49: 102362, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31610484

RESUMO

INTRODUCTION: Myotonia congenita (MC) is caused by pathogenic variants in the CLCN1 gene coding the chloride channel protein. METHODS: To test the hypothesis that needle EMG could be helpful in distinguishing between the recessive and dominant MC, we performed EMG examination in 36 patients (23 men) aged 4-61 years with genetically proven MC: in 30 patients with autosomal recessive MC (Becker MC) and in 6 with autosomal dominant MC (Thomsen MC). RESULTS: Myotonic discharges were recorded in 95.8% of examined muscles. For the whole MC group we observed a significant positive correlation between parameters of motor unit activity potentials (MUAPs) in vastus lateralis and tibialis anterior muscles and the duration of the disease. Similar correlation for biceps brachii also was found in Becker MC subgroup only. DISCUSSION: EMG could still be helpful in diagnosis of MC and together with provocative tests might be useful in differentiation between recessive and autosomal MC.


Assuntos
Eletromiografia/métodos , Potencial Evocado Motor , Mutação , Miotonia Congênita/fisiopatologia , Adolescente , Adulto , Criança , Pré-Escolar , Diagnóstico Diferencial , Feminino , Genes Dominantes , Genes Recessivos , Humanos , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/fisiopatologia , Miotonia Congênita/diagnóstico , Miotonia Congênita/genética
10.
Spine (Phila Pa 1976) ; 44(20): 1435-1440, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31589200

RESUMO

STUDY DESIGN: Prospective multicenter study. OBJECTIVE: The aim of this study was to study the incidence of nonneurologic adverse events related to transcranial electric stimulation (TES) for intraoperative spinal cord monitoring (IOM) with motor-evoked potentials (MEPs) (Tc(E)- MEPs) and determine the need for safety precautions. SUMMARY OF BACKGROUND DATA: Tc(E)-MEPs monitoring requires high-voltage multipulse TES that causes widespread muscle contraction and movement. Improved awareness of TES-induced movement-related adverse events is needed. METHODS: We analyzed data from 2643 patients who underwent high-risk spinal surgery with intraoperative Tc(E)-MEPs at 11 spinal centers from 2010 to 2016. Information about neurologic and non-neurologic postoperative complications was collected, including type of surgical procedure, operative time, estimated blood loss, and treatment for postoperative adverse events. RESULTS: A 70% drop in Tc(E)-MEPs amplitude, which was the alarm criterion to interrupt surgery, predicted postoperative motor deficits with 93.5% sensitivity, 91.0% specificity, a false-positive rate of 8.2%, and a false-negative rate of 0.3%. Non-neurologic adverse events developed in 17 (0.64%) patients and were most commonly because of bite injuries (0.57%), including 11 cases of tongue laceration, two cases of lip laceration, and two cases of tooth breakage. Four (0.15%) tongue lacerations required surgical repair with sutures and two tooth breakages required dental treatment. One patient had hair loss corresponding to the TES site. One patient, who underwent additional IOM with transpharyngeal stimulation, had severe nasal hemorrhage following electrode placement by nasal route, which resolved spontaneously. Non-neurologic adverse events did not significantly affect the accuracy of IOM assessment. Neither operative times nor blood loss significantly influenced the occurrence of adverse events. CONCLUSION: During TES-IOM, both the surgeon and monitoring team must consider the possibility-although rare-of non-neurologic adverse events, particularly bite injuries. Such complications can be minimized by using a soft bite-block and frequently evaluating the intraoral integrity of the anesthetized patient. LEVEL OF EVIDENCE: 4.


Assuntos
Potencial Evocado Motor/fisiologia , Monitorização Neurofisiológica Intraoperatória/efeitos adversos , Procedimentos Neurocirúrgicos/métodos , Complicações Pós-Operatórias , Estimulação Transcraniana por Corrente Contínua/efeitos adversos , Humanos , Estudos Prospectivos
11.
Turk Neurosurg ; 29(6): 909-914, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31573062

RESUMO

AIM: To demonstrate the value of special intraoperative neuromonitoring techniques for cauda equina and conus medullaris tumors (CECMT) by describing standard methods used at our center. MATERIAL AND METHODS: Neurophysiological records were retrospectively reviewed for 16 patients (eight females and eight males; age range: 27â€"60 years) who underwent surgery for CECMT at our department between 2016 and 2018. RESULTS: Motor and/or sensorial deficits were preoperatively identified in 10 patients; no patients had bladder or sexual dysfunction. Motor evoked potential (MEP) loss occurred in seven patients with full or partial recovery. No changes were seen in pudendal somatosensory evoked potential (SEP) or bulbocavernosus reflex (BCR), and morphological deterioration and amplitude loss of tibial SEPs were present in four patients. Postoperatively, no new neurological deficits and/or bladder and sexual dysfunction were present. CONCLUSION: Pudendal SEP and BCR are useful tests for monitoring CECMT surgeries. BCR is an easily obtainable modality for preserving sacral functions and recommended as a primary monitoring modality in conjunction with traditional neurophysiological techniques during CECMT surgery.


Assuntos
Cauda Equina/fisiologia , Cauda Equina/cirurgia , Monitorização Neurofisiológica Intraoperatória/métodos , Neoplasias da Medula Espinal/cirurgia , Medula Espinal/fisiologia , Medula Espinal/cirurgia , Adulto , Cauda Equina/diagnóstico por imagem , Potencial Evocado Motor/fisiologia , Potenciais Somatossensoriais Evocados/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Medula Espinal/diagnóstico por imagem , Neoplasias da Medula Espinal/diagnóstico por imagem
12.
Artigo em Russo | MEDLINE | ID: mdl-31577270

RESUMO

OBJECTIVE: Development of a quantitative indicator for the risk level of intraoperative iatrogenic motor disorders in the process of surgical correction of spinal deformity based on current neurophysiological monitoring data. MATERIAL AND METHODS: 288 patients 12.6±0.35 y.o. underwent surgical correction of spinal deformities under the control of intraoperative neuromonitoring. The nature of changes in motor evoked potentials was assessed according to the earlier proposed ranking scale. The incidence of different variants of changes in the rank values of the state of the pyramidal system during the operation and the resulting postoperative motor disturbances was calculated. RESULTS: By comparing probabilities of various changes in the conduction properties of pyramidal tracts during surgery with the incidence of the observed motor deficiencies we quantitatively assessed the possible correlation between these phenomena. We propose a method for calculating the risk index for postoperative motor disorders depending on the maximum rank of the pyramidal system's response to surgical aggression. CONCLUSION: The developed system of ranking evaluation of changes in motor evoked potentials during surgical correction of spinal deformity makes it possible to quantify the risk of postoperative motor disorders and, accordingly, to monitor the level of anxiety for a neurosurgeon during individual stages of surgical intervention.


Assuntos
Potenciais Somatossensoriais Evocados , Doença Iatrogênica , Tratos Piramidais , Coluna Vertebral , Potencial Evocado Motor , Humanos , Monitorização Intraoperatória , Tratos Piramidais/lesões , Coluna Vertebral/anormalidades , Coluna Vertebral/cirurgia
13.
PLoS Biol ; 17(10): e3000469, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31613874

RESUMO

Newly learned motor skills are initially labile and then consolidated to permit retention. The circuits that enable the consolidation of motor memories remain uncertain. Most work to date has focused on primary motor cortex, and although there is ample evidence of learning-related plasticity in motor cortex, direct evidence for its involvement in memory consolidation is limited. Learning-related plasticity is also observed in somatosensory cortex, and accordingly, it may also be involved in memory consolidation. Here, by using transcranial magnetic stimulation (TMS) to block consolidation, we report the first direct evidence that plasticity in somatosensory cortex participates in the consolidation of motor memory. Participants made movements to targets while a robot applied forces to the hand to alter somatosensory feedback. Immediately following adaptation, continuous theta-burst transcranial magnetic stimulation (cTBS) was delivered to block retention; then, following a 24-hour delay, which would normally permit consolidation, we assessed whether there was an impairment. It was found that when mechanical loads were introduced gradually to engage implicit learning processes, suppression of somatosensory cortex following training almost entirely eliminated retention. In contrast, cTBS to motor cortex following learning had little effect on retention at all; retention following cTBS to motor cortex was not different than following sham TMS stimulation. We confirmed that cTBS to somatosensory cortex interfered with normal sensory function and that it blocked motor memory consolidation and not the ability to retrieve a consolidated motor memory. In conclusion, the findings are consistent with the hypothesis that in adaptation learning, somatosensory cortex rather than motor cortex is involved in the consolidation of motor memory.


Assuntos
Potencial Evocado Motor/fisiologia , Retroalimentação Sensorial/fisiologia , Consolidação da Memória/fisiologia , Memória de Longo Prazo/fisiologia , Córtex Somatossensorial/fisiologia , Adolescente , Adulto , Feminino , Humanos , Masculino , Córtex Motor/anatomia & histologia , Córtex Motor/fisiologia , Destreza Motora/fisiologia , Plasticidade Neuronal/fisiologia , Córtex Somatossensorial/anatomia & histologia , Estimulação Magnética Transcraniana
14.
Artigo em Russo | MEDLINE | ID: mdl-31626216

RESUMO

AIM: A quantitative evaluation of the relationship between the level of postoperative motor deficit and the intensity of reaction of pyramidal tract to the correction of spinal deformity. MATERIAL AND METHODS: The correction of spinal deformities of different etiology was performed under neurophysiological control for 87 patients (30 men, 57 women), aged 15.6±0.6 years. Reaction intensity of pyramidal tract was evaluated using the scale developed by the authors. RESULTS: The relationship between the intensity of intraoperative reaction of somatic motor system and EMG-signs of postoperative subclinical motor deficit in temperature-and-pain sensitivity disorders was shown. CONCLUSION: EMG evaluation of the level of intensity of subclinical motor deficit in combination with changes in temperature-and-pain sensitivity after the spinal deformity correction complies the reaction intensity of somatic motor system to surgical aggression. Neurologists should pay more attention to the patients with V type reaction not only during postoperative period, but before the next stage of surgery.


Assuntos
Doenças do Tecido Conjuntivo , Potencial Evocado Motor , Doenças da Coluna Vertebral , Adolescente , Feminino , Humanos , Masculino , Monitorização Intraoperatória , Estudos Retrospectivos , Doenças da Coluna Vertebral/fisiopatologia , Doenças da Coluna Vertebral/cirurgia
16.
No Shinkei Geka ; 47(9): 957-960, 2019 Sep.
Artigo em Japonês | MEDLINE | ID: mdl-31564656

RESUMO

OBJECTIVE: Motor evoked potentials(MEPs)have been developed and utilized as safe surgical procedures. A correlation between the threshold intensity of direct stimulation MEPs and the distance of the corticospinal tract(CST)has been already established. However, MEPs are affected by anesthesia and patient-related conditions. Here, we describe a unique technique to avoid these effects. METHOD: When tumors developed in proximity to the CST, the transcortical MEP monitoring was done by placing grid electrodes on the primary motor cortex continuously while direct subcortical MEP mapping was conducted with a monopolar probe. The ratios of the subcortical to the transcortical stimulation intensity were calculated. The point at which the ratios reached 50% was defined as the surgical excision limit. DISCUSSION: MEPs are affected by anesthesia, paralysis, body temperature, and other factors. By measuring the ratio of the cortical stimulation intensity instead of the absolute value of the white matter stimulation intensity, various affecting factors can be avoided, and more accurate monitoring can become possible. CONCLUSION: By calculating the ratio of subcortical to cortical stimulation intensity, the corticospinal tract mapping is less likely to be influenced by the stimulation condition or facility setup, and this warrants further investigation.


Assuntos
Mapeamento Encefálico , Potencial Evocado Motor , Córtex Motor , Estimulação Elétrica , Humanos , Tratos Piramidais
17.
J Vet Intern Med ; 33(5): 2312-2318, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31490026

RESUMO

BACKGROUND: Transcranial magnetic stimulation (TMS) and recording of magnetic motor evoked potentials (MMEP) can detect neurological dysfunction in horses but cutoff values based on confirmed spinal cord dysfunction are lacking. OBJECTIVES: To determine latency time cutoff for neurological dysfunction. ANIMALS: Five control horses and 17 horses with proprioceptive ataxia. METHODS: Case-control study with receiver operating characteristic curve analysis, based on diagnostic imaging, TMS, and histopathological findings. Horses were included if all 3 examinations were performed. RESULTS: Diagnostic imaging and histopathology did not show abnormalities in the control group but confirmed spinal cord compression in 14 of 17 ataxic horses. In the remaining 3 horses, histopathological lesions were mild to severe, but diagnostic imaging did not confirm spinal cord compression. In control horses, latency time values of thoracic and pelvic limbs were significantly lower than in ataxic horses (20 ± 1 vs 34 ± 16 milliseconds, P = .05; and 39 ± 1 vs 78 ± 26 milliseconds, P = .004). Optimal cutoff values to detect spinal cord dysfunction were 22 milliseconds (sensitivity [95% CI interval], 88% [73%-100%]; specificity, 100% [100%-100%]) in thoracic and 40 milliseconds (sensitivity, 94% [83%-100%]; specificity, 100% [100%-100%]) in pelvic limbs. To detect spinal cord dysfunction caused by compression, the optimal cutoff for thoracic limbs remained 22 milliseconds, while it increased to 43 milliseconds in pelvic limbs (sensitivity, 100% [100%-100%]; specificity, 100% [100%-100%] for thoracic and pelvic limbs). CONCLUSIONS AND CLINICAL IMPORTANCE: Magnetic motor evoked potential analysis using these cutoff values is a promising diagnostic tool for spinal cord dysfunction diagnosis in horses.


Assuntos
Potencial Evocado Motor , Doenças dos Cavalos/fisiopatologia , Doenças da Medula Espinal/veterinária , Estimulação Magnética Transcraniana/veterinária , Animais , Ataxia/diagnóstico por imagem , Ataxia/fisiopatologia , Ataxia/veterinária , Estudos de Casos e Controles , Feminino , Doenças dos Cavalos/diagnóstico por imagem , Cavalos , Masculino , Medula Espinal/diagnóstico por imagem , Medula Espinal/fisiopatologia , Compressão da Medula Espinal/diagnóstico por imagem , Compressão da Medula Espinal/fisiopatologia , Compressão da Medula Espinal/veterinária , Doenças da Medula Espinal/diagnóstico por imagem , Doenças da Medula Espinal/fisiopatologia
18.
Exp Brain Res ; 237(10): 2595-2605, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31372688

RESUMO

The neural mechanisms of walking impairment after stroke are not well characterized. Specifically, there is a need for understanding the mechanisms of impaired plantarflexor power generation in late stance. Here, we investigated the association between two neurophysiologic markers, the long-latency reflex (LLR) response and dynamic facilitation of antagonist motor-evoked responses, and walking function. Fourteen individuals with chronic post-stroke hemiparesis and thirteen healthy controls performed both isometric and dynamic plantarflexion. Transcranial magnetic stimulation (TMS) assessed supraspinal drive to the tibialis anterior. LLR activity was assessed during dynamic voluntary plantarflexion and individuals post-stroke were classified as either LLR present (LLR+) or absent (LLR-). All healthy controls and nine individuals post-stroke exhibited LLRs, while five did not. LLR+ individuals revealed higher clinical scores, walking speeds, and greater ankle plantarflexor power during walking compared to LLR- individuals. LLR- individuals exhibited exaggerated responses to TMS during dynamic plantarflexion relative to healthy controls. The LLR- subset revealed dysfunctional modulation of stretch responses and antagonist supraspinal drive relative to healthy controls and the higher functioning LLR+ individuals post-stroke. These abnormal physiologic responses allow for characterization of individuals post-stroke along a dimension that is clinically relevant and provides additional information beyond standard behavioral assessments. These findings provide an opportunity to distinguish among the heterogeneity of lower extremity motor impairments present following stroke by associating them with responses at the nervous system level.


Assuntos
Extremidade Inferior/fisiopatologia , Reflexo/fisiologia , Acidente Vascular Cerebral/fisiopatologia , Caminhada/fisiologia , Adulto , Idoso , Potencial Evocado Motor/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/fisiologia , Tempo de Reação/fisiologia , Reflexo de Estiramento/fisiologia , Acidente Vascular Cerebral/complicações , Estimulação Magnética Transcraniana/métodos
19.
Brain Stimul ; 12(6): 1588-1591, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31378601

RESUMO

BACKGROUND: Stimulatory cerebellar TMS is a promising tool to improve motor control in neurodegenerative disorders. OBJECTIVE/HYPOTHESIS: Our goal was to use 10Hz cerebellar rTMS to augment cerebellar-brain inhibition (CBI) for improved postural stability and speech in patients with progressive supranuclear palsy (PSP). METHODS: We performed CBI assessments with neuronavigation before and after high frequency cerebellar rTMS or sham TMS in two patients with PSP, using a double cone coil for the conditioning pulse and a figure-of-eight coil for the test pulse and treatments. We collected posturography data and speech samples before and after treatment. RESULTS: After treatment, CBI increased by 50% in subject 1 and by 32% in subject 2, and postural stability and speech improved. The protocol was well tolerated, but the sham was not consistently believable. CONCLUSION: Cerebellar rTMS may improve postural stability and speech in PSP, but cooled coils with vibrotactile sham capability are needed for larger future studies.


Assuntos
Cerebelo/fisiologia , Equilíbrio Postural/fisiologia , Fala/fisiologia , Paralisia Supranuclear Progressiva/fisiopatologia , Paralisia Supranuclear Progressiva/terapia , Estimulação Magnética Transcraniana/métodos , Potencial Evocado Motor/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Paralisia Supranuclear Progressiva/diagnóstico
20.
Brain Stimul ; 12(6): 1537-1552, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31377097

RESUMO

BACKGROUND: Transcranial magnetic stimulation (TMS) evokes voltage deflections in electroencephalographic (EEG) recordings, known as TMS-evoked potentials (TEPs), which are increasingly used to study brain dynamics. However, the extent to which TEPs reflect activity directly evoked by magnetic rather than sensory stimulation is unclear. OBJECTIVE: To characterize and minimize the contribution of sensory inputs to TEPs. METHODS: Twenty-four healthy participants received TMS over the motor cortex using two different intensities (below and above cortical motor threshold) and waveforms (monophasic, biphasic). TMS was also applied over the shoulder as a multisensory control condition. Common sensory attenuation measures, including coil padding and noise masking, were adopted. We examined spatiotemporal relationships between the EEG responses to the scalp and shoulder stimulations at sensor and source levels. Furthermore, we compared three different filters (independent component analysis, signal-space projection with source informed reconstruction (SSP-SIR) and linear regression) designed to attenuate the impact of sensory inputs on TEPs. RESULTS: The responses to the scalp and shoulder stimulations were correlated in both temporal and spatial domains, especially after ∼60 ms, regardless of the intensity and stimuli waveform. Among the three filters, SSP-SIR showed the best trade-off between removing sensoryrelated signals while preserving data not related to the control condition. CONCLUSIONS: The findings demonstrate that TEPs elicited by motor cortex TMS reflect a combination of transcranially and peripherally evoked brain responses despite adopting sensory attenuation methods during experiments, thereby highlighting the importance of adopting sensory control conditions in TMS-EEG studies. Offline filters may help to isolate the transcranial component of the TEP from its peripheral component, but only if these components express different spatiotemporal patterns. More realistic control conditions may help to improve the characterization and attenuation of sensory inputs to TEPs, especially in early responses.


Assuntos
Eletroencefalografia/métodos , Potencial Evocado Motor/fisiologia , Córtex Motor/fisiologia , Estimulação Magnética Transcraniana/métodos , Adolescente , Adulto , Feminino , Voluntários Saudáveis , Humanos , Masculino , Adulto Jovem
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