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1.
Clin Neurophysiol ; 158: 1-15, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38113692

RESUMO

OBJECTIVE: The aim of this study was to clarify the roles of the cerebellum and basal ganglia for temporal integration. METHODS: We studied 39 patients with spinocerebellar degeneration (SCD), comprising spinocerebellar atrophy 6 (SCA6), SCA31, Machado-Joseph disease (MJD, also called SCA3), and multiple system atrophy (MSA). Thirteen normal subjects participated as controls. Participants were instructed to tap on a button in synchrony with isochronous tones. We analyzed the inter-tap interval (ITI), synchronizing tapping error (STE), negative asynchrony, and proportion of delayed tapping as indicators of tapping performance. RESULTS: The ITI coefficient of variation was increased only in MSA patients. The standard variation of STE was larger in SCD patients than in normal subjects, especially for MSA. Negative asynchrony, which is a tendency to tap the button before the tones, was prominent in SCA6 and MSA patients, with possible basal ganglia involvement. SCA31 patients exhibited normal to supranormal performance in terms of the variability of STE, which was surprising. CONCLUSIONS: Cerebellar patients generally showed greater STE variability, except for SCA31. The pace of tapping was affected in patients with possible basal ganglia pathology. SIGNIFICANCE: Our results suggest that interaction between the cerebellum and the basal ganglia is essential for temporal processing. The cerebellum and basal ganglia and their interaction regulate synchronized tapping, resulting in distinct tapping pattern abnormalities among different SCD subtypes.


Assuntos
Atrofia de Múltiplos Sistemas , Ataxias Espinocerebelares , Degenerações Espinocerebelares , Humanos , Cerebelo , Ataxias Espinocerebelares/patologia , Gânglios da Base/patologia
2.
Front Hum Neurosci ; 17: 1197380, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37497041

RESUMO

This study introduces a body-weight-support (BWS) robot actuated by two pneumatic artificial muscles (PAMs). Conventional BWS devices typically use springs or a single actuator, whereas our robot has a split force-controlled BWS (SF-BWS), in which two force-controlled actuators independently support the left and right sides of the user's body. To reduce the experience of weight, vertical unweighting support forces are transferred directly to the user's left and right hips through a newly designed harness with an open space around the shoulder and upper chest area to allow freedom of movement. A motion capture evaluation with three healthy participants confirmed that the proposed harness does not impede upper-body motion during laterally identical force-controlled partial BWS walking, which is quantitatively similar to natural walking. To evaluate our SF-BWS robot, we performed a force-tracking and split-force control task using different simulated load weight setups (40, 50, and 60 kg masses). The split-force control task, providing independent force references to each PAM and conducted with a 60 kg mass and a test bench, demonstrates that our SF-BWS robot is capable of shifting human body weight in the mediolateral direction. The SF-BWS robot successfully controlled the two PAMs to generate the desired vertical support forces.

3.
Sci Rep ; 11(1): 12469, 2021 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-34127750

RESUMO

Electroencephalographic synchrony can help assess brain network status; however, its usefulness has not yet been fully proven. We developed a clinically feasible method that combines the phase synchrony index (PSI) with resting-state 19-channel electroencephalography (EEG) to evaluate post-stroke motor impairment. In this study, we investigated whether our method could be applied to aphasia, a common post-stroke cognitive impairment. This study included 31 patients with subacute aphasia and 24 healthy controls. We assessed the expressive function of patients and calculated the PSIs of three motor language-related regions: frontofrontal, left frontotemporal, and right frontotemporal. Then, we evaluated post-stroke network alterations by comparing PSIs of the patients and controls and by analyzing the correlations between PSIs and aphasia scores. The frontofrontal PSI (beta band) was lower in patients than in controls and positively correlated with aphasia scores, whereas the right frontotemporal PSI (delta band) was higher in patients than in controls and negatively correlated with aphasia scores. Evaluation of artifacts suggests that this association is attributed to true synchrony rather than spurious synchrony. These findings suggest that post-stroke aphasia is associated with alternations of two different networks and point to the usefulness of EEG PSI in understanding the pathophysiology of aphasia.


Assuntos
Afasia/diagnóstico , Sincronização de Fases em Eletroencefalografia , Rede Nervosa/fisiopatologia , Acidente Vascular Cerebral/complicações , Idoso , Idoso de 80 Anos ou mais , Afasia/etiologia , Afasia/fisiopatologia , Estudos Transversais , Estudos de Viabilidade , Feminino , Lobo Frontal/fisiopatologia , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Descanso/fisiologia , Índice de Gravidade de Doença , Acidente Vascular Cerebral/fisiopatologia , Lobo Temporal/fisiopatologia
4.
Neurorehabil Neural Repair ; 34(8): 711-722, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32691673

RESUMO

Background. Motor recovery after stroke is of great clinical interest. Besides magnetic resonance imaging functional connectivity, electroencephalographic synchrony is also an available biomarker. However, the clinical relevance of electroencephalographic synchrony in hemiparesis has not been fully understood. Objective. We aimed to demonstrate the usefulness of the phase synchrony index (PSI) by showing associations between the PSI and poststroke outcome in patients with hemiparesis. Methods. This observational study included 40 participants with cortical ischemic stroke (aged 69.8 ± 13.8 years) and 22 healthy controls (aged 66.9 ± 6.5 years). Nineteen-channel electroencephalography was recorded at 36.9 ± 11.8 days poststroke. Upper extremity Fugl-Meyer scores were assessed at the time of admission/before discharge (FM-UE1/FM-UE2; 32.6 ± 12.3/121.0 ± 44.7 days poststroke). Then, correlations between the PSIs and FM-UE1 as well as impairment reduction after rehabilitation (FM-UEgain) were analyzed. Results. The interhemispheric PSI (alpha band) between the primary motor areas (M1s) was lower in patients than in controls and was selectively correlated with FM-UE1 (P = .001). In contrast, the PSI (theta band) centered on the contralesional M1 was higher in patients than in controls and was selectively correlated with FM-UEgain (P = .003). These correlations remained significant after adjusting for confounding factors (age, time poststroke, National Institute of Health Stroke Scale, and lesion volume). Furthermore, the latter correlation was significant in severely impaired patients (FM-UE1 ≤ 10). Conclusions. This study showed that the PSIs were selectively correlated with motor impairment and recovery. Therefore, the PSIs may be potential biomarkers in persons with a hemispheric infarction.


Assuntos
Ondas Encefálicas/fisiologia , Sincronização de Fases em Eletroencefalografia/fisiologia , AVC Isquêmico/fisiopatologia , Córtex Motor/fisiopatologia , Paresia/fisiopatologia , Recuperação de Função Fisiológica/fisiologia , Extremidade Superior/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Biomarcadores , Feminino , Humanos , AVC Isquêmico/complicações , AVC Isquêmico/reabilitação , Masculino , Pessoa de Meia-Idade , Paresia/etiologia , Paresia/reabilitação , Prognóstico , Reabilitação do Acidente Vascular Cerebral
5.
Neurophotonics ; 4(4): 045003, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29152530

RESUMO

Near-infrared spectroscopy-mediated neurofeedback (NIRS-NFB) is a promising therapeutic intervention for patients with neurological diseases. Studies have shown that NIRS-NFB can facilitate task-related cortical activation and induce task-specific behavioral changes. These findings indicate that the effect of neuromodulation depends on local cortical function. However, when the target cortical region has multiple functions, our understanding of the effects is less clear. This is true in the supplementary motor area (SMA), which is involved both in postural control and upper-limb movement. To address this issue, we investigated the facilitatory effect of NIRS SMA neurofeedback on cortical activity and behavior, without any specific task. Twenty healthy individuals participated in real and sham neurofeedback. Balance and hand dexterity were assessed before and after each NIRS-NFB session. We found a significant interaction between assessment periods (pre/post) and condition (real/sham) with respect to balance as assessed by the center of the pressure path length but not for hand dexterity as assessed by the 9-hole peg test. SMA activity only increased during real neurofeedback. Our findings indicate that NIRS-NFB itself has the potential to modulate focal cortical activation, and we suggest that it be considered a therapy to facilitate the SMA for patients with postural impairment.

6.
Neurorehabil Neural Repair ; 31(6): 561-570, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28506148

RESUMO

BACKGROUND AND PURPOSE: Stroke-induced focal brain lesions often exert remote effects via residual neural network activity. Electroencephalographic (EEG) techniques can assess neural network modifications after brain damage. Recently, EEG phase synchrony analyses have shown associations between the level of large-scale phase synchrony of brain activity and clinical symptoms; however, few reports have assessed such associations in stroke patients. OBJECTIVE: The aim of this study was to investigate the clinical relevance of hemispheric phase synchrony in stroke patients by calculating its correlation with clinical status. METHODS: This cross-sectional study included 19 patients with post-acute ischemic stroke admitted for inpatient rehabilitation. Interhemispheric phase synchrony indices (IH-PSIs) were computed in 2 frequency bands (alpha [α], and beta [ß]), and associations between indices and scores of the Functional Independence Measure (FIM), the National Institutes of Health Stroke Scale (NIHSS), and the Fugl-Meyer Motor Assessment (FMA) were analyzed. For further assessments of IH-PSIs, ipsilesional intrahemispheric PSIs (IntraH-PSIs) as well as IH- and IntraH-phase lag indices (PLIs) were also evaluated. RESULTS: IH-PSIs correlated significantly with FIM scores and NIHSS scores. In contrast, IH-PSIs did not correlate with FMA scores. IntraH-PSIs correlate with FIM scores after removal of the outlier. The results of analysis with PLIs were consistent with IH-PSIs. CONCLUSIONS: The PSIs correlated with performance on the activities of daily living scale but not with scores on a pure motor impairment scale. These results suggest that large-scale phase synchrony represented by IH-PSIs provides a novel surrogate marker for clinical status after stroke.


Assuntos
Isquemia Encefálica/fisiopatologia , Sincronização Cortical , Reabilitação do Acidente Vascular Cerebral , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/fisiopatologia , Idoso , Ritmo alfa , Ritmo beta , Isquemia Encefálica/complicações , Isquemia Encefálica/patologia , Estudos Transversais , Eletroencefalografia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Vias Neurais/diagnóstico por imagem , Vias Neurais/patologia , Vias Neurais/fisiopatologia , Índice de Gravidade de Doença , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/patologia
7.
Neuroimage ; 85 Pt 1: 547-54, 2014 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-23684871

RESUMO

Balance problems are a major sequelae of stroke and are implicated in poor recovery of activities of daily living. In a cross-sectional study, using 50-channel event-related functional near-infrared spectroscopy we previously reported a significant correlation between individual balance ability after stroke and postural perturbation-related cortical activation in the supplementary motor area (SMA) and the prefrontal cortex. However, the neural mechanisms underlying balance recovery after stroke remain unclear. Herein, we examined the cortical involvement in balance recovery after stroke by determining longitudinal regional cortical activation changes in patients with hemiplegic stroke. Twenty patients with subcortical stroke admitted to our hospital for post-acute inpatient rehabilitation participated in this study. Before and after intensive inpatient physical and occupational therapy rehabilitation, we evaluated cortical activation associated with external postural perturbations induced by combined brisk forward and backward movement on a platform. Postural perturbation-related cortical activation in the SMA of the affected and unaffected hemispheres was significantly increased after intensive rehabilitation. The increment of the postural-perturbation-related oxygenated hemoglobin signals in the SMA of the unaffected hemisphere was significantly correlated with the gain in balance function measured by the Berg Balance Scale. These findings support the conclusion that the SMA plays an important role in postural balance control, and suggest that the SMA is a crucial area for balance recovery after hemiplegic stroke.


Assuntos
Córtex Cerebral/fisiologia , Hemiplegia/reabilitação , Equilíbrio Postural/fisiologia , Recuperação de Função Fisiológica/fisiologia , Reabilitação do Acidente Vascular Cerebral , Adulto , Idoso , Fenômenos Biomecânicos , Estudos Transversais , Feminino , Lateralidade Funcional/fisiologia , Neuroimagem Funcional , Hemiplegia/etiologia , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Córtex Motor/fisiopatologia , Postura/fisiologia , Espectroscopia de Luz Próxima ao Infravermelho
8.
Stroke ; 44(4): 1091-8, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23404723

RESUMO

BACKGROUND AND PURPOSE: Despite the findings that motor imagery and execution are supposed to share common neural networks, previous studies using imagery-based rehabilitation have revealed inconsistent results. In the present study, we investigated whether feedback of cortical activities (neurofeedback) using near-infrared spectroscopy could enhance the efficacy of imagery-based rehabilitation in stroke patients. METHODS: Twenty hemiplegic patients with subcortical stroke received 6 sessions of mental practice with motor imagery of the distal upper limb in addition to standard rehabilitation. Subjects were randomly allocated to REAL and SHAM groups. In the REAL group, cortical hemoglobin signals detected by near-infrared spectroscopy were fed back during imagery. In the SHAM group, irrelevant randomized signals were fed back. Upper limb function was assessed using the finger and arm subscales of the Fugl-Meyer assessment and the Action Research Arm Test. RESULTS: The hand/finger subscale of the Fugl-Meyer assessment showed greater functional gain in the REAL group, with a significant interaction between time and group (F(2,36)=15.5; P<0.001). A significant effect of neurofeedback was revealed even in severely impaired subjects. Imagery-related cortical activation in the premotor area was significantly greater in the REAL group than in the SHAM group (T(58)=2.4; P<0.05). CONCLUSIONS: Our results suggest that near-infrared spectroscopy-mediated neurofeedback may enhance the efficacy of mental practice with motor imagery and augment motor recovery in poststroke patients with severe hemiparesis.


Assuntos
Imagens, Psicoterapia/métodos , Neurorretroalimentação/métodos , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Reabilitação do Acidente Vascular Cerebral , Adulto , Idoso , Braço/fisiopatologia , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Destreza Motora , Paresia/fisiopatologia , Projetos Piloto , Reprodutibilidade dos Testes , Acidente Vascular Cerebral/fisiopatologia , Resultado do Tratamento
9.
Rinsho Shinkeigaku ; 52(11): 1174-7, 2012.
Artigo em Japonês | MEDLINE | ID: mdl-23196554

RESUMO

Recent studies of functional neuroimaging and clinical neurophysiology have implied that functional recovery after stroke is associated with use-dependent plasticity of the damaged brain. However the property of the reorganized neural network depends on site and size of the lesion, which makes it difficult to assess what the adaptive plasticity is. From clinical point of view there is accumulating randomized controlled trials for the benefit of task-oriented rehabilitative intervention including constraint-induced movement therapy, robotics, and body-weight supported treadmill training. However dose-matched control intervention is usually as effective as a specific intervention. This raises a question regarding the specificity of a task-oriented intervention. Second question is whether such intervention goes beyond the biological destiny of human. Specifically there is no known strategy enhancing recovery of severely impaired hand. To augment functional gain, several methods of neuro-modulation may bring break-through on the assumption that they induce greater adaptive plasticity. Such neuro-modulative methods include neuropharmacological modulation, brain stimulation using transcranial magnetic stimulation and direct current stimulation, peripheral nerve stimulation, neurofeedback using real-time fMRI and real-time fNIRS, and brain-machine interface. A preliminary randomized controlled trial regarding real-time feedback of premotor activities revealed promising results for recovery of paretic hand in patients with stroke.


Assuntos
Encéfalo/fisiologia , Reabilitação do Acidente Vascular Cerebral , Humanos , Plasticidade Neuronal/fisiologia
10.
PLoS One ; 7(3): e32234, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22396753

RESUMO

Accumulating evidence indicates that motor imagery and motor execution share common neural networks. Accordingly, mental practices in the form of motor imagery have been implemented in rehabilitation regimes of stroke patients with favorable results. Because direct monitoring of motor imagery is difficult, feedback of cortical activities related to motor imagery (neurofeedback) could help to enhance efficacy of mental practice with motor imagery. To determine the feasibility and efficacy of a real-time neurofeedback system mediated by near-infrared spectroscopy (NIRS), two separate experiments were performed. Experiment 1 was used in five subjects to evaluate whether real-time cortical oxygenated hemoglobin signal feedback during a motor execution task correlated with reference hemoglobin signals computed off-line. Results demonstrated that the NIRS-mediated neurofeedback system reliably detected oxygenated hemoglobin signal changes in real-time. In Experiment 2, 21 subjects performed motor imagery of finger movements with feedback from relevant cortical signals and irrelevant sham signals. Real neurofeedback induced significantly greater activation of the contralateral premotor cortex and greater self-assessment scores for kinesthetic motor imagery compared with sham feedback. These findings suggested the feasibility and potential effectiveness of a NIRS-mediated real-time neurofeedback system on performance of kinesthetic motor imagery. However, these results warrant further clinical trials to determine whether this system could enhance the effects of mental practice in stroke patients.


Assuntos
Córtex Cerebral/fisiologia , Neurorretroalimentação/métodos , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Adulto , Feminino , Hemoglobinas/metabolismo , Humanos , Imagens, Psicoterapia/métodos , Imaginação/fisiologia , Masculino , Destreza Motora , Movimento/fisiologia , Oxigênio/química , Oxiemoglobinas/metabolismo , Desempenho Psicomotor/fisiologia , Acidente Vascular Cerebral/fisiopatologia
11.
Neuroreport ; 23(5): 314-9, 2012 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-22357394

RESUMO

Despite its remarkable effect on the activities of daily living, the precise mechanism underlying balance control after stroke remains to be elucidated. In this study, we investigated the cortical activation induced by postural perturbation in 20 patients with stroke using a 50-channel event-related functional near-infrared spectroscopy. A combination of brisk forward and backward movements of a platform without any prior cue was used as an external postural perturbation. Multi-participant analysis of oxygenated hemoglobin signals showed postural perturbation-related cortical activation in the prefrontal cortical areas in both hemispheres as well as the premotor and parietal association cortical areas in the unaffected hemisphere. Regression analysis using the individual Berg Balance Scale as the regressor showed a significant positive correlation between balance ability and the postural perturbation-related changes in oxygenated hemoglobin signals in the supplementary motor areas and prefrontal cortical areas in both hemispheres. Consistent with the previous findings in healthy participants, these findings suggest that the broad cortical network, including the prefrontal, premotor, supplementary motor, and parietal cortical areas in both hemispheres, was essential for balance control even in poststroke patients.


Assuntos
Lobo Frontal/fisiologia , Hemiplegia/fisiopatologia , Lobo Parietal/fisiologia , Equilíbrio Postural/fisiologia , Córtex Pré-Frontal/fisiologia , Acidente Vascular Cerebral/fisiopatologia , Idoso , Sinais (Psicologia) , Feminino , Neuroimagem Funcional , Humanos , Masculino , Pessoa de Meia-Idade , Espectroscopia de Luz Próxima ao Infravermelho
12.
Neurorehabil Neural Repair ; 26(3): 293-300, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-21959676

RESUMO

BACKGROUND: Motor learning is essential to gain skills with neurorehabilitation. OBJECTIVE: To investigate whether capacity for motor learning affects rehabilitation outcome and its relevant brain activation in ataxic patients with stroke. METHODS: Twelve patients presenting with ataxia admitted for inpatient rehabilitation 2 to 3 months after infratentorial stroke and 6 control subjects performed 8 repetitions of 30-second pursuit rotor (PR) task. Cortical oxygenated hemoglobin (oxyHb) signals were measured using functional near-infrared spectroscopy. RESULTS: Both patients and controls learned the PR skill, although the gains in PR performance were significantly lower in patients. In patients, the less learning significantly correlated with smaller rehabilitation gains assessed by the Functional Independence Measure. The Fugl-Meyer score for coordination and balance did not change. Center of task-related increase of cortical oxyHb signals shifted from the presupplementary motor area (preSMA) to the supplementary motor area (SMA) with task repetitions in controls but not in patients. Accordingly, serial changes of ratio of oxyHb increase in the preSMA to SMA (preSMA/SMA ratio) were significantly different between the groups. In patients and controls, gains in PR performance and changes of the preSMA/SMA ratio correlated. CONCLUSIONS: Impaired motor sequence learning by the PR task was correlated with reduced rehabilitation gains for ataxic patients with stroke.


Assuntos
Ataxia/reabilitação , Aprendizagem/fisiologia , Destreza Motora/fisiologia , Recuperação de Função Fisiológica/fisiologia , Análise de Variância , Ataxia/etiologia , Ataxia/patologia , Encéfalo/metabolismo , Encéfalo/patologia , Mapeamento Encefálico , Terapia por Exercício/métodos , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Terapia Ocupacional/métodos , Oxiemoglobinas/metabolismo , Espectroscopia de Luz Próxima ao Infravermelho , Acidente Vascular Cerebral/complicações , Resultado do Tratamento
13.
Neurorehabil Neural Repair ; 26(5): 515-22, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22140200

RESUMO

OBJECTIVE: To investigate short- and long-term effects of intensive rehabilitation on ataxia, gait, and activities of daily living (ADLs) in patients with degenerative cerebellar disease. METHODS: A total of 42 patients with pure cerebellar degeneration were randomly assigned to the immediate group or the delayed-entry control group. The immediate group received 2 hours of inpatient physical and occupational therapy, focusing on coordination, balance, and ADLs, on weekdays and 1 hour on weekends for 4 weeks. The control group received the same intervention after a 4-week delay. Short-term outcome was compared between the immediate and control groups. Long-term evaluation was done in both groups at 4, 12, and 24 weeks after the intervention. Outcome measures included the assessment and rating of ataxia, Functional Independence Measure, gait speed, cadence, functional ambulation category, and number of falls. RESULTS: The immediate group showed significantly greater functional gains in ataxia, gait speed, and ADLs than the control group. Improvement of truncal ataxia was more prominent than limb ataxia. The gains in ataxia and gait were sustained at 12 weeks and 24 weeks, respectively. At least 1 measure was better than at baseline at 24 weeks in 22 patients. CONCLUSIONS: Short-term benefit of intensive rehabilitation was evident in patients with degenerative cerebellar diseases. Although functional status tended to decline to the baseline level within 24 weeks, gains were maintained in more than half of the participants.


Assuntos
Ataxia Cerebelar/etiologia , Ataxia Cerebelar/reabilitação , Terapia por Exercício/métodos , Doenças Neurodegenerativas/complicações , Modalidades de Fisioterapia , Atividades Cotidianas , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Neurodegenerativas/reabilitação , Curva ROC , Estatísticas não Paramétricas , Fatores de Tempo , Resultado do Tratamento
14.
Brain Nerve ; 62(2): 125-32, 2010 Feb.
Artigo em Japonês | MEDLINE | ID: mdl-20192032

RESUMO

Functional near-infrared spectroscopy (fNIRS) is an effective tool to non-invasively investigate cerebral oxygenation and hemodynamics. fNIRS as well as other functional neuroimaging techniques including functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) have been used for investigating the neural mechanisms of functional recovery after a stroke or a traumatic brain injury. fNIRS has several advantages over other neuroimaging techniques in terms of clinical application in the field of rehabilitation medicine. In addition to its portability and low equipment cost, fNIRS does not require strict motion restriction during measurement, unlike other functional imaging techniques. Therefore, this technique enables the examination of cortical activation during physically dynamic activities, like gait or balance perturbation. Studies using fNIRS have revealed several implications for gait recovery after stroke. These studies have shown that the medial sensorimotor cortex (SMC) and the supplementary motor area (SMA) are mainly involved in steadying gait and that the prefrontal cortex (PFC) is involved in the adjustment of walking speed. In hemiparetic patients, lateralization of SMC activation during gait is reduced, and additional cortical activations in the premotor cortex and PFC during gait became evident after focused rehabilitation for several months. The cortical activation pattern may be modified after different types of rehabilitative interventions. These results imply that fNIRS data is a potential biomarker for functional recovery and the response to rehabilitative interventions. Although further studies are required, fNIRS might provide useful information for customizing rehabilitation programs in order to enhance functional recovery.


Assuntos
Encéfalo/fisiologia , Marcha/fisiologia , Postura/fisiologia , Espectroscopia de Infravermelho com Transformada de Fourier , Braço/fisiologia , Lesões Encefálicas/reabilitação , Humanos , Reabilitação do Acidente Vascular Cerebral
15.
Neuroimage ; 43(2): 329-36, 2008 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-18718542

RESUMO

Although recent studies have demonstrated cortical involvement in human balance control, there is insufficient information regarding the regions of the cerebral cortex that contribute to human balance control and their mechanism of action. Using a functional near-infrared spectroscopic system, we investigated perturbation-related cortical activation. External perturbations were provided with and without the preceding auditory warning signals 2 s before the perturbation. Statistical analysis by applying the general linear model showed significant activation in the prefrontal cortex, including the dorsolateral prefrontal cortex and frontal eye field after external perturbation, regardless of the preceding auditory warning signals. A time-line analysis revealed similar temporal profiles for prefrontal activation in 2 different conditions. Based on the contrast between the 2 conditions, we detected enhanced activation in the right posterior parietal cortex and supplementary motor area in the condition where the auditory warning signals were provided. We presumed that prefrontal involvement may be relevant to adequate allocation of visuospatial attention. Our results may facilitate the understanding of cortical mechanisms for balance control in humans and the underlying pathophysiology of falls.


Assuntos
Mapeamento Encefálico/métodos , Sinais (Psicologia) , Movimento/fisiologia , Equilíbrio Postural/fisiologia , Postura/fisiologia , Córtex Pré-Frontal/fisiologia , Espectrofotometria Infravermelho/métodos , Adulto , Retroalimentação/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
16.
Neuroimage ; 37(4): 1338-45, 2007 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-17683949

RESUMO

There is accumulated evidence that cortical reorganization plays an important role in motor recovery after supratentorial stroke. However neural mechanisms underlying functional recovery of ataxia after infratentorial stroke remain unclear. We investigated cortical activations during ataxic gait in patients with infratentorial stroke to test the hypothesis that cerebral cortices were involved in compensatory mechanisms for ataxic gait. Twelve patients with infratentorial stroke (mean duration+/-S.D. from the onset: 88.3+/-44.8 days) and 11 age-matched healthy subjects participated in this study. All patients had predominant ataxia without severe hemiparesis. We measured cortical activation as assessed by task-related increase of oxygenated hemoglobin during gait on a treadmill using functional near-infrared spectroscopy. Task consisted of three repetitions of gait period alternated with rest period. In controls, cortical activations in the lateral and medial prefrontal cortex during the acceleration phase tended to be attenuated during the steady phase of the gait period while these activations were sustained throughout the gait period in ataxic patients. Repeated measures ANOVA for cortical activation revealed significant interactions (p<0.005) between phase (acceleration/steady) and group (control/stroke) in the medial and lateral prefrontal regions. These results suggest that sustained prefrontal activation during ataxic gait might be relevant to compensatory mechanisms for ataxic gait after infratentorial stroke.


Assuntos
Marcha Atáxica/fisiopatologia , Marcha/fisiologia , Córtex Pré-Frontal/fisiopatologia , Adolescente , Idoso , Análise de Variância , Criança , Feminino , Marcha Atáxica/etiologia , Humanos , Locomoção/fisiologia , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Oxigênio/sangue , Espectroscopia de Luz Próxima ao Infravermelho , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/fisiopatologia
17.
Cerebrovasc Dis ; 24(4): 369-74, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17690550

RESUMO

BACKGROUND: Inferior olivary hypertrophy (IOH) may develop after pontine hemorrhage and may become a pacemaker for symptomatic palatal tremor (SPT). However, there is no information available that elucidates how IOH may affect the functional outcome. The purpose of this study was to investigate how frequently IOH was associated with clinical manifestations of involuntary movements, including ocular myoclonus (OM) and SPT, and whether IOH influenced the functional outcome after pontine hemorrhage. METHODS: In 20 consecutive patients undergoing inpatient multidisciplinary rehabilitation after pontine hemorrhage, the location of lesions (tegmental vs. ventral) and the presence of IOH were examined by magnetic resonance imaging, and the functional outcome was assessed by means of Fugl-Meyer scale for neurological impairment and Functional Independence Measure for disability on admission and discharge. RESULTS: In 10 patients, IOH was detected, and the tegmentum was involved in 7 of the 10 patients. OM or SPT was present in 7 of these 10 patients. In the remaining 10 patients, IOH was not detected, and the tegmentum was involved only in 2 of these 10 patients. None of them had OM or SPT. The presence of IOH was associated with a lower functional status on admission and discharge. CONCLUSION: After pontine hemorrhage, IOH may be associated with tegmental lesions with OM or SPT and may impose a detrimental effect on the functional outcome.


Assuntos
Hemorragias Intracranianas/patologia , Mioclonia/etiologia , Núcleo Olivar/patologia , Ponte/irrigação sanguínea , Tegmento Mesencefálico/patologia , Tremor/etiologia , Adulto , Feminino , Humanos , Hipertrofia , Hemorragias Intracranianas/complicações , Hemorragias Intracranianas/fisiopatologia , Hemorragias Intracranianas/reabilitação , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Mioclonia/patologia , Mioclonia/fisiopatologia , Mioclonia/reabilitação , Núcleo Olivar/fisiopatologia , Recuperação de Função Fisiológica , Índice de Gravidade de Doença , Tegmento Mesencefálico/fisiopatologia , Fatores de Tempo , Resultado do Tratamento , Tremor/patologia , Tremor/fisiopatologia , Tremor/reabilitação
18.
Neurology ; 69(4): 348-55, 2007 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-17646626

RESUMO

OBJECTIVE: To characterize the physiologic and neuroanatomical features and functional outcome of proximal dominant paresis of the upper extremity (UE) in poststroke patients. METHODS: The authors studied 34 hemiparetic patients after the first subcortical stroke (mean age 65 years; males/females = 21/13; mean 45 days after stroke; right/left hemiparesis = 20/14). They were divided into proximal and distal paresis groups according to the distribution of UE paresis. Transcranial magnetic stimulation (TMS) was used to assess residual function of the descending pathways to the UE muscles. The location and size of lesions were assessed by MRI. RESULTS: The lesion density maps revealed damages in the posterior putamen, posterior limb of the internal capsule, and posterior half of the corona radiata in the distal group (n = 19), whereas lesions in the proximal group (n = 15) uniformly encompassed the middle part of the corona radiata, usually sparing the posterior half of the posterior limb of the internal capsule. TMS indicated that the descending pathways to proximal muscles were disrupted in patients with proximal UE paresis, whereas innervation to distal muscles was spared. Functional outcome of the affected UE after inpatient rehabilitation was better in the proximal group. It depended on the initial severity of UE paresis, but not on TMS findings, age, or the size of the lesions. CONCLUSION: Although the distribution of upper extremity (UE) paresis was associated with distinct MRI and transcranial magnetic stimulation (TMS) findings, the clinical examination of UE paresis was more sensitive than MRI or TMS findings in predicting functional outcome of the paretic UE.


Assuntos
Braço/fisiopatologia , Músculo Esquelético/fisiopatologia , Paresia/etiologia , Paresia/fisiopatologia , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/fisiopatologia , Idoso , Braço/inervação , Mapeamento Encefálico , Dominância Cerebral , Vias Eferentes/patologia , Vias Eferentes/fisiopatologia , Eletromiografia , Potencial Evocado Motor , Humanos , Lactente , Cápsula Interna/patologia , Cápsula Interna/fisiopatologia , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Córtex Motor/patologia , Córtex Motor/fisiopatologia , Músculo Esquelético/inervação , Paresia/patologia , Valor Preditivo dos Testes , Prognóstico , Tratos Piramidais/patologia , Tratos Piramidais/fisiopatologia , Acidente Vascular Cerebral/patologia , Estimulação Magnética Transcraniana
19.
Neuroimage ; 34(1): 109-16, 2007 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-17067821

RESUMO

To investigate cerebral mechanisms underlying learning of motor skill, we assessed serial changes of cortical activation patterns during a pursuit rotor (PR) task in 18 right-handed, healthy subjects using a functional near-infrared spectroscopy (fNIRS) system. Subjects performed the task with the right hand for 30 s alternated with 30-s rest for 8 repetitions (cycle1 to 8). Gains in motor skill were evaluated by time for keeping the stylus on the target (max 30 s), surface EMG patterns and trajectories of the arm. Performance improved with repetitions of the task cycles (12.9/17.1/19.3/20.0/21.1/22.2/23.6/23.9 s on average) and reached plateau at the 7th cycle. Reciprocal EMG patterns and steady trajectories were associated with acquisition of the motor skill. Task-related increases of oxygenated hemoglobin (oxyHb) were observed in the channels covering the sensorimotor cortex (SMC), premotor and prefrontal regions. There were also task-related decreases of deoxygenated hemoglobin (deoxyHb) in these areas although the changes were smaller compared with those of oxyHb. The center of task-related increases of oxyHb was initially located in the presupplementary motor area (preSMA) and shifted caudally to the supplementary motor area (SMA) with cycle repetitions. The ratios of oxyHb changes in preSMA to SMA significantly decreased with task repetitions. DeoxyHb changes confirmed the activation patterns. These data suggest that preSMA plays an important role in the early phase of motor learning while the SMA might be more involved in the late learning phase of the motor skill.


Assuntos
Lobo Frontal/fisiologia , Aprendizagem/fisiologia , Destreza Motora/fisiologia , Espectroscopia de Luz Próxima ao Infravermelho , Adulto , Idoso , Humanos , Pessoa de Meia-Idade
20.
Arch Phys Med Rehabil ; 87(4): 529-35, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16571393

RESUMO

OBJECTIVE: To assess benefit of the facilitation technique (FT) coupled with body weight-supported treadmill training (BWSTT) in nonambulatory patients with stroke. DESIGN: Randomized controlled trial. SETTING: Inpatient rehabilitation hospital. PARTICIPANTS: Forty-nine patients with nonambulatory patients with stroke were randomly allocated to BWSTT coupled with the FT or mechanical assistance (control). INTERVENTIONS: Swinging and stance of the paretic leg were assisted using the FT or mechanically (control) during BWSTT. MAIN OUTCOME MEASURES: The FIM instrument, Fugl-Meyer Assessment, gait speed, and cadence. RESULTS: Demographic and clinical features of the FT (n=22) and control (n=25) groups on admission were comparable after excluding 2 dropouts. There were no differences in the gains of the main outcome measures between the FT and control groups. Patients with severe impairment in the FT group had greater gains in arm function than those in the control group. CONCLUSIONS: The FT did not add significantly to locomotor outcome of BWSTT in nonambulatory patients with stroke but it did require more therapists' assistance.


Assuntos
Transtornos Neurológicos da Marcha/reabilitação , Hemiplegia/reabilitação , Modalidades de Fisioterapia , Reabilitação do Acidente Vascular Cerebral , Análise de Variância , Distribuição de Qui-Quadrado , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Resultado do Tratamento
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