Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Resultados 1 - 20 de 92
Filtrar
1.
Med Sci Monit ; 30: e943802, 2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38741355

RESUMEN

BACKGROUND The thalamocortical tract (TCT) links nerve fibers between the thalamus and cerebral cortex, relaying motor/sensory information. The default mode network (DMN) comprises bilateral, symmetrical, isolated cortical regions of the lateral and medial parietal and temporal brain cortex. The Coma Recovery Scale-Revised (CRS-R) is a standardized neurobehavioral assessment of disorders of consciousness (DOC). In the present study, 31 patients with hypoxic-ischemic brain injury (HI-BI) were compared for changes in the TCT and DMN with consciousness levels assessed using the CRS-R. MATERIAL AND METHODS In this retrospective study, 31 consecutive patients with HI-BI (17 DOC,14 non-DOC) and 17 age- and sex-matched normal control subjects were recruited. Magnetic resonance imaging was used to diagnose HI-BI, and the CRS-R was used to evaluate consciousness levels at the time of diffusion tensor imaging (DTI). The fractional anisotropy (FA) values and tract volumes (TV) of the TCT and DMN were compared. RESULTS In patients with DOC, the FA values and TV of both the TCT and DMN were significantly lower compared to those of patients without DOC and the control subjects (p<0.05). When comparing the non-DOC and control groups, the TV of the TCT and DMN were significantly lower in the non-DOC group (p<0.05). Moreover, the CRS-R score had strong positive correlations with the TV of the TCT (r=0.501, p<0.05), FA of the DMN (r=0.532, p<0.05), and TV of the DMN (r=0.501, p<0.05) in the DOC group. CONCLUSIONS This study suggests that both the TCT and DMN exhibit strong correlations with consciousness levels in DOC patients with HI-BI.


Asunto(s)
Corteza Cerebral , Coma , Estado de Conciencia , Imagen de Difusión Tensora , Hipoxia-Isquemia Encefálica , Tálamo , Humanos , Femenino , Masculino , Persona de Mediana Edad , Tálamo/fisiopatología , Tálamo/diagnóstico por imagen , Hipoxia-Isquemia Encefálica/fisiopatología , Hipoxia-Isquemia Encefálica/diagnóstico por imagen , Adulto , Estado de Conciencia/fisiología , Imagen de Difusión Tensora/métodos , Corteza Cerebral/fisiopatología , Corteza Cerebral/diagnóstico por imagen , Estudios Retrospectivos , Coma/fisiopatología , Coma/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Red en Modo Predeterminado/fisiopatología , Red en Modo Predeterminado/diagnóstico por imagen , Trastornos de la Conciencia/fisiopatología , Trastornos de la Conciencia/diagnóstico por imagen , Anciano
2.
BMC Neurosci ; 23(1): 17, 2022 03 22.
Artículo en Inglés | MEDLINE | ID: mdl-35317746

RESUMEN

OBJECTIVE: Cerebellar injury can not only cause gait and postural instability, nystagmus, and vertigo but also affect the vestibular system. However, changes in connectivity regarding the vestibular projection pathway after cerebellar injury have not yet been reported. Therefore, in the current study, we investigated differences in the connectivity of the vestibular projection pathway after cerebellar injury using diffusion tensor imaging (DTI) tractography. METHODS: We recruited four stroke patients with cerebellar injury. Neural connectivity in the vestibular nucleus (VN) of the pons and medulla oblongata in patients with cerebellar injury was measured using DTI. Connectivity was defined as the incidence of connection between the VN on the pons and medulla oblongata and target brain regions such as the cerebellum, thalamus, parieto-insular vestibular cortex (PIVC), and parietal lobe. RESULTS: At thresholds of 10 and 30, there was lower connectivity in the ipsilateral hemisphere between the VN at the medullar level and thalamus in the patients than in healthy adults. At a threshold of 1 and 10, the patient group showed lower VN connectivity with the PIVC than healthy adults. At a threshold of 1, VN connectivity with the parietal lobe in the contralateral hemisphere was lower in the patients than in healthy adults. Additionally, at a threshold of 30, VN connectivity at the pons level with the cerebellum was lower in healthy adults than in the patients. CONCLUSION: Cerebellar injury seems to be associated with decreased vestibular projection pathway connectivity, especially in the ipsilateral thalamus, PIVC, and contralateral parietal lobe.


Asunto(s)
Imagen de Difusión Tensora , Lóbulo Parietal , Adulto , Encéfalo , Mapeo Encefálico , Cerebelo/diagnóstico por imagen , Imagen de Difusión Tensora/métodos , Humanos
3.
Sensors (Basel) ; 20(5)2020 Feb 29.
Artículo en Inglés | MEDLINE | ID: mdl-32121456

RESUMEN

Inertial measurement unit systems are wearable sensors that can measure the movement of a human in real-time with relatively little space and high portability. The purpose of this study was to investigate the accuracy of the inertial measurement unit (IMU) system for gait analysis by comparing it with measurements obtained using an optical motion capture (OMC) system. To compare the accuracies of these two different motion capture systems, the Spatio-temporal and kinematic parameters were measured in young adults during normal walking. Thirty healthy participants participated in the study. Data were collected while walking 5 strides on a 7 m walkway at a self-selected speed. Results of gait analysis showed that the Spatio-temporal (stride time, stride length, cadence, step length) and kinematic (knee joint peak to peak of movement) parameters were not significantly different in the participant. Spatio-temporal and kinematic parameters of the two systems were compared using the Bland-Altman method. The results obtained showed that the measurements of Spatio-temporal and kinematic parameters of gait by the two systems were similar, which suggested that IMU and OMC systems could be used interchangeably for gait measurements. Therefore, gait analysis performed using the wearable IMU system might efficiently provide gait measurements and enable accurate analysis.


Asunto(s)
Marcha/fisiología , Articulación de la Rodilla/fisiología , Adulto , Fenómenos Biomecánicos , Femenino , Humanos , Masculino , Análisis Espacio-Temporal , Adulto Joven
4.
J Stroke Cerebrovasc Dis ; 29(11): 105252, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-33066903

RESUMEN

BACKGROUND: Unilateral lesions of vestibular nucleus can cause lateral medullary syndrome. Little is known about injury of medial and lateral vestibulospinal tract (VST) after dorsolateral medullary infarct. We investigated injury of the lateral VST in patients with typical central vestibular disorder using diffusion tensor tractography (DTT). METHODS: Seven patients with lateral medullary syndrome and ten control subjects were recruited. For the medial VST, we determined seed region of interest (ROI) as medial vestibular nuclei of pons and target ROI on posteromedial medulla. For the lateral VST, the seed ROI was placed on lateral vestibular nuclei of pons, and the target ROI on posterolateral medulla. Fractional anisotropy (FA), mean diffusivity (MD), and tract volume were measured. RESULT: Reconstructed lateral VST on both sides had significantly lower FA values in patients than controls (p<0.05). Tract volume of lateral VST in affected side was significantly lower than unaffected side and control group (p<0.05). However, no DTI parameters of the medial VST differed between patients and controls (p>0.05). CONCLUSION: Injury of the lateral VST was demonstrated in patients with lateral vestibular syndrome following dorsolateral medullary infarct. Analysis of the lateral VST using DTT would be helpful in evaluation of patients with lateral medullary syndrome.


Asunto(s)
Imagen de Difusión Tensora , Síndrome Medular Lateral/diagnóstico por imagen , Tractos Piramidales/diagnóstico por imagen , Núcleos Vestibulares/diagnóstico por imagen , Adulto , Anciano , Femenino , Humanos , Síndrome Medular Lateral/fisiopatología , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Pronóstico , Tractos Piramidales/fisiopatología , Estudios Retrospectivos , Núcleos Vestibulares/fisiopatología
5.
J Stroke Cerebrovasc Dis ; 29(7): 104857, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-32409256

RESUMEN

BACKGROUND AND PURPOSE: Gait disturbance due to injuries of the descending motor pathway, including corticospinal tract (CST), corticoreticular pathway (CRP), and medial and lateral vestibulospinal tracts (VSTs), are commonly encountered disabling sequelae of pontine hemorrhage. We investigated relations between changes in the CST, CRP, and medial and lateral VST and corresponding changes in gait function in patients with pontine hemorrhage. METHOD: Nine consecutive stroke patients with pontine hemorrhage, and 6 age-matched normal subjects were recruited. Four patients were allocated to group A (can't walk independently) and 5 to group B (can walk independently). Diffusion tensor imaging (DTI) data were acquired twice at acute to subacute stage and chronic stage after stroke onset. Diffusion tensor tractography (DTT) was used to reconstruct CST, CRP, medial and lateral VST. RESULT: The CRP shows a significantly different between groups A and B in both initial and follow up DTT (p > 0.05). In contrast, CST, medial VST and lateral VST did not show a significant difference (p > 0.05). Regarding DTI parameters of CRPs in group A, percentages of patients with fractional anisotropy (FA) and mean diffusivity (MD) values more than two standard deviation from normal were higher by follow up DTI than by initial DTI, however, the CRPs in group B only showed increased abnormal range of MD. CONCLUSIONS: The CST does not play an essential role in recovery of independent walking and vestibulospinal tracts may not crucially affect recovery of independent walking in patients with pontine hemorrhage. In contrast, and intact CRP or changes of the CRP integrity appear to be related to the recovery of gait function.


Asunto(s)
Deambulación Dependiente , Vías Eferentes/fisiopatología , Marcha , Hemorragias Intracraneales/fisiopatología , Limitación de la Movilidad , Puente/irrigación sanguínea , Adulto , Anciano , Estudios de Casos y Controles , Imagen de Difusión Tensora , Vías Eferentes/diagnóstico por imagen , Femenino , Humanos , Hemorragias Intracraneales/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Tractos Piramidales/diagnóstico por imagen , Tractos Piramidales/fisiopatología , Recuperación de la Función , Formación Reticular/diagnóstico por imagen , Formación Reticular/fisiopatología , Núcleo Vestibular Lateral/diagnóstico por imagen , Núcleo Vestibular Lateral/fisiopatología
6.
Int J Sports Med ; 39(12): 924-928, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30206918

RESUMEN

Wheelchair skills training can improve independent wheeled mobility for daily living activities as well as functional and social participation of adults with cervical spinal cord injury (C-SCI). The objective of this study was to examine the effectiveness of wheelchair skills training in improving both wheelchair skills and upper arm skilled performance in adults with C-SCI. In a randomized controlled study, 24 adults with tetraplegia were randomized and allocated to training group (n=13) or control group (n=11). The training group attended wheelchair skills training sessions, whereas the control group attended conventional exercise sessions. All interventions lasted 8 weeks, with a frequency of 3 days per week. All individuals were tested with the Wheelchair Skills Test (WST) and the Van Lieshout Test (VLT). The test was repeated at pre- and post-training (after 4 weeks and 8 weeks). For WST, univariate analysis demonstrated significant main effects in between-group, within-group, and group-by-time interaction (p<0.05). VLT showed no significant effect in between-group comparison (p>0.05), whereas within-group comparison of test times and group-by-time interaction showed significant main effects (p<0.05). Thus, wheelchair skills training is more beneficial for adults with C-SCI than conventional exercise.


Asunto(s)
Actividades Cotidianas , Destreza Motora , Acondicionamiento Físico Humano , Traumatismos de la Médula Espinal/terapia , Silla de Ruedas , Adulto , Femenino , Humanos , Masculino , Traumatismos de la Médula Espinal/fisiopatología
7.
J Stroke Cerebrovasc Dis ; 27(6): e98-e101, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29395645

RESUMEN

OBJECTIVES: We investigated injury of the pre- or postcommissural fornix in a patient with subarachnoid hemorrhage (SAH) using diffusion tensor imaging. CASE DESCRIPTION: A 48-year-old male patient was diagnosed as SAH due to rupture of the right middle cerebral artery bifurcation aneurysm. After 9 weeks from onset, he was transferred to the rehabilitation department and he showed memory impairment. The whole fornix was reconstructed using single-tract fornix model based on a fiber assignment by continuous tracking, and separated fornices (pre- and postcommissural fornices) were reconstructed using 2-tract fornix model based on a probabilistic tractography method. The fractional anisotropy (FA), mean diffusivity, and fiber volume were measured in the patient and 6 normal control subjects. The integrities of both reconstructed whole fornices that were reconstructed using probabilistic tractography method were preserved. By contrast, in the results of 2-tract fornix model, the precommissural fornices showed discontinuations in both fornical cruses. In addition, the FA and fiber volume of both precommissural fornices in the patient were decreased by more than 2 standard deviations of those of normal control subjects. CONCLUSIONS: Separate evaluations of the pre- and postcommissural fornices using 2-tract fornix model would be useful for diagnosis in patients with memory impairment following SAH.


Asunto(s)
Fórnix/diagnóstico por imagen , Fórnix/lesiones , Trastornos de la Memoria/diagnóstico por imagen , Trastornos de la Memoria/etiología , Hemorragia Subaracnoidea/complicaciones , Hemorragia Subaracnoidea/diagnóstico por imagen , Adulto , Diagnóstico Diferencial , Imagen de Difusión Tensora , Femenino , Humanos , Masculino , Persona de Mediana Edad , Hemorragia Subaracnoidea/rehabilitación
8.
Neuroradiology ; 59(4): 397-401, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28303377

RESUMEN

PURPOSE: The precommissural fornix and postcommissural fornix have different connections to the basal forebrain and septal region, and mammillary body, respectively. However, little is known about the differences of the precommissural fornix and postcommissural fornix in the hippocampal location. In this study, using diffusion tensor tractography, we investigated the differences of the precommissural fornix and postcommissural fornix in the hippocampal location. METHODS: We recruited 25 healthy volunteers for this study. For reconstruction of the precommissural fornix and postcommissural fornix, we placed the seed region of interest on the septal nucleus, and the mammillary body, respectively. The target regions of interest (ROI) was given on the crus of the fornix on the coronal image. Evaluations of the anatomical location of the precommissural fornix and postcommissural fornix were performed using the highest probabilistic location in the hippocampal formation. RESULTS: The precommissural fornix and postcommissural fornix were located at an average of 83.9 and 87.5% between the lateral margin of the red nucleus and collateral sulcus on the axial plane, and 77.2 and 81.4% between the lateral margin of the midbrain and the inferior longitudinal fasciculus on the coronal plane. Significant differences of location in the medio-lateral direction were observed in the axial and coronal plane (p < 0.05). However, no significant differences of location in the antero-posterior direction were observed between precommissrual and postcommissural fornix (p > 0.05). CONCLUSIONS: The reconstructed precommissural fornix and postcommissural fornix were connected to the cornu ammonis 1(CA1) of the hippocampus, and the precommissural fornix was located more laterally to the postcommissural fornix in the CA1.


Asunto(s)
Imagen de Difusión Tensora/métodos , Fórnix/anatomía & histología , Hipocampo/anatomía & histología , Adulto , Femenino , Voluntarios Sanos , Humanos , Masculino , Persona de Mediana Edad
9.
Somatosens Mot Res ; 33(1): 1-7, 2016 03.
Artículo en Inglés | MEDLINE | ID: mdl-26891746

RESUMEN

We investigated changes of the corticospinal tract (CST) in the unaffected hemisphere according to severity of the CST injury, using diffusion tensor imaging (DTI). According to the severity of the CST injury in the affected hemisphere, the stroke patients showed different aspects of fiber volume increment of the CST in the unaffected hemisphere; the fiber volume was increased in the early phase in patients with mild injury of CST and later phase in patients with severe injury of CST.


Asunto(s)
Imagen de Difusión Tensora , Lateralidad Funcional/fisiología , Tractos Piramidales/diagnóstico por imagen , Accidente Cerebrovascular/diagnóstico por imagen , Accidente Cerebrovascular/fisiopatología , Adulto , Anciano , Estudios de Casos y Controles , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Persona de Mediana Edad , Estadísticas no Paramétricas
10.
BMC Neurol ; 14: 108, 2014 May 19.
Artículo en Inglés | MEDLINE | ID: mdl-24886278

RESUMEN

BACKGROUND: Several studies have reported on injury of the corticoreticular pathway (CRP), however, little is known about the mechanism for recovery of an injured CRP. We report on a patient with intracerebral hemorrhage (ICH) who showed recovery of an injured CRP via transcallosal fibers, which was demonstrated by diffusion tensor tractography (DTT). CASE PRESENTATION: A 67-year-old man presented with complete paralysis (Medical Research Council: 0/5) of the left extremities at the onset of a right putaminal hemorrhage. At six weeks after onset, he presented with more severe weakness of proximal joint muscles than distal joint muscles (right shoulder abductor; 2-, finger extensor; 3+, hip flexor; 2+, ankle dorsiflexor; 3). Although his right hemiplegia had recovered well, he consistently showed more severe proximal weakness (right shoulder abductor; 3, finger extensor; 4, hip flexor; 3+, ankle dorsiflexor; 4) until 16 weeks after onset. On both six- and 16-week DTTs, in the left (affected) hemisphere, the CRP showed severe narrowing with discontinuation of the anterior fibers at the corona radiata on six-week DTT, however, the discontinued anterior fibers of the CRP were connected to the right cerebral cortex via transcallosal fibers on 16-week DTT. CONCLUSION: We demonstrated recovery of an injured CRP via transcallosal fibers in a patient with ICH. We believe that this might be a mechanism for recovery of an injured CRP.


Asunto(s)
Corteza Cerebral/lesiones , Hemorragia Cerebral/patología , Cuerpo Calloso/lesiones , Vías Nerviosas/lesiones , Formación Reticular/lesiones , Anciano , Corteza Cerebral/patología , Hemorragia Cerebral/terapia , Cuerpo Calloso/patología , Imagen de Difusión Tensora , Humanos , Masculino , Fibras Nerviosas/patología , Vías Nerviosas/patología , Recuperación de la Función , Formación Reticular/patología , Estimulación Magnética Transcraneal , Resultado del Tratamiento
11.
Neuroradiology ; 56(11): 965-70, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25119256

RESUMEN

INTRODUCTION: Many studies have reported on vulnerable areas and neural tracts of the brain after hypoxic-ischemic brain injury (HI-BI). However, little is known about injury of the ascending reticular activating system (ARAS). We attempted to investigate on injury of the lower portion of the ARAS in patients with HI-BI using diffusion tensor tractography (DTT). METHODS: Fourteen consecutive patients with HI-BI and 10 control subjects were recruited for this study. We classified the patients into two subgroups according to the preservation of arousal: subgroup A (eight patients)-intact arousal and subgroup B (six patients)-impaired arousal. The lower portion of the ARAS between the pontine reticular formation and the thalamus was reconstructed using the probabilistic tractography method. Fractional anisotropy (FA), mean diffusivity (MD), and tract volume (TV) were measured. RESULTS: The FA value and TV were decreased in subgroup B compared with those of the control group, although no difference was observed in the MD value (p < 0.05). However, for all DTT parameters, no difference was observed between subgroup A and the control group and between subgroup A and subgroup B (p > 0.05). CONCLUSION: Injury of the lower portion of the ARAS was found between the pontine reticular formation and the thalamus in patients with impaired arousal after HI-BI. We believe that analysis using DTT could be helpful in the evaluation of patients with impaired arousal after HI-BI.


Asunto(s)
Imagen de Difusión Tensora , Hipoxia-Isquemia Encefálica/patología , Tegmento Pontino/patología , Tálamo/patología , Adolescente , Adulto , Anciano , Anisotropía , Nivel de Alerta , Estudios de Casos y Controles , Femenino , Escala de Coma de Glasgow , Humanos , Hipoxia-Isquemia Encefálica/etiología , Masculino , Persona de Mediana Edad , Adulto Joven
12.
J Neuroeng Rehabil ; 11: 29, 2014 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-24597550

RESUMEN

OBJECTIVES: Neuromuscular electrical stimulation (NMES) has been used in the field of rehabilitation for a long time. Previous studies on NMES have focused on the peripheral effect, in contrast, relatively little is known about the effect on the cerebral cortex. In the current study, we attempted to investigate the change of cortical activation pattern induced by NMES during execution of hand movements in normal subjects, using functional near infrared spectroscopy (fNIRS). METHODS: Twelve healthy normal subjects were randomly assigned to the NMES group (six subjects) and the sham group (six subjects). We measured oxy-hemoglobin (HbO) in six regions of interest (ROI) during pre-NMES and post-NMES motor phase; the left dorsolateral and ventrolateral prefrontal cortex, premotor cortex, primary sensory-motor cortex (SM1), hand somatotopic area of SM1, and posterior parietal cortex. Between the pre-NMES and the post-NMES motor phases, real or sham NMES was applied on finger and wrist extensors of all subjects during a period of 5 minutes. RESULTS: In all groups, during the pre-NMES motor phase, the HbO value in the hand somatotopic area of the left SM1 was higher than those of other ROIs. In the NMES group, during the post-NMES motor phase, HbO value variation in the hand somatotopic area of the left SM1 showed a significant decrease, compared with that of sham group (p < 0.05). However, in the sham group, similar aspect of results in HbO values of all ROIs was observed between pre-NMES and post-NMES motor phases (p > 0.05). CONCLUSIONS: Results of this study showed that NMES induced a decrease of cortical activation during execution of hand movements. This finding appears to indicate that application of NMES can increase the efficiency of the cerebral cortex during execution of motor tasks.


Asunto(s)
Mapeo Encefálico , Corteza Cerebral/fisiología , Estimulación Eléctrica , Mano/fisiología , Movimiento/fisiología , Adulto , Femenino , Humanos , Masculino , Espectroscopía Infrarroja Corta
13.
Sci Rep ; 14(1): 8093, 2024 04 06.
Artículo en Inglés | MEDLINE | ID: mdl-38582769

RESUMEN

This study investigated brain responses during cybersickness in healthy adults using functional near-infrared spectroscopy (fNIRS). Thirty participants wore a head-mounted display and observed a virtual roller coaster scene that induced cybersickness. Cortical activation during the virtual roller coaster task was measured using fNIRS. Cybersickness symptoms were evaluated using a Simulator Sickness Questionnaire (SSQ) administered after the virtual rollercoaster. Pearson correlations were performed for cybersickness symptoms and the beta coefficients of hemodynamic responses. The group analysis of oxyhemoglobin (HbO) and total hemoglobin (HbT) levels revealed deactivation in the bilateral angular gyrus during cybersickness. In the Pearson correlation analyses, the HbO and HbT beta coefficients in the bilateral angular gyrus had a significant positive correlation with the total SSQ and disorientation. These results indicated that the angular gyrus was associated with cybersickness. These findings suggest that the hemodynamic response in the angular gyrus could be a biomarker for evaluating cybersickness symptoms.


Asunto(s)
Mareo por Movimiento , Adulto , Humanos , Interfaz Usuario-Computador , Hemodinámica/fisiología , Oxihemoglobinas , Encéfalo
14.
Bioengineering (Basel) ; 11(6)2024 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-38927854

RESUMEN

This study investigated the effects of different surface conditions on postural stability in response to unexpected perturbations. Thirty healthy adults underwent balance assessments on flat, incline ramp, balance pad, and balance pad on incline ramp surfaces. The center of pressure (COP) displacement in the mediolateral (ML) and anteroposterior (AP) directions, the velocity, and the area were measured. We found that the flat and ramp conditions resulted in significantly lower COP ML (F(3, 87) = 38.272, p < 0.001, ηp2 = 0.569) and AP displacements (F(3, 87) = 89.177, p < 0.001, ηp2 = 0.755), velocity (F(3, 87) = 89.177, p < 0.001, ηp2 = 0.755), and area (F(3, 87) = 52.659, p < 0.001, ηp2 = 0.645) compared to the balance pad and balance pad on ramp conditions (p < 0.05). The use of a balance pad, particularly on a ramp, significantly increased all the COP measurements, suggesting greater challenges to postural control. Through these findings, we demonstrate the adaptability and limitations of the human postural control system in response to varying surface conditions and perturbations.

15.
Brain Sci ; 14(2)2024 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-38391761

RESUMEN

BACKGROUND: Vestibular migraine (VM) is common migraine that occurs in patients with dizziness. Vestibular rehabilitation for managing VM generally remains unclear. Recently, it has been reported that transcranial direct current stimulation (tDCS) has positive effects in alleviating dizziness. This study investigated the effects of tDCS on dizziness and cortical activation in a patient with VM. METHODS: We recruited a male patient aged 31 years with no dizziness. The patient watched a video to induce dizziness using a virtual reality device. The study applied the intervention using tDCS for 4 weeks and measured 4 assessments: functional near-infrared spectroscopy (fNIRS), quantitative electroencephalography (qEEG), dizziness handicap inventory, and visual vertigo analog scale. RESULTS: We showed the activation in the middle temporal gyrus and inferior temporal gyrus (ITG) of the left hemisphere and in the superior temporal gyrus and ITG of the right hemisphere in the pre-intervention. After the intervention, the activation of these areas decreased. In the results of qEEG, excessive activation of C3, P3, and T5 in the left hemisphere and C4 in the right hemisphere before intervention disappeared after the intervention. CONCLUSIONS: This study indicated that tDCS-based intervention could be considered a viable approach to treating patients with vestibular dysfunction and dizziness caused by VM.

16.
Stroke ; 44(4): 1099-104, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23444306

RESUMEN

BACKGROUND AND PURPOSE: The corticoreticular pathway (CRP) is known to be an important extrapyramidal tract for walking ability. However, little is known about the functional role of the CRP in recovery of walking ability. We investigated relation between the CRP and walking ability in chronic hemiparetic stroke patients. METHODS: Among 209 consecutive patients, 54 patients, who showed complete injury of the corticospinal tract (CST) in the affected hemisphere on diffusion tensor tractography, and 20 normal subjects were recruited. Functional ambulation category was used in measurement of walking ability. The fractional anisotropy value, apparent diffusion coefficient value, and fiber volume of the CRP and CST were used for the diffusion tensor imaging parameters. RESULTS: In the affected hemisphere, no significant difference in diffusion tensor imaging parameters of the CRP was observed between patient subgroups. In the unaffected hemisphere, patients who were able to walk showed significantly increased fiber volume of the CRP, compared with patients who could not walk and normal control subjects (P<0.05), without significant difference in fractional anisotropy and apparent diffusion coefficient values. In addition, the fiber volume of the CRP in the unaffected hemisphere showed positive correlation with functional ambulation category (P<0.05). In contrast, diffusion tensor imaging parameters of the CST in the unaffected hemisphere showed no correlation with functional ambulation category (P>0.05). CONCLUSIONS: The increased fiber volume of the CRP in the unaffected hemisphere seems to be related to walking ability in patients with chronic stroke. Therefore, the compensation of the CRP in the unaffected hemisphere seems to be one of the mechanisms for recovery of walking ability after stroke.


Asunto(s)
Paresia/fisiopatología , Tractos Piramidales/fisiopatología , Rehabilitación de Accidente Cerebrovascular , Accidente Cerebrovascular/fisiopatología , Adulto , Anciano , Anisotropía , Estudios de Casos y Controles , Difusión , Imagen de Difusión Tensora/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Paresia/patología , Accidente Cerebrovascular/patología , Caminata
17.
Int J Neurosci ; 123(12): 892-5, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23796149

RESUMEN

OBJECTIVE: We report on a patient with hemorrhage of the corpus callosum (CC) in whom unusual compensatory neural connections were observed following disruption of CC fibers. METHODS: A 42-year-old female patient presented with callosal alien hand syndrome (AHS) after the onset of the hemorrhage. She showed a rapid recovery and the symptoms of her AHS had almost disappeared at 7 weeks after onset. We performed diffusion tensor tractography (DTT) for the evaluation of CC fibers and performed a comparison with DTT findings acquired from a normal subject (a 47-year-old female). RESULTS: Findings on DTT of the patient revealed extensive disruption of CC fibers passing through the anterior portion of the genu and most of the CC body. We observed that CC fibers in the right and left temporal lobes joined with the right and left inferior fronto-occipital fasciculus, respectively, and these neural fibers were connected to each other through the anterior commissure. These changes of neural connections were not observed in the normal subject. CONCLUSION: We think that the unusual neural connections in this patient were compensatory phenomena for disruption of CC fibers. In addition, the good recovery from symptoms of AHS in this patient appears to be correlated with these unusual compensatory neural connections. We believe that the results of this study suggest a mechanism for neural recovery following injury of the CC fibers.


Asunto(s)
Cuerpo Calloso/patología , Hemorragias Intracraneales/patología , Fibras Nerviosas Mielínicas/patología , Vías Nerviosas/patología , Adulto , Anisotropía , Imagen de Difusión Tensora , Femenino , Humanos , Imagen por Resonancia Magnética , Tomógrafos Computarizados por Rayos X
18.
Int J Neurosci ; 123(6): 420-4, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23293909

RESUMEN

OBJECTIVES: Many diffusion tensor imaging (DTI) studies have described the effects of hydrocephalus on periventricular white matter in patients with normal pressure hydrocephalus. However, little is known about hydrocephalus following stroke. We investigated the effect of hydrocephalus on periventricular white matter in patients with hydrocephalus after an intracerebral hemorrhage (ICH) using DTI. METHODS: Fourteen patients with ICH and hydrocephalus, and 17 age- and sex-matched normal control subjects were recruited. DTI parameters were estimated in six regions of interest (ROIs) in periventricular white matter: the anterior corona radiata, the posterior corona radiata, the genu of the corpus callosum, the splenium of corpus callosum, the anterior limb of the internal capsule, and the posterior limb of the internal capsule. RESULTS: Mean fractional anisotropy of the anterior corona radiata in patients was significantly higher than in controls (p < 0.05), but apparent diffusion coefficient (ADC) was not different in the two groups (p > 0.05). No significant differences between fractional anisotropies and ADCs were observed in the other five ROIs (p > 0.05). CONCLUSIONS: The anterior corona radiata was found to be more compressed by hydrocephalus than the other five regions of periventricular white matter examined in patients with hydrocephalus following ICH. It is believed that the results of the present study will be useful for the diagnosis and management of hydrocephalus following stroke.


Asunto(s)
Hemorragia Cerebral/patología , Cuerpo Calloso/patología , Imagen de Difusión Tensora , Hidrocefalia/patología , Cápsula Interna/patología , Fibras Nerviosas Mielínicas/patología , Neuroimagen , Adulto , Anciano , Anisotropía , Estudios de Casos y Controles , Hemorragia Cerebral/complicaciones , Ventrículos Cerebrales/patología , Femenino , Humanos , Hidrocefalia/complicaciones , Masculino , Persona de Mediana Edad , Vías Nerviosas/patología
19.
J Stroke Cerebrovasc Dis ; 22(7): e240-4, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23246180

RESUMEN

We report a patient who presented with callosal disconnection syndrome (CDS) and fiber disconnection on diffusion tensor tractography (DTT) after an infarct of the corpus callosum (CC). A 72-year-old woman presented with manifestations of CDS, including frontal alien hand syndrome (AHS), left agraphia, right hemiparesis, right somatosensory deficit, left neglect, and impaired visual recognition. DTT was performed for the evaluation of CC fibers, followed by comparison with DTT findings of normal subjects. DTT of the normal subject revealed bilateral extension of CC fibers to the frontal, parietal, and occipitotemporal cortices. By contrast, CC fibers of the patient revealed extensive disruption, with the exception of CC fibers passing through the anterior genu and the posterior splenium. The extensive disruption of CC fibers appears to explain the patient's various CDS symptoms. In brief, DTT could be useful for detection of CC lesions in patients with CDS.


Asunto(s)
Agrafia/fisiopatología , Fenómeno de la Extremidad Ajena/fisiopatología , Infarto Encefálico/fisiopatología , Cuerpo Calloso/fisiopatología , Paresia/fisiopatología , Trastornos de la Percepción/fisiopatología , Anciano , Agrafia/etiología , Fenómeno de la Extremidad Ajena/etiología , Infarto Encefálico/complicaciones , Mapeo Encefálico , Imagen de Difusión Tensora , Femenino , Humanos , Paresia/etiología , Trastornos de la Percepción/etiología
20.
Sci Rep ; 13(1): 15160, 2023 09 13.
Artículo en Inglés | MEDLINE | ID: mdl-37704674

RESUMEN

In sensorimotor conflicts, the brain forms and updates a new sensorimotor relationship through sensorimotor integration. As humans adapt to new sensorimotor mapping, goal-directed movements become increasingly precise. Using functional near-infrared spectroscopy, we investigated the changes in cortical activity during sensorimotor adaptation in a spatial orientation task with sensorimotor conflict. Individuals performed a reversed spatial orientation training in which the visual feedback guiding hand movements was reversed. We measured cortical activity and spatial orientation performance, including the response time, completion number, error, and accuracy. The results revealed the continuous activation in the left SMG during sensorimotor adaptation and decreased activation in the right SAC, AG and SMG after sensorimotor adaptation. These findings indicated the contribution of the left SMG to sensorimotor adaptation and the improved efficiency of cortical activity after sensorimotor adaptation, respectively. Our studies suggest the neural mechanisms related to sensorimotor adaptation to a reversed spatial orientation task.


Asunto(s)
Orientación Espacial , Percepción Espacial , Humanos , Encéfalo , Retroalimentación Sensorial , Mano
SELECCIÓN DE REFERENCIAS
Detalles de la búsqueda