RESUMO
Motor threshold (MT) measured by transcranial magnetic stimulation (TMS) has diagnostic utility in central nervous system disorders. Its diagnostic sensitivity may be enhanced by identification of non-pathological factors which may influence this measure. The aim of this study was to provide a description of MT variability across physiological and non-pathological behaviour characteristics in a large cohort, including hemispheric asymmetries. In a cross-sectional study, age, handedness, physical activity level, body mass index, gender/menstrual cycle phase, glycemic index and degree of stress were collected from 115 healthy participants. The resting MT of the first dorsal interosseous muscle to TMS was recorded in both hemispheres and served as an indicator of the cortical excitability level. Repeated measures ANOVAs revealed higher MT values in the non-dominant hemisphere, elderly people, stressed individuals and women with amenorrhea. Other biological and behavioral individual characteristics did not influence cortical excitability. Although the degree of interhemispheric difference varied (range: 0.2 to 4.3), depending on biological and behavioral characteristics, this variation was not significant (0.1â¯≤â¯pâ¯≤â¯0.8). In conclusion, MT varied considerably between subjects. The difference between the hemisphere excitability that was less influenced by external factors, may be an alternative method of TMS measure to identify pathological changes of cortical excitability.
Assuntos
Excitabilidade Cortical/fisiologia , Adolescente , Adulto , Envelhecimento/fisiologia , Amenorreia/fisiopatologia , Variação Biológica Individual , Índice de Massa Corporal , Estudos Transversais , Potencial Evocado Motor/fisiologia , Feminino , Lateralidade Funcional , Índice Glicêmico/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Comportamento Sedentário , Caracteres Sexuais , Estimulação Magnética Transcraniana , Adulto JovemRESUMO
El objetivo del estudio fue identificar modelos de pensamiento y habilidades en correspondencia al puesto y área laboral, mediante la evaluación del instrumento Herrmann de Dominancia Cerebral HBDI (Herrmann Brain Dominance Instrument, 1989), en una planta industrial de Ciudad Juárez, Chih. Participaron 176 gerentes y personal administrativo mexicanos. Se describen estadísticos de cuatro categorías de dominancia en tres áreas laborales. Se encontraron puntuaciones elevadas en las categorías lógico-controlador para todas las áreas laborales respecto a las habilidades interpersonales-holísticas, lo cual corresponde al manejo de dominancia cerebral del hemisferio cortical superior. Con una varianza total explicada del 76 por ciento en factorial confirmatorio y fiabilidad aceptable de la escala (alfa=.657), el instrumento fue identificado como versátil, económico y de fácil evaluación, al servir adecuadamente para selección, promoción, desarrollo organizacional y comprensión del clima laboral.
The objective of the study was to identify models of thought and abilities in correspondence to the position and labor area by means of the evaluation of the instrument Herrmann de Cerebral Dominance HBDI (Herrmann Brain Dominance Instrument, 1989), in an industrial plant of City Juarez, Chih. To 176 Mexican managers and administrative personnel participated. They describe themselves statistical of four categories of dominance in three labor areas. Were scores elevated in the categories logical-controller for all the labor areas with respect to the interpersonal-holistic abilities, which corresponds to the handling of cerebral dominance of the superior cortical hemisphere. With an explained total variance of confirming factorial 76 percent in and acceptable reliability of the scale (alpha=.657), the instrument was identified like versatile, economic and of easy evaluation when being used suitably for selection, promotion, organizational development and understanding of the labor climate.
Assuntos
Humanos , Dominância Cerebral/fisiologia , Neuropsicologia , Análise de Variância , Aptidão , Análise Fatorial , Indústrias , México , Local de TrabalhoRESUMO
OBJETIVO: Identificar as regiões cerebrais responsáveis pelas funções de linguagem através de Ressonância Magnética funcional (RMf) em pacientes com epilepsia refratária de lobo temporal. METODOLOGIA: Foi realizada RMf utilizando-se o paradigma de geração de verbos. Os pacientes ouviam palavras concretas e eram orientados a pensar na sua finalidade, sem verbalizar (ex: faca-cortar). Utilizou-se o cálculo de índice de lateralidade (IL) e a verificação do grau de ativação das áreas classicamente envolvidas na linguagem. RESULTADOS E CONCLUSÕES: Constatou-se que 92,3 por cento dos pacientes investigados apresentaram linguagem em hemisfério esquerdo, e 7,7 por cento, linguagem mista. Observou-se que existe maior freqüência de pacientes com ativação nas regiões de Broca esquerda, Córtex Pré-motor esquerdo, área de Wernicke esquerda e Córtex Auditivo esquerdo.
PURPOSE: The purpose of this study was to identify the brain regions for language functions with the functional Magnetic Resonance Image (fMRI) in patients suffering from intractable temporal lobe epilepsy. METHODS: During fMRI, patients performed a verb-generation task. They heard concrete words through headphones and were asked to think of their utility (e.g. pencil - to write), without verbalizing or making any facial or tongue movements, keeping silent and with eyes shut. A laterality index (LI) was calculated and we verify the brain regions activities for language. RESULTS AND CONCLUSIONS: Our results identified that that 92.3 percent of the patients analyzed by fMRI presented left hemisphere language and 7.7 percent presented mixed language representation. It was observed more patients with activation in left Broca area, left pré-motor cortex, left Wernicke area and left hearing cortex.
Assuntos
Humanos , Imageamento por Ressonância Magnética , Dominância Cerebral , Epilepsia do Lobo Temporal , Idioma , Epilepsia Resistente a MedicamentosRESUMO
PURPOSE: To identify brain dominance for language functions with DLT and correlate these results with those obtained from fMRI in patients suffering from intractable temporal lobe epilepsy. METHOD: This study reports on 13 patients who underwent pre-surgical epileptic evaluation between April and October 2004 at the Epilepsy Surgery Program, Hospital Sao Lucas, PUCRS. In DLT, dominance was assessed through a consonant-vowel task, whereas in fMRI patients performed a verb generation task. RESULTS: Our results identified a correlation between the fMRI lateralization index and the DLT ear predominance index and reply difference index (r=0.6, p=0.02; Pearson Correlation Coefficient), showing positive correlation between results obtained from fMRI and DLT. CONCLUSION: DLT was found to significantly correlate with fMRI. These findings indicate that DLT (a non-invasive procedure) could be a useful tool to evaluate language brain dominance in pre-surgical epileptic patients as it is cheaper to perform than fMRI.
OBJETIVO: Identificar a dominância cerebral para funções de linguagem através do teste de escuta dicótica (TED) e correlacionar com os resultados de ressonância magnética funcional (RMf) em pacientes com epilepsia refratária de lobo temporal. MÉTODO: Foram estudados 13 pacientes com epilepsia refratária de lobo temporal, que realizaram avaliações pré-cirúrgicas no período de abril a outubro de 2004 no Programa de Cirurgia de Epilepsia do Hospital São Lucas da PUCRS. Realizada investigação da dominância hemisférica para linguagem através do TED Consoante-Vogal e da RMf pela geração de verbos. RESULTADOS: Verificou-se a existência de correlação entre os índices de lateralidade (RMf) e os índices de predomínio de orelha e de diferença de resposta (TED) (r=0,6, p=0,02). CONCLUSÃO: Existe correlação entre os resultados obtidos através da RMf (índice de lateralidade) e do TED (índice de predomínio de orelha e índice de diferença de resposta) em pacientes com epilepsia refratária de lobo temporal.