ABSTRACT
OBJECTIVE: The object of this study to analyse and compare the efficacy of the classic language tasks (repetition, phonological fluency and lexical decision), for the purpose of identifying the dominant hemisphere for language by means of functional magnetic resonance. SUBJECTS AND METHODS: The three tasks were performance with a groups of 10 right handed subjects with ages of 22 to 40 years. The examination was carried out using a 1,5 T MRI apparatus. An eight sequence of planar echo gradient (BOLD technique) was used, making the oblique axial plane coincide with the line between the anterior and posterior commissures (CA CP line) and covering the entire brain. RESULTS: Dominance was calculated by means of the lateralization index, comparing the activation in each hemisphere in two locations: first, taking account the temporal lobe together with the right and left frontal lobes, and second, taking into account only the right and left frontal lobes. CONCLUSION: The result indicate that the most effective test for obtaining the dominant hemisphere was the one for phonological fluency, this task activated the frontal areas, which showed greater participation in the left hemisphere.
Subject(s)
Brain/anatomy & histology , Brain/physiology , Functional Laterality/physiology , Magnetic Resonance Imaging , Adult , Decision Making , Female , Frontal Lobe/anatomy & histology , Frontal Lobe/physiology , Humans , Language Tests , Male , Phonetics , VocabularyABSTRACT
Objetivo. El objetivo de este estudio es analizar y comparar la eficacia de tres tareas clásicas del lenguaje, la de repetición, la de fluidez fonológica y la de decisión léxica, con el fin de identificar el hemisferio dominante para el lenguaje mediante una resonancia magnética (RM) funcional. Sujetos y métodos. Las tres tareas se realizaron a un grupo de 10 sujetos diestros con edades comprendidas entre 22 y 40 años, para cuya evaluación se empleó un aparato de RM de 1,5 T, en ocho secuencias de gradiente eco planar (técnica BOLD) que se hicieron en el plano axial oblicuo, y que coincidían con la línea entre la comisura anterior y la posterior y cubrían todo el cerebro (línea CA-CP). Resultados. La dominancia se calculó mediante el índice de lateralización, al comparar la activación en cada hemisferio en dos situaciones. En primer lugar, se tuvo en cuenta el lóbulo temporal y el frontal derechos e izquierdos, y en segundo lugar, sólo los lóbulos frontales derechos e izquierdos. Conclusiones. Los resultados que se obtuvieron indican que la prueba más efectiva para obtener el hemisferio dominante es la de fluidez fonológica, y que la activación de las áreas frontales muestra una mayor participación del hemisferio izquierdo (AU)
Subject(s)
Adult , Male , Female , Humans , Magnetic Resonance Imaging , Vocabulary , Phonetics , Decision Making , Frontal Lobe , Telencephalon , Language Tests , Functional LateralityABSTRACT
INTRODUCTION: Whole head magnetoencephalography (MEG) systems facilitate simultaneous recording from the entire brain surface and deep structures. Thus MEG may be accepted as a clinically feasible method for the evaluation of epileptic patients not diagnosed with EEG. CLINICAL CASE: A 11 year old female, with tonic generalized seizures since birth. At the present time, seizures consist of initial focal signs followed by fear sensation and both eyes and cephalic deviation to the right, tonic extension of the superior limbs and prolonged apnea. Complementary examinations (EEG, Holter EEG, Video EEG, CT, MRI, SPECT) were normal. MEG study was conclusive, diagnosing sharp waves in the internal face of the left precentral circunvolution. CONCLUSIONS: MEG study s utility in seizures focus localization and pseudo seizures differential diagnosis has been demonstrated.
Subject(s)
Benzodiazepines , Epilepsy, Rolandic/diagnosis , Magnetoencephalography/methods , Anti-Anxiety Agents/therapeutic use , Anticonvulsants/therapeutic use , Child , Clobazam , Electroencephalography , Epilepsy, Rolandic/drug therapy , Female , Humans , Lamotrigine , Triazines/therapeutic use , Valproic Acid/therapeutic useABSTRACT
Introducción. El sistema whole-head de magnetoencefalografía (MEG) permite el registro simultáneo de toda la superficie cerebral y de estructuras profundas. Así, la MEG puede aceptarse como un método clínico fiable para la evaluación de pacientes epilépticos no diagnosticados mediante el EEG. Caso clínico. Paciente mujer, de 11 años de edad, con crisis tonicoclónicas generalizadas desde el nacimiento. Actualmente, las crisis se inician con signos focales seguidos de sensación de miedo, desviación ocular y cefálica, extensión tónica de las extremidades superiores y apnea prolongada. Las exploraciones complementarias (EEG, Holter-EEG, vídeo-EEG, TAC, RM y SPECT) fueron normales. El estudio de MEG fue concluyente y diagnosticó ondas agudas en la cara interna de la circunvolución precentral. Conclusión. Se ha demostrado la utilidad del estudio mediante MEG en la localización del foco epiléptico y en el diagnóstico diferencial de pseudocrisis (AU)
Subject(s)
Child , Female , Humans , Benzodiazepines , Anti-Anxiety Agents , Triazines , Magnetoencephalography , Epilepsy, Rolandic , Anticonvulsants , Electroencephalography , Valproic AcidABSTRACT
Event related potentials have been examined in depression and Alzheimer disease like clinical utility. To evaluate the influence of visual and auditory stimuli on the P300 latency we studied 12 patients with major depression, 12 patients with Alzheimer disease and 12 normal subjects. The experimental tasks applied was, first a series of 300 auditory stimuli, 255 (85%), with tones of 1,000 Hz, and considered as the frequent stimulus, whereas 45 (15%) were tones of 2,000 Hz and referred as the rare stimulus. A second series of 300 visual stimuli, 255 (85%) that were black circles on a white background, and considered the frequent stimulus (9 cm diameter, 200 ms duration), whereas 45 (15%) were black squares on a white background and referred as the rare stimulus (9 cm diameter, 200 ms duration) in the centre of a computer screen. The results show an increase of P300 latency in depressive and Alzheimer patients during auditory and visual tasks. Differences were found in reaction time to visual or auditory stimuli in Alzheimer disease. These results are consistent with an impairment in brain function in depressive patients that is associated with cortical hypoactivity and deficits in perceptive, auditory or visual, functions, whereas deterioration in Alzheimer's disease is sensorymotor, according to the slowness latency in the reaction time.
Subject(s)
Alzheimer Disease/physiopathology , Depressive Disorder/physiopathology , Electromyography , Event-Related Potentials, P300/physiology , Evoked Potentials, Motor/physiology , Acoustic Stimulation , Aged , Cerebral Cortex/physiopathology , Evoked Potentials/physiology , Evoked Potentials, Somatosensory/physiology , Female , Humans , Male , Middle Aged , Photic Stimulation , Reaction Time/physiologyABSTRACT
Alzheimer's disease is a degenerative disorder characterised by cerebral atrophy with cortical and subcortical changes. Our objective is to investigate the patterns of atrophic changes in the corpus callosum in patients with Alzheimer's disease and healthy elderly subjects and to clarify the relations of callosal impairment and the presence of associated electromyographic responses. We compare cross-sectional area of the corpus callosum by age, group and associated electromyographic responses, using quantitative magnetic resonance imaging from 47 subjects (twenty four healthy subjects and twenty three Alzheimer's disease patients). The control population was selected by criteria of optimal health; medical, neurological or psychiatric illnesses were excluded. We find that the first anterior and medial-anterior corpus callosum areas show an atrophy in Alzheimer group patients. These sectors show a clear relationship with the presence of associated movements.
Subject(s)
Aging/physiology , Alzheimer Disease/diagnosis , Alzheimer Disease/physiopathology , Corpus Callosum/pathology , Electromyography , Magnetic Resonance Imaging , Aged , Anatomy, Cross-Sectional , Atrophy , Discriminant Analysis , Humans , Middle Aged , Movement , Reaction Time , Reference ValuesABSTRACT
In general terms, epileptic patients with temporal lobe epilepsy (TLE) show mnesic deficits. In the case of medically intractable epilepsy (around 20%) the neurosurgery intervention is a widely accepted treatment. The cognitive effects of surgery have been reported in last years; they emphasize the mnesic positive changes of contralateral area. In the same sense they have reported a negative change on mnesic modality in ipsilateral area. This paper present a study in which the mnesic deficits of twenty eight pharmaco resistant epileptic patients have been evaluated and followed up. These patients have been submittes to a surgical treatment at the Epilepsy Surgical Unit of the Hospital de La Princesa (Madrid). The assessment pre and postoperative tested six months apart. The most common cognitive deficit affect bimodally to mnesic functions: so in the verbal as in the visospatial modality. This deficit correlated with the years epilepsy. Meanwhile, the following up study indicates that a relevant numbers of these patients show an improvement in the function of the contralateral hemisphere with respect to the area surgically treated. This finding probably is the consequence of seizure free.
