Cases reported "Epilepsy"

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1/8. language area localization with three-dimensional functional magnetic resonance imaging matches intrasulcal electrostimulation in Broca's area.

    In this study, intraoperative electrocortical stimulation mapping (ioESM), the current gold standard for the localization of critical language areas, is compared with functional magnetic resonance imaging (fMRI) in a 14-year-old girl with medically intractable epilepsy caused by a tumor in the region of Broca's area. Prior to the operation, four different fMRI tasks that target inferior frontal language areas were applied. Prior to the resection, ioESM as well as fMRI detected no language areas at the exposed cortical area. After removal of the tumor, a unique opportunity presented itself, where ioESM could be performed in the depth of a now exposed and intact gyrus. One specific locus that was indicated to be a critical language area by multiple-task fMRI was targeted. IoESM selectively confirmed the location of this language area to within an estimated 3 mm. We propose that the combined use of different fMRI tasks increases the sensitivity and specificity for the detection of essential language areas.
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2/8. Insights into the functional specificity of the human corpus callosum.

    Patient VP underwent complete callosotomy for the control of intractable epilepsy at the age of 27 years. Subsequent MRI, however, revealed spared callosal fibres in the rostral and splenial ends of the corpus callosum. We report a series of experiments designed to determine whether these fibres support functional transfer of information between the two cerebral hemispheres. Although we found no evidence for transfer of colour, shape or size information, there is good evidence for transfer of word information. This suggests that the spared splenial fibres in VP's corpus callosum are material-specific. The results of these experiments illustrate the remarkable degree of functional specificity within the corpus callosum
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3/8. Direction-specific motion blindness induced by focal stimulation of human extrastriate cortex.

    Motion blindness (MB) or akinetopsia is the selective disturbance of visual motion perception while other features of the visual scene such as colour and shape are normally perceived. Chronic and transient forms of MB are characterized by a global deficit of direction discrimination (pandirectional), which is generally assumed to result from damage to, or interference with, the motion complex MT /V5. However, the most characteristic feature of primate MT-neurons is not their motion specificity, but their preference for one direction of motion (direction specificity). Here, we report that focal electrical stimulation in the human posterior temporal lobe selectively impaired the perception of motion in one direction while the perception of motion in other directions was completely normal (unidirectional MB). In addition, the direction of MB was found to depend on the brain area stimulated. It is argued that direction specificity for visual motion is not only represented at the single neuron level, but also in much larger cortical units.
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4/8. Epileptic seizure prediction using hybrid feature selection over multiple intracranial EEG electrode contacts: a report of four patients.

    Epileptic seizure prediction has steadily evolved from its conception in the 1970s, to proof-of-principle experiments in the late 1980s and 1990s, to its current place as an area of vigorous, clinical and laboratory investigation. As a step toward practical implementation of this technology in humans, we present an individualized method for selecting electroencephalogram (EEG) features and electrode locations for seizure prediction focused on precursors that occur within ten minutes of electrographic seizure onset. This method applies an intelligent genetic search process to EEG signals simultaneously collected from multiple intracranial electrode contacts and multiple quantitative features derived from these signals. The algorithm is trained on a series of baseline and preseizure records and then validated on other, previously unseen data using split sample validation techniques. The performance of this method is demonstrated on multiday recordings obtained from four patients implanted with intracranial electrodes during evaluation for epilepsy surgery. An average probability of prediction (or block sensitivity) of 62.5% was achieved in this group, with an average block false positive (FP) rate of 0.2775 FP predictions/h, corresponding to 90.47% specificity. These findings are presented as an example of a method for training, testing and validating a seizure prediction system on data from individual patients. Given the heterogeneity of epilepsy, it is likely that methods of this type will be required to configure intelligent devices for treating epilepsy to each individual's neurophysiology prior to clinical deployment.
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5/8. Depth electrode recorded cerebral responses with deep brain stimulation of the anterior thalamus for epilepsy.

    OBJECTIVE: We investigated the relation between anterior thalamic stimulation and the morphology of the evoked cerebral responses (CRs) using intracerebral depth electrodes in patients with intractable epilepsy undergoing deep brain stimulation (DBS) of the thalamus. methods: Monopolar cathodic and bipolar stimuli were delivered at a rate of 2 or 1 Hz to the anterior nucleus (AN) and the dorsomedian nucleus (DM) of two patients using the programmable stimulation device (Medtronic ITREL II) or a GRASS stimulation device (S12). CRs were recorded from depth or DBS electrodes, situated bilaterally in mesial temporal (hippocampus, both patients), lateral temporal (one patient), orbitofrontal (Brodmann area 11, one patient) and anterior thalamic sites (one patient). RESULTS: The distribution and morphology of the CRs depended primarily on the site of stimulation within the anterior thalamic region. overall, monopolar cathodic and bipolar stimulation of the AN elicited CRs mainly in ipsilateral mesial temporal cortical areas, whereas stimulation of the DM evoked high-amplitude CRs predominantly in ipsilateral orbitofrontal areas. The amplitude of the CR was positively related to the strength of the stimulus and generally higher with monopolar than with bipolar stimulation. The differences between CRs elicited during wakefulness or slow wave sleep were minimal. CONCLUSIONS: The distribution of the CRs corresponded with the intracerebral pathways of the involved structures and the findings are in good accordance with those of our previous study investigating the sources of CRs using statistical non-parametric mapping of low resolution electromagnetic tomography (LORETA) values. SIGNIFICANCE: Our findings indicate a certain degree of point-to-point specificity within the thalamocortical circuitry, which may make optimal localization of DBS electrodes important in patients with epilepsy.
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6/8. Epilepsia arithmetices revisited.

    Three patients whose epileptic seizures are precipitated by arithmetic calculations are reported and their clinical and EEG features analysed along with those of 7 previous cases. The seizure disorder, in general, was characterised by an onset, in adolescence, of myoclonic jerks with or without tonic-clonic seizures and generalised bisynchronous 2-5 Hz spike-and-wave discharges in the EEG. Problems involving processing of spatial information were among the tasks which induced the dysrhythmia. The specificity and the consistency of the seizure-provoking stimuli suggest that in these patients the cortical areas responsible for calculations and related functions are abnormally hyperexcitable and the repeated stimulation during cognitive activities triggers seizure discharges. Two or our patients responded well to clobazam during a follow-up period of 6 months.
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7/8. Neuropsychiatric studies of the "pellucidumsyndrom".

    Twenty-nine cases with the cavum septi pellucidi were examined by the brain X-ray CT comparing with the reported cases of "Pellucidumsyndrom" in the previous literatures. As to the clinical diagnoses of the 29 cases with the cavum septi pellucidi, there is no specificity of the clinical disorder in relation to the cavum septi pellucidi. But one case had an extremely large cavum septi pellucidi showing various types of mental and neurological symptoms similar to the "Pellucidumsyndrom" described by Wilder. It is suggested that the extremely large cavum septi pellucidi of the present case may produce the neuropsychiatric symptoms according to the direct action to the neighboring regions of the cerebrum.
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8/8. Acute confusional state in childhood.

    Acute confusional state (ACS) relates to a sudden alteration of the mental status. The impairment may be global or confined to a specific faculty of higher cortical function. Such specificity does not depend on the nature of the pathological process, but rather on the anatomical location of the area of the brain which is involved. In the absence of relevant medical history and associated signs and symptoms, the differential diagnosis of ACS may be difficult. Two case reports of unusual causes of ACS are presented: basilar migraine manifesting as transient global amnesia, and absence status. These are followed by a brief review of etiological causes of ACS commonly encountered in the pediatric practice, and a more detailed review of rare causes, such as non-convulsive epilepsy and migraine. A list of auxiliary tests for cases which are not readily diagnosed is presented.
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ranking = 1
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