Browsing by Author "Calado, E"
Now showing 1 - 10 of 43
Results Per Page
Sort Options
- 0 Impacto da lnvestigação Neurofisiológica na Referenciação para Cirurgia da Epilepsia na Esclerose TuberosaPublication . Borges, D; Calado, E; Vieira, JP; Moreira, A; Leal, A; Dias, AI
- Analysis of the Dynamics and Origin of Epileptic Activity in Patients with Tuberous Sclerosis Evaluated for Surgery of EpilepsyPublication . Leal, A; Dias, AI; Vieira, JP; Moreira, A; Távora, L; Calado, EObjective: The epilepsies associated with the tuberous sclerosis complex (TSC) are very often refractory to medical therapy. Surgery for epilepsy is an effective alternative when the critical link between the localization of seizure onset in the scalp and a particular cortical tuber can be established. In this study we perform analysis of ictal and interictal EEG to improve such link. Methods: The ictal and interictal recordings of four patients with TSC undergoing surgery for epilepsy were submitted to independent component analysis (ICA), followed by source analysis, using the sLORETA algorithm. The localizations obtained for the ictal EEG and for the average interictal spikes were compared. Results: The ICA of ictal EEG produced consistent results in different events, and there was good agreement with the tubers that were successfully removed in three of the four patients (one patient refused surgery). In some patients there was a large discrepancy between the localization of ictal and interictal sources. The interictal activity produced more widespread source localizations. Conclusions: The use of ICA of ictal EEG followed by the use of source analysis methods in four cases of epilepsy and TSC was able to localize the epileptic generators very near the lesions successfully removed in surgery for epilepsy. Significance: The ICA of ictal EEG events may be a useful add-on to the tools used to establish the connection between epileptic scalp activity and the cortical tubers originating it, in patients with TSC considered for surgery of epilepsy.
- Analysis of the Generators of Epileptic Activity in Early-Onset Childhood Benign Occipital Lobe EpilepsyPublication . Leal, A; Nunes, S; Dias, AI; Vieira, JP; Moreira, A; Calado, EObjective: The Panayiotopoulos type of idiopathic occipital epilepsy has peculiar and easily recognizable ictal symptoms, which are associated with complex and variable spike activity over the posterior scalp areas. These characteristics of spikes have prevented localization of the particular brain regions originating clinical manifestations. We studied spike activity in this epilepsy to determine their brain generators. Methods: The EEG of 5 patients (ages 7–9) was recorded, spikes were submitted to blind decomposition in independent components (ICs) and those to source analysis (sLORETA), revealing the spike generators. Coherence analysis evaluated the dynamics of the components. Results: Several ICs were recovered for posterior spikes in contrast to central spikes which originated a single one. Coherence analysis supports a model with epileptic activity originating near lateral occipital area and spreading to cortical temporal or parietal areas. Conclusions: Posterior spikes demonstrate rapid spread of epileptic activity to nearby lobes, starting in the lateral occipital area. In contrast, central spikes remain localized in the rolandic fissure. Significance: Rapid spread of posterior epileptic activity in the Panayitopoulos type of occipital lobe epilepsy is responsible for the variable and poorly localized spike EEG. The lateral occipital cortex is the primary generator of the epileptic activity.
- Anatomical and Physiological Basis of Continuous Spike-Wave of Sleep Syndrome after Early Thalamic LesionsPublication . Leal, A; Calado, E; Vieira, JP; Mendonça, C; Ferreira, JC; Ferreira, H; Carvalho, D; Furtado, F; Gomes, R; Monteiro, JPOBJECTIVE: Early neonatal thalamic lesions account for about 14% of continuous spike-wave of sleep (CSWS) syndrome, representing the most common etiology in this epileptic encephalopathy in children, and promise useful insights into the pathophysiology of the disease. METHODS: We describe nine patients with unilateral neonatal thalamic lesions which progressed to CSWS. Longitudinal whole-night and high-density electroencephalograms (EEGs) were performed, as well as detailed imaging and clinical evaluation. Visual evoked potentials were used to probe cortical excitability. RESULTS: Thalamic volume loss ranged from 19% to 94%, predominantly on medial and dorsal nuclei and sparing the ventral thalamus. Lesions produced white matter loss and ventricle enlargement on the same hemisphere, which in four patients was associated with selective loss of thalamic-cortical fibers. Cortical thickness quantification failed to reveal hemispheric asymmetries. Impact on EEG rhythms was mild, with a volume-loss-related decrease in alpha power and preservation of sleep spindles. The sleep continuous spiking was lateralized to the hemisphere with the lesion. Visual cortex stimulation in five patients with posterior cortex spiking revealed an abnormal frequency-dependent excitability at 10-20Hz on the side of the lesion. SIGNIFICANCE: Unilateral selective thalamic-cortical disconnection is a common feature in our patients and is associated with both a focal pattern of CSWS and a pathological type of frequency-dependent excitability (peak: 10-20Hz). We propose that this excitability represents an abnormal synaptic plasticity previously described as the augmenting response. This synaptic plasticity has been described as absent in the corticocortical interactions in healthy experimental animals, emerging after ablation of the thalamus and producing a frequency-dependent potentiation with a peak at 10-20Hz. Because this response is potentiated by sleep states of reduced brainstem activation and by appropriate stimulating rhythms, such as sleep spindles, the simultaneous occurrence of these two factors in nonrapid-eye-movement sleep is proposed as an explanation for CSWS in our patients.
- Atypical Phenotype in Two Patients with LAMA2 MutationsPublication . Marques, J; Duarte, S; Costa, S; Jacinto, S; Oliveira, J; Oliveira, M; Santos, R; Bronze-da-Rocha, E; Silvestre, AR; Calado, E; Evangelista, TCongenital muscular dystrophy type 1A is caused by mutations in the LAMA2 gene, which encodes the a2-chain of laminin. We report two patients with partial laminin-a2 deficiency and atypical phenotypes, one with almost exclusive central nervous system involvement (cognitive impairment and refractory epilepsy) and the second with marked cardiac dysfunction, rigid spine syndrome and limb-girdle weakness. Patients underwent clinical, histopathological, imaging and genetic studies. Both cases have two heterozygous LAMA2 variants sharing a potentially pathogenic missense mutation c.2461A>C (p.Thr821Pro) located in exon 18. Brain MRI was instrumental for the diagnosis, since muscular examination and motor achievements were normal in the first patient and there was a severe cardiac involvement in the second. The clinical phenotype of the patients is markedly different which could in part be explained by the different combination of mutations types (two missense versus a missense and a truncating mutation).
- A Brother or a Sister With CP. How Much it Makes a Difference in Childhood and Adulthood?Publication . Calado, EEvery month we see to be published dozens of scientific papers about etiology and physiopathology of CP, imaging, treatment, survival, quality of life of patients and of mothers (just a few) and so on. Papers dealing with the feelings and the problems of siblings of children and adults with CP in the most important scientific journals are extremely rare. However in internet we can find the sites of the most important Cerebral Palsy Societies, like the British, the Australian and the American ones already devoting a special attention to the issue of siblings; we also can see several interesting blogs of parents sharing their experiences not only with the handicapped child but also with the siblings, even counseling some books written for children giving practical advices how to deal and live with a handicapped sibling. What was a surprise to me were the several sites of adults having a disabled sibling, frequently with CP, in a new situation: without parents to care them.
- Cirurgia da Epilepsia na Esclerose TuberosaPublication . Calado, E; Dias, AI; Leal, A
- Clinical and Molecular Findings in Four New Patients Harbouring the mtDNA 8993T C MutationPublication . Vilarinho, L; Carrozzo, R; Barbot, C; Calado, E; Tessa, A; Dionisi-Vici, C; Guimarães, A; Santorelli, FM
- Comentários ao Número de Verão da Acta Pediátrica Portuguesa (2008:39(4))Publication . Pimentel, S; Silva, R; Calado, E
- Defeitos do Tubo Neural e Medula Ancorada na Criança e Adolescente. Um Olhar Neurológico…Publication . Calado, E; Marreiros, H; Loff, C