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1.
Epilepsy Behav ; 147: 109413, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37716331

RESUMEN

OBJECTIVE: The relationship of preoperative memory deficits in patients with mesial temporal lobe epilepsy (mTLE) and hippocampal sclerosis (HS) to the distribution of neuronal loss is uncertain. Building on the material specificity theory, we tested the hypothesis that visual memory deficits are associated with posterior hippocampal atrophy, whereas verbal memory deficits are associated with anterior hippocampal atrophy. METHODS: We studied 22 adults with mTLE and HS, calculating hippocampal head, body, and tail volumes, correcting for estimated total intracranial volume, using automated segmentation. Preoperative memory ability was evaluated with the Wechsler Memory Scale (WMS-II: logical memory, verbal paired associates, family pictures, and faces subtests). We correlated memory ability with hippocampal division volumes using SPSS 26.1 (repeated measures ANOVAs, one-way ANOVAs, Pearson r correlations) for statistical analysis. RESULTS: We found a significant main effect of hippocampal subdivision, reporting volumetric differences between the head, body, and tail. Pairwise comparisons reported that the hippocampal head had significantly greater volume than both the body and tail (p < 0.001). For both left and right focus groups, the ipsilateral hippocampi were significantly smaller than the contralateral. Linear regression reported a left hippocampal model (head, body, and tail volumes) predicted performance on logical memory with the left hippocampal tail volume being the strongest predictor. A right hippocampal model (head, body, and tail volumes) predicted memory ability for family pictures and verbal paired associates at a trend level. CONCLUSIONS: Ipsilateral hippocampal head and tail seem more vulnerable to injury than the body in both the left and right mTLE. Our study suggests there may be functional differences along the hippocampal longitudinal axis, particularly for the left hippocampal tail with verbal memory. Our findings are consistent with material-specific right-left differences in memory processing.

2.
HIV Med ; 17(2): 118-23, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26200721

RESUMEN

OBJECTIVES: The aim of the study was to describe patient characteristics and outcomes among HIV-positive adults presenting to a Zambian tertiary care hospital with new-onset seizures. METHODS: From July 2011 to June 2013, adults with seizures and a known or probable diagnosis of HIV infection were screened for a cohort study. Demographic and clinical data were obtained, including information on engagement in HIV services and in-patient mortality. Analyses were conducted to identify characteristics associated with poor engagement in care and death. RESULTS: A total of 320 of 351 screened adults were HIV-positive, with 268 of 320 experiencing new-onset seizures. Of these, 114 of 268 (42.5%) were female, and their mean age was 36.8 years. Seventy-nine of the 268 patients (29.5%) were diagnosed with HIV infection during the index illness. Among those who were aware of their HIV-positive status, 59 of 156 (37.8%) had disengaged from care. Significant functional impairment (Karnofsky score < 50) was evident in 44.0% of patients. Cerebrospinal fluid was not obtained in 108 of 268 (40.3%). In-patient mortality outcomes were available for 214 patients, and 47 of these 214 (22.0%) died during hospitalization. Patients with significant functional impairment were more likely to undergo lumbar puncture (P = 0.046). Women and the functionally impaired were more likely to die (P = 0.04 and < 0.001, respectively). CONCLUSIONS: Despite the availability of care, less than half of HIV-infected people with new-onset seizures were actively engaged in care and in-patient mortality rates were high. In the absence of clinical contraindication, lumbar puncture should be performed to diagnose treatable conditions and reduce morbidity and mortality. Continued efforts are needed to expand community-based testing and improve HIV care retention rates. Qualitative studies are needed to elucidate factors contributing to lumbar puncture usage in this population.


Asunto(s)
Atención a la Salud/estadística & datos numéricos , Infecciones por VIH/fisiopatología , Accesibilidad a los Servicios de Salud/estadística & datos numéricos , Tamizaje Masivo/estadística & datos numéricos , Derivación y Consulta/estadística & datos numéricos , Convulsiones/virología , Punción Espinal/estadística & datos numéricos , Adolescente , Adulto , Linfocitos T CD4-Positivos , Recuento de Células , Niño , Comorbilidad , Femenino , Infecciones por VIH/líquido cefalorraquídeo , Infecciones por VIH/complicaciones , Infecciones por VIH/mortalidad , Mortalidad Hospitalaria , Humanos , Masculino , Estudios Prospectivos , Convulsiones/líquido cefalorraquídeo , Convulsiones/etiología , Convulsiones/mortalidad , Carga Viral , Zambia/epidemiología
3.
Acta Neurol Scand ; 125(1): 30-7, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21615350

RESUMEN

BACKGROUND: Previous studies have shown that status epilepticus can lead to neuronal injury. However, the effect of a small number of isolated seizures is uncertain. METHODS: We used structural MRI and neuropathology to study the effects of isolated seizures induced by kainic acid (KA), (RS)-2-amino-3-(3-hydroxy-5-tert-butylisoxazole-4-yl)propanoic acid (ATPA), and α-amino-3-hydroxyl-5-methyl-4-isoxazole-propionate in rats. A group of animals received normal saline. After seizure induction, animals were followed for 12 weeks. RESULTS: ATPA and KA led to small but significant increases in ADC. There were no changes in T2 signal intensity or hippocampal volume. Blinded pathological examination showed no differences between animals receiving saline or glutamatergic agents. CONCLUSION: Our study suggests that isolated seizures cause minimal neuronal injury in rats.


Asunto(s)
Hipocampo/patología , Neuronas/patología , Convulsiones/patología , Animales , Hipocampo/efectos de los fármacos , Ácido Kaínico/farmacología , Imagen por Resonancia Magnética , Masculino , Neuronas/efectos de los fármacos , Tamaño de los Órganos/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Convulsiones/inducido químicamente
4.
Neurology ; 76(15): 1322-9, 2011 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-21368285

RESUMEN

BACKGROUND: Atypical language dominance is common in patients with temporal lobe epilepsy. We examined the association of left temporal hypometabolism with laterality of fMRI activation in a language task in a cross-sectional study. METHODS: Thirty patients with temporal lobe epilepsy (mean age 32.4 ± 11.0 years [range 18-55]; epilepsy onset 15.3 ± 11.3 years [range 0.8-40]; 22 left focus, 8 right focus) had (18)fluoro-deoxyglucose (FDG)-PET using noninvasive cardiac input function. After MRI-based partial volume correction, regional glucose metabolism (CMRglc) was measured and asymmetry index, AI = 2(l - R)/(L + R), calculated. fMRI language dominance was assessed with an auditory definition decision paradigm at 3 T. fMRI data were analyzed in SPM2 using regions of interest from Wake Forest PickAtlas (Wernicke area [WA], inferior frontal gyrus [IFG], middle frontal gyrus [MFG]) and bootstrap laterality index, LI = (l - R/L + R). RESULTS: Nineteen patients had ipsilateral temporal hypometabolism; 3 of 4 patients with atypical language had abnormal FDG-PET. Increasing left midtemporal hypometabolism correlated with decreased MFG LI (r = -0.41, p < 0.05) and showed trends with WA LI (r = -0.37, p = 0.055) and IFG LI (r = -0.31, p = 0.099); these relationships became more significant after controlling for age at onset. Increasing hypometabolism was associated with fewer activated voxels in WA ipsilateral to the focus and more activated voxels contralaterally, but overall, activation amount in left WA was similar to subjects without left temporal hypometabolism (t = -1.39, p > 0.10). CONCLUSIONS: We did not find evidence of impaired blood oxygenation level-dependent response in hypometabolic cortex. Regional hypometabolism appears to be a marker for the temporal lobe dysfunction that leads to displacement of language function.


Asunto(s)
Dominancia Cerebral , Epilepsia del Lóbulo Temporal/psicología , Fluorodesoxiglucosa F18/farmacocinética , Lenguaje , Imagen por Resonancia Magnética , Tomografía de Emisión de Positrones , Radiofármacos/farmacología , Lóbulo Temporal/metabolismo , Adolescente , Estudios Transversales , Epilepsia del Lóbulo Temporal/diagnóstico , Epilepsia del Lóbulo Temporal/metabolismo , Epilepsia del Lóbulo Temporal/fisiopatología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Lóbulo Temporal/diagnóstico por imagen , Lóbulo Temporal/fisiopatología
5.
Acta Neurol Scand ; 121(3): 209-16, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19951270

RESUMEN

OBJECTIVES: To investigate acute effects of intra-amygdalar excitatory amino acid administration on blood flow, relaxation time and apparent diffusion coefficient in rat brain. MATERIALS AND METHODS: Several days after MR-compatible cannula placement in right basolateral amygdala, anesthetized rats were imaged at 7 T. Relative cerebral blood flow (CBF) was measured before and 60 min after infusion of 10 nmol KA, cAMPA, ATPA, or normal saline using arterial spin labeling. Quantitative T(2) and diffusion-weighted images were acquired. rCBF, T(2) and ADC values were evaluated in bilateral basolateral amygdala, hippocampus, basal ganglia, frontal and parietal regions. RESULTS: KA led to the highest, and ATPA lowest bilateral rCBF increases. Time courses varied among drugs. T(2) for KA and AMPA was higher while ADC was lower for KA. CONCLUSIONS: Intra-amygdalar injection of GluR agonists evoked bilateral seizure activity and increased rCBF, greater for KA and AMPA than selective ATPA GluR5 activation.


Asunto(s)
Amígdala del Cerebelo/irrigación sanguínea , Amígdala del Cerebelo/efectos de los fármacos , Circulación Cerebrovascular/efectos de los fármacos , Agonistas de Aminoácidos Excitadores/farmacología , Animales , Arterias/efectos de los fármacos , Presión Sanguínea/efectos de los fármacos , Mapeo Encefálico , Imagen de Difusión por Resonancia Magnética/métodos , Modelos Animales de Enfermedad , Electroencefalografía , Lateralidad Funcional/efectos de los fármacos , Lateralidad Funcional/fisiología , Procesamiento de Imagen Asistido por Computador/métodos , Masculino , Ratas
6.
Neurology ; 72(21): 1830-6, 2009 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-19470965

RESUMEN

OBJECTIVE: To investigate interhemispheric and intrahemispheric reorganization in patients with localization-related epilepsy. METHOD: We studied 50 patients with a left hemispheric focus and 20 normal right-handed controls with a 3T echoplanar imaging blood oxygen level dependent functional MRI auditory-based word definition decision task. Data were analyzed using SPM 2. Using region of interest for Broca and Wernicke areas and an asymmetry index (AI), patients were categorized as left language (LL; AI > or = 0.20) or atypical language (AL; AI <0.20) for region. The point maxima activation for normal controls (p <0.05 corrected FDR) was identified in Broca and midtemporal regions and then used as a point of reference for individual point maxima identified at p < 0.001, uncorrected. RESULTS: Patient groups showed increased frequency of having activation in right homologues. Activation in AL groups occurred in homologous right regions; distances for point maxima activation in homologous regions were the same as point maxima distances in normal control activation in left regions. Distances for LL patient in left regions showed a trend for differences for midtemporal gyrus (6 mm posterior, 3 mm superior) but variability around mean difference distance was significant. There was no effect of age at epilepsy onset, duration, or pathology on activation maxima. CONCLUSIONS: Right hemisphere language regions in patients with left hemispheric focus are homologues of left hemisphere Broca and broadly defined Wernicke areas. We found little evidence for intrahemispheric reorganization in patients with left hemisphere epilepsy who remain left language dominant by these methods.


Asunto(s)
Epilepsia Parcial Compleja/fisiopatología , Lóbulo Frontal/fisiopatología , Lateralidad Funcional , Lenguaje , Lóbulo Temporal/fisiopatología , Adolescente , Adulto , Edad de Inicio , Mapeo Encefálico , Niño , Preescolar , Femenino , Humanos , Lactante , Pruebas del Lenguaje , Imagen por Resonancia Magnética , Masculino , Plasticidad Neuronal , Adulto Joven
7.
J Inherit Metab Dis ; 32(3): 343-52, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19172412

RESUMEN

Succinic semialdehyde dehydrogenase (SSADH) deficiency, a disorder of GABA degradation with subsequent elevations in brain GABA and GHB, is a neurometabolic disorder with intellectual disability, epilepsy, hypotonia, ataxia, sleep disorders, and psychiatric disturbances. Neuroimaging reveals increased T2-weighted MRI signal usually affecting the globus pallidus, cerebellar dentate nucleus, and subthalamic nucleus, and often cerebral and cerebellar atrophy. EEG abnormalities are usually generalized spike-wave, consistent with a predilection for generalized epilepsy. The murine phenotype is characterized by failure-to-thrive, progressive ataxia, and a transition from generalized absence to tonic-clonic to ultimately fatal convulsive status epilepticus. Binding and electrophysiological studies demonstrate use-dependent downregulation of GABA(A) and (B) receptors in the mutant mouse. Translational human studies similarly reveal downregulation of GABAergic activity in patients, utilizing flumazenil-PET and transcranial magnetic stimulation for GABA(A) and (B) activity, respectively. Sleep studies reveal decreased stage REM with prolonged REM latencies and diminished percentage of stage REM. An ad libitum ketogenic diet was reported as effective in the mouse model, with unclear applicability to the human condition. Acute application of SGS-742, a GABA(B) antagonist, leads to improvement in epileptiform activity on electrocorticography. Promising mouse data using compounds available for clinical use, including taurine and SGS-742, form the framework for human trials.


Asunto(s)
Encefalopatías Metabólicas Innatas/etiología , Succionato-Semialdehído Deshidrogenasa/deficiencia , Animales , Encefalopatías Metabólicas Innatas/diagnóstico , Encefalopatías Metabólicas Innatas/genética , Encefalopatías Metabólicas Innatas/terapia , Modelos Animales de Enfermedad , Humanos , Ratones , Ratones Transgénicos , Modelos Biológicos , Succionato-Semialdehído Deshidrogenasa/genética
8.
Brain ; 132(Pt 2): 347-56, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19059978

RESUMEN

Neural networks for processing language often are reorganized in patients with epilepsy. However, the extent and location of within and between hemisphere re-organization are not established. We studied 45 patients, all with a left hemisphere seizure focus (mean age 22.8, seizure onset 13.3), and 19 normal controls (mean age 24.8) with an fMRI word definition language paradigm to assess the location of language processing regions. Individual patient SPM maps were compared to the normal group in a voxel-wise comparison; a voxel was considered to be significant if its z-value exceeded mid R:2mid R:. Subsequently, we used principal component analysis with hierarchical clustering of variance patterns from individual difference maps to identify four patient sub-groups. One did not differ from normal controls; one had increased left temporal activation on the margin of regions activated in controls; two others had recruitment in right inferior frontal gyrus, middle frontal gyrus and temporal cortex. Right hemisphere activation in these two groups occurred in homologues of left hemisphere regions that sustained task activation. Our study used novel data driven methods to find evidence for constraints on inter-hemispheric reorganization of language in recruitment of right homologues, and, in a subpopulation of patients, evidence for intra-hemispheric reorganization of language limited to the margins of typical left temporal regional activation. These methods may be applied to investigate both normal and pathological variance in other developmental disorders and cognitive domains.


Asunto(s)
Epilepsia/fisiopatología , Procesamiento de Imagen Asistido por Computador , Lenguaje , Red Nerviosa/fisiopatología , Adolescente , Adulto , Mapeo Encefálico , Estudios de Casos y Controles , Niño , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Plasticidad Neuronal , Pruebas Neuropsicológicas , Análisis de Componente Principal , Adulto Joven
9.
Neurology ; 71(24): 1973-80, 2008 Dec 09.
Artículo en Inglés | MEDLINE | ID: mdl-19064878

RESUMEN

BACKGROUND: Autosomal dominant partial epilepsy with auditory features (ADPEAF) is an idiopathic focal epilepsy syndrome with auditory symptoms or receptive aphasia as major ictal manifestations, frequently associated with mutations in the leucine-rich, glioma inactivated 1 (LGI1) gene. Although affected subjects do not have structural abnormalities detected on routine MRI, a lateral temporal malformation was identified through high resolution MRI in one family. We attempted to replicate this finding and to assess auditory and language processing in ADPEAF using fMRI and magnetoencephalography (MEG). METHODS: We studied 17 subjects (10 affected mutation carriers, 3 unaffected carriers, 4 noncarriers) in 7 ADPEAF families, each of which had a different LGI1 mutation. Subjects underwent high-resolution structural MRI, fMRI with an auditory description decision task (ADDT) and a tone discrimination task, and MEG. A control group comprising 26 volunteers was also included. RESULTS: We found no evidence of structural abnormalities in any of the 17 subjects. On fMRI with ADDT, subjects with epilepsy had significantly less activation than controls. On MEG with auditory stimuli, peak 2 auditory evoked field latency was significantly delayed in affected individuals compared to controls. CONCLUSIONS: These findings do not support the previous report of a lateral temporal malformation in autosomal dominant partial epilepsy with auditory features (ADPEAF). However, our fMRI and magnetoencephalography data suggest that individuals with ADPEAF have functional impairment in language processing.


Asunto(s)
Corteza Auditiva/fisiopatología , Percepción Auditiva/genética , Epilepsias Parciales/complicaciones , Trastornos del Lenguaje/fisiopatología , Percepción del Habla/genética , Estimulación Acústica , Adulto , Corteza Auditiva/patología , Mapeo Encefálico , Trastornos de los Cromosomas/complicaciones , Trastornos de los Cromosomas/genética , Epilepsias Parciales/genética , Femenino , Lateralidad Funcional/genética , Genes Dominantes/genética , Humanos , Péptidos y Proteínas de Señalización Intracelular , Trastornos del Lenguaje/genética , Trastornos del Lenguaje/patología , Pruebas del Lenguaje , Imagen por Resonancia Magnética , Magnetoencefalografía , Masculino , Mutación/genética , Proteínas/genética , Tiempo de Reacción/genética
10.
Acta Neurol Scand ; 118(4): 240-4, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18355392

RESUMEN

OBJECTIVES: To evaluate the feasibility and safety of head-neck cooling in conscious normal volunteers (10) and patients with medically refractory epilepsy (5) without causing shivering. PATIENTS AND METHODS: We used a non-invasive head-neck cooling system (CoolSystems Inc., Lincoln, CA, USA). The tympanic temperature (TT) and intestinal temperature (IT) were measured as two measurements of 'core temperature' (CT), and multi-site external temperatures, several physiologic variables and EEG were monitored. Seizure counts over 4-week precooling, treatment and follow-up phases were compared. RESULTS: All 15 participants completed all the cooling sessions without significant complaints. At the end of 60 min of cooling, scalp temperature fell on average by 12.2 degrees C (P < 0.001), TT by 1.67 degrees C (P < 0.001), and IT by 0.12 degrees C (P = NS). Average weekly seizure frequency decreased from 2.7 to 1.7 events per patient per week (MANOVA: P < 0.05). CONCLUSIONS: Non-invasive head-neck cooling is safe and well-tolerated. Initial pilot data in patients suggest that additional therapeutic studies are warranted.


Asunto(s)
Hipotermia Inducida/instrumentación , Hipotermia Inducida/métodos , Convulsiones/terapia , Adulto , Temperatura Corporal , Electroencefalografía , Femenino , Humanos , Masculino , Persona de Mediana Edad , Proyectos Piloto
11.
Neurology ; 69(18): 1761-71, 2007 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-17967992

RESUMEN

OBJECTIVE: We investigated the relationship between partial epilepsy, MRI findings, and atypical language representation. METHODS: A total of 102 patients (4 to 55 years) with left hemisphere epileptogenic zones were evaluated using three fMRI language tasks obtained at 1.5 or 3T with EPI BOLD techniques: verbal fluency, reading comprehension, and auditory comprehension. fMRI maps were visually interpreted at a standard threshold and rated as left or atypical language. RESULTS: Atypical language dominance occurred in 30 patients (29%) and varied with MRI type (p < 0.01). Atypical language representation occurred in 36% (13/36) with normal MRI, 21% (6/29) with mesial temporal sclerosis, 14% (4/28) with focal cortical lesions (dysplasia, tumor, vascular malformation), and all (6/6) with a history of stroke. Multivariate logistic regression analysis found handedness, seizure onset, and MRI type accounted for much of the variance in language activation patterns (chi(2) = 24.09, p < 0.01). Atypical language was more prevalent in patients with early seizure onset (43.2%, p < 0.05) and atypical handedness (60%, p < 0.01). None of the three clinical factors were correlated with each other (p > 0.40). Patients with atypical language had lower verbal abilities (F = 6.96, p = 0.01) and a trend toward lower nonverbal abilities (F = 3.58, p = 0.06). There were no differences in rates of atypical language across time, age groups, or MRI scanner. CONCLUSION: Early seizure onset and atypical handedness, as well as the location and nature of pathologic substrate, are important factors in language reorganization.


Asunto(s)
Epilepsia Parcial Compleja , Trastornos del Lenguaje , Conducta Verbal/fisiología , Adolescente , Adulto , Edad de Inicio , Niño , Preescolar , Epilepsia Parcial Compleja/complicaciones , Epilepsia Parcial Compleja/fisiopatología , Femenino , Lateralidad Funcional , Humanos , Lactante , Pruebas de Inteligencia , Trastornos del Lenguaje/etiología , Trastornos del Lenguaje/fisiopatología , Pruebas del Lenguaje , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Estudios Retrospectivos , Semántica
12.
Neurology ; 69(18): 1772-80, 2007 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-17967993

RESUMEN

OBJECTIVE: To reassess the value of neuroimaging of the emergency patient presenting with seizure as a screening procedure for providing information that will change acute management, and to reassess clinical and historical features associated with an abnormal neuroimaging study in these patients. METHODS: A broad-based panel with topic expertise evaluated the available evidence based on a structured literature review using a Medline search from 1966 until November 2004. RESULTS: The 15 articles meeting criteria were Class II or III evidence since interpretation was not masked to the patient's clinical presentation; most were series including 22 to 875 patients. There is evidence that for adults with first seizure, cranial CT will change acute management in 9 to 17% of patients. CT in the emergency department for children presenting with first seizure will change acute management in approximately 3 to 8%. There is no clear difference between rates of abnormal emergent CT for patients with chronic seizures vs first. Children <6 months presenting with seizures have clinically relevant abnormalities on CT scans 50% of the time. Persons with AIDS and first seizure have high rates of abnormalities, and CNS toxoplasmosis is frequently found. Abnormal neurologic examination, predisposing history, or focal seizure onset are probably predictive of an abnormal CT study in this context. CONCLUSIONS: Immediate noncontrast CT is possibly useful for emergency patients presenting with seizure to guide appropriate acute management especially where there is an abnormal neurologic examination, predisposing history, or focal seizure onset.


Asunto(s)
Urgencias Médicas , Convulsiones , Evaluación de la Tecnología Biomédica , Tomografía Computarizada por Rayos X/estadística & datos numéricos , Academias e Institutos , Adolescente , Adulto , Niño , Preescolar , Servicio de Urgencia en Hospital , Guías como Asunto , Humanos , Lactante , MEDLINE , Masculino , Examen Neurológico , Literatura de Revisión como Asunto , Convulsiones/diagnóstico por imagen , Convulsiones/etiología , Convulsiones/patología
13.
Acta Neurochir Suppl ; 97(Pt 2): 261-72, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17691312

RESUMEN

Brain stimulation has been receiving increasing attention as an alternative therapy for epilepsy that cannot be treated by either antiepileptic medication or surgical resection of the epileptogenic focus. The stimulation methods include transcranial magnetic stimulation (TMS) or electrical stimulation by implanted devices of the vagus nerve (VNS), deep brain structures (DBS) (thalamic or hippocampal), cerebellar or cortical areas. TMS is the simplest and least invasive approach. However, the most common epileptogenic areas (mesial temporal structures) probably lie too deep beneath the surface of the skull for effective TMS. The efficacy of VNS in reducing the frequency or severity of seizures is quite variable and depends on many factors which are currently investigated. VNS is well-tolerated and approved in many countries. DBS is much more invasive than either TMS or VNS. Currently, a number of targets for DBS are investigated including caudate, centromedian or anterior thalamic nuclei, and subthalamic nucleus. Direct stimulation of the epileptic cortical focus is another approach to the neuromodulation in epilepsy. Finally, another line of research investigates the usefulness of implantable seizure detection devices. The current chapter presents the most important evidence on the above methods. Furthermore, other important issues are reviewed such as the selection criteria of patients for brain stimulation and the potential role of brain stimulation in the treatment of depression in epileptic patients.


Asunto(s)
Encéfalo/fisiología , Estimulación Encefálica Profunda/métodos , Epilepsia/terapia , Electrodos Implantados , Epilepsia/complicaciones , Humanos , Estimulación Magnética Transcraneal , Nervio Vago/fisiología
14.
Neurology ; 68(9): 655-9, 2007 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-17325271

RESUMEN

OBJECTIVE: To study the evolution of cerebral glucose metabolism after partial seizure onset in children, and its relation to clinical variables. METHODS: Thirty-eight children had 3.4 +/-.8 (18)FDG-PET scans over 3.0 +/- 1.3 years starting within a year after their third unprovoked partial seizure. (18)FDG-PET was analyzed with a region of interest template to measure normalized metabolism in 12 paired anatomic areas. Scans with absolute asymmetry index, |AI|, greater than 0.13 in at least one cortical region other than the cerebellum were considered abnormal. Standard clinical T1- and T2-weighted MRI (1.5 T) scans were obtained. RESULTS: Patients with initial normal PET (n = 28) were significantly more likely to remain in good seizure control than those with abnormal initial PET. Patients with initially normal PET scans that became abnormal had longer epilepsy duration before the first PET scan, but not greater seizure frequency, than those with PET always normal. There was no evidence for progression of hypometabolism. Patients with shorter time since last seizure and higher seizure frequency were more likely to have abnormal PET scans. Six of the seven patients whose PET scans were always abnormal had poor seizure control. Febrile seizure history did not affect PET findings. MRI was strongly predictive of initial PET results (chi(2) = 13.1; p < 0.02) but did not predict fluctuation hypometabolism. A model combining MRI and initial PET was strongly predictive of clinical course. CONCLUSIONS: Initial imaging studies can help predict clinical course for children who have had at least three partial seizures. Serial FDG-PET is affected by seizure frequency and time since last seizure.


Asunto(s)
Epilepsias Parciales/diagnóstico , Fluorodesoxiglucosa F18 , Interpretación de Imagen Asistida por Computador/métodos , Imagen por Resonancia Magnética/métodos , Tomografía de Emisión de Positrones/métodos , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Pronóstico , Radiofármacos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad
15.
Acta Neurol Scand ; 113(3): 139-55, 2006 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-16441243

RESUMEN

The understanding of neurobiological mechanisms of epileptogenesis is essential for rational approaches for a possible disease modification as well as treatment of underlying causes of the epilepsies. More effort is necessary to translate results from basic investigations into new approaches for clinical research and to better understand a relationship with findings from clinical studies. The following report is a condensed synapsis in which molecular mechanisms of epileptogenesis, pharmacological modulation of epileptogenesis, evidence based therapy, refractoriness and prediction of outcome is provided in order to stimulate further collaborative international research.


Asunto(s)
Anticonvulsivantes/uso terapéutico , Epilepsia/tratamiento farmacológico , Epilepsia/fisiopatología , Emparejamiento Cromosómico/fisiología , Medicina Basada en la Evidencia , Humanos , Pronóstico , Resultado del Tratamiento
16.
Neurology ; 65(10): 1604-11, 2005 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-16301489

RESUMEN

OBJECTIVE: To investigate the degree of language dominance in patients with left and right hemisphere seizure foci compared to normal volunteers using a fMRI reading comprehension task. METHODS: Fifty patients with complex partial epilepsy, aged 8 to 56 years and 33 normal volunteers, aged 7 to 34 had fMRI (1.5 T) and neuropsychological testing. Participants silently named an object described by a sentence compared to a visual control. Data were analyzed with region of interest (ROI) analysis based on t maps for inferior frontal gyrus (IFG), midfrontal gyrus (MFG), and Wernicke area (WA). Regional asymmetry indices (AIs) were calculated [(L - R)/(L + R)]; AI > 0.20 was deemed left dominant and AI < 0.20 as atypical language. RESULTS: Left hemisphere focus patients had a higher likelihood of atypical language than right hemisphere focus patients (21% vs 0%, chi2 < 0.002). Left hemisphere focus patients, excluding those with atypical language, had lower regional AI in IFG, MFG, and WA than controls. Right hemisphere focus patients were all left language dominant and had a lower AI than controls in WA and MFG, but not for IFG. AI in MFG and WA were similar between left hemisphere focus/left language patients and right hemisphere focus patients. Patients activated more voxels than healthy volunteers. Lower AIs were attributable to greater activation in right homologous regions. Less activation in the right-side WA correlated with better verbal memory performance in right focus/left hemisphere-dominant patients, whereas less strongly lateralized activation in IFG correlated better with Verbal IQ in left focus/left hemisphere-dominant patients. CONCLUSIONS: Patients had lower asymmetry indices than healthy controls, reflecting increased recruitment of homologous right hemisphere areas for language processing. Greater right hemisphere activation may reflect greater cognitive effort in patient populations, the effect of epilepsy, or its treatment. Regional activation patterns reflect adaptive efforts at recruiting more widespread language processing networks that are differentially affected based on hemisphere of seizure focus.


Asunto(s)
Corteza Cerebral/fisiopatología , Epilepsia/complicaciones , Lateralidad Funcional/fisiología , Trastornos del Lenguaje/etiología , Trastornos del Lenguaje/fisiopatología , Red Nerviosa/fisiopatología , Adaptación Fisiológica/fisiología , Adolescente , Adulto , Niño , Epilepsia/fisiopatología , Femenino , Humanos , Lenguaje , Trastornos del Lenguaje/diagnóstico , Pruebas del Lenguaje , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Vías Nerviosas/fisiopatología , Plasticidad Neuronal/fisiología , Valor Predictivo de las Pruebas , Conducta Verbal/fisiología
17.
Clin Neurophysiol ; 116(5): 1105-12, 2005 May.
Artículo en Inglés | MEDLINE | ID: mdl-15826851

RESUMEN

OBJECTIVE: Previous reports characterized the effects of administration of single oral doses of antiepileptic drugs (AED) on cortical excitability. However, AED effects on cortical excitability, and their relationship to plasma blood levels, during chronic drug administration at therapeutic doses are not known. The objective of the study was to determine whether plasma blood levels during chronic administration at therapeutic doses would accurately predict changes in corticomotor excitability. METHODS: We used transcranial magnetic stimulation (TMS) to measure cortical excitability during 5 weeks administration of carbamazepine (CBZ) and lamotrigine (LTG), and subsequent AED withdrawal in 20 healthy volunteers. Data were analyzed using ANOVA(RM) and regression analysis. RESULTS: Resting motor thresholds (r-MT) increased with increasing total and free CBZ and LTG levels during drug administration, but not drug withdrawal. After acute AED withdrawal, r-MT elevation persisted in most individuals with CBZ despite undetectable plasma levels, compared to a rapid normalization with LTG. In contrast, acute drug withdrawal resulted in a transient decrease in r-MT in 3/10 individuals with CBZ and 2/10 with LTG. CONCLUSIONS: Plasma levels provide information on motor cortical function during active treatment phases but not during AED withdrawal. SIGNIFICANCE: The transient decrease in r-MT associated with acute AED withdrawal could represent a physiological substrate contributing to AED withdrawal seizures.


Asunto(s)
Anticonvulsivantes/efectos adversos , Anticonvulsivantes/sangre , Corteza Motora/efectos de los fármacos , Síndrome de Abstinencia a Sustancias/fisiopatología , Adulto , Carbamazepina/efectos adversos , Carbamazepina/sangre , Estimulación Eléctrica , Potenciales Evocados Motores , Humanos , Lamotrigina , Magnetismo , Inhibición Neural/efectos de los fármacos , Triazinas/efectos adversos , Triazinas/sangre
18.
Neurology ; 63(8): 1403-8, 2004 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-15505156

RESUMEN

BACKGROUND: fMRI language tasks reliably identify language areas in presurgical epilepsy patients, but activation using single paradigms may disagree with the intracarotid amobarbital test (IAT). OBJECTIVE: To determine whether a panel of fMRI tasks targeting different aspects of language processing increases accuracy in determining hemisphere language dominance. METHODS: Twenty-six patients age 12 to 56 years, predominantly with temporal lobe epilepsy, were studied using whole-brain 1.5 T fMRI (echo planar imaging, blood oxygenation level-dependent) with three task categories using a block design: verbal fluency, reading comprehension, and auditory comprehension. fMRI t maps were visually rated at three thresholds. All patients had assessment of language lateralization by IAT. RESULTS: fMRI showed left dominance in 21 patients, right dominance in 2, and bilateral activation in 2; raters disagreed over a left vs right bilateral rating in 1 patient. There was full agreement between IAT and fMRI in 21 of 25 patients (IAT failed in 1). In three instances of partial disparity with IAT, the fMRI panel showed consistent findings across raters. Agreement between raters was excellent (partial disagreement in only one patient); the panel of tasks was superior to any single task for interrater agreement (Cramer V 0.93 [range 0.91 to 1.0] vs 0.72 [range 0.60 to 0.86]). CONCLUSIONS: A panel of fMRI language paradigms may be more accurate for evaluating partial epilepsy patients than a single task. A panel of tasks reduces the likelihood of nondiagnostic findings, improves interrater reliability, and helps confirm language laterality.


Asunto(s)
Corteza Cerebral/fisiología , Dominancia Cerebral/fisiología , Epilepsia/cirugía , Pruebas del Lenguaje/normas , Imagen por Resonancia Magnética/métodos , Cuidados Preoperatorios/métodos , Conducta Verbal/fisiología , Adolescente , Adulto , Mapeo Encefálico/instrumentación , Mapeo Encefálico/métodos , Corteza Cerebral/anatomía & histología , Circulación Cerebrovascular/fisiología , Niño , Epilepsia/fisiopatología , Femenino , Humanos , Lenguaje , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Reproducibilidad de los Resultados , Percepción del Habla/fisiología , Lóbulo Temporal/patología , Lóbulo Temporal/fisiopatología
19.
Neurology ; 62(8): 1252-60, 2004 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-15111659

RESUMEN

OBJECTIVE: To assess the evidence demonstrating efficacy, tolerability, and safety of seven new antiepileptic drugs (AEDs) (gabapentin, lamotrigine, topiramate, tiagabine, oxcarbazepine, levetiracetam, and zonisamide-reviewed in the order in which these agents received approval by the US Food and Drug Administration) in the treatment of children and adults with newly diagnosed partial and generalized epilepsies. METHODS: A 23-member committee, including general neurologists, pediatric neurologists, epileptologists, and doctors in pharmacy, evaluated the available evidence based on a structured literature review including MEDLINE, Current Contents, and Cochrane library for relevant articles from 1987 until September 2002, with selected manual searches up until 2003. RESULTS: There is evidence either from comparative or dose-controlled trials that gabapentin, lamotrigine, topiramate, and oxcarbazepine have efficacy as monotherapy in newly diagnosed adolescents and adults with either partial or mixed seizure disorders. There is also evidence that lamotrigine is effective for newly diagnosed absence seizures in children. Evidence for effectiveness of the new AEDs in newly diagnosed patients with other generalized epilepsy syndromes is lacking. CONCLUSIONS: The results of this evidence-based assessment provide guidelines for the prescription of AEDs for patients with newly diagnosed epilepsy and identify those seizure types and syndromes where more evidence is necessary.


Asunto(s)
Aminas , Anticonvulsivantes/efectos adversos , Anticonvulsivantes/uso terapéutico , Ácidos Ciclohexanocarboxílicos , Epilepsia/tratamiento farmacológico , Fructosa/análogos & derivados , Ácido gamma-Aminobutírico , Acetatos/efectos adversos , Acetatos/farmacocinética , Acetatos/uso terapéutico , Enfermedad Aguda , Adolescente , Adulto , Anticonvulsivantes/farmacocinética , Carbamazepina/efectos adversos , Carbamazepina/análogos & derivados , Carbamazepina/farmacocinética , Carbamazepina/uso terapéutico , Niño , Ensayos Clínicos Controlados como Asunto/estadística & datos numéricos , Interacciones Farmacológicas , Medicina Basada en la Evidencia/estadística & datos numéricos , Fructosa/efectos adversos , Fructosa/farmacocinética , Fructosa/uso terapéutico , Gabapentina , Humanos , Lamotrigina , Oxcarbazepina , Topiramato , Resultado del Tratamiento , Triazinas/efectos adversos , Triazinas/farmacocinética , Triazinas/uso terapéutico
20.
Neurology ; 62(8): 1261-73, 2004 Apr 27.
Artículo en Inglés | MEDLINE | ID: mdl-15111660

RESUMEN

OBJECTIVE: To assess the evidence demonstrating efficacy, tolerability, and safety of seven new antiepileptic drugs (AEDs) (gabapentin, lamotrigine, topiramate, tiagabine, oxcarbazepine, levetiracetam, and zonisamide) in the treatment of children and adults with refractory partial and generalized epilepsies. METHODS: A 23-member committee including general neurologists, pediatric neurologists, epileptologists, and doctors in pharmacy evaluated the available evidence based on a structured literature review including MEDLINE, Current Contents, and Cochrane library for relevant articles from 1987 until March 2003. RESULTS: All of the new AEDs were found to be appropriate for adjunctive treatment of refractory partial seizures in adults. Gabapentin can be effective for the treatment of mixed seizure disorders, and gabapentin, lamotrigine, oxcarbazepine, and topiramate for the treatment of refractory partial seizures in children. Limited evidence suggests that lamotrigine and topiramate are also effective for adjunctive treatment of idiopathic generalized epilepsy in adults and children, as well as treatment of the Lennox Gastaut syndrome. CONCLUSIONS: The choice of AED depends upon seizure and/or syndrome type, patient age, concomitant medications, AED tolerability, safety, and efficacy. The results of this evidence-based assessment provide guidelines for the prescription of AEDs for patients with refractory epilepsy and identify those seizure types and syndromes where more evidence is necessary.


Asunto(s)
Aminas , Anticonvulsivantes/efectos adversos , Anticonvulsivantes/uso terapéutico , Ácidos Ciclohexanocarboxílicos , Epilepsias Parciales/tratamiento farmacológico , Epilepsia Generalizada/tratamiento farmacológico , Fructosa/análogos & derivados , Ácido gamma-Aminobutírico , Acetatos/efectos adversos , Acetatos/uso terapéutico , Adulto , Carbamazepina/efectos adversos , Carbamazepina/análogos & derivados , Carbamazepina/uso terapéutico , Niño , Ensayos Clínicos como Asunto/estadística & datos numéricos , Resistencia a Medicamentos , Medicina Basada en la Evidencia/estadística & datos numéricos , Fructosa/efectos adversos , Fructosa/uso terapéutico , Gabapentina , Humanos , Isoxazoles/efectos adversos , Isoxazoles/uso terapéutico , Lamotrigina , Levetiracetam , Ácidos Nipecóticos/efectos adversos , Ácidos Nipecóticos/uso terapéutico , Oxcarbazepina , Piracetam/efectos adversos , Piracetam/análogos & derivados , Piracetam/uso terapéutico , Tiagabina , Topiramato , Resultado del Tratamiento , Triazinas/efectos adversos , Triazinas/uso terapéutico , Zonisamida
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