RESUMEN
Precipitation and inhibition of seizures and epileptic discharges by sensory stimuli are receiving increasing attention because they provide insight into natural seizure generation in human epilepsies and can identify potential nonpharmacological therapies. We aimed to investigate modulation (provocation or inhibition) of epileptiform discharges (EDs) in mesial temporal lobe epilepsy (MTLE) versus idiopathic generalized epilepsy (IGE) by olfactory stimulation (OS) compared with standard provocation methods. The underlying hypothesis was that any response would be more likely to occur in MTLE, considering the anatomical connections of the temporal lobe to the olfactory system. This multicenter, international study recruited patients with either MTLE or IGE who were systematically compared for responses to OS using an EEG/video-EEG protocol including a 30-min baseline, twice 3-min olfactory stimulation with ylang-ylang, hyperventilation, and intermittent photic stimulation. The 95% confidence interval (CI) for the baseline EDs in each patient was calculated, and modulation was assumed when the number of EDs during any 3-min test period was outside this CI. A total of 134 subjects (55 with MTLE, 53 with IGE, and 26 healthy controls) were included. Epileptiform discharges were inhibited during OS in about half the patients with both MTLE and IGE, whereas following OS, provocation was seen in 29.1% of patients with MTLE and inhibition in 28.3% of patients with IGE. Olfactory stimulation was less provocative than standard activation methods. The frequent subclinical modulation of epileptic activity in both MTLE and IGE is in striking contrast with the rarity of reports of olfactory seizure precipitation and arrest. Inhibition during OS can be explained by nonspecific arousal. The delayed responses seem to be related to processing of olfactory stimuli in the temporal lobe, thalamus, and frontal cortex.
Asunto(s)
Encéfalo/fisiopatología , Epilepsia Generalizada/fisiopatología , Epilepsia del Lóbulo Temporal/fisiopatología , Percepción Olfatoria/fisiología , Adolescente , Adulto , Estudios de Casos y Controles , Electroencefalografía , Femenino , Lóbulo Frontal/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Lóbulo Temporal/fisiopatología , Tálamo/fisiopatología , Adulto JovenRESUMEN
PURPOSE: To investigate if phenotypic variations have prognostic implications in juvenile myoclonic epilepsy (JME). METHODS: Sixty-five consecutive JME patients had video-EEG recording and were followed for at least three years. Reflex traits were defined as seizures and/or EEG discharges induction by eye-closure, photic stimulation, language, praxis or calculation. Patients had psychiatric evaluation and answered to STAI (State-Trait Anxiety Inventory). Seizure control was classified according to Prasad et al. (2003).(24) Patients were divided into Group 1: good seizure control and Group 2: moderate or poor seizure control. Video-EEG/EEG evaluation was repeated in 21 patients. RESULTS: Forty of 65 (61.5%) patients reached good seizure control, 25 (38.5%) of whom became seizure free. Group 2 patients had longer epilepsy duration (13.9±9.0 vs. 8.7±8.2; p=0.019); higher prevalence of the combination of all three seizure types (72.0% vs. 30.0%; p=0.003); discharges in baseline EEG (56.0% vs. 22.5%; p=0.008); seizure recording (68% vs. 20%; p<0.001) and sensitivity to praxis (63.6% vs. 29.6%; p=0.023). Compared to seizure-free patients, those with persistent seizures presented younger age at epilepsy onset (12.6±3.33 years vs. 15.4±5.47 years; p=0.015); higher prevalence of personality disorders (25% vs. 4%; p=0.029); higher scores in STAI-T (45.9±11.31 vs. 36.6±11.43; p=0.011) and higher incidence of sensitivity to praxis (58.6% vs. 25.0%; p=0.04) and to language (53.8 vs. 16.7%; p=0.026) tasks. Repetition of EEG/video-EEG revealed a parallel evolution of reflex traits disappearance and seizure control. DISCUSSION: Clinical features and reflex traits have prognosis implications in JME.
Asunto(s)
Endofenotipos , Epilepsia Mioclónica Juvenil/diagnóstico , Epilepsia Mioclónica Juvenil/fisiopatología , Adolescente , Adulto , Electroencefalografía/métodos , Femenino , Estudios de Seguimiento , Humanos , Masculino , Pronóstico , Estudios Prospectivos , Factores de Riesgo , Grabación en Video/métodos , Adulto JovenRESUMEN
PURPOSE: Personality traits characterized by emotional instability and immaturity, unsteadiness, lack of discipline, hedonism, frequent and rapid mood changes, and indifference toward one's disease have been associated with patients who have juvenile myoclonic epilepsy (JME). Literature data demonstrate worse seizure control and more psychosocial dysfunctions among patients with JME who have those traits. In this controlled study we performed a correlation analysis of psychiatric scores with magnetic resonance spectroscopy (MRS) values across JME patients, aiming to verify the existence of a possible relation between frontal lobe dysfunction and the prevalence of personality disorders (PDs) in JME. METHODS: Sixteen JME patients with cluster B PDs, 41 JME patients without any psychiatric disorder, and 30 healthy controls were submitted to a psychiatric evaluation and to a quantitative multivoxel MRS of thalamus; insula; cingulate gyrus; striatum; and frontal, parietal, and occipital lobes. Groups were homogeneous according to age, gender, and manual dominance. Psychiatric evaluation was performed through the Scheduled Clinical Interview for DSM-IV, Axis I and II (SCID I and II, respectively). RESULTS: A significant reduction of N-acetyl-aspartate over creatinine (NAA/Cr) ratio was observed mainly in the left frontal lobe in the JME and PD group. In addition, a significant increase in the glutamate-glutamine over creatinine GLX/Cr ratio was also observed in this referred region in the same group. DISCUSSION: These data support the hypothesis that PDs in JME could represent neuronal dysfunction and possibly a more severe form of this epileptic syndrome.
Asunto(s)
Encefalopatías/complicaciones , Lóbulo Frontal/patología , Epilepsia Mioclónica Juvenil , Trastornos de la Personalidad/complicaciones , Personalidad , Adolescente , Adulto , Ácido Aspártico/análogos & derivados , Ácido Aspártico/metabolismo , Encefalopatías/metabolismo , Creatina/metabolismo , Femenino , Lóbulo Frontal/metabolismo , Ácido Glutámico/metabolismo , Glutamina/metabolismo , Humanos , Imagen por Resonancia Magnética , Espectroscopía de Resonancia Magnética/métodos , Masculino , Epilepsia Mioclónica Juvenil/complicaciones , Epilepsia Mioclónica Juvenil/metabolismo , Epilepsia Mioclónica Juvenil/patología , Trastornos de la Personalidad/metabolismo , Inventario de Personalidad , Protones , Escalas de Valoración Psiquiátrica , Estudios Retrospectivos , Adulto JovenRESUMEN
Studies involving juvenile myoclonic epilepsy (JME) patients have demonstrated an elevated prevalence of cluster B personality disorders (PD) characterized as emotional instability, immaturity, unsteadiness, lack of discipline, and rapid mood changes. We aimed to verify a possible correlation between structural brain abnormalities in magnetic resonance image (MRI) and the PD in JME using voxel-based morphometry (VBM). Sixteen JME patients with cluster B PD, 38 JME patients without psychiatric disorders, and 30 healthy controls were submitted to a psychiatric evaluation through SCID I and II and to a MRI scan. Significant reduction in thalami and increase in mesiofrontal and frontobasal regions' volumes were observed mainly in JME patients with PD. Structural alterations of the orbitofrontal cortex (OFC), involved in regulation of mood reactivity, impulsivity, and social behavior, were also observed. This study supports the hypothesis of frontobasal involvement in the pathophysiology of cluster B PD related to JME.
Asunto(s)
Epilepsia Mioclónica Juvenil/complicaciones , Epilepsia Mioclónica Juvenil/patología , Trastornos de la Personalidad/complicaciones , Personalidad , Corteza Prefrontal/patología , Adulto , Mapeo Encefálico , Estudios de Casos y Controles , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética/métodos , Masculino , Escalas de Valoración Psiquiátrica , Estudios Retrospectivos , Encuestas y Cuestionarios , Adulto JovenRESUMEN
PURPOSE: Hyperventilation is an activation method that provokes physiological slowing of brain rhythms, interictal discharges, and seizures, especially in generalized idiopathic epilepsies. In this study we assessed its effectiveness in inducing focal seizures during video-EEG monitoring. METHODS: We analyzed the effects of hyperventilation (HV) during video-EEG monitoring (video-EEG) of patients with medically intractable focal epilepsies. We excluded children younger than 10 years, mentally retarded patients, and individuals with frequent seizures. RESULTS: We analyzed 97 patients; 24 had positive seizure activation (PSA), and 73 had negative seizure activation (NSA). No differences were found between groups regarding sex, age, age at epilepsy onset, duration of epilepsy, frequency of seizures, and etiology. Temporal lobe epilepsies were significantly more activated than frontal lobe epilepsies. Spontaneous and activated seizures did not differ in terms of their clinical characteristics, and the activation did not affect the performance of ictal single-photon emission computed tomography (SPECT). CONCLUSIONS: HV is a safe and effective method of seizure activation during monitoring. It does not modify any of the characteristics of the seizures and allows the obtaining of valuable ictal SPECTs. This observation is clinically relevant and suggests the effectiveness and the potential of HV in shortening the presurgical evaluation, especially of temporal lobe epilepsy patients, consequently reducing its costs and increasing the number of candidates for epilepsy surgery.