RESUMEN
OBJECTIVE: We used transcranial magnetic stimulation to investigate the effect of diurnal variability on cortical excitability in patients with epilepsy. METHODS: Thirty drug-naive patients with epilepsy (20 idiopathic generalized epilepsy [IGE], including 10 juvenile myoclonic epilepsy [JME], and 10 focal epilepsy) and 10 control subjects without epilepsy were studied both early in the morning and late in the afternoon. We measured the mean motor thresholds and constructed recovery curves at short (2-15 msec) and long (50-400 msec) interstimulus intervals. RESULTS: An increase in cortical excitability indicated by decreased short and long intracortical inhibition was observed early in the morning compared to the afternoon in patients with JME. In other IGE syndromes, there was decreased long intracortical inhibition only. No effect was found in subjects with focal epilepsy or controls without epilepsy. CONCLUSION: Cortical excitability measured by transcranial magnetic stimulation increases early in the morning in patients with idiopathic generalized epilepsy, particularly in juvenile myoclonic epilepsy, but not in subjects with focal epilepsy or controls without epilepsy. This may explain the increased seizure susceptibility in this cohort at this time of day.
Asunto(s)
Ritmo Circadiano/fisiología , Epilepsia Generalizada/fisiopatología , Epilepsia/fisiopatología , Adolescente , Adulto , Corteza Cerebral/fisiopatología , Estudios de Cohortes , Dominancia Cerebral/fisiología , Potenciales Evocados/fisiología , Potenciales Evocados Motores/fisiología , Femenino , Lateralidad Funcional/fisiología , Humanos , Masculino , Persona de Mediana Edad , Epilepsia Mioclónica Juvenil/fisiopatología , Inhibición Neural/fisiología , Valor Predictivo de las Pruebas , Tiempo de Reacción/fisiología , Sueño/fisiología , Estimulación Magnética Transcraneal , Vigilia/fisiología , Adulto JovenRESUMEN
OBJECTIVE: To use transcranial magnetic stimulation (TMS) to investigate the hypothesis that sleep deprivation increases cortical excitability in people with epilepsy. METHODS: We performed paired pulse TMS stimulation, using a number of interstimulus intervals (ISIs) on each hemisphere of 30 patients with untreated newly diagnosed epilepsy (15 idiopathic generalized epilepsy [IGE] and 15 focal epilepsy) and on the dominant hemisphere of 13 healthy control subjects, before and after sleep deprivation. RESULTS: Both hemispheres in patients with IGE and the hemisphere ipsilateral to the EEG seizure focus in those with focal epilepsy showed an increase in cortical excitability following sleep deprivation at a number of ISIs. This change in excitability was most prominent in the patients with IGE. Although there were minor changes after sleep deprivation in control subjects and the contralateral hemisphere in the focal epilepsy group seen at the 250-millisecond ISI, it was less than in the other groups. CONCLUSIONS: Sleep deprivation increases cortical excitability in epilepsy; the pattern of change is syndrome dependent.
Asunto(s)
Corteza Cerebral/fisiopatología , Epilepsia/fisiopatología , Privación de Sueño/fisiopatología , Adolescente , Adulto , Anciano , Electroencefalografía/métodos , Femenino , Lateralidad Funcional , Humanos , Masculino , Persona de Mediana Edad , Fase de Descanso del Ciclo Celular/fisiología , Factores de Tiempo , Estimulación Magnética Transcraneal/métodosRESUMEN
OBJECTIVES: To examine the risk and determinants of a progressive dementia syndrome and cognitive impairment not dementia (CIND) in community-based nonaphasic first-ever stroke cases 1 year after stroke, relative to a matched community-based stroke-free group. METHODS: Matched cohort design, with cognitive tests given on two occasions 9 months apart to 99 mild-to-moderate first-ever stroke patients and 99 age- and sex-matched people without stroke. At follow-up, progressive dementia or CIND were diagnosed, with judges blinded to stroke/nonstroke status. RESULTS: Progressive dementia was diagnosed in 12.5% of stroke patients and 15.4% of those without strokes (RR 1.1, 95% CI 0.5 to 2.2, p = 0.85). CIND was diagnosed in 37.5% of stroke patients and 17.6% of participants without strokes (RR 2.1, 95% CI 1.2 to 3.4, p = 0.003). In multivariable regression, age (p = 0.04) and baseline cognition (p < 0.001) were independently associated with dementia whereas stroke (p = 0.002), age (p = 0.05), baseline cognition (p = 0.001), and baseline mood (p = 0.03) were independently associated with CIND at follow-up. CONCLUSIONS: In this community-based nonaphasic sample, mild-to moderate first-ever stroke was not associated with the presence of progressive dementia 1 year later, but was clearly associated with a greater risk of cognitive impairment not dementia (CIND). Baseline mood impairment remained independently associated with CIND at 1 year after taking into account stroke, age, and baseline cognitive ability.
Asunto(s)
Infarto Cerebral/complicaciones , Demencia/epidemiología , Anciano , Anciano de 80 o más Años , Sesgo , Estudios de Casos y Controles , Infarto Cerebral/clasificación , Infarto Cerebral/epidemiología , Trastornos del Conocimiento/epidemiología , Trastornos del Conocimiento/etiología , Estudios de Cohortes , Comorbilidad , Demencia/etiología , Progresión de la Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Pruebas Neuropsicológicas , Selección de Paciente , Factores de Riesgo , Método Simple Ciego , Estados Unidos/epidemiologíaRESUMEN
BACKGROUND AND PURPOSE: Informal caregivers play an important role in the lives of stroke patients, but the cost of providing this care has not been estimated. The purpose of this study was to determine the nature and amount of informal care provided to stroke patients and to estimate the economic cost of that care. METHODS: The primary caregivers of stroke patients registered in the North East Melbourne Stroke Incidence Study (NEMESIS) were interviewed at 3, 6, and 12 months after stroke, and the nature and amount of informal care provided were documented. The opportunity and replacement costs of informal care for all first-ever-in-a-lifetime strokes (excluding subarachnoid hemorrhages) that occurred in 1997 in Australia were estimated. RESULTS: Among 3-month stroke survivors, 74% required assistance with activities of daily living and received informal care from family or friends. Two thirds of primary caregivers were women, and most primary caregivers (>90%) provided care during family or leisure time. Total first-year caregiver time costs for all first-ever-in-a-lifetime strokes were estimated to be A$21.7 million (opportunity cost approach) or A$42.5 million (replacement cost approach), and the present values of lifetime caregiver time costs were estimated to be A$171.4 million (opportunity cost approach) or A$331.8 million (replacement cost approach). CONCLUSIONS: Informal care for stroke survivors represents a significant hidden cost to Australian society. Because our community is rapidly aging, this informal care burden may increase significantly in the future.