Reduced NREM sleep instability in benign childhood epilepsy with centro-temporal spikes
To analyze sleep architecture and NREM sleep instability by means of the cyclic alternating pattern (CAP) in children with benign epilepsy with rolandic spikes (BERS). Ten children with BERS, drug free at the time of the study and 10 age-matched normal controls were included in this study. Sleep was visually scored for sleep architecture and CAP using standard criteria. Sleep architecture in BERS showed only few significant differences vs. controls with a reduction of total sleep time, sleep efficiency, and REM sleep percentage. CAP analysis revealed several significant differences: reduced total CAP rate, mainly in sleep stage 2, and reduced EEG slow oscillations and arousals during stages N1 and N2. Sleep architecture is not importantly affected in BERS but CAP analysis reveals a decrease of NREM instability, mainly in sleep stage 2. Since there is a spindle-related spike activation in BERS, we speculate that the decrease of CAP and of EEG slow oscillations and arousals might be linked with the inhibitory action of spindling activity and spikes on arousals. CAP analysis discloses sleep structure abnormalities in children with BERS not shown by the classical sleep scoring. Spike activity and CAP A1 subtypes seem to be mutually exclusive probably because centro-temporal spikes disturb the physiological synchronization mechanisms needed for the generation of slow-wave components of CAP.
[Show abstract] [Hide abstract] ABSTRACT: Purpose: Increased evidence of subnormal neuropsychological functioning in new-onset childhood epilepsy has been obtained, although results are still rare and controversial. With a prospective study, we aimed to define the very early neuropsychological profile of children with benign epilepsy with centrotemporal spikes (BECTS), including executive functions (EF) because of their key role in learning. Additionally, we enrolled drug-naïve children, with a NREM sleep frequency of discharges <85% and with a Performance Intelligence Quotient equal or superior to 85, in order to exclude additional effects on the neuropsychological functioning. Methods: Fifteen school-aged children with BECTS (mean age: 8.8years, standard deviation [SD]: 2.4years) and fifteen healthy children (mean age: 9.2years, [SD]: 2.5years) were enrolled and assessed with a comprehensive neuropsychological battery. The assessment included domain-specific standardized tests of language, EF, academic skills, visuomotor and visuospatial skills, and short-term memory. A p-value<0.05 was considered significant. Results: Significant differences between patients and controls emerged with respect to 3 domains. Language was affected in color naming (p=.026), spoonerism (p=.003), and phonemic synthesis (p=.009). Executive functions appeared inadequate in the five point test with respect to the number of correct figures (p=.003) and errors (p=.008). In the domain of academic skills, significant differences between groups emerged regarding the number of mistakes in nonword writing (p=.001), nonword reading speed (p=.027), nonword reading number of mistakes (p=.019), and word reading errors (p=.023). Discussion: Results showed that children with new-onset BECTS may demonstrate a range of neuropsychological dysfunctions, particularly affecting executive attention, despite a normal IQ, a low frequency of NREM sleep discharges, and the absence of drugs. These difficulties indicate a frontal dysfunction with cascading effects on language and academic skills. The inclusion of EF in the assessment battery and in the intervention since the very onset is warranted in order to avoid further and persistent academic difficulties.0Comments 0Citations
- "Indeed, a whole night EEG would have allowed the study not only of the whole night sleep, in terms of both IED frequency, but also of sleep structure. Sleep structure abnormalities have been demonstrated in children with BECTS, indicating a decrease in NREM instability beyond the number of spikes . Consequently, the role of sleep structure alterations on the results in our patients is not ruled out. "
[Show abstract] [Hide abstract] ABSTRACT: Benign Epilepsy with centrotemporal spikes (BECTS) is considered a benign type of epilepsy; nevertheless a significant number of children present clear and heterogeneous cognitive deficits such as memory disturbances. Thus far, evidence about memory impairment has been less than conclusive. To clarify the quality of memory functioning in BECTS children, an analysis of existing findings has been conducted trying to identify the type of memory deficits and their underlying factors. Short- and long-term declarative memory are impaired in BECTS children, with both verbal and non-verbal material; co-occurrence of attentional, linguistic and behavioral disturbances is reported. In children with continuous spikes and waves during the slow-wave sleep pattern the normal downscaling of slow-wave activity is absent, disrupting plastic brain processes of sleep-related memory consolidation. In BECTS children, NREM sleep interictal epileptiform discharges (IED) may interfere in the dialogue between temporal and frontal cortex, causing declarative memory deficits: the role of NREM sleep IED acquires a special importance, leading to methodological guidance and suggesting aims for future researches in the field of childhood neuroscience.0Comments 16Citations
- "In last years, a study performed in children with BECTS suggested a normal sleep organization and the number of arousals was not increased (Clemens & Olah, 1987). More recently, Bruni et al. (2010) analyzed sleep architecture and NREM sleep instability by evaluating the cyclic alternating pattern (CAP) in children with BECTS. They studied ten drug free patients and ten age-matched normal controls. "
[Show abstract] [Hide abstract] ABSTRACT: We investigated 50 young patients with a diagnosis of Rolandic Epilepsy (RE) for the presence of abnormalities in autonomic tone compared with 50 young patients with idiopathic generalized epilepsy with absences and 50 typically developing children of comparable age. We analyzed time domain (N-N interval, pNN50) and frequency domain (High Frequency (HF), Low Frequency (LF) and LF/HF ratio) indices from ten-minute resting EKG activity. Patients with RE showed significantly higher HF and lower LF power and lower LF/HF ratio than controls, independent of the epilepsy group, and did not show significant differences in any other autonomic index with respect to the two control groups. In RE, we found a negative relationship between both seizure load and frequency of sleep interictal EEG abnormalities with parasympathetic drive levels. These changes might be the expression of adaptive mechanisms to prevent the excessive sympathetic drive seen in patients with refractory epilepsies.0Comments 2Citations
- "One of the possible neurochemical substrates could be the increase in GABA-ergic transmission , a mechanism invoked to explain the effect of direct vagal nerve stimulation . Further corroborating evidence comes from a recent report of reduced cyclic alternating pattern (CAP) rate in patients with RE . Cyclic alternating pattern rate is an index of sleep instability and is positively correlated with predominance of sympathetic drive . "