Effects of partial sleep deprivation on prefrontal cognitive functions in adolescents.

Purpose: The effect of sleep deprivation on cognitive functions associated with the frontal lobe, such as attention, executive functions, and working memory, is not well known. This study aimed to investigate the effect of partial sleep deprivation in adolescents on the cognitive tasks of the frontal lobe, including visuospatial working memory, processing speed, sustained attention, executive functions, and short-term visual memory. Methods: Participants were recruited from voluntary students of Çukurova University. Eighteen adolescents underwent four consecutive nights of monitored sleep restriction (6-6.5 h/night) and four nights of sleep extension (10-10.5 h/night) in a counterbalanced order and separated by a washout period. Following each sleep period, the cognitive performance was assessed, at a fixed morning time, using a computerized neuropsychological test battery based on frontal lobe functions tasks, which was a timed test providing both accuracy and reaction time outcome measures. Results: Only the spatial working memory performance of cognitive tasks was found to be statistically lower in the restricted-sleep condition than in the extended-sleep condition (p < 0.05). No significant difference was found in the performance of cognitive tasks evaluating simple attention, constant attention, executive functions, and cognitive flexibility. Conclusions: The findings of this study indicated that partial sleep restriction negatively affects specifically working memory and strategic thinking skills among cognitive functions based on the frontal lobe. Especially the visuospatial working memory and strategic thinking skills of adolescents might be susceptible to chronic partial sleep deprivation.

Risk of recurrence after discontinuation of antiepileptic drug therapy in children with epilepsy.

OBJECTIVES: The numerous antiepileptic drug (AED) withdrawal studies published in the last 40 years have relied mainly on heterogeneous study groups. There is still no general agreement on the criteria to predict safe discontinuation. The goal of this study was to assess the outcome of AED withdrawal in epileptic children. MATERIALS AND METHODS: Three hundred and eight children with epilepsy were enrolled, and these patients followed at least 1 year after drug withdrawal. Time to seizure relapse and predictive factors were analyzed by survival methods. RESULTS: Among the 308 patients, 179 (58.1%) were boys and 129 (41.9%) were girls and the mean age at the seizure onset was 60.41 ± 36.54 months (2-144 months). The recurrence occurred in 73 (23.7%) patients. Mental retardation, history of febrile seizure, etiological of epilepsy, abnormal first electroencephalogram (EEG), abnormal neuroimaging findings, and total number of AED before remission were significantly associated with relapse risk according to univariate analysis. In the multivariate analysis, abnormal first EEG and number of AED before remission (polytherapy) were the risk factors influencing seizure recurrence. CONCLUSIONS: In our study, recurrence rate was 23.7% in children and most occurred during the 1(st) year. The potential risk factors of recurrence are history of febrile seizure, mental retardation, etiological of epilepsy, abnormal first EEG, abnormal neuroimaging findings, and total number of AED before remission. However, we found abnormal first EEG and polytherapy as risk factors of recurrence in multivariate analysis.

Relationship between metabolic control and neurocognitive functions in children diagnosed with type I diabetes mellitus before and after 5 years of age.

We aimed to investigate the effects of age onset of diabetes, glycemic control and frequency of hypoglycemia on neurocognitive functions in type I diabetic children. Sixty type I diabetic children with diagnosis before (Group 1) or after (Group 2) five years of age and 40 healthy children were tested. Wechsler Intelligence Scale for Children Revised (WISC-R), Stroop Test, and Visual Auditory Digit Span Test Form B were applied to all children in the two groups. Neurocognitive functions such as visual perception, short-term memory and selective attention were seen to be negatively affected at a significant level. Group 1 patients with poor glycemic control were found to have significant dysfunction in verbal, performance and general intelligence. Neurocognitive functions were negatively affected by early onset of diagnosis, poor glycemic control and frequent hypoglycemia in children with type I diabetes mellitus. We suggest that negative effects on neurocognitive functions in type I diabetes should be considered in the follow-up of these patients.

Factors affecting epilepsy development and epilepsy prognosis in cerebral palsy.

A study was conducted between November 2006 and October 2009 to determine the factors predicting the presence and prognosis of epilepsy in patients with cerebral palsy. We enrolled 2 groups of patients: 42 with cerebral palsy in group 1 and 56 patients with cerebral palsy and epilepsy in group 2. The subjects in group 2 were considered to have good epilepsy prognosis if they were free of seizures for the previous year; otherwise they were considered to have poor epilepsy prognosis. In group 2, neonatal epilepsy, family history of epilepsy, and moderate to severe mental retardation were significantly higher than in group 1 (P < 0.05). In univariate analysis, neonatal seizures, epileptic activity as measured by electroencephalography, and polytherapy were found to be predictors of poor epilepsy prognosis. Additionally, the need for long-term medication to control seizures unfavorably affects prognosis. In logistic regression analysis, neonatal seizure and interictal epileptic activity in electroencephalography were found to be independent predictors of poor epilepsy outcome. In addition, logistic regression analysis revealed that increasing age reduces the success of epilepsy treatment. Neonatal seizures, family history of epilepsy, and mental retardation were found to be important and independent predictors of development of epilepsy in patients with cerebral palsy.

Cognitive functions in neurofibromatosis type 1 patients and unaffected siblings.

Attention, learning, and perceptual problems have been reported at various degrees and rates in neurofibromatosis type 1 (NF1). We aimed to define the cognitive profiles frequently associated with NF1. Children and adolescents with NF1 (n=58) were tested using Wechsler Intelligence Scales for Children-Revised (WISC-R), Judgment of Line Orientation, and Bender Visual-Motor Gestalt tests. Comparison groups were unaffected siblings of NF1 patients (n=20), children with attention deficit and hyperactivity disorder (ADHD, n=40), and normal children (n=40). No difference was found between familial or sporadic NF1 cases. Seventeen/58 (29%) of NF1 cases had a full scale IQ<70. The subgroup of NF1 patients with full scale IQ>80 (n=27) scored lower in WISC-R subtests measuring visual perception when compared to a healthy control group of similar intelligence, and lower in arithmetic but better in Bender-Gestalt and Judgment of Line Orientation tests when compared to an ADHD group of similar intelligence. These results indicate a high prevalence of mental retardation in a clinical NF1 series. NF1 patients who have normal intelligence may have impaired visual perception, but their visual perceptual problems are less than in ADHD. The tendency of unaffected siblings of NF1 patients to have mildly but consistently low test scores compared to healthy controls needs to be studied further for underlying genetic or environmental factors.

Clinical characteristics of 10 patients with continuous spikes and waves during slow sleep syndrome.

Continuous spikes and waves during slow sleep syndrome is characterized by the presence of spike-and-wave discharges in at least 85% of non-rapid eye movement sleep. Associated clinical features vary. Here, features of 10 patients with this syndrome are compared to those in the literature. Patients ranged in age from 4 to 11 years. All patients had predominantly nocturnal partial motor or generalized tonic-clonic seizures; four patients also had daily atonic seizures. All 10 patients had different degrees of neuropsychologic disturbances: 9 patients had low intelligence quotient scores (the 10th, diagnosed attention deficit and hyperactivity disorder, had normal intelligence quotient score); 4 patients had autistic-like features. Apart from mental retardation (7 of 10), physical and neurologic findings were normal. Significant pyramidal signs and microcephaly were detected in two patients, and hypotonia, ataxia, and bilateral pyramidal signs were found in one other. Cranial magnetic resonance imaging findings were normal for 6 patients; the other 4 had some abnormal findings. Continuous spikes and waves during slow sleep syndrome is a rare epileptic syndrome in childhood. A variety of clinical and neurocognitive features were found in patients with continuous spikes and waves during slow sleep syndrome.