Sleep spindle activity in children with obstructive sleep apnea as a marker of neurocognitive performance: A pilot study.

STUDY OBJECTIVES: To assess spindle activity as possible markers for neurocognitive consequences in children with mild obstructive sleep apnea. METHODS: Children aged 6-11 years diagnosed with mild OSA (i.e., an apnea hypopnea index <5.0) were recruited and compared with age and gender-matched healthy controls. Polysomnographic recordings were analyzed for sleep microstructure and spindle activity. All children completed also an intelligence test battery (i.e., the Wechsler intelligence test for children, 4th version). RESULTS: Nineteen children with OSA (13 boys, mean age 7.1 ± 1.4 y), and 14 controls (7 boys, mean age 8.1 ± 1.9 y) were included. Mean IQ was 110 ± 12 for the complete sample, in children with OSA 111 ± 13, and in controls 108 ± 12 (p = 0.602). Controls showed a higher spindle index in N2 stage than children with OSA: 143.0 ± 42.5 vs 89.5 ± 56.9, respectively (p = 0.003). Spindle index in NREM was strongly and significantly correlated with Verbal Comprehension Index (VCI), Working Memory Index (WMI), Processing Speed Index (PSI), and total IQ in children with OSA. CONCLUSIONS: Children with mild OSA demonstrate a different pattern of sleep spindle activity that seems to be linked with neurocognitive performance, especially concerning memory. Sleep spindle activity seems to be involved with mechanisms related with neurocognitive consequences in children with OSA.

Theta and Alpha Oscillation Impairments in Autistic Spectrum Disorder Reflect Working Memory Deficit.

A dysfunction in the excitatory-inhibitory (E/I) coordination in neuronal assembly has been proposed as a possible neurobiological mechanism of Autistic Spectrum Disorder (ASD). However, the potential impact of this mechanism in cognitive performance is not fully explored. Since the main consequence of E/I dysfunction is an impairment in oscillatory activity and its underlying cognitive computations, we assessed the electroencephalographic activity of ASD and typically developing (TD) subjects during a working-memory task. We found that ASD subjects committed more errors than TD subjects. Moreover, TD subjects demonstrated a parametric modulation in the power of alpha and theta band while ASD subjects did not demonstrate significant modulations. The preceding leads to significant differences between the groups in both the alpha power placed on the occipital cortex and the theta power placed on the left premotor and the right prefrontal cortex. The impaired theta modulation correlated with autistic symptoms. The results indicated that ASD may present an alteration in the recruitment of the oscillatory activity during working-memory, and this alteration could be related to the physiopathology of the disorder.

Trastorno por déficit de atención e hiperactividad en niños aymara: primera aproximación clínica / Attention deficit hyperactivity disorder in Aymara children

Background: The assessment of Attentional Deficit Hyperactivity Disorder (ADHD) among ethnic groups may reveal environmental or cultural variables that influence the appearance of this disorder. Aim: To assess the presence and characteristics of ADHD in two communities of the inland Arica valleys (Azapa and Lluta), where the Aymara population predominates. Material and Methods: Startingfrom a screening based on the Conner's test, we evaluated 79 children aged 8 to 13 years. Sixty children were of Aymara origin and 19 children were of non-Aymara origin. Twenty Aymara and 9 non-Aymara children had ADHD. They were compared with a group of patients from Santiago, Chile (110 children) that were previously assessed. Results: Patientsfrom Azapa/Lluta displayed similar characteristics to those from Santiago. However the former had significantly less psychiatric comorbidities than the latter. On the other hand, the non-Aymara subgroup of Azapa/ Lluta displayed an increased rate of comorbidities and was exclusively of the combined subtype, although their sample size is too small to draw strong conclusions. Conclusions: Although we cannot dismiss biological variables, the importance of family values and the respect to authorities may be protective factors for ADHD, associated to Aymara culture. Our findings suggest that the clinical characteristics of ADHD are not uniform among ethnic groups and cultures. The relative contribution of environmental and genetic factors in this variability remain to be determined.

[Attention deficit hyperactivity disorder in Aymara children]. / Trastorno por déficit de atención e hiperactividad en niños aymara: primera aproximación clínica.

BACKGROUND: The assessment of Attentional Deficit Hyperactivity Disorder (ADHD) among ethnic groups may reveal environmental or cultural variables that influence the appearance of this disorder. AIM: To assess the presence and characteristics of ADHD in two communities of the inland Arica valleys (Azapa and Lluta), where the Aymara population predominates. MATERIAL AND METHODS: Starting from a screening based on the Conner's test, we evaluated 79 children aged 8 to 13 years. Sixty children were of Aymara origin and 19 children were of non-Aymara origin. Twenty Aymara and 9 non-Aymara children had ADHD. They were compared with a group of patients from Santiago, Chile (110 children) that were previously assessed. RESULTS: Patients from Azapa/Lluta displayed similar characteristics to those from Santiago. However the former had significantly less psychiatric comorbidities than the latter. On the other hand, the non-Aymara subgroup of Azapa/Lluta displayed an increased rate of comorbidities and was exclusively of the combined subtype, although their sample size is too small to draw strong conclusions. CONCLUSIONS: Although we cannot dismiss biological variables, the importance of family values and the respect to authorities may be protective factors for ADHD, associated to Aymara culture. Our findings suggest that the clinical characteristics of ADHD are not uniform among ethnic groups and cultures. The relative contribution of environmental and genetic factors in this variability remain to be determined.