Evolution of Cortical Functional Networks in Healthy Infants.

During normal childhood development, functional brain networks evolve over time in parallel with changes in neuronal oscillations. Previous studies have demonstrated differences in network topology with age, particularly in neonates and in cohorts spanning from birth to early adulthood. Here, we evaluate the developmental changes in EEG functional connectivity with a specific focus on the first 2 years of life. Functional connectivity networks (FCNs) were calculated from the EEGs of 240 healthy infants aged 0-2 years during wakefulness and sleep using a cross-correlation-based measure and the weighted phase lag index. Topological features were assessed via network strength, global clustering coefficient, characteristic path length, and small world measures. We found that cross-correlation FCNs maintained a consistent small-world structure, and the connection strengths increased after the first 3 months of infancy. The strongest connections in these networks were consistently located in the frontal and occipital regions across age groups. In the delta and theta bands, weighted phase lag index networks decreased in strength after the first 3 months in both wakefulness and sleep, and a similar result was found in the alpha and beta bands during wakefulness. However, in the alpha band during sleep, FCNs exhibited a significant increase in strength with age, particularly in the 21-24 months age group. During this period, a majority of the strongest connections in the networks were located in frontocentral regions, and a qualitatively similar distribution was seen in the beta band during sleep for subjects older than 3 months. Graph theory analysis suggested a small world structure for weighted phase lag index networks, but to a lesser degree than those calculated using cross-correlation. In general, graph theory metrics showed little change over time, with no significant differences between age groups for the clustering coefficient (wakefulness and sleep), characteristics path length (sleep), and small world measure (sleep). These results suggest that infant FCNs evolve during the first 2 years with more significant changes to network strength than features of the network structure. This study quantifies normal brain networks during infant development and can serve as a baseline for future investigations in health and neurological disease.

Scalp EEG markers of normal infant development using visual and computational approaches.

The infant brain is rapidly developing, and these changes are reflected in scalp electroencephalography (EEG) features, including power spectrum and sleep spindle characteristics. These biomarkers not only mirror infant development, but they are also altered by conditions such as epilepsy, autism, developmental delay, and trisomy 21. Prior studies of early development were generally limited by small cohort sizes, lack of a specific focus on infancy (0-2 years), and exclusive use of visual marking for sleep spindles. Therefore, we measured the EEG power spectrum and sleep spindles in 240 infants ranging from 0-24 months. To rigorously assess these metrics, we used both clinical visual assessment and computational techniques, including automated sleep spindle detection. We found that the peak frequency and power of the posterior dominant rhythm (PDR) increased with age, and a corresponding peak occurred in the EEG power spectra. Based on both clinical and computational measures, spindle duration decreased with age, and spindle synchrony increased with age. Our novel metric of spindle asymmetry suggested that peak spindle asymmetry occurs at 6-9 months of age.Clinical Relevance- Here we provide a robust characterization of the development of EEG brain rhythms during infancy. This can be used as a basis of comparison for studies of infant neurological disease, including epilepsy, autism, developmental delay, and trisomy 21.

Therapeutic interventions employed by Greater Toronto Area chiropractors on pregnant patients: results of a cross-sectional online survey.

INTRODUCTION: Due to different biomechanical, nutritional, and hormonal considerations, it is possible that chiropractors may employ different therapeutic interventions and recommendations for pregnant patients than non-pregnant ones. The objective of this study was to determine the therapeutic interventions that chiropractors who are members of the Ontario Chiropractic Association in the Greater Toronto Area most commonly provide to pregnant patients. METHODS: An introductory e-mail was sent in October 2011 to 755 members of the Ontario Chiropractic Association within the Greater Toronto Area five days prior to a 15 question survey being distributed via e-mail. Reminder e-mails were sent 13 days and 27 days later. Using descriptive statistics, demographic information was reported along with reported use of different treatments and recommendations for pregnant patients. RESULTS: A response rate of 23% was obtained. The majority of the respondents (90%) reported using the Diversified technique on pregnant patients, followed by soft tissue therapy (62%) and Activator (42%). The most common adjunctive therapy recommended to pregnant patients was referral to massage therapy (90%). Most of the respondents (92%) indicated that they prescribe stretching exercises to pregnant patients and recommend a multivitamin (84%) or folic acid (81%) to pregnant patients. CONCLUSION: In agreement with previous research on chiropractic technique usage on non-pregnant patients, the majority of respondents indicated treating pregnant patients with the Diversified technique, with other chiropractic techniques being utilized at varying rates on pregnant patients. Most respondents indicated prescribing exercise, and making adjunctive and nutritional recommendations frequently for their pregnant patients.

INTRODUCTION: En raison de considérations biomécaniques, nutritionnelles et hormonales différentes, il est possible que les chiropraticiens emploient différentes interventions thérapeutiques et différentes recommandations pour les patientes enceintes et les patientes non-enceintes. L'objectif de cette étude était de déterminer les interventions thérapeutiques que les chiropraticiens membres de l'Association chiropratique de l'Ontario dans la région du Grand Toronto proposent aux patientes enceintes. MÉTHODOLOGIE: Un courriel d'accueil a été envoyé en octobre 2011 aux 755 membres de l'Association chiropratique de l'Ontario dans la région du Grand Toronto, cinq jours avant l'envoi d'un sondage de 15 questions par courriel. Des courriels de rappel ont été envoyés 13 et 27 jours après. À l'aide de statistiques descriptives, des informations démographiques ont été rapportées ainsi que l'administration de différents traitements et recommandations pour les patientes enceintes. RÉSULTATS: Un taux de réponse de 23 % a été obtenue. La majorité des répondants (90 %) a indiqué utiliser la technique diversifiée sur les patientes enceintes, suivi par les traitements des tissus mous (62 %) et l'activateur (42 %) Les traitements auxiliaires les plus fréquemment recommandés aux patients sont les massothérapies (90 %). La plupart des répondants (92 %) ont indiqué prescrire des exercices d'étirements pour les patientes enceintes et recommander des comprimés multivitaminés (84 %) ou de l'acide folique (81 %) aux patientes enceintes. CONCLUSION: En accord avec des précédentes recherches sur l'utilisation de techniques chiropratiques sur les patientes non-enceintes, la majorité des répondants a indiqué traiter les patients avec la technique diversifiée, ainsi que d'autres techniques chiropratiques utilisées à différents fréquences sur les patientes enceintes. La plupart des répondants ont indiqué fréquemment prescrire des exercices, et faire des recommandations auxiliaires et nutritionnelles pour leurs patientes enceintes.