Antiseizure Medications Normalize Electroencephalographic Functional Connectivity and Power in Children With Benign Epilepsy With Centrotemporal Spikes.

BACKGROUND: The decision to treat children with benign epilepsy with centrotemporal spikes (BECTS) using antiseizure medications (ASM) is controversial. Our goal is to compare the effect of ASM treatment on the alteration of electroencephalographic (EEG) functional connectivity and power across four frequency bands in children with BECTS. METHODS: Children with BECTS with two-year follow-up were retrospectively divided into ASM versus non-ASM groups. The network properties of the EEGs as based on network-based statistic and graph theory were evaluated by the following indices: global efficiency, clustering coefficient, betweenness centrality, and nodal strength in four frequency bands (delta, theta, alpha, and beta). EEG power including absolute power (AP) and relative power (RP) was analyzed in four frequency bands. RESULTS: In children with BECTS with ASM treatment, there was no significant change in EEG connectivity across all bands before and after two years of ASM. In children with BECTS without ASM treatment, there was a significant increase of global efficiency, clustering coefficient, and nodal strength but not the betweenness centrality in the delta band after two years of follow-up. A decrease in AP in the delta and theta bands and a decrease in RP in the theta band were found in the ASM group after two years of treatment. CONCLUSIONS: Our results suggest that ASM may play a role in modulating the development of increasing overall brain connectivity and in downregulating overt synaptic activity, but not intrinsic focal connectivity, in the early years of BECTS. The changes in the EEG power indicate that ASM significantly normalized slow-wave band power.

Giant cystic hypothalamic hamartoma in an infant associated with persistent syndrome of inappropriate antidiuretic hormone secretion.

BACKGROUND: A giant hypothalamic hamartoma (GHH) is a rare congenital malformation only reported in a few cases in the literature and is often associated with precocious puberty, gelastic seizures, or less commonly, Pallister-Hall syndrome. Persistent syndrome of inappropriate antidiuretic hormone secretion (SIADH) is very rare in infancy, and most patients with GHH do not develop persistent SIADH, usually only transient electrolyte disturbances postoperatively. Previous cases of GHH have not been associated with persistent derangements in antidiuretic hormone levels. CASE DESCRIPTION: A 7-month-old male infant presented to our hospital with a history of an intracranial cystic lesion diagnosed at 23 weeks gestational age (GA), later impressed as a solid-cystic mass at 37 weeks GA by ultrasound prenatally. Postnatal MRI after birth showed a large mass with a dorsal cyst occupying the hypothalamus, causing hydrocephalus and brainstem compression. The patient started to have subtle seizures on the seventh day after birth and eventually developed dacrystic seizures. Hyponatremia with persistent SIADH was observed at 3 months of age before surgery. He received long-term oral sodium supplementation, polytherapy of anti-epileptic medications, ventriculocystostomy for progressive enlargement of the cystic cavity, and later surgical treatment for disconnection and partial resection which confirmed a histological diagnosis of hypothalamic hamartoma. CONCLUSION: In this case study, we present a novel association of GHH with persistent SIADH and a rare presentation of a cystic component at the dorsal part of the tumor. Clinicians should be aware of this potential endocrine derangement and provide emergent treatment.

Long-Range Optogenetic Control of Axon Guidance Overcomes Developmental Boundaries and Defects.

Axons connect neurons together, establishing the wiring architecture of neuronal networks. Axonal connectivity is largely built during embryonic development through highly constrained processes of axon guidance, which have been extensively studied. However, the inability to control axon guidance, and thus neuronal network architecture, has limited investigation of how axonal connections influence subsequent development and function of neuronal networks. Here, we use zebrafish motor neurons expressing a photoactivatable Rac1 to co-opt endogenous growth cone guidance machinery to precisely and non-invasively direct axon growth using light. Axons can be guided over large distances, within complex environments of living organisms, overriding competing endogenous signals and redirecting axons across potent repulsive barriers to construct novel circuitry. Notably, genetic axon guidance defects can be rescued, restoring functional connectivity. These data demonstrate that intrinsic growth cone guidance machinery can be co-opted to non-invasively build new connectivity, allowing investigation of neural network dynamics in intact living organisms.