Continuous Spike-Wave during Slow Wave Sleep and Related Conditions

Continuous spike and wave during slow wave sleep (CSWS) is an epileptic encephalopathy that presents with neurocognitive regression and clinical seizures, and that demonstrates an electroencephalogram (EEG) pattern of electrical status epilepticus during sleep, as defined by the Commission on Classification and Terminology of the International League Against Epilepsy 1989. CSWS is an age-related condition, typically presenting in children around 5 years of age, with clinical seizures which progress within 2 years to a severe epileptic encephalopathy. The pathophysiology of CSWS is not completely understood, but the corticothalamic neuronal network involved in sleep patterns is thought to be involved. Genetic predisposition and injury in early development are thought to play etiological roles. Treatment strategies have involved traditional anticonvulsants, hormonal therapies, and other newer techniques. Outcomes are fair, and the thought is that earlier diagnosis and intervention preserve neurocognitive development, as in the case of other epileptic encephalopathies. Further understanding of the mechanisms of CSWS may lead to improved therapeutic options and thus outcomes of children with CSWS

Role of trauma and infection in childhood hemorrhagic stroke due to vascular lesions.

ObjectiveTrauma and infection have been postulated as "triggers" for hemorrhage from underlying brain vascular lesions (arteriovenous malformations, cavernous malformations, and aneurysms) in pediatric hemorrhagic stroke. We decided to perform an association study examining these environmental risk factors.MethodsIn this case-control study nested within the cohort of 2.3 million children enrolled in a Northern California integrated health plan (1993-2004), we identified childhood hemorrhagic stroke cases through electronic searches of diagnostic and radiology databases, confirmed through chart review. Three age- and facility-matched controls per case were randomly selected from the study population. Exposure variables were measured using medical records documented before stroke diagnosis. Main outcome measure was hemorrhagic stroke.ResultsOf 132 childhood, non-neonatal hemorrhagic stroke cases, 65 had underlying vascular lesions: 34 arteriovenous malformations, 16 cavernous malformations, and 15 aneurysms. A documented exposure to head and neck trauma in the prior 12 weeks was present in 3 cases (4.6%) with underlying vascular lesions, compared with no controls (p < 0.015). However, all 3 vascular lesions were aneurysms, and traumatic pseudoaneurysms were possible. Recent minor infection (prior 4 weeks) was present in 5 cases (7.7%) and 9 controls (4.6%) (p = 0.34).ConclusionsOur observed association between trauma and hemorrhagic stroke with a vascular lesion may be explained by traumatic pseudoaneurysms. Neither recent head or neck trauma nor infection appeared to be a "trigger" for pediatric hemorrhagic stroke due to underlying vascular malformations

SLC35A2â CDG: Functional characterization, expanded molecular, clinical, and biochemical phenotypes of 30 unreported Individuals

Pathogenic de novo variants in the Xâ linked gene SLC35A2 encoding the major Golgiâ localized UDPâ galactose transporter required for proper protein and lipid glycosylation cause a rare type of congenital disorder of glycosylation known as SLC35A2â congenital disorders of glycosylation (CDG; formerly CDGâ IIm). To date, 29 unique de novo variants from 32 unrelated individuals have been described in the literature. The majority of affected individuals are primarily characterized by varying degrees of neurological impairments with or without skeletal abnormalities. Surprisingly, most affected individuals do not show abnormalities in serum transferrin Nâ glycosylation, a common biomarker for most types of CDG. Here we present data characterizing 30 individuals and add 26 new variants, the single largest study involving SLC35A2â CDG. The great majority of these individuals had normal transferrin glycosylation. In addition, expanding the molecular and clinical spectrum of this rare disorder, we developed a robust and reliable biochemical assay to assess SLC35A2â dependent UDPâ galactose transport activity in primary fibroblasts. Finally, we show that transport activity is directly correlated to the ratio of wildâ type to mutant alleles in fibroblasts from affected individuals.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/150498/1/humu23731_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150498/2/humu23731-sup-0001-Supp_Mat__2019.2.10_.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150498/3/humu23731.pd

Continuous Spike-Wave during Slow Wave Sleep and Related Conditions.

Continuous spike and wave during slow wave sleep (CSWS) is an epileptic encephalopathy that presents with neurocognitive regression and clinical seizures, and that demonstrates an electroencephalogram (EEG) pattern of electrical status epilepticus during sleep, as defined by the Commission on Classification and Terminology of the International League Against Epilepsy 1989. CSWS is an age-related condition, typically presenting in children around 5 years of age, with clinical seizures which progress within 2 years to a severe epileptic encephalopathy. The pathophysiology of CSWS is not completely understood, but the corticothalamic neuronal network involved in sleep patterns is thought to be involved. Genetic predisposition and injury in early development are thought to play etiological roles. Treatment strategies have involved traditional anticonvulsants, hormonal therapies, and other newer techniques. Outcomes are fair, and the thought is that earlier diagnosis and intervention preserve neurocognitive development, as in the case of other epileptic encephalopathies. Further understanding of the mechanisms of CSWS may lead to improved therapeutic options and thus outcomes of children with CSWS

Continuous Spike-Wave during Slow Wave Sleep and Related Conditions.

Continuous spike and wave during slow wave sleep (CSWS) is an epileptic encephalopathy that presents with neurocognitive regression and clinical seizures, and that demonstrates an electroencephalogram (EEG) pattern of electrical status epilepticus during sleep, as defined by the Commission on Classification and Terminology of the International League Against Epilepsy 1989. CSWS is an age-related condition, typically presenting in children around 5 years of age, with clinical seizures which progress within 2 years to a severe epileptic encephalopathy. The pathophysiology of CSWS is not completely understood, but the corticothalamic neuronal network involved in sleep patterns is thought to be involved. Genetic predisposition and injury in early development are thought to play etiological roles. Treatment strategies have involved traditional anticonvulsants, hormonal therapies, and other newer techniques. Outcomes are fair, and the thought is that earlier diagnosis and intervention preserve neurocognitive development, as in the case of other epileptic encephalopathies. Further understanding of the mechanisms of CSWS may lead to improved therapeutic options and thus outcomes of children with CSWS

Role of trauma and infection in childhood hemorrhagic stroke due to vascular lesions.

ObjectiveTrauma and infection have been postulated as "triggers" for hemorrhage from underlying brain vascular lesions (arteriovenous malformations, cavernous malformations, and aneurysms) in pediatric hemorrhagic stroke. We decided to perform an association study examining these environmental risk factors.MethodsIn this case-control study nested within the cohort of 2.3 million children enrolled in a Northern California integrated health plan (1993-2004), we identified childhood hemorrhagic stroke cases through electronic searches of diagnostic and radiology databases, confirmed through chart review. Three age- and facility-matched controls per case were randomly selected from the study population. Exposure variables were measured using medical records documented before stroke diagnosis. Main outcome measure was hemorrhagic stroke.ResultsOf 132 childhood, non-neonatal hemorrhagic stroke cases, 65 had underlying vascular lesions: 34 arteriovenous malformations, 16 cavernous malformations, and 15 aneurysms. A documented exposure to head and neck trauma in the prior 12 weeks was present in 3 cases (4.6%) with underlying vascular lesions, compared with no controls (p < 0.015). However, all 3 vascular lesions were aneurysms, and traumatic pseudoaneurysms were possible. Recent minor infection (prior 4 weeks) was present in 5 cases (7.7%) and 9 controls (4.6%) (p = 0.34).ConclusionsOur observed association between trauma and hemorrhagic stroke with a vascular lesion may be explained by traumatic pseudoaneurysms. Neither recent head or neck trauma nor infection appeared to be a "trigger" for pediatric hemorrhagic stroke due to underlying vascular malformations

De novo KCNA6 variants with attenuated KV1.6 channel deactivation in patients with epilepsy

OBJECTIVE: Mutations in the genes encoding neuronal ion channels are a common cause of Mendelian neurological diseases. We sought to identify novel de novo sequence variants in cases with early infantile epileptic phenotypes and neurodevelopmental anomalies. METHODS: Following clinical diagnosis, we performed whole exome sequencing of the index cases and their parents. Identified channel variants were expressed in Xenopus oocytes and their functional properties assessed using two-electrode voltage-clamp. RESULTS: We identified novel de novo variants in KCNA6 in four unrelated individuals variably affected with neurodevelopmental disorders and seizures with onset in the first year of life. Three of the four identified mutations affect pore lining S6 α-helix of KV 1.6. Prominent finding of functional characterisation in Xenopus oocytes was that the channel variants showed only minor effects on channel activation but slowed channel closure and shifted the voltage dependence of deactivation in a hyperpolarizing direction. Channels with a mutation affecting the S6 helix display dominant effects on channel deactivation when co-expressed with wild-type KV 1.6 or KV 1.1 subunits. SIGNIFICANCE: This is the first report of de novo non-synonymous variants in KCNA6 associated with neurological or any clinical features. Channel variants showed a consistent effect on channel deactivation, slowing the rate of channel closure following normal activation. This specific gain-of-function feature is likely to underlie the neurological phenotype in our patients. Our data highlight KCNA6 as a novel channelopathy gene associated with early infantile epileptic phenotypes and neurodevelopmental anomalies

SLC35A2‐CDG: Functional characterization, expanded molecular, clinical, and biochemical phenotypes of 30 unreported Individuals

Pathogenic de novo variants in the X-linked gene SLC35A2 encoding the major Golgi-localized UDP-galactose transporter required for proper protein and lipid glycosylation cause a rare type of congenital disorder of glycosylation known as SLC35A2-congenital disorders of glycosylation (CDG; formerly CDG-IIm). To date, 29 unique de novo variants from 32 unrelated individuals have been described in the literature. The majority of affected individuals are primarily characterized by varying degrees of neurological impairments with or without skeletal abnormalities. Surprisingly, most affected individuals do not show abnormalities in serum transferrin N-glycosylation, a common biomarker for most types of CDG. Here we present data characterizing 30 individuals and add 26 new variants, the single largest study involving SLC35A2-CDG. The great majority of these individuals had normal transferrin glycosylation. In addition, expanding the molecular and clinical spectrum of this rare disorder, we developed a robust and reliable biochemical assay to assess SLC35A2-dependent UDP-galactose transport activity in primary fibroblasts. Finally, we show that transport activity is directly correlated to the ratio of wild-type to mutant alleles in fibroblasts from affected individuals