Crisis Standard of Care: Management of Infantile Spasms during COVID‐19

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156180/2/ana25792_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156180/1/ana25792.pd

Stability of transcranial magnetic stimulation electroencephalogram evoked potentials in pediatric epilepsy

Abstract Transcranial magnetic stimulation paired with electroencephalography (TMS–EEG) can measure local excitability and functional connectivity. To address trial-to-trial variability, responses to multiple TMS pulses are recorded to obtain an average TMS evoked potential (TEP). Balancing adequate data acquisition to establish stable TEPs with feasible experimental duration is critical when applying TMS–EEG to clinical populations. Here we aim to investigate the minimum number of pulses (MNP) required to achieve stable TEPs in children with epilepsy. Eighteen children with Self-Limited Epilepsy with Centrotemporal Spikes, a common epilepsy arising from the motor cortices, underwent multiple 100-pulse blocks of TMS to both motor cortices over two days. TMS was applied at 120% of resting motor threshold (rMT) up to a maximum of 100% maximum stimulator output. The average of all 100 pulses was used as a “gold-standard” TEP to which we compared “candidate” TEPs obtained by averaging subsets of pulses. We defined TEP stability as the MNP needed to achieve a concordance correlation coefficient of 80% between the candidate and “gold-standard” TEP. We additionally assessed whether experimental or clinical factors affected TEP stability. Results show that stable TEPs can be derived from fewer than 100 pulses, a number typically used for designing TMS-EEG experiments. The early segment (15–80 ms) of the TEP was less stable than the later segment (80–350 ms). Global mean field amplitude derived from all channels was less stable than local TEP derived from channels overlying the stimulated site. TEP stability did not differ depending on stimulated hemisphere, block order, or antiseizure medication use, but was greater in older children. Stimulation administered with an intensity above the rMT yielded more stable local TEPs. Studies of TMS-EEG in pediatrics have been limited by the complexity of experimental set-up and time course. This study serves as a critical starting point, demonstrating the feasibility of designing efficient TMS–EEG studies that use a relatively small number of pulses to study pediatric epilepsy and potentially other pediatric groups

Systemic Manifestations in Pyridox(am)ine 5'-Phosphate Oxidase Deficiency.

Abstract Objective Pyridoxine is converted to its biologically active form pyridoxal-5-phosphate (P5P) by the enzyme pyridox(am)ine 5′-phosphate oxidase and serves as a cofactor in nearly 200 reactions in the central nervous system. Pyridox(am)ine 5′-phosphate oxidase deficiency leads to P5P dependent epilepsy, typically a neonatal- or infantile-onset epileptic encephalopathy treatable with P5P or in some cases, pyridoxine. Following identification of retinopathy in a patient with pyridox(am)ine 5′-phosphate oxidase deficiency that was reversible with P5P therapy, we describe the systemic manifestations of pyridox(am)ine 5′-phosphate oxidase deficiency. Methods A series of six patients with homozygous mutations of PNPO , the gene coding pyridox(am)ine 5′-phosphate oxidase, were evaluated in our center over the course of two years for phenotyping of neurological and systemic manifestations. Results Five of six were born prematurely, three had anemia and failure to thrive, and two had elevated alkaline phosphatase. A movement disorder was observed in two children, and a reversible retinopathy was observed in the most severely affected infant. All patients had neonatal-onset epilepsy and were on a continuum of developmental delay to profound encephalopathy. Electroencephalographic features included background slowing and disorganization, absent sleep features, and multifocal and generalized epileptiform discharges. All the affected probands carried a homozygous PNPO mutation (c.674 G>T, c.686 G>A and c.352G>A). Conclusion In addition to the well-described epileptic encephalopathy, pyridox(am)ine 5′-phosphate oxidase deficiency causes a range of neurological and systemic manifestations. A movement disorder, developmental delay, and encephalopathy, as well as retinopathy, anemia, and failure to thrive add to the broadening clinical spectrum of P5P dependent epilepsy

Corpus callosum white matter diffusivity reflects cumulative neurological comorbidity in tuberous sclerosis complex

Introduction: Neurological manifestations in Tuberous Sclerosis Complex (TSC) are highly variable. Diffusion tensor imaging (DTI) may reflect the neurological disease burden. We analyzed the association of autism spectrum disorder (ASD), intellectual disability (ID) and epilepsy with callosal DTI metrics in subjects with and without TSC. Methods: 186 children underwent 3T MRI DTI: 51 with TSC (19 with concurrent ASD), 46 with non-syndromic ASD and 89 healthy controls (HC). Subgroups were based on presence of TSC, ASD, ID, and epilepsy. Density-weighted DTI metrics obtained from tractography of the corpus callosum were fitted using a 2-parameter growth model. We estimated distributions using bootstrapping and calculated half-life and asymptote of the fitted curves. Results: TSC was associated with a lower callosal fractional anisotropy (FA) than ASD, and ASD with a lower FA than HC. ID, epilepsy and ASD diagnosis were each associated with lower FA values, demonstrating additive effects. In TSC, the largest change in FA was related to a comorbid diagnosis of ASD. Mean diffusivity (MD) showed an inverse relationship to FA. Some subgroups were too small for reliable data fitting. Conclusions: Using a cross-disorder approach, this study demonstrates cumulative abnormality of callosal white matter diffusion with increasing neurological comorbidity

Corpus callosum white matter diffusivity reflects cumulative neurological comorbidity in tuberous sclerosis complex

Introduction: Neurological manifestations in Tuberous Sclerosis Complex (TSC) are highly variable. Diffusion tensor imaging (DTI) may reflect the neurological disease burden. We analyzed the association of autism spectrum disorder (ASD), intellectual disability (ID) and epilepsy with callosal DTI metrics in subjects with and without TSC. Methods: 186 children underwent 3T MRI DTI: 51 with TSC (19 with concurrent ASD), 46 with non-syndromic ASD and 89 healthy controls (HC). Subgroups were based on presence of TSC, ASD, ID, and epilepsy. Density-weighted DTI metrics obtained from tractography of the corpus callosum were fitted using a 2-parameter growth model. We estimated distributions using bootstrapping and calculated half-life and asymptote of the fitted curves. Results: TSC was associated with a lower callosal fractional anisotropy (FA) than ASD, and ASD with a lower FA than HC. ID, epilepsy and ASD diagnosis were each associated with lower FA values, demonstrating additive effects. In TSC, the largest change in FA was related to a comorbid diagnosis of ASD. Mean diffusivity (MD) showed an inverse relationship to FA. Some subgroups were too small for reliable data fitting. Conclusions: Using a cross-disorder approach, this study demonstrates cumulative abnormality of callosal white matter diffusion with increasing neurological comorbidity

Mapping causal circuit dynamics in stroke using simultaneous electroencephalography and transcranial magnetic stimulation

BackgroundMotor impairment after stroke is due not only to direct tissue loss but also to disrupted connectivity within the motor network. Mixed results from studies attempting to enhance motor recovery with Transcranial Magnetic Stimulation (TMS) highlight the need for a better understanding of both connectivity after stroke and the impact of TMS on this connectivity. This study used TMS-EEG to map the causal information flow in the motor network of healthy adult subjects and define how stroke alters these circuits.MethodsFourteen stroke patients and 12 controls received TMS to two sites (bilateral primary motor cortices) during two motor tasks (paretic/dominant hand movement vs. rest) while EEG measured the cortical response to TMS pulses. TMS-EEG based connectivity measurements were derived for each hemisphere and the change in connectivity (ΔC) between the two motor tasks was calculated. We analyzed if ΔC for each hemisphere differed between the stroke and control groups or across TMS sites, and whether ΔC correlated with arm function in stroke patients.ResultsRight hand movement increased connectivity in the left compared to the right hemisphere in controls, while hand movement did not significantly change connectivity in either hemisphere in stroke. Stroke patients with the largest increase in healthy hemisphere connectivity during paretic hand movement had the best arm function.ConclusionsTMS-EEG measurements are sensitive to movement-induced changes in brain connectivity. These measurements may characterize clinically meaningful changes in circuit dynamics after stroke, thus providing specific targets for trials of TMS in post-stroke rehabilitation

Diagnosis of adenylosuccinate lyase deficiency by metabolomic profiling in plasma reveals a phenotypic spectrum

Adenylosuccinate lyase (ADSL) deficiency is a rare autosomal recessive neurometabolic disorder that presents with a broad-spectrum of neurological and physiological symptoms. The ADSL gene produces an enzyme with binary molecular roles in de novo purine synthesis and purine nucleotide recycling. The biochemical phenotype of ADSL deficiency, accumulation of SAICAr and succinyladenosine (S-Ado) in biofluids of affected individuals, serves as the traditional target for diagnosis with targeted quantitative urine purine analysis employed as the predominate method of detection. In this study, we report the diagnosis of ADSL deficiency using an alternative method, untargeted metabolomic profiling, an analytical scheme capable of generating semi-quantitative z-score values for over 1000 unique compounds in a single analysis of a specimen. Using this method to analyze plasma, we diagnosed ADSL deficiency in four patients and confirmed these findings with targeted quantitative biochemical analysis and molecular genetic testing. ADSL deficiency is part of a large a group of neurometabolic disorders, with a wide range of severity and sharing a broad differential diagnosis. This phenotypic similarity among these many inborn errors of metabolism (IEMs) has classically stood as a hurdle in their initial diagnosis and subsequent treatment. The findings presented here demonstrate the clinical utility of metabolomic profiling in the diagnosis of ADSL deficiency and highlights the potential of this technology in the diagnostic evaluation of individuals with neurologic phenotypes

Association of Time to Clinical Remission With Sustained Resolution in Children With New-Onset Infantile Spasms

Background and objectivesStandard therapies (adrenocorticotropic hormone [ACTH], oral steroids, or vigabatrin) fail to control infantile spasms in almost half of children. Early identification of nonresponders could enable rapid initiation of sequential therapy. We aimed to determine the time to clinical remission after appropriate infantile spasms treatment initiation and identify predictors of the time to infantile spasms treatment response.MethodsThe National Infantile Spasms Consortium prospectively followed children aged 2-24 months with new-onset infantile spasms at 23 US centers (2012-2018). We included children treated with standard therapy (ACTH, oral steroids, or vigabatrin). Sustained treatment response was defined as having the last clinically recognized infantile spasms on or before treatment day 14, absence of hypsarrhythmia on EEG 2-4 weeks after treatment, and persistence of remission to day 30. We analyzed the time to treatment response and assessed clinical characteristics to predict sustained treatment response.ResultsAmong 395 infants, clinical infantile spasms remission occurred in 43% (n = 171) within the first 2 weeks of treatment, of which 81% (138/171) responded within the first week of treatment. There was no difference in the median time to response across standard therapies (ACTH: median 4 days, interquartile range [IQR] 3-7; oral steroids: median 3 days, IQR 2-5; vigabatrin: median 3 days, IQR 1-6). Individuals without hypsarrhythmia on the pretreatment EEG (i.e., abnormal but not hypsarrhythmia) were more likely to have early treatment response than infants with hypsarrhythmia at infantile spasms onset (hazard ratio 2.23, 95% CI 1.39-3.57). No other clinical factors predicted early responders to therapy.DiscussionRemission after first infantile spasms treatment can be identified by treatment day 7 in most children. Given the importance of early and effective treatment, these data suggest that children who do not respond to standard infantile spasms therapy within 1 week should be reassessed immediately for additional standard treatment. This approach could optimize outcomes by facilitating early sequential therapy for children with infantile spasms

Inequities in Therapy for Infantile Spasms: A Call to Action

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/172939/1/ana26363_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/172939/2/ana26363.pd