Carbamazepine responsive episodic dystonia and hallucination due to pyruvate dehydrogenase E2 (DLAT) gene mutation.

Pyruvate Dehydrogenase (PDH) E2 deficiency due to Dihydrolipoamide acetyltransferase (DLAT) mutations is a very rare condition with only nine reported cases to date. We describe a 15-year-old girl with mild intellectual disability, paroxysmal dystonia and bilateral basal ganglia signal abnormalities on brain magnetic resonance imaging (MRI). Additionally, neurophysiological, imaging, metabolic and exome sequencing studies were performed. Routine metabolite testing, and GLUT1 and PRRT2 mutation analysis were negative. A repeat brain MRI revealed 'Eye-of-the-tiger-sign'. Exome sequencing identified homozygous valine to glycine alteration at amino acid position 157 in the DLAT gene. Bioinformatic and family analyses indicated that the alteration was likely pathogenic. Patient's dystonia was responsive to low-dose carbamazepine. On weaning carbamazepine, patient developed hallucinations which resolved after carbamazepine was restarted. PDH E2 deficiency due to DLAT mutation has a more benign course compared to common forms of PDH E1 deficiency due to X-linked PDHA1 mutations. All known cases of PDH E2 deficiency due to DLAT mutations share the features of episodic dystonia and intellectual disability. Our patient's dystonia and hallucinations responded well to low-dose carbamazepine.

Poison exon annotations improve the yield of clinically relevant variants in genomic diagnostic testing.

PURPOSE: Neurodevelopmental disorders (NDDs) often result from rare genetic variation, but genomic testing yield for NDDs remains below 50%, suggesting that clinically relevant variants may be missed by standard analyses. Here, we analyze "poison exons" (PEs), which are evolutionarily conserved alternative exons often absent from standard gene annotations. Variants that alter PE inclusion can lead to loss of function and may be highly penetrant contributors to disease. METHODS: We curated published RNA sequencing data from developing mouse cortex to define 1937 conserved PE regions potentially relevant to NDDs, and we analyzed variants found by genome sequencing in multiple NDD cohorts. RESULTS: Across 2999 probands, we found 6 novel clinically relevant variants in PE regions. Five of these variants are in genes that are part of the sodium voltage-gated channel alpha subunit family (SCN1A, SCN2A, and SCN8A), which is associated with epilepsies. One variant is in SNRPB, associated with cerebrocostomandibular syndrome. These variants have moderate to high computational impact assessments, are absent from population variant databases, and in genes with gene-phenotype associations consistent with each probands reported features. CONCLUSION: With a very minimal increase in variant analysis burden (average of 0.77 variants per proband), annotation of PEs can improve diagnostic yield for NDDs and likely other congenital conditions.

Long-Term Video Electroencephalographic Monitoring in <30-Week Gestational Age Infants With High-Grade Intraventricular Hemorrhage.

BACKGROUND: Despite recognizing high seizure risk, the current consensus guidelines on evaluating seizures in preterm neonates are based on limited data. We chose to investigate the seizure risk in high-risk preterm (<30 weeks gestation) asymptomatic (without a clinical concern for seizures) infants with high-grade intraventricular hemorrhage who underwent long-term video electroencephalographic monitoring. METHODS: We performed a comprehensive retrospective review on all infants of <30-week gestational age admitted to the University of Alabama at Birmingham Regional Neonatal Intensive Care Unit from June 2018 to October 2022. We selected those patients who underwent electroencephalographic monitoring without a prior clinical concern for seizures. We recorded gender, gestational age, APGAR scores (one and five minutes), intraventricular hemorrhage (grade, age at diagnosis), and electroencephalographic monitoring (timing and duration) data. RESULTS: Among 37 premature infants, six had seizures detected on electroencephalographic monitoring. All six infants had subclinical seizures. Only two of six patients had a clinical correlation (although not identified by the providers) with some of their seizures. Patients with seizures were significantly younger in chronological age (median age 6.5 days vs 9 days, P value 0.009) at the time of the electroencephalographic monitoring initiation and were more likely to have subsequent monitoring studies (P value 0.0418). CONCLUSIONS: Long-term video electroencephalographic monitoring performed after the diagnosis of high-grade intraventricular hemorrhage captured seizures in ∼16% of asymptomatic premature neonates of <30 weeks' gestation. Patients identified to have seizures were significantly younger (chronological age) at the time of the electroencephalographic monitoring initiation and were more likely to be remonitored.

Brain Magnetic Resonance Imaging (MRI) White Matter Hyperintensities in Cyclic Vomiting Syndrome With or Without Migraine.

BACKGROUND: Cyclic vomiting syndrome is classified as a possible subset of migraine. Brain magnetic resonance imaging (MRI) findings of white matter hyperintensities are well documented in migraineurs, but not in patients with cyclic vomiting syndrome. This study focuses on white matter hyperintensities in children with cyclic vomiting syndrome. METHODS: We investigated our database of outpatient medical records for the diagnosis codes associated with cyclic vomiting syndrome from January 2008 to October 2018. RESULTS: Brain MRIs were obtained in 31 of 185 patients (∼17%) with a diagnosis code related to cyclic vomiting syndrome. We excluded 13 of 31 patients because of the inaccessibility of images or a confounding diagnosis. Remaining patients were divided into 2 groups: 13 of 18 cyclic vomiting syndrome with migraine (CVS+M), and 5 of 18 cyclic vomiting syndrome without migraine (CVS-M). We found that 3 of the 13 patients in the CVS+M group had migraine-like white matter hyperintensities compared to 0 of the 5 in the CVS-M group. CONCLUSION: This small study suggests a possible relationship between white matter hyperintensities and CVS+M. A larger study is required to validate these findings.

Evolution of Surgical Management for Intractable Epileptic Spasms.

The understanding and management of epileptic spasms has considerably evolved since the mid 19th century. The realization that epileptic spasms can be generated from a focal brain lesion played a pivotal role in the development of neurosurgical management for intractable forms of this epilepsy. During pre-surgical planning, the addition of functional FDG PET imaging has further refined the electroencephalographic localization of epileptogenic lesions. In some cases, neurosurgical resection of a focus that is co-localized by the FDG PET scan and electroencephalography can lead to partial or complete reversal of developmental delay along with reduced seizure frequency or seizure freedom. In cases where near-complete hemispheric cortex is implicated in spasm generation, subtotal hemispherectomy has shown encouraging results. Moreover, palliative resection of the major perpetrating focus in carefully chosen patients with bilateral multifocal spasms has also led to favorable outcomes. However, in patients with tuberous sclerosis with high tuber burden, the localizing value of FDG PET imaging may be limited. In such cases, employment of AMT PET technology has become a valuable tool for localization of actively epileptogenic tubers. This article highlights the historic steps in the successful advancements of neurosurgical interventions for the treatment of intractable epileptic spasms.

Spinal Cord Diffuse Midline Glioma in a 4-Year-Old Boy.

OBJECTIVE: We report a child presenting with spinal myelopathy secondary to H3K27M mutant diffuse midline glioma. CASE REPORT: A 4-year-old boy presented with a 3-week history of progressive gait difficulty. Examination revealed bilateral hand and lower extremity weakness, left leg hypertonia with ankle clonus, and a right hemisensory deficit. Magnetic resonance imaging of neuroaxis showed cervical and thoracic spinal cord with expansion and irregular areas of enhancement. Serum and cerebrospinal fluid studies were unremarkable for infectious, autoimmune, inflammatory, and neoplastic causes but showed mild cerebrospinal fluid pleocytosis, hypoglycorrhachia, and high protein level. A thoracic cord biopsy revealed a diffuse midline glioma (World Health Organization grade IV). Consequently, the tumor involved intracranial structures and patient died within 4 months after diagnosis. CONCLUSION: High-grade spinal cord gliomas are very rare but should be considered in the differential diagnosis of pediatric myelopathy. Tissue biopsy is recommended in indeterminate cases to facilitate diagnosis and to guide management.