Seizures in trisomy 18: Prevalence, description, and treatment.

Changes in medical intervention over the last decade have improved outcomes for individuals with trisomy 18, the second most common human aneuploidy syndrome at birth. As children with trisomy 18 live longer, a shared concern of medical experts and parents is the occurrence and treatment of seizures. Previously published surveillance guidelines for this condition have not addressed seizure management. Using parent-reported data collected as part of the Tracking Rare Incidence Syndromes project, we report on the prevalence, course, and management of seizures in individuals with trisomy 18. Twenty-eight percent (52/186) of individuals diagnosed with trisomy 18 in our retrospective cohort experienced generalized, focal, or mixed seizures at some point in their lifetime. For many individuals, seizures were effectively managed by broad-spectrum anti-seizure medications. Correlation analysis showed that focal and generalized seizures were more likely to occur in individuals who had previously experienced infantile spasms or central apnea. Electroencephalogram testing should be considered as part of a standard screening approach in individuals with trisomy 18 to enable early diagnosis and treatment of seizures. An international registry that incorporates parent-reported and clinical data for patients with trisomy 18 may facilitate ongoing research and recruitment into clinical trials for seizure management.

Pediatric Migraine Phenomena and Variants: Don't Let Them Go Over Your Head.

PURPOSE OF REVIEW: Primary care providers, general pediatric neurologists, and other related subspecialty providers require a clear understanding of pediatric migraine with typical aura and its variants. RECENT FINDINGS: We highlight some of the genetic mutations known to contribute to specific types of migraine with aura, discuss the ophthalmologic phenomena of migraine and call attention to some of the earliest manifestations of migraine in children, many of which have correlates in adulthood. While the majority of headaches in children are migraine with or without aura or tension type, many migraine and aura variants exist. Early and accurate diagnosis of episodic syndromes associated with migraine, as defined by the 2018 ICHD-3 criteria, can help to reduce unnecessary imaging, referrals, cost and anxiety, thereby benefiting patients and their families.

A ten-year retrospective evaluation of acute flaccid myelitis at 5 pediatric centers in the United States, 2005-2014.

BACKGROUND: Acute flaccid myelitis (AFM) is a severe illness similar to paralytic poliomyelitis. It is unclear how frequently AFM occurred in U.S. children after poliovirus elimination. In 2014, an AFM cluster was identified in Colorado, prompting passive US surveillance that yielded 120 AFM cases of unconfirmed etiology. Subsequently, increased reports were received in 2016 and 2018. To help inform investigations on causality of the recent AFM outbreaks, our objective was to determine how frequently AFM had occurred before 2014, and if 2014 cases had different characteristics. METHODS: We conducted a retrospective study covering 2005-2014 at 5 pediatric centers in 3 U.S. regions. Possible AFM cases aged ≤18 years were identified by searching discharge ICD-9 codes and spinal cord MRI reports (>37,000). Neuroradiologists assessed MR images, and medical charts were reviewed; possible cases were classified as AFM, not AFM, or indeterminate. RESULTS: At 5 sites combined, 26 AFM cases were identified from 2005-2013 (average annual number, 3 [2.4 cases/100,000 pediatric hospitalizations]) and 18 from 2014 (12.6 cases/100,000 hospitalizations; Poisson exact p<0.0001). A cluster of 13 cases was identified in September-October 2014 (temporal scan p = 0.0001). No other temporal or seasonal trend was observed. Compared with cases from January 2005-July 2014 (n = 29), cases from August-December 2014 (n = 15) were younger (p = 0.002), more frequently had a preceding respiratory/febrile illness (p = 0.03), had only upper extremities involved (p = 0.008), and had upper extremity monoplegia (p = 0.03). The cases had higher WBC counts in cerebrospinal fluid (p = 0.013). CONCLUSION: Our data support emergence of AFM in 2014 in the United States, and those cases demonstrated distinctive features compared with preceding sporadic cases.

miRNA contributions to pediatric-onset multiple sclerosis inferred from GWAS.

OBJECTIVE: Onset of multiple sclerosis (MS) occurs in childhood for approximately 5% of cases (pediatric MS, or ped-MS). Epigenetic influences are strongly implicated in MS pathogenesis in adults, including the contribution from microRNAs (miRNAs), small noncoding RNAs that affect gene expression by binding target gene mRNAs. Few studies have specifically examined miRNAs in ped-MS, but individuals developing MS at an early age may carry a relatively high burden of genetic risk factors, and miRNA dysregulation may therefore play a larger role in the development of ped-MS than in adult-onset MS. This study aimed to look for evidence of miRNA involvement in ped-MS pathogenesis. METHODS: GWAS results from 486 ped-MS cases and 1362 controls from the U.S. Pediatric MS Network and Kaiser Permanente Northern California membership were investigated for miRNA-specific signals. First, enrichment of miRNA-target gene network signals was evaluated using MIGWAS software. Second, SNPs in miRNA genes and in target gene binding sites (miR-SNPs) were tested for association with ped-MS, and pathway analysis was performed on associated target genes. RESULTS: MIGWAS analysis showed that miRNA-target gene signals were enriched in GWAS (P = 0.038) and identified 39 candidate biomarker miRNA-target gene pairs, including immune and neuronal signaling genes. The miR-SNP analysis implicated dysregulation of miRNA binding to target genes in five pathways, mainly involved in immune signaling. INTERPRETATION: Evidence from GWAS suggests that miRNAs play a role in ped-MS pathogenesis by affecting immune signaling and other pathways. Candidate biomarker miRNA-target gene pairs should be further studied for diagnostic, prognostic, and/or therapeutic utility.

Whole-genome analysis for effective clinical diagnosis and gene discovery in early infantile epileptic encephalopathy.

Early infantile epileptic encephalopathy (EIEE) is a devastating epilepsy syndrome with onset in the first months of life. Although mutations in more than 50 different genes are known to cause EIEE, current diagnostic yields with gene panel tests or whole-exome sequencing are below 60%. We applied whole-genome analysis (WGA) consisting of whole-genome sequencing and comprehensive variant discovery approaches to a cohort of 14 EIEE subjects for whom prior genetic tests had not yielded a diagnosis. We identified both de novo point and INDEL mutations and de novo structural rearrangements in known EIEE genes, as well as mutations in genes not previously associated with EIEE. The detection of a pathogenic or likely pathogenic mutation in all 14 subjects demonstrates the utility of WGA to reduce the time and costs of clinical diagnosis of EIEE. While exome sequencing may have detected 12 of the 14 causal mutations, 3 of the 12 patients received non-diagnostic exome panel tests prior to genome sequencing. Thus, given the continued decline of sequencing costs, our results support the use of WGA with comprehensive variant discovery as an efficient strategy for the clinical diagnosis of EIEE and other genetic conditions.

Comprehensive population-based determination of pediatric multiple sclerosis health care costs.

OBJECTIVE: To determine the health care costs associated with pediatric multiple sclerosis (MS). METHODS: We performed a retrospective analysis of all patients with MS 18 years of age or younger who were diagnosed or treated between 2002 and 2012 in a population-based cohort. Demographics and health care costs were extracted from the Intermountain Healthcare Enterprise Data Warehouse. Patients were divided into high-cost (>84th percentile) and low-cost groups and differences in health care utilization between the groups were analyzed. RESULTS: Fifty-seven pediatric patients with MS were identified. Health care costs for the cohort totaled more than $1.5 million over the 10-year period, with the top 16th percentile of patients contributing nearly two-thirds. Outpatient visits represented the majority of health care encounters and expenditures, accounting for 83.1% of total costs. Costs per encounter were highest for inpatient stays, averaging $2,924 per stay. CONCLUSIONS: The burden of health care expenses for pediatric patients with MS is significant. Expenditures related to outpatient visits were the largest contributor to costs, but inpatient stays were the most costly per encounter. A small proportion of patients incurred the bulk of costs and spent significantly more time receiving care compared to the majority of patients. Avoidance of inpatient treatment and efficient outpatient management are potential areas for health care cost reduction and improvement in care.

White matter lesions in children and adolescents with migraine.

BACKGROUND: The etiology and clinical importance of white matter lesions in migraine remain poorly understood. To understand these issues more fully, we reviewed the brain magnetic resonance imaging scans of pediatric patients and assessed the relationships between white matter lesions, migraine type, patent foramen ovale, and right-to-left shunting. METHODS: The magnetic resonance imaging scans of a cohort of children (n = 89) and adolescents, ages 6 to 18 years, who participated in a study of migraine and patent foramen ovale were reviewed. All children in the cohort had undergone saline contrast transthoracic echocardiography and transcranial Doppler studies. RESULTS: White matter lesions were detected in 15 of the 89 patients (17%). White matter lesions were small (<5 mm) in the majority (10/15; 66%). We observed no relationship between the presence of white matter lesions and (1) migraine type (six patients with white matter lesions among 35 with migraine with aura [17%] vs. nine with white matter lesions among 54 without aura [17%]; P = 1.0); (2) patent foramen ovale (five with white matter lesions among 35 with patent foramen ovale [14%] vs. 10 with white matter lesions among 54 without patent foramen ovale [19%]; P = 0.77); or (3) shunt size (two large shunts in 15 with white matter lesions [13%] vs. nine large shunts among 72 without white matter lesions [13%]; P = 1.0). CONCLUSIONS: These results indicate that small white matter lesions are not infrequent in children and adolescents with migraine. However, no relationships between white matter lesions and migraine type, patent foramen ovale, or degree of right-to-left shunting were observed.

Clinical reasoning: a 12-year-old boy with ascending weakness.

A 12-year-old boy presented with 3 weeks of calf pain, tripping, and progressive inability to walk. The onset was preceded by a sore throat 4 weeks prior, but no recent immunizations and no sick contacts. He began having problems "catching his toes" for 2 weeks. He had no visual complaints and no bowel or bladder incontinence. He had no recent travel and there were no heavy metal or solvent exposures. He had no prior medical history and he was on no prescription medications. Developmentally, he was on track and had just successfully completed fifth grade. However, he was reported to be behaviorally oppositional, especially regarding his diet which was restricted to beef jerky, yogurt from a squeeze tube, and fruit drinks. Family history included diabetic peripheral neuropathy in his mother, idiopathic peripheral neuropathy in his maternal grandfather, and left lower extremity neuropathy from trauma in his father. There was no known family history of recurrent pressure palsies or cardiac problems.

Seizure characteristics in Pallister-Killian syndrome.

Pallister-Killian syndrome (PKS) is a congenital disorder attributed to supernumerary isochromosome 12p mosaicism. Craniofacial dysmorphism, learning impairment and seizures are considered cardinal features. However, little is known regarding the seizure and epilepsy patterns in PKS. To better define the prevalence and spectrum of seizures in PKS, we studied 51 patients (39 male, 12 female; median age 4 years and 9 months; age range 7 months to 31 years) with confirmed 12p tetrasomy. Using a parent-based structured questionnaire, we collected data regarding seizure onset, frequency, timing, semiology, and medication therapy. Patients were recruited through our practice, at PKS Kids family events, and via the PKS Kids website. Epilepsy occurred in 27 (53%) with 23 (85%) of those with seizures having seizure onset prior to 3.5 years of age. Mean age at seizure onset was 2 years and 4 months. The most common seizure types were myoclonic (15/27, 56%), generalized convulsions (13/27, 48%), and clustered tonic spasms (similar to infantile spasms; 8/27, 30%). Thirteen of 27 patients with seizures (48%) had more than one seizure type with 26 out of 27 (96%) ever having taken antiepileptic medications. Nineteen of 27 (70%) continued to have seizures and 17/27 (63%) remained on antiepileptic medication. The most commonly used medications were: levetiracetam (10/27, 37%), valproic acid (10/27, 37%), and topiramate (9/27, 33%) with levetiracetam felt to be "most helpful" by parents (6/27, 22%). Further exploration of seizure timing, in-depth analysis of EEG recordings, and collection of MRI data to rule out confounding factors is warranted.

Occurrence and clinical features of epileptic and non-epileptic paroxysmal events in five children with Pallister-Killian syndrome.

Pallister-Killian syndrome (PKS) is a rare, sporadic genetic disorder caused by tetrasomy 12p mosaicism associated with a supernumerary isochromosome. Craniofacial dysmorphism, learning impairment and seizures are considered characteristic. However, little is known of the seizure and epilepsy patterns seen in PKS. To better define the occurrence and nature of epileptic and non-epileptic paroxysmal events in PKS, we describe our experience with 5 patients and compare their features with data from a larger cohort of PKS patients ascertained via a web-based parental questionnaire. Three of the 5 patients have had definite epileptic seizures, and one other has had paroxysmal events as yet not clarified. Four of the 5 have also had either non-epileptic paroxysmal events or episodes of uncertain nature. In those with epilepsy, all have had some period of relatively refractory seizures, all have required more than one antiepileptic drug, but none experienced status epilepticus. Only one of the patients with epilepsy (the oldest) has gone into remission. In two of the four with non-epileptic events, video-electroencephalographic monitoring has been valuable in clarifying the nature of the events. EEG characteristics include a slow dominant frequency as well as generalized and focal epileptiform features. Brain MRI findings can be normal but are variable. These specific findings correspond well to information reported by parents in a larger cohort of 51 individuals with PKS. Better understanding of the nature of epileptic and non-epileptic events in PKS will result from a more detailed analysis of objective data obtained from this larger cohort, and from deeper understanding of the molecular impact of 12p tetrasomy in selected cell lines.