Summary Purpose To examine patterns of use, efficacy and safety of intravenous ketamine for the treatment of refractory status epilepticus (RSE). Methods Multicenter retrospective review of medical records and EEG reports in ten academic medical centers in North America and Europe, including 58 subjects, representing 60 episodes of RSE were identified between 1999 and 2012. Seven episodes occurred after anoxic brain injury. Key findings Permanent control of RSE was achieved in 57% (34/60) of episodes. Ketamine was felt to have contributed to permanent control (“possible” or “likely” responses) in 32% (19/60) including seven (12%) in which ketamine was the last drug added (likely responses). Four of the seven likely responses, but none of the 12 possible ones, occurred in patients with post-anoxic brain injury. No likely responses were observed when infusion rates were lower than 0.9mg/kg/h; when ketamine was introduced at least eight days after SE onset; or after failure of seven or more drugs. Ketamine was discontinued due to possible adverse events in five patients. Complications were mostly attributed to concurrent drugs, especially other anesthetics. Mortality rate was 43% (26/60), but was lower when SE was controlled within 24h of ketamine initiation (16% vs. 56%, p=0.0047). Significance Ketamine appears to be a relatively effective and safe drug for the treatment of RSE. This retrospective series provides preliminary data on effective dose and appropriate time of intervention to aid in the design of a prospective trial to further define the role of ketamine in the treatment of RSE.

Purpose Pathogenic autosomal recessive variants in CAD, encoding the multienzymatic protein initiating pyrimidine de novo biosynthesis, cause a severe inborn metabolic disorder treatable with a dietary supplement of uridine. This condition is difficult to diagnose given the large size of CAD with over 1000 missense variants and the nonspecific clinical presentation. We aimed to develop a reliable and discerning assay to assess the pathogenicity of CAD variants and to select affected individuals that might benefit from uridine therapy. Methods Using CRISPR/Cas9, we generated a human CAD-knockout cell line that requires uridine supplements for survival. Transient transfection of the knockout cells with recombinant CAD restores growth in absence of uridine. This system determines missense variants that inactivate CAD and do not rescue the growth phenotype. Results We identified 25 individuals with biallelic variants in CAD and a phenotype consistent with a CAD deficit. We used the CAD-knockout complementation assay to test a total of 34 variants, identifying 16 as deleterious for CAD activity. Combination of these pathogenic variants confirmed 11 subjects with a CAD deficit, for whom we describe the clinical phenotype. Conclusions We designed a cell-based assay to test the pathogenicity of CAD variants, identifying 11 CAD-deficient individuals who could benefit from uridine therapy.

We report two consanguineous families with probands that exhibit intellectual disability, developmental delay, short stature, aphasia, and hypotonia in which homozygous non-synonymous variants were identified in IQSEC1 (GenBank: NM_001134382.3). In a Pakistani family, the IQSEC1 segregating variant is c.1028C>T (p.Thr343Met), while in a Saudi Arabian family the variant is c.962G>A (p.Arg321Gln). IQSEC1-3 encode guanine nucleotide exchange factors for the small GTPase ARF6 and their loss affects a variety of actin-dependent cellular processes, including AMPA receptor trafficking at synapses. The ortholog of IQSECs in the fly is schizo and its loss affects growth cone guidance at the midline in the CNS, also an actin-dependent process. Overexpression of the reference IQSEC1 cDNA in wild-type flies is lethal, but overexpression of the two variant IQSEC1 cDNAs did not affect viability. Loss of schizo caused embryonic lethality that could be rescued to 2 nd instar larvae by moderate expression of the human reference cDNA. However, the p.Arg321Gln and p.Thr343Met variants failed to rescue embryonic lethality. These data indicate that the variants behave as loss-of-function mutations. We also show that schizo in photoreceptors is required for phototransduction. Finally, mice with a conditional Iqsec1 deletion in cortical neurons exhibited an increased density of dendritic spines with an immature morphology. The phenotypic similarity of the affecteds and the functional experiments in flies and mice indicate that IQSEC1 variants are the cause of a recessive disease with intellectual disability, developmental delay, and short stature, and that axonal guidance and dendritic projection defects as well as dendritic spine dysgenesis may underlie disease pathogenesis.

Homozygous pathogenic variants in WDR45B were first identified in six subjects from three unrelated families with global development delay, refractory seizures, spastic quadriplegia, and brain malformations. Since the initial report in 2018, no further cases have been described. In this report, we present 12 additional individuals from seven unrelated families and their clinical, radiological, and molecular findings. Six different variants in WDR45B were identified, five of which are novel. Microcephaly and global developmental delay were observed in all subjects, and seizures and spastic quadriplegia in most. Common findings on brain imaging include cerebral atrophy, ex vacuo ventricular dilatation, brainstem volume loss, and symmetric under‐opercularization. El‐Hattab‐Alkuraya syndrome is associated with a consistent phenotype characterized by early onset cerebral atrophy resulting in microcephaly, developmental delay, spastic quadriplegia, and seizures. The phenotype appears to be more severe among individuals with loss‐of‐function variants whereas those with missense variants were less severely affected suggesting a potential genotype–phenotype correlation in this disorder. A brain imaging pattern emerges which is consistent among individuals with loss‐of‐function variants and could potentially alert the neuroradiologists or clinician to consider WDR45B‐related El‐Hattab‐Alkuraya syndrome.

Objectives: Patients with epilepsy have a high risk of accidents and injuries, resulting in minimized physical activity and social withdrawal. Therefore, we surveyed the prevalence and the types of injuries that patients with epilepsy may endure, and the factors that may increase the risk of injuries. Methods:In this cohort study, adult and pediatric patients diagnosed with epilepsy (age ≥ 7 years) and a close family member (parents/guardian) attending the outpatient epilepsy clinics at King Fahd Medical City (Riyadh, Saudi Arabia) were interviewed by neurologists. They reviewed the patients' medical records and administered a structured questionnaire to identify and compare several variables, including injury frequency versus seizure type and seizure frequency, number of antiseizure medications used, medication compliance, and work and social limitations.Results: Out of 200 patients, 86 (43%) sustained injuries during an attack of their habitual seizures. Almost half of this group showed a tendency for recurrent injuries. The most common traumas were soft tissue injury (36.5%), head injury (32%), dental injury (8.5%), burns (7%), dislocation (7%), fractures (6.5%), and submersion (2%). Two-thirds of the patients had their injury at home. 64% of patients who had seizures for more than 10 years sustained multiple injuries (P = .003). Injury frequency was higher among patients with daily or monthly seizures (P = .03). 76% of patients who suffered injuries more than twice had generalised tonic-clonic seizures, and genetic generalised epilepsy was encountered more in injured patients (P = .02). Also, patients on polytherapy were more likely than those on monotherapy to have an injury (P = .003).Significance: Two-fifths of the patients reported seizure-related injuries. The most common were soft-tissue injuries and head traumas, while homes were the most frequent site. In addition, longer epilepsy duration, generalized tonicclonic seizures, and polytherapy were associated with a higher prevalence of injuries. Therefore, injury prevention strategies should be developed for PWE, especially for those at higher risk.