Child Neurology: Infantile Biotin Thiamine Responsive Basal Ganglia Disease: Case Report and Brief Review

Biotin thiamine responsive basal ganglia disease (BTRBGD) is an inherited autosomal recessive disorder that results from the inability of thiamine to cross the blood-brain barrier. It is considered a treatable condition if vitamin supplementation, most commonly with thiamine and biotin, is initiated early. BTRBGD can present as an infantile form, classical childhood form, or adult Wernicke-like encephalopathy. The infantile form is often the most severe and portends a worse prognosis with high mortality despite vitamin supplementation. We present a two-month-old who presented with irritability, opisthotonos, and abnormal eye movements who was found to have compound heterozygous variants in the SLC19A3 gene inherited in trans, including one known pathogenic intronic variant and a novel variant presumed to be pathogenic. She was therefore diagnosed with infantile BTRBGD. In this report, we discuss the differential for infantile BTRBGD, the clinical and radiologic features of BTRBGD, and describe a rapid, positive response to early vitamin supplementation in an infant with a likely pathogenic novel variant in SLC19A3.

Pediatric GAD-65 Autoimmune Encephalitis: Assessing Clinical Characteristics and Response to Therapy With a Novel Assessment Scale

BACKGROUND

Glutamic acid decarboxylase (GAD) encephalitis is a neuroinflammatory disease characterized by a broad range of symptoms including cognitive deficits, behavioral changes, and seizures. Children with this disorder have heterogeneous presentations, and little is known about symptom progression over time and response to immunotherapy.

METHODS

This study reports 10 pediatric GAD encephalitis cases and symptoms found at presentation and follow-up. In addition, symptom severity was reported utilizing a novel scale evaluating functional outcomes across the domains affected by autoimmune encephalitis including cognition, language, seizures, psychiatric symptoms, sleep, and movement. Retrospective chart review was conducted for 10 patients aged <18 years, diagnosed with GAD encephalitis, and followed for one year or more. Chart review included clinical, imaging, and laboratory findings at time of diagnosis and at six- and 12-month follow-ups.

RESULTS

At presentation, cognitive deficits were found in all patients, seizures in six of 10, and language decline in seven of 10. Psychiatric symptoms were prominent for all but one patient with three of nine patients presenting with psychosis. Fatigue, sleep disruption, and movement disorders were less prominent symptoms, occurring in approximately half of the cohort. Cognition and fatigue improved significantly over time when compared with symptom severity, whereas seizures, psychiatric symptoms, and sleep did not. Language and sleep showed improvement only in early stages. Analysis of seizure frequency and type noted variability mirroring trends noted in adult studies of GAD encephalitis.

CONCLUSIONS

This study demonstrated the variability of symptom profiles of pediatric GAD encephalitis and benefits of symptom severity scales. Symptom profiles and progression vary in this population.

De Novo Pathogenic Variants in CACNA1E Cause Developmental and Epileptic Encephalopathy with Contractures, Macrocephaly, and Dyskinesias

Developmental and epileptic encephalopathies (DEEs) are severe neurodevelopmental disorders often beginning in infancy or early childhood that are characterized by intractable seizures, abundant epileptiform activity on EEG, and developmental impairment or regression. CACNA1E is highly expressed in the central nervous system and encodes the α₁-subunit of the voltage-gated Ca_V2.3 channel, which conducts high voltage-activated R-type calcium currents that initiate synaptic transmission. Using next-generation sequencing techniques, we identified de novo CACNA1E variants in 30 individuals with DEE, characterized by refractory infantile-onset seizures, severe hypotonia, and profound developmental impairment, often with congenital contractures, macrocephaly, hyperkinetic movement disorders, and early death. Most of the 14, partially recurring, variants cluster within the cytoplasmic ends of all four S6 segments, which form the presumed Ca_V2.3 channel activation gate. Functional analysis of several S6 variants revealed consistent gain-of-function effects comprising facilitated voltage-dependent activation and slowed inactivation. Another variant located in the domain II S4-S5 linker results in facilitated activation and increased current density. Five participants achieved seizure freedom on the anti-epileptic drug topiramate, which blocks R-type calcium channels. We establish pathogenic variants in CACNA1E as a cause of DEEs and suggest facilitated R-type calcium currents as a disease mechanism for human epilepsy and developmental disorders.

Outcomes of preterm infants treated with hypothermia for hypoxic-ischemic encephalopathy

BACKGROUND

Therapeutic hypothermia reduces the risk of death, or moderate to severe neurodevelopmental impairment (NDI) in term infants with hypoxic-ischemic encephalopathy (HIE). Reports of its safety and efficacy in preterm infants are scarce.

OBJECTIVE

Report short and long-term outcomes of preterm infants with HIE who received therapeutic hypothermia.

METHODS

A retrospective cohort analysis of all preterm infants <36 weeks' gestation with HIE who received whole body hypothermia in a single center from January 2007 to April 2015. The primary outcome was death or moderate to severe NDI defined by moderate or severe cerebral palsy, severe hearing or visual impairment, or cognitive score < 85 on the Bayley Scales of Infant Development III (BSID III) at 18-24 months' adjusted age.

RESULTS

30 infants with a median gestational age and birthweight of 35 weeks' (range; 33-35) and 2575 g (1850-4840) and a median first postnatal blood pH of 6.81 (6.58-7.14). Complications included coagulopathy (50%), early clinical seizures (43.3%), arterial hypotension (40%), persistent metabolic acidosis (37%) and thrombocytopenia (20%). Four infants died before or soon after discharge (18.2%). Eighteen surviving infants (69.2%) had follow up data; 7 of them had moderate to severe NDI (38.9%). Cognitive, motor and language mean composite BSID III scores were 84 (54-110), 83 (46-118), and 78 (46-112). Death or moderate to severe NDI occurred in 11/22 (50%) infants with known outcomes.

CONCLUSION

Large randomized trials on efficacy and safety are needed in this highly vulnerable population as the incidence of complications and the combined outcome of death and NDI is concerning.

Epilepsy in neurofibromatosis type 1

OBJECTIVES

To describe the characteristics of epilepsy in patients with Neurofibromatosis type 1 (NF1).

METHODS

Analysis of a cohort of consecutive NF1 patients seen in our NF1 clinic during a three-year period.

RESULTS

Of the 184 NF1 patients seen during that period, 26 had epilepsy and three had febrile seizures. Of the 26, 17 (65%) had localization-related epilepsy, seven of whom (41%) were drug resistant. Six (23%) had apparently primary generalized epilepsy (0/6 drug resistant), two (8%) Lennox-Gastaut syndrome, and one (4%) West syndrome (all three were drug-resistant). As compared to the patients with no epilepsy, those with epilepsy were more likely to have MRI findings of mesial temporal sclerosis (MTS) (23% vs. 5%, p=0.0064), and cerebral hemisphere tumors (31% vs. 10%, p=0.0079), but not of the other MRI findings including neurofibromatosis bright objects, or optic gliomas. Three of the six patients with MTS underwent temporal lobectomy with subsequent control of their seizures with confirmation of MTS on pathology in 3/3 and presence of coexisting focal cortical dysplasia (FCD) in 2/3. We also have observed three additional patients outside the above study with the association of NF1, MTS, and intractable epilepsy.

SIGNIFICANCE

Epilepsy is relatively common in NF1, often occurs in patients with brain tumors or with MTS which can coexist with FCD, can be associated with multiple types of epilepsy syndromes, and when localization-related is often drug-resistant. Patients with NF1 and MTS can respond to medial temporal lobectomy and may have coexisting medial temporal lobe cortical dysplasia.

Gabapentin Use in the Neonatal Intensive Care Unit

Gabapentin was used for the treatment of term and preterm infants with suspected visceral hyperalgesia caused by a variety of neurologic and gastrointestinal morbidities. Improved feeding tolerance and decreased irritability were seen, as well as decreased usage of opioids and benzodiazepines. Adverse events occurred with abrupt discontinuation of this medication.