Utility of next generation sequencing in paediatric neurological disorders: experience from South Africa.

Next generation sequencing (NGS)-based tests have become routine first-line investigative modalities in paediatric neurology clinics in many high-income countries (HICs). Studies from these countries show that these tests are both cost-effective and reliable in diagnosing many complex childhood neurological diseases. However, NGS-based testing in low-and middle-income countries (LMICs) is limited due to affordability constraints. The primary objective of this study was to evaluate the diagnostic yield and impact of targeted gene panel sequencing in a selected paediatric cohort attending a tertiary paediatric neurology clinic in the Western Cape Province of South Africa. This retrospective study included 124 consecutive paediatric patients with neurological disease, aged 6 weeks to 17 years, referred for NGS-based multi-gene panel testing over a 41-month period. Twenty-four different disease group-specific panels were utilized. A caregiver experience questionnaire was administered when a pathogenic variant was identified. The overall study diagnostic yield (DY) was 45% (56/124 patients). The diagnostic yield in this study is similar to previously reported paediatric cohorts in HICs. The high yields for neuromuscular disorders (52%) and early epileptic encephalopathies (41%) suggest that NGS-based panels may be more cost-effective as first-line testing in well-defined phenotypes. The latter finding argues for early inclusion of all children with developmental epileptic encephalopathies (DEE), as early diagnosis leads to better treatment and avoidance of unnecessary investigations.

Variables included in cerebral palsy registries globally: A scoping review.

AIM: To identify cerebral palsy (CP) variables collected in CP registries from high-income countries (HICs) and low- and middle-income countries (LMICs) to assist with the development of a regional CP registry relevant to the African region. METHOD: A systematic search of online databases to identify peer-reviewed publications and grey literature about CP risk-factor variables, using Ovid MEDLINE, Embase Ovid, CINAHL, and Google Scholar. RESULTS: A total of 197 studies published from global CP registries between 1990 and 2023 were identified. CP registries both from HICs and from LMICs included variables on prenatal CP risk factors. LMIC registries focused more on socioeconomic factors (the physical structure of the family home [21.1%, n = 8, in LMICs vs 1.7%, n = 2, in HICs]). Prenatal modifiable and non-modifiable risk factors were emphasized in HICs. LMIC registries included more postnatal CP risk-factor variables than HIC registries, including history of postnatal jaundice (15.8%, n = 6, in LMICs vs 6.9%, n = 8, in HICs) and postnatal head trauma (10.5%, n = 4, in LMICs vs 5.2%, n = 6, in HICs). INTERPRETATION: CP registries are currently more available in HICs than in LMICs. Differences in CP risk factors account for most of the differences in variables included in HICs and LMICs. Comparing variables used by CP registries in HICs and LMICs suggests the importance of understanding contextually relevant factors for regional registry design.

Diagnosis and Management of Tuberculous Meningitis in Children- an Update.

UPDATE ON THE DIAGNOSIS AND MANAGEMENT OF TUBERCULOUS MENINGITIS IN CHILDREN: Ronald van Toorn, Regan Solomons Seminars in Pediatric Neurology Volume 21, Issue 1, March 2014, Pages 12-18 Tuberculous meningitis (TBM), the most devastating manifestation of tuberculosis, is often missed or overlooked because of nonspecific symptoms and difficulties in diagnosis. It continues to be an important cause of neurologic handicap in resource-poor countries. Owing to the suboptimal performance of diagnostic tests of TBM, diagnosis relies on thorough history, clinical examination, and relevant investigations. The development of affordable, accurate diagnostic tests for TBM in resource-poor settings remains a priority. Short intensified treatment is safe and effective in both human immunodeficiency virus (HIV)-infected and HIV-uninfected children. Treatment of tuberculous hydrocephalus depends on the level of the cerebrospinal fluid obstruction. Corticosteroids reduce risk of neurodisability and death in HIV-uninfected children. Thalidomide should be considered in children compromised by tuberculosis abscesses and tuberculous-related optochiasmic arachnoiditis. In resource-poor countries, home-based TBM treatment after initial in-hospital stabilization is feasible in carefully selected patients. Early diagnosis and treatment of TBM is the single most important factor determining outcome.

Pathology-supported genetic testing presents opportunities for improved disability outcomes in multiple sclerosis.

Background: Lipid metabolism may impact disability in people with multiple sclerosis (pwMS). Methods: Fifty-one pwMS entered an ultrasound and MRI study, of whom 19 had followed a pathology-supported genetic testing program for more than 10 years (pwMS-ON). Genetic variation, blood biochemistry, vascular blood flow velocities, diet and exercise were investigated. Results: pwMS-ON had significantly lower (p < 0.01) disability (Expanded Disability Status Scale) than pwMS not on the program (1.91 ± 0.75 vs 3.87 ± 2.32). A genetic variant in the lipid transporter FABP2 gene (rs1799883; 2445G>A, A54T) was significantly associated (p < 0.01) with disability in pwMS not on the program, but not in pwMS-ON (p = 0.88). Vascular blood flow velocities were lower in the presence of the A-allele. Conclusion: Pathology-supported genetic testing may provide guidance for lifestyle interventions with a significant impact on improved disability in pwMS.

This study investigated the role of a genetic variant that increases saturated fat absorption and may make people with multiple sclerosis (MS) more susceptible to disability progression. Of 51 people with MS, 19 had followed a program which includes normalization of blood test results and daily intake of unsaturated fatty acids for more than 10 years, while the others had not. The latter group had significantly greater disability than the people who had followed the program, suggesting that the unsaturated fatty acids modulated the effect of the genetic variant. Six MS cases are presented as examples, including a marathon athlete (Case 1) and a patient who showed a dramatic decrease in disability from being wheelchair-bound for 15 years to walking freely (Case 2).

Bacterial meningitis in Africa.

Bacterial meningitis differs globally, and the incidence and case fatality rates vary by region, country, pathogen, and age group; being a life-threatening disease with a high case fatality rate and long-term complications in low-income countries. Africa has the most significant prevalence of bacterial meningitis illness, and the outbreaks typically vary with the season and the geographic location, with a high incidence in the meningitis belt of the sub-Saharan area from Senegal to Ethiopia. Streptococcus pneumoniae (pneumococcus) and Neisseria meningitidis (meningococcus) are the main etiological agents of bacterial meningitis in adults and children above the age of one. Streptococcus agalactiae (group B Streptococcus), Escherichia coli, and Staphylococcus aureus are neonatal meningitis's most common causal agents. Despite efforts to vaccinate against the most common causes of bacterial neuro-infections, bacterial meningitis remains a significant cause of mortality and morbidity in Africa, with children below 5 years bearing the heaviest disease burden. The factors attributed to this continued high disease burden include poor infrastructure, continued war, instability, and difficulty in diagnosis of bacterial neuro-infections leading to delay in treatment and hence high morbidity. Despite having the highest disease burden, there is a paucity of African data on bacterial meningitis. In this article, we discuss the common etiologies of bacterial neuroinfectious diseases, diagnosis and the interplay between microorganisms and the immune system, and the value of neuroimmune changes in diagnostics and therapeutics.

Adar-associated Aicardi Goutières syndrome in a child with bilateral striatal necrosis and recurrent episodes of transaminitis.

Aicardi-Goutières syndrome (AGS) refers to a group of genetic diseases characterised by severe inflammatory encephalopathy that usually present within the first year of life, resulting in progressive loss of cognition, spasticity, dystonia and motor disability. Pathogenic variants in the adenosine deaminase acting on RNA (Adar) enzyme have been linked to AGS type 6 (AGS6, Online Mendelian Inheritance in Man (OMIM) 615010). In knockout mouse models, loss of Adar activates the interferon (IFN) pathway and causes autoimmune pathogenesis in the brain or liver. Bilateral striatal necrosis (BSN) has previously been reported in case series of children with biallelic pathogenic variants in Adar We describe a unique, previously unreported case of a child with AGS6, with clinical manifestations of BSN and recurrent transient episodes of transaminitis. The case highlights the importance of Adar in protecting the brain and liver from IFN-induced inflammation. Adar-related disease should therefore be considered in the differential diagnosis of BSN accompanied by recurrent episodes of transaminitis.

Epileptic spasms: A South African overview of aetiologies, interventions, and outcomes.

AIM: To better understand the aetiologies of epileptic spasms in infants, as well as the safety and efficacy of high dose corticosteroids in tuberculosis and human immunodeficiency virus (HIV) endemic resource-limited settings. METHOD: This was a retrospective analysis of infants with epileptic spasms managed at the tertiary referral centres in the Western Cape, South Africa. RESULTS: Of 175 children with epileptic spasms, the median age at onset was 6 months (interquartile range 4-8 months). Structural aetiologies were most common (115 out of 175 [66%]), with two-thirds related to perinatal insults. A lead time to treatment (LTTT) of less than 1 month was more likely in the epileptic encephalopathy/developmental and epileptic encephalopathy (DEE) group: 58 out of 92 (63%), compared to 28 out of 76 (37%) of those with developmental encephalopathy (p = 0.001). Failure to recognize preceding developmental delay was common. Ninety-nine children (57%) received first line hormonal therapy such as adrenocorticotropic hormone. A total of 111 out of 172 children (65%) from the developmental encephalopathy and epileptic encephalopathy/DEE groups had clinical and/or electroencephalogram resolution of spasms within 14 days. In our population, children in whom an aetiology could not be identified were statistically more likely to have moderate to profound developmental delay at 1 year of age: 33 out of 44 (p = 0.001). Based on reported incidence of epileptic spasms, 23 to 58 cases per annum would be expected but a far smaller proportion presented to our centres. INTERPRETATION: Whilst this is the largest cohort of infants with epileptic spasms from sub-Saharan Africa, the study size is less than expected; this may reflect misdiagnosis and failure of referral pathways. Despite a reported shorter LTTT, infants with DEE had worse developmental outcomes compared to international studies. Hormonal therapy was safe and effective in our setting, despite exposure to high levels of tuberculosis and HIV. WHAT THIS PAPER ADDS: The number of unreferred cases of epileptic spasms in South Africa remains high. Caregivers and health care workers in primary care facilities often fail to recognize developmental delay. The burden of disease from hypoxic-ischaemic encephalopathy remains high in our resource-limited setting. Hormonal treatment (e.g. adrenocorticotropic hormone) was safe and effective despite the high prevalence of human immunodeficiency virus and tuberculosis.

Risk factors of poor developmental outcome in children with tuberculous meningitis.

BACKGROUND: Neurodevelopmental delay is a significant long-term complication of childhood tuberculous meningitis (TBM). The objective of this study was to assess risk factors for neurodevelopmental delay in children with TBM. METHODS: We conducted a retrospective cohort study of children diagnosed with TBM at Tygerberg Hospital, Cape Town, South Africa, over a 30-year period between 1985 and 2015. We assessed the relationship between demographic, clinical, laboratory and neuro-imaging characteristics, and cognitive impairment at the conclusion of anti-tuberculous treatment. Poor outcome was defined as moderate-to severe cognitive impairment. RESULTS: A total of 327 TBM patients were included, 71 (21.7%) suffered a poor outcome. Multivariate analysis revealed that decreased level of consciousness (adjusted OR (aOR): 4.68; 95%CI: 2.43-13.88; p = 0.005), brainstem dysfunction (aOR: 3.20; 95%CI: 1.70-6.00; p < 0.001), and radiological infarction (aOR: 3.47; 95%CI: 1.87-6.45; p < 0.001) were associated with a poor developmental outcome. Left hemispherical (single and multiple) stroke and bilateral stroke were associated with poor developmental outcomes. CONCLUSION: Certain neurological signs as well as radiological infarct characteristics are important predictors of poor developmental outcome. Anticipation of the likely level of cognitive impairment at diagnosis allows more accurate prognostication and prompt institution of supportive and rehabilitative measures, after the acute illness.

Utility of genetic testing in children with developmental and epileptic encephalopathy (DEE) at a tertiary hospital in South Africa: A prospective study.

OBJECTIVES: The developmental and epileptic encephalopathies (DEE) are a heterogeneous group of rare neurodevelopmental disorders, characterised by early-onset seizures that are often intractable, electroencephalographic abnormalities, and developmental delay or regression. There is a paucity of data from sub-Saharan Africa on the genetic basis of DEE. The aim of this study was to investigate the genetic background of DEE using targeted next generation sequencing (NGS) analysis in a tertiary pediatric neurology outpatient department at Tygerberg Hospital, South Africa. In addition, we assessed the value of the genetic results to the parents and managing physicians. METHODS: A prospective cohort study of 41 consecutive children with DEE (onset before 3 years of age) that were recruited over a 2-year period (2019-2021). Pre- and post-test genetic counselling were offered to all study participants. The results were categorized as either: positive (pathogenic/likely pathogenic variant identified), inconclusive (variant(s) of unknown significance identified), or negative (no variants identified). Result interpretation and careful matching of the variant to the clinical phenotype was performed. Subsequently, questionnaires were administered to both the physicians and the parents. RESULTS: A genetic underlying cause for DEE was identified in 18 of 41 children (diagnostic yield 43.9%). Variants in SCN1A (n=7), KANSL1 (n=2), KCNQ2 (n=2) and CDKL5 (n=2) were identified in more than one patient. Rarer genes included IQSEC2, SMC1A and STXBP1. All of the identified pathogenic variants fully explained and matched the respective phenotypic description of the patient at the time of clinical diagnosis. In 26% of patients the genetic result facilitated precision medicine management changes to anti-seizure medication. Both parents and physicians expressed benefit of genetic testing in patients with DEE. CONCLUSION: Targeted NGS analysis proved an efficient diagnostic tool in detection of a genetic cause of DEE in a large proportion of South African children. The 43.9% diagnostic yield is similar to previously reported international pediatric cohorts. Additionally, the genetic findings proved useful for targeted therapeutic decision-making and accurate genetic counseling.

Comparative Effectiveness of Regimens for Drug-Susceptible Tuberculous Meningitis in Children and Adolescents: A Systematic Review and Aggregate-Level Data Meta-Analysis.

Background: Before August 2021, the only regimen recommended by the World Health Organization (WHO) to treat pediatric drug-susceptible tuberculous meningitis was a 12-month regimen consisting of isoniazid, rifampicin, ethambutol, and pyrazinamide (2HRZE/10HR). The comparative effectiveness of shorter regimens is unknown. Methods: To inform a WHO guideline update, we undertook a systematic review and meta-analysis to evaluate outcomes from regimens of 6- to less than 12-months' duration that included, at a minimum, isoniazid, rifampicin, and pyrazinamide. We included studies that applied rigorous diagnostic criteria and reported outcomes for ≥10 children or adolescents. Using generalized linear mixed models, we estimated the random effects pooled proportions of patients with key outcomes. Results: Of 7 included studies, none compared regimens head-to-head. Three studies (724 patients) used a 6-month intensive regimen, which includes isoniazid and rifampicin at higher doses, pyrazinamide, and ethionamide instead of ethambutol (6HRZEto). Outcomes for this versus the 12-month regimen (282 patients, 3 studies) were, respectively, as follows: death, 5.5% (95% confidence interval [CI], 2.1%-13.4%) vs 23.9% (95% CI, 17.5%-31.7%); treatment success (survival with or without sequelae), 94.6% (95% CI, 73.9%-99.1%) vs 75.4% (95% CI, 68.7%-81.1%); and neurological sequelae among survivors, 66.0% (95% CI, 55.3%-75.3%) vs 36.3% (95% CI, 30.1%-43.0%). Relapse did not occur among 148 patients followed-up for 2 years after completing the 6-month intensive regimen. Conclusions: Our findings are limited by the small number of studies and substantial potential for confounding. Nonetheless, the 6HRZEto regimen was associated with high treatment success and is now recommended by WHO as an alternative to the 12-month regimen.

Deciphering Genetic Susceptibility to Tuberculous Meningitis.

Tuberculous meningitis (TBM) is the most severe form of extrapulmonary tuberculosis (TB) that arises when a caseating meningeal granuloma discharges its contents into the subarachnoid space. It accounts for ~1% of all disease caused by Mycobacterium tuberculosis and the age of peak incidence is from 2-4 years. The exact pathogenesis of TBM is still not fully understood and the mechanism(s) by which the bacilli initially invade the blood-brain-barrier are still to be elucidated. This study investigated the involvement of the host genome in TBM susceptibility, by considering common variants (minor allele frequency (MAF) >5%) using microarray genotyping and rare variants (MAF <1%) via exome sequencing. A total of 123 TBM cases, 400 pulmonary TB (pTB) cases and 477 healthy controls were genotyped on the MEGA array. A genome-wide association study (GWAS) comparing 114 TBM cases to 395 healthy controls showed no association with TBM susceptibility. A second analysis comparing 114 TBM cases to 382 pTB cases was conducted to investigate variants associated with different TB phenotypes. No significant associations were found with progression from pTB to TBM. Ten TBM cases and 10 healthy controls were exome sequenced. Gene set association tests SKAT-O and SKAT Common Rare were used to assess the association of rare SNPs and the cumulative effect of both common and rare SNPs with susceptibility to TBM, respectively. Ingenuity Pathway Analysis (IPA) of the top-hits of the SKAT-O analysis showed that NOD2 and CYP4F2 are both important in TBM pathogenesis and highlighted these as targets for future study. For the SKAT Common Rare analysis Centriolar Coiled-Coil Protein 110 (CCP110) was nominally associated (p = 5.89x10-6) with TBM susceptibility. In addition, several top-hit genes ascribed to the development of the central nervous system (CNS) and innate immune system regulation were identified. Exome sequencing and GWAS of our TBM cohort has identified a single previously undescribed association of CCP110 with TBM susceptibility. These results advance our understanding of TBM in terms of both variants and genes that influence susceptibility. In addition, several candidate genes involved in innate immunity have been identified for further genotypic and functional investigation.

Giant cerebral tuberculoma mimicking a high-grade tumour in a child.

We present an 11-year-old girl who manifested with unprovoked right-sided focal motor seizures. CT revealed a large lobulated hypodense mass in the left temporoparietal lobe, with perilesional oedema and postcontrast peripheral enhancement. Diagnostic uncertainty resulted in further neuroimaging, which included MRI with modalities including diffusion-weighted imaging, perfusion imaging, as well as spectroscopy. We discuss the radiological features of the lesion, which steered us in the direction of an infective cause. Definitive diagnosis was achieved by brain needle biopsy, which demonstrated necrotising granulomatous inflammation indicative of tuberculous infection on histology. In addition, GeneXpert yielded a positive result. We believe this unique case highlights the diagnostic dilemma clinicians face in differentiating ring-enhancing lesions on neuroimaging in tuberculosis-endemic regions. It also highlights the potential benefit of a brain needle biopsy (histology and GeneXpert) in cases of uncertainty.

Intrapartum Basal Ganglia-Thalamic Pattern Injury and Radiologically Termed "Acute Profound Hypoxic-Ischemic Brain Injury" Are Not Synonymous.

OBJECTIVE: Human cases of acute profound hypoxic-ischemic (HI) injury (HII), in which the insult duration timed with precision had been identified, remains rare, and there is often uncertainty of the prior state of fetal health. STUDY DESIGN: A retrospective analysis of 10 medicolegal cases of neonatal encephalopathy-cerebral palsy survivors who sustained intrapartum HI basal ganglia-thalamic (BGT) pattern injury in the absence of an obstetric sentinel event. RESULTS: Cardiotocography (CTG) admission status was reassuring in six and suspicious in four of the cases. The median time from assessment by admission CTG or auscultation to birth was 687.5 minutes (interquartile range [IQR]: 373.5-817.5 minutes), while the median time interval between first pathological CTG and delivery of the infant was 179 minutes (IQR: 137-199.25 minutes). The mode of delivery in the majority of infants (60%) was by unassisted vaginal birth; four were delivered by delayed caesarean section. The median (IQR) interval between the decision to perform a caesarean section and delivery was 169 minutes (range: 124-192.5 minutes). CONCLUSION: The study shows that if a nonreassuring fetal status develops during labor and is prolonged, a BGT pattern HI injury may result, in the absence of a perinatal sentinel event. Intrapartum BGT pattern injury and radiologically termed "acute profound HI brain injury" are not necessarily synonymous. A visualized magnetic resonance imaging (MRI) pattern should preferably solely reflect the patterns description and severity, rather than a causative mechanism of injury. KEY POINTS: · BGT HI injury pattern on MRI may develop in the absence of a perinatal sentinel event.. · BGT pattern injury may not be synonymous with "acute profound HI brain injury.". · MRI pattern and severity thereof should be described rather than a causative mechanism of injury..

The use of thalidomide to treat children with tuberculosis meningitis: A review.

Much of the morbidity and mortality caused by tuberculous meningitis (TBM) is mediated by a dysregulated immune response. Effective host-directed therapy is therefore critical to improve survival and clinical outcomes. Currently only one host-directed therapy (HDT), corticosteroids, is proven to improve mortality. However, there is no evidence that corticosteroids reduce morbidity and the mechanism of action for mortality reduction is uncertain. Further, it has no proven benefit in HIV co-infected individuals. One promising host-directed therapy approach is to restrict the immunopathology arising from tumour necrosis factor (TNF)-α excess is via TNF-α inhibitors. There are accumulating data on the role of thalidomide, anti-TNF-α monoclonal antibodies (infliximab, adalimumab) and the soluble TNF-α receptor (etanercept) in TBM treatment. Thalidomide was developed nearly seventy years ago and has been a highly controversial drug. Birth defects and toxic adverse effects have limited its use but an improved understanding of its immunological mechanism of action suggest that it may have a crucial role in regulating the destructive host response seen in inflammatory conditions such as TBM. Observational studies at our institution found low dosage adjunctive thalidomide safe in treating tuberculous mass lesions and blindness related to optochiasmatic arachnoiditis, with good clinical and radiological response. In this review, we discuss possible mechanisms of action for thalidomide, based on our clinico-radiologic experience and post-mortem histopathological work. We also propose a rationale for its use in the treatment of certain TBM-related complications.

Transient acetylcholine receptor-related myasthenia gravis, post multisystem inflammatory syndrome in children (MIS-C) temporally associated with COVID-19 infection.

We report on a unique case of a 7-year-old girl with new onset ocular myasthenia gravis shortly after recovery from multisystem inflammatory syndrome in children (MIS-C) temporally associated with SARS-CoV-2 infection. The diagnosis of myasthenia gravis was based on suggestive symptoms of fatigable bilateral orbital ptosis, diplopia, positive ocular cold compression test and serum acetylcholine receptor antibody positivity, as well as a favourable treatment response to pyridostigmine. The addition of corticosteroids and methotrexate resulted in complete resolution of the ocular signs.

Acquired unilateral upper limb hypertrophy as a late complication of tuberculous meningitis complicated by Chiari 1 malformation and syringomyelia.

Syringomyelia associated with tuberculous meningitis (TBM) is an extremely rare condition. Only a few adult cases have been reported. A 12-year-old woman, who previously suffered TBM at the age of 6 months, presented with a long-standing history of right upper limb panhypertrophy, dissociate anaesthesia, frequent headaches, scoliosis and acquired macrocephaly. MRI demonstrated hydrocephalus, descent of the cerebral tonsils and an intramedullary syrinx extending from C2 to L1. Endoscopic third ventriculostomy (ETV) leads to reduction in the size of the syringomyelia and resolution of the thermoanaesthesia. This case highlights a very rare long-term complication associated with childhood TBM and the potential benefit offered by ETV.