Rifampicin and protein concentrations in paired spinal versus ventricular cerebrospinal fluid samples of children with tuberculous meningitis.

BACKGROUND: Tuberculous meningitis (TBM) is the most lethal form of TB. To study the disease, drug concentrations in samples obtained from the spinal CSF are usually used to reflect brain concentrations. Emerging data suggest that transport of substances across capillaries in the brain (ventricular CSF) and spinal cord may differ. METHODS: We examined paired, time-linked samples of ventricular CSF (VCSF) and lumbar CSF (LCSF) of 28 patients with TBM and analysed these for rifampicin and total protein concentrations. Clinically indicated samples from procedures to determine the level of CSF block were collected from children being treated for TBM and hydrocephalus. Total protein concentrations were determined using the bicinchoninic acid (BCA) or turbidimetry assay, and rifampicin concentrations were determined using a validated LC coupled with tandem MS method. A paired Wilcoxon signed-rank test was used to determine significance. RESULTS: TBM was confirmed in 19 cases (68%) using TB culture or GeneXpert Mtb/Rifampicin assay. All other cases were classified as probable. The median total protein concentration in LCSF was 6.0 g/L and in VCSF was 1.3 g/L. The median rifampicin concentration in LCSF was 299 ng/mL and 133 ng/mL in VCSF. The median ratio of LCSF/VSCF for protein was 4.23 and 1.57 for rifampicin. CONCLUSIONS: Total protein and rifampicin concentrations differed significantly between the two compartments, both being higher in LCSF than in VCSF samples (P < 0.0001 for total protein and P = 0.0046 for rifampicin). Further studies are required to explore the causative reasons for the observed differences.

Efficacy of deep brain stimulation of the anterior-medial globus pallidus internus in tic and non-tic related symptomatology in refractory Tourette syndrome.

Introduction: Although refractory Tourette Syndrome (TS) is rare, it poses great challenges in clinical practice. Co-morbid psychiatric symptoms often occur, negatively impacting quality of life. Deep brain stimulation (DBS) targeting different brain structures seems effective for tics, but specific literature regarding response of psychiatric symptoms is more limited.This study aimed to assess the outcome of tics and non-tic related symptomatology in refractory TS treated with antero-medial globus pallidus interna (amGPi) DBS. Methods: We included all patients with refractory TS (January 2013-August 2020) from the Brain Nerve Centre and Steve Biko Academic Hospital, Pretoria, South Africa, treated with bilateral amGPi DBS; retrospective baseline, early (up to 3 months) post-DBS follow-up assessment data, as well as prospective data from the latest follow-up (mean 37.4 months) were collected using standardised scoring tools and scales. Results: Five patients were identified. Tics decreased by 63,9% (p = 0,002); quality of life improved by 39,8% (p = 0,015); self-injurious behaviour ceased; obsessive-compulsive symptoms resolved in all but one. The number of different chronic medications used more than halved. Transient stimulation-related adverse events occurred in four patients. Conclusion: This study contributes to the data of the efficacy of amGPi-targeted DBS in refractory TS, showing improvement in quality of life and both tic- and non-tic-related symptomatology..

A pilot study of inflammatory mediators in brain extracellular fluid in paediatric TBM.

Tuberculous meningitis (TBM) is the most fatal form of tuberculosis and frequently occurs in children. The inflammatory process initiates secondary brain injury processes that lead to death and disability. Much remains unknown about this cerebral inflammatory process, largely because of the difficulty in studying the brain. To date, studies have typically examined samples from sites distal to the site of disease, such as spinal cerebrospinal fluid (CSF) and blood. In this pilot study, we examined the feasibility of using direct brain microdialysis (MD) to detect inflammatory mediators in brain extracellular fluid (ECF) in TBM. MD was used to help guide neurocritical care in 7 comatose children with TBM by monitoring brain chemistry for up to 4 days. Remnant ECF fluid was stored for offline analysis. Samples of ventricular CSF, lumbar CSF and blood were collected at clinically indicated procedures for comparison. Inflammatory mediators were quantified using multiplex technology. All inflammatory markers, with the exception of interleukin (IL)-10 and IL-12p40, were detected in the ECF. Cytokine concentrations were generally lower in ECF than ventricular CSF in time-linked specimens. Individual cases showed ECF cytokine increases coinciding with marked increases in ECF glycerol or decreases in ECF glucose. Cytokine levels and glycerol were generally higher in patients with more severe disease. This is the first report of inflammatory marker analysis from samples derived directly from the brain and in high temporal resolution, demonstrating feasibility of cerebral MD to explore disease progression and possibly therapy response in TBM.

Tuberculous meningitis in children is characterized by compartmentalized immune responses and neural excitotoxicity.

Tuberculous meningitis (TBM) is the most severe form of TB with high rates of mortality and morbidity. Here we conduct RNA-sequencing on whole blood as well as on ventricular and lumbar cerebrospinal fluid (CSF) of pediatric patients treated for TBM. Differential transcript expression of TBM cases are compared with healthy controls in whole blood and with non-TB cerebral infection controls in CSF. Whole blood RNA-Seq analysis demonstrates a distinct immune response pattern in TBM, with significant increase in both canonical and non-canonical inflammasome activation and decrease in T-cell activation. In ventricular CSF, a significant enrichment associated with neuronal excitotoxicity and cerebral damage is detected in TBM. Finally, compartmental comparison in TBM indicates that the ventricular profile represents brain injury whereas the lumbar profile represents protein translation and cytokine signaling. Together, transcriptomic analysis shows that disease processes differ between the periphery and the central nervous system, and within brain compartments.

Targeted treatment in severe traumatic brain injury in the age of precision medicine.

In recent years, much progress has been made in our understanding of traumatic brain injury (TBI). Clinical outcomes have progressively improved, but evidence-based guidelines for how we manage patients remain surprisingly weak. The problem is that the many interventions and strategies that have been investigated in randomized controlled trials have all disappointed. These include many concepts that had become standard care in TBI. And that is just for adult TBI; in children, the situation is even worse. Not only is pediatric care more difficult than adult care because physiological norms change with age, but also there is less evidence for clinical practice. In this article, we discuss the heterogeneity inherent in TBI and why so many clinical trials have failed. We submit that a key goal for the future is to appreciate important clinical differences between patients in their pathophysiology and their responses to treatment. The challenge that faces us is how to rationally apply therapies based on the specific needs of an individual patient. In doing so, we may be able to apply the principles of precision medicine approaches to the patients we treat.

Biomarkers of Cerebral Injury and Inflammation in Pediatric Tuberculous Meningitis.

Background: Tuberculous meningitis (TBM) leads to death or disability in half the affected individuals. Tools to assess severity and predict outcome are lacking. Neurospecific biomarkers could serve as markers of the severity and evolution of brain injury, but have not been widely explored in TBM. We examined biomarkers of neurological injury (neuromarkers) and inflammation in pediatric TBM and their association with outcome. Methods: Blood and cerebrospinal fluid (CSF) of children with TBM and hydrocephalus taken on admission and over 3 weeks were analyzed for the neuromarkers S100B, neuron-specific enolase (NSE), and glial fibrillary acidic protein (GFAP), in addition to multiple inflammatory markers. Results were compared with 2 control groups: patients with (1) a fatty filum (abnormal filum terminale of the spinal cord); and (2) pulmonary tuberculosis (PTB). Imaging was conducted on admission and at 3 weeks. Outcome was assessed at 6 months. Results: Data were collected from 44 patients with TBM (cases; median age, 3.3 [min-max 0.3-13.1] years), 11 fatty filum controls (median age, 2.8 [min-max 0.8-8] years) and 9 PTB controls (median age, 3.7 [min-max 1.3-11.8] years). Seven cases (16%) died and 16 (36%) had disabilities. Neuromarkers and inflammatory markers were elevated in CSF on admission and for up to 3 weeks, but not in serum. Initial and highest concentrations in week 1 of S100B and NSE were associated with poor outcome, as were highest concentration overall and an increasing profile over time in S100B, NSE, and GFAP. Combined neuromarker concentrations increased over time in patients who died, whereas inflammatory markers decreased. Cerebral infarcts were associated with highest overall neuromarker concentrations and an increasing profile over time. Tuberculomas were associated with elevated interleukin (IL) 12p40, interferon-inducible protein 10, and monocyte chemoattractant protein 1 concentrations, whereas infarcts were associated with elevated tumor necrosis factor α, macrophage inflammatory protein 1α, IL-6, and IL-8. Conclusions: CSF neuromarkers are promising biomarkers of injury severity and are predictive of mortality. An increasing trend suggested ongoing brain injury, even though markers of inflammation declined with treatment. These findings could offer novel insight into the pathophysiology of TBM.