Detection of Neuroinflammation Induced by Typhoid Vaccine Using Quantitative Magnetization Transfer MR: A Randomized Crossover Study

BACKGROUND

The role of neuroinflammation in psychiatric disorders is not well-elucidated. A noninvasive technique sensitive to low-level neuroinflammation may improve understanding of the pathophysiology of these conditions.

PURPOSE

To test the ability of quantitative magnetization transfer (QMT) MR at 3 T for detection of low-level neuroinflammation induced by typhoid vaccine within a clinically reasonable scan time.

STUDY TYPE

Randomized, crossover, placebo-controlled.

SUBJECTS

Twenty healthy volunteers (10 males; median age 34 years).

FIELD STRENGTH/SEQUENCE

Magnetization prepared rapid gradient-echo and MT-weighted 3D fast low-angle shot sequences at 3 T.

ASSESSMENT

Participants were randomized to either vaccine or placebo first with imaging, then after a washout period received the converse with a second set of imaging. MT imaging, scan time, and blood-based inflammatory marker concentrations were assessed pre- and post-vaccine and placebo. Mood was assessed hourly using the Profile of Mood States questionnaire. QMT parameter maps, including the exchange rate from bound to free pool (kba) were generated using a two-pool model and then segmented into tissue type.

STATISTICAL TESTS

Voxel-wise permutation-based analysis examined inflammatory-related alterations of QMT parameters. The threshold-free cluster enhancement method with family-wise error was used to correct voxel-wise results for multiple comparisons. Region of interest averages were fed into mixed models and Bonferroni corrected. Spearman correlations assessed the relationship between mood scores and QMT parameters. Results were considered significant if corrected P < 0.05.

RESULTS

Scan time for the MT-weighted acquisition was approximately 11 minutes. Blood-based analysis showed higher IL-6 concentrations post-vaccine compared to post-placebo. Voxel-wise analysis found three clusters indicating an inflammatory-mediated increase in kba in cerebellar white matter. Cerebellar kba for white matter was negatively associated with vigor post-vaccine but not post-placebo.

DATA CONCLUSION

This study suggested that QMT at 3 T may show some sensitivity to low-level neuroinflammation. Further studies are needed to assess the viability of QMT for use in inflammatory-based disorders.

EVIDENCE LEVEL

1 TECHNICAL EFFICACY: Stage 2.

A callosal biomarker of behavioral intervention outcomes for autism spectrum disorder? A case-control feasibility study with diffusion tensor imaging

Tentative results from feasibility analyses are critical for planning future randomized control trials (RCTs) in the emerging field of neural biomarkers of behavioral interventions. The current feasibility study used MRI-derived diffusion imaging data to investigate whether it would be possible to identify neural biomarkers of a behavioral intervention among people diagnosed with autism spectrum disorder (ASD). The corpus callosum has been linked to cognitive processing and callosal abnormalities have been previously found in people diagnosed with ASD. We used a case-control design to evaluate the association between the type of intervention people diagnosed with ASD had previously received and their current white matter integrity in the corpus callosum. Twenty-six children and adolescents with ASD, with and without a history of parent-managed behavioral intervention, underwent an MRI scan with a diffusion data acquisition sequence. We conducted tract-based spatial statistics and a region of interest analysis. The fractional anisotropy values (believed to indicate white matter integrity) in the posterior corpus callosum was significantly different across cases (exposed to parent-managed behavioral intervention) and controls (not exposed to parent-managed behavioral intervention). The effect was modulated by the intensity of the behavioral intervention according to a dose-response relationship. The current feasibility case-control study provides the basis for estimating the statistical power required for future RCTs in this field. In addition, the study demonstrated the effectiveness of purposely-developed motion control protocols and helped to identify regions of interest candidates. Potential clinical applications of diffusion tensor imaging in the evaluation of treatment outcomes in ASD are discussed.

The Use of Helplines and Telehealth Support in Aotearoa/New Zealand During COVID-19 Pandemic Control Measures: A Mixed-Methods Study

BACKGROUND

Early evidence suggests that the COVID-19 pandemic and associated interventions have affected mental well-being and associated health service use.

AIMS

the aim of this study was to examine the effect of the COVID-19 pandemic and associated public health measures on helpline and telehealth service demand.

METHODS

the study utilized a mixed methods research design. Segmented regression analyses were used first to identify changes in patterns of demand for Aotearoa/New Zealand national helplines (n = 11) from January 2020 until the end of March 2021. Thematic analysis of 23 in-depth interviews was used next to explore the reasons behind the quantitative findings from the perspective of various organizational stakeholders.

RESULTS

the data from 1,244,293 Aotearoa/New Zealand national helplines' contacts between January 2020 and March 2021 showed a non-significant (1.4%) upward trend for the full range of observations. Throughout this period, a peak and trough pattern was observed. Significant demand increases were observed in anticipation of containment measures (12.4% increase from January to March 2020) and significant demand decreases coincided with relaxation of restrictions (6.9% decrease from April to June 2020). There were spikes in demand during public health interventions (i.e., mental health promotion, introduction of new helpline services) and regional lockdowns, but these did not result in significant changes in trends. In general, the demand for helplines stabilized at a new higher level. Most of the contacts occurred by telephone calls. Contacts by other methods (webchat, text, email) have shown higher uptake during the periods of lockdowns. Quantitative-qualitative data triangulation showed that youth and populations who were disproportionally negatively affected by unstable economic conditions and underemployment made more frequent contacts. Providers emphasized that increased demand could be viewed positively as a successful outcome of public health messaging; however, greater capacity is needed to better serve higher demand.

CONCLUSIONS

COVID-19, related interventions, and measures of control were associated with an increase in contacts to helplines. However, the extent of the demand increases was lower than observed internationally. Moreover, in Aotearoa/New Zealand the reasons for increases in demand were often beyond the COVID-19 pandemic and measures of control.

Coenzyme A-Dependent Tricarboxylic Acid Cycle Enzymes Are Decreased in Alzheimer's Disease Consistent With Cerebral Pantothenate Deficiency

Sporadic Alzheimer's disease (sAD) is the commonest cause of age-related neurodegeneration and dementia globally, and a leading cause of premature disability and death. To date, the quest for a disease-modifying therapy for sAD has failed, probably reflecting our incomplete understanding of aetiology and pathogenesis. Drugs that target aggregated Aβ/tau are ineffective, and metabolic defects are now considered to play substantive roles in sAD pathobiology. We tested the hypothesis that the recently identified, pervasive cerebral deficiency of pantothenate (vitamin B5) in sAD, might undermine brain energy metabolism by impairing levels of tricarboxylic acid (TCA)-cycle enzymes and enzyme complexes, some of which require the pantothenate-derived cofactor, coenzyme A (CoA) for their normal functioning. We applied proteomics to measure levels of the multi-subunit TCA-cycle enzymes and their cytoplasmic homologues. We analysed six functionally distinct brain regions from nine sAD cases and nine controls, measuring 33 cerebral proteins that comprise the nine enzymes of the mitochondrial-TCA cycle. Remarkably, we found widespread perturbations affecting only two multi-subunit enzymes and two enzyme complexes, whose function is modulated, directly or indirectly by CoA: pyruvate dehydrogenase complex, isocitrate dehydrogenase, 2-oxoglutarate dehydrogenase complex, and succinyl-CoA synthetase. The sAD cases we studied here displayed widespread deficiency of pantothenate, the obligatory precursor of CoA. Therefore, deficient cerebral pantothenate can damage brain-energy metabolism in sAD, at least in part through impairing levels of these four mitochondrial-TCA-cycle enzymes.

Cerebral Vitamin B5 (D-Pantothenic Acid) Deficiency as a Potential Cause of Metabolic Perturbation and Neurodegeneration in Huntington's Disease

Huntington's disease (HD) is a neurodegenerative disorder caused by an expanded CAG repeat in exon 1 of the HTT gene. HD usually manifests in mid-life with loss of GABAergic projection neurons from the striatum accompanied by progressive atrophy of the putamen followed by other brain regions, but linkages between the genetics and neurodegeneration are not understood. We measured metabolic perturbations in HD-human brain in a case-control study, identifying pervasive lowering of vitamin B5, the obligatory precursor of coenzyme A (CoA) that is essential for normal intermediary metabolism. Cerebral pantothenate deficiency is a newly-identified metabolic defect in human HD that could potentially: (i) impair neuronal CoA biosynthesis; (ii) stimulate polyol-pathway activity; (iii) impair glycolysis and tricarboxylic acid cycle activity; and (iv) modify brain-urea metabolism. Pantothenate deficiency could lead to neurodegeneration/dementia in HD that might be preventable by treatment with vitamin B5.

Cluster randomised controlled trial of a guided self-help mental health intervention in primary care

OBJECTIVES

To ascertain whether an ultrabrief intervention (UBI) improves mental health outcomes for patients in general practice with mild-to-moderate mental health concerns.

TRIAL DESIGN

Two-arm cluster randomised controlled trial.

METHODS

Participants: general practitioners (GPs) were invited based on working in a participating general practice. Patients were eligible to participate if aged 18-65 years, scored ≤35 on the Kessler-10 (K10) and if meeting local mental health access criteria (based on age, low income or ethnic group).

INTERVENTIONS

intervention arm GPs were trained on the UBI approach, with participating patients receiving three structured appointments over 5 weeks. GPs randomised to practice as usual (PAU) did not receive training, and delivered support following their existing practice approaches.

OUTCOME MEASURES

primary outcome was patient-level K10 score at 6 months postrecruitment.Randomisation: GP practices were randomised to UBI training or PAU at the start of the study.Blinding: GPs were not blinded to group assignment.

RESULTS

Numbers randomised: 62 GPs (recruiting 85 patients) were randomised to UBI, and 50 to PAU (recruiting 75 patients).Numbers analysed: 31 GPs recruited at least one patient in the UBI arm (70 patients analysed), and 21 GPs recruited at least one patient in the PAU arm (69 patients analysed).

OUTCOME

K10 scores from an intention-to-treat analysis were similar in UBI and PAU arms, with a wide CI (mean adjusted K10 difference=1.68 points higher in UBI arm, 95% CI -1.18 to 4.55; p=0.255). Secondary outcomes were also similar in the two groups.

CONCLUSIONS

the UBI intervention did not lead to better outcomes than practice as usual, although the study had lower than planned power due to poor recruitment. The study results can still contribute to the continuing debate about brief psychological therapy options for primary care and their development.

TRIAL REGISTRATION NUMBER

ACTRN12613000041752; Pre-results.