There has been a surge of interest in the structure and function of the mammalian claustrum in recent years. However, most anatomical and physiological studies treat the claustrum as a relatively homogenous structure. Relatively little attention has been directed toward possible compartmentalization of the claustrum complex into anatomical subdivisions, and how this compartmentalization is reflected in claustrum connections with other brain structures. In this study, we examined the cyto- and myelo-architecture of the claustrum of the common marmoset (Callithrix jacchus), to determine whether the claustrum contains internal anatomical structures or compartments, which could facilitate studies focused on understanding its role in brain function. NeuN, Nissl, calbindin, parvalbumin, and myelin-stained sections from eight adult marmosets were studied using light microscopy and serial reconstruction to identify potential internal compartments. Ultra high resolution (9.4T) post-mortem magnetic resonance imaging was employed to identify tractographic differences between identified claustrum subcompartments by diffusion-weighted tractography. Our results indicate that the classically defined marmoset claustrum includes at least two major subdivisions, which correspond to the dorsal endopiriform and insular claustrum nuclei, as described in other species, and that the dorsal endopiriform nucleus (DEnD) contains architecturally distinct compartments. Furthermore, the dorsal subdivision of the DEnD is tractographically distinguishable from the insular claustrum with respect to cortical connections.

ImportanceNeurocritical care (NCC) aims to improve the outcomes of critically ill patients with brain injury, although the benefits of such subspecialized care are yet to be determined.ObjectiveTo evaluate the association of NCC with patient-centered outcomes in adults with acute brain injury who were admitted to intensive care units (ICUs). The protocol was preregistered on PROSPERO (CRD42020177190).Data SourcesThree electronic databases were searched (Ovid MEDLINE, Embase, Cochrane Central Register of Controlled Trials) from inception through December 15, 2021, and by citation chaining.Study SelectionStudies were included for interventions of neurocritical care units (NCCUs), neurointensivists, or NCC consulting services compared with general care in populations of neurologically ill adults or adults with acute brain injury in ICUs.Data Extraction and SynthesisData extraction was performed in keeping with PRISMA guidelines and risk of bias assessed through the ROBINS-I Cochrane tool by 2 independent reviewers. Data were pooled using a random-effects model.Main Outcomes and MeasuresThe primary outcome was all-cause mortality at longest follow-up until 6 months. Secondary outcomes were ICU length of stay (LOS), hospital LOS, and functional outcomes. Data were measured as risk ratio (RR) if dichotomous or standardized mean difference if continuous. Subgroup analyses were performed for disease and models of NCC delivery.ResultsAfter 5659 nonduplicated published records were screened, 26 nonrandomized observational studies fulfilled eligibility criteria. A meta-analysis of mortality outcomes for 55 792 patients demonstrated a 17% relative risk reduction (RR, 0.83; 95% CI, 0.75-0.92; P = .001) in those receiving subspecialized care (n = 27 061) compared with general care (n = 27 694). Subgroup analyses did not identify subgroup differences. Eight studies including 4667 patients demonstrated a 17% relative risk reduction (RR, 0.83; 95% CI, 0.70-0.97; P = .03) for an unfavorable functional outcome with subspecialized care compared with general care. There were no differences in LOS outcomes. Heterogeneity was substantial in all analyses.Conclusions and RelevanceSubspecialized NCC is associated with improved survival and functional outcomes for critically ill adults with brain injury. However, confidence in the evidence is limited by substantial heterogeneity. Further investigations are necessary to determine the specific aspects of NCC that contribute to these improved outcomes and its cost-effectiveness.

Background Headache is a common presentation of postural tachycardia syndrome, yet robust prevalence data is lacking. Objectives To undertake a systematic review and meta-analysis to estimate the prevalence of headache disorders in postural tachycardia syndrome, and to explore the potential shared pathophysiological mechanisms that underpin these conditions as well as treatment options. Methods Three databases were searched for publications evaluating prevalence of migraine (primary outcome) and general and orthostatic headache (secondary outcomes) in patients with postural tachycardia syndrome. Two independent reviewers selected studies and extracted data. A random-effects meta-analysis calculated the pooled prevalence of migraine in postural tachycardia syndrome. A narrative literature review explored the pathophysiology and treatment options for concurrent headache disorders and postural tachycardia syndrome. Results Twenty-three articles met inclusion criteria. Estimated pooled prevalence of migraine in postural tachycardia syndrome was 36.8% (95% CI 2.9–70.7%). Various shared pathophysiological pathways for these conditions, as well as proposed treatment strategies, were identified. Limitations: Heterogeneity of study design, populations, and methodology for identifying headache disorders and postural tachycardia syndrome limited the generalisability of results. Conclusions Migraine is a commonly reported comorbidity in POTS, however the true prevalence cannot be determined from the current literature. Further studies are required to assess this comorbidity and investigate the underlying mechanisms, as well as identify effective treatment strategies.

IntroductionNeurocritical care is a rapidly developing subspecialty within intensive care medicine which aims to improve outcomes of critically ill neurological patients. This has inspired the formation of specialised intensive care units or services to provide dedicated care of brain-injured patients, as well as new training pathways for physicians. However, expansion has been variable worldwide and it is yet to be determined if there are clear benefits in regard to patient outcomes. We are planning a systematic review with meta-analysis to assess whether the introduction of neurocritical care units or services, or neurointensivists have favourable effects on survival.Methods and analysisWe will include all observational and interventional studies comparing specialised neurocritical care units or services with general or non-specialised units in the care of acutely brain-injured adults. The primary outcome will be all-cause mortality at the longest follow-up, and secondary outcomes will be intensive care unit and hospital length of stay, and functional outcomes. All relevant studies will be identified through database searches. All study selection and data extraction will be conducted by two independent reviewers. We will conduct a random-effects meta-analysis to synthesise evidence for all outcomes. In addition, we will perform a subgroup analysis by disease process. We will assess confidence in the cumulative evidence using the Grading of Recommendations, Assessment, Development and Evaluations framework.Ethics and disseminationThis systematic review and meta-analysis does not require ethical approval. We will publish findings from this systematic review in a peer-reviewed scientific journal and present these at conferences. It will be included in the primary author’s higher degree research thesis.PROSPERO registration numberCRD42020177190.