Background: Intensive care unit-acquired weakness (ICU-AW) is associated with poorer outcome of critically ill patients. Microcirculatory changes and altered vascular permeability of skeletal muscles might contribute to the pathogenesis of ICU-AW. Muscular ultrasound (MUS) displays increased muscle echogenicity, although its pathogenesis is uncertain. Objective: We investigated the combined measurement of serum and ultrasound markers to assess ICU-AW and clinical patient outcome. Methods: Fifteen patients and five healthy controls were longitudinally assessed for signs of ICU-AW at study days 3 and 10 using a muscle strength sum score. The definition of ICU-AW was based on decreased muscle strength assessed by the muscular research council-sum score. Ultrasound echogenicity of extremity muscles was assessed using a standardized protocol. Serum markers of inflammation and endothelial damage were measured. The 3-month outcome was assessed on the modified Rankin scale. Results: ICU-AW was present in eight patients, and seven patients and the control subjects did not develop ICU-AW. The global muscle echogenicity score (GME) differed significantly between controls and patients (mean GME, 1.1 ± 0.06 vs. 2.3 ± 0.41; p = 0.001). Mean GME values significantly decreased in patients without ICU-AW from assessment 1 (2.30 ± 0.48) to assessment 2 (2.06 ± 0.45; p = 0.027), which was not observed in patients with ICU-AW. Serum levels of syndecan-1 at day 3 significantly correlated with higher GME values at day 10 (r = 0.63, p = 0.012). Furthermore, the patients’ GME significantly correlated with mRS at day 100 (r = 0.67, p = 0.013). Conclusion: The combined use of muscular ultrasound and inflammatory biomarkers might be helpful to diagnose ICU-AW and to predict long-term outcome in critical illness.

Background: Endovascular thrombectomy (EVT) has shown efficacy in acute ischemic stroke (AIS) patients with infective endocarditis (IE). The possibility to undertake advanced histopathological clot analysis following EVT offers a new avenue to establish the etiological basis of the stroke – which is often labelled “cryptogenic.” In this paper, we present our findings from four consecutive patients with IE who underwent EVT following an AIS at our tertiary referral comprehensive stroke centre. Methods: Comprehensive histopathological analysis of clot retrieved after EVT, including morphology, was undertaken. Results: The consistent observation was the presence of dense paucicellular fibrinoid material mixed/interspersed with clusters of bacterial cocci. This clot morphology may be specific to septic embolus due to IE unlike incidental bacteraemia and could possibly explain the refractoriness of such clots to systemic thrombolysis. Conclusion: Detailed morphological and histopathological analysis of EVT-retrieved clots including Gram staining can assist in etiological classification of the clot. Understanding the composition of the clot may be of clinical value in early diagnostics and mapping treatment planning in IE.

Background: We recently demonstrated that late functional improvement between 3-12 months post-stroke occurs in about one-fourth of patients with ischaemic stroke. It is unknown whether this improvement is associated with better long-term clinical or health-economic outcomes. Methods: In a prospective, population-based cohort of 1-year ischaemic stroke survivors (Oxford Vascular Study;2002-2014), we determined changes in functional status (modified Rankin Scale[mRS], Rivermead Mobility Index[RMI], Barthel Index[BI]) from 3-12 months post-stroke. We examined the association of late improvement (by ≥1 mRS grades, ≥1 RMI points, and/or ≥2 BI points) with 5-year mortality, institutionalization (Cox regressions), and health/social-care costs (generalized linear models), adjusted for age/sex/3-month disability/stroke subtype. Results: Among 1,288 1-year survivors, 1,135 had 3-month mRS>0, with 319(28.1%) demonstrating late improvement. 1-year survivors with late mRS improvement had lower 5-year mortality (aHR:0.68,95%CI 0.51-0.91,p=0.009), institutionalization (aHR:0.48,0.33-0.72,p<0.001), and costs (margin -$17,369,-25,271 to -9,469,p<0.001). These associations remained on excluding patients with recurrent strokes during follow-up (e.g. 5-year death/institutionalization aHR:0.59,0.44-0.79,p<0.001) and on examining late improvement per RMI and/or BI (e.g. 5-year death/institutionalization aHR:0.67,0.53-0.84,p=0.001). Conclusions: Late functional improvement post-stroke is associated with lower 5-year mortality, institutionalization, and costs. These findings should motivate patients and clinicians to maximize late recovery and encourage payers to consider access to rehabilitative services for at least 1-year post-stroke.

Human brain is a complex organ comprising multiple cell types of differing function. Although histological evaluation remains the mainstay approach for evaluating tissue, comprehensive molecular characterization is now possible due to advanced -omic approaches. microRNAs (miRNAs) are small (~22 nt) RNA molecules that regulate gene expression and mediate cellular differentiation in normal brain development. miRNAs also make excellent tissue markers due to their abundance, cell-type and disease-stage specificity, and stability in solid/liquid clinical samples. To advance our knowledge of miRNA-mediated gene regulation in human brain, we generated comprehensive miRNA expression profiles from 117 fresh normal brain samples through barcoded small RNA sequencing; tissues included neocortex, allocortex, white matter, cerebellum, olfactory bulb, optic nerve, pineal gland and spinal cord. FASTQ sequence files were annotated using state-of-the-art sequence annotation available through the Renwick lab. Following data pre-processing, high expression analysis of miRNA profiles showed that miR-9 was the highest expressed miRNA in neocortex, cerebellum and olfactory bulb, whereas miR-22 was highest expressed in cingulate cortex, optic nerve and spinal cord; interestingly, miR-29 was the highest expressed miRNA in hippocampus. Our analyses showed a trend towards unique miRNA signatures in different anatomical areas of the brain. Our next step is to perform miRNA fluorescence in situ hybridization on formalin-fixed paraffin-embedded tissues using a novel method developed in the Renwick lab. Accurate miRNA characterization of normal tissues will provide a firm basis for understanding miRNA changes in neurological diseases.

Background: Sleep-related hypermotor epilepsy (SHE) is a focal epilepsy characterized by abrupt sleep-related hypermotor seizures (SRHS) with complex semiology. Although difficult to localize within the frontal lobe recent studies using intracerebral EEG recordings have suggested the existence of four distinct semiology patterns (SP) organized in a rostro-caudal manner. It remains unclear however if these SP are clinically useful. Methods: We aimed to estimate the inter-rater reliability (IR) of classifying SP in SHE amongst epilepsy and sleep medicine experts. Following a short training session, ten experts were asked to review and classify 40 videos of SRHS in patients with confirmed SHE. IR was calculated using Kappa statistics. Results: SP1 and SP4, who are at the opposite ends of the SHE semiology spectrum, had substantial IR (0.82 and 0.67, respectively). Meanwhile, SP2 and SP3 showed fair agreement (0.25 and 0.35, respectively) and represented the major source of variance, with a small difference favouring epilepsy experts. Conclusions: Amongst epilepsy and sleep medicine experts, IR of classifying SRHS into four SP was only mildly satisfactory. SP1 and SP4 were shown to be easily recognizable while SP2 and SP3 were frequently confounded. Improvements in SP recognition are needed before widespread clinical use.

Introduction: Lewis–Sumner syndrome (LSS) is a demyelinating peripheral neuropathy described in 1982. Methods: We reviewed the charts of nine LSS patients in neurological care for their symptoms, response to different treatment regimens, and pattern of nerve involvement. Results: One patient had an Adie’s pupil. Every patient studied had median nerve involvement. Seven of nine patients required intravenous immunoglobulin (IVIg) therapy and all showed improvement with IVIg. Four of nine patients received oral steroid therapy and had some improvement. Two of nine patients received azathioprine to little effect. Two of nine patients experienced significant trauma while receiving neurological follow-up and their symptoms worsened to a clinically significant degree afterward. Discussion: We noticed a possible association between trauma and symptom severity in cases of LSS with preexisting neurological follow-up. We hypothesize that physical trauma exacerbates LSS. To our knowledge, this is an unreported phenomenon.

Background: High levels of uric acid (UA) are associated with various peripheral neuropathies. Furthermore, uric acid levels have been found to correlate with both the clinical and electrophysiological severity of diabetic sensorimotor polyneuropathy, mainly with sensory functions. Objectives: To determine whether higher UA levels are associated negatively with nerve function in healthy subjects. Methods: A total of 126 healthy subjects recruited prospectively for another study were included. We extracted demographic data, body mass index (BMI), blood pressure, Toronto Clinical Neuropathy Score (TCNS), electrophysiological findings, vibration perception thresholds (VPT), and laboratory test results including UA, hemoglobin A1c (HbA1c), estimated glomerular filtration rate (eGFR), and lipid levels. Results: The mean age of the cohort was 56 ± 17 years with 56% females. Males had higher UA values compared with females. Univariate beta regression coefficient analysis between UA levels and demographic, clinical, electrophysiological, and laboratory findings showed significant positive correlations with male gender, components of the metabolic syndrome, and with VPT, while an inverse correlation was found with electrophysiological sensory parameters. A multivariate regression model showed positive correlations only with BMI, finger VPT, and triglycerides. Conclusion: Higher UA levels correlate with lower sensory nerve function in healthy subjects, expanding the evidence of possible negative influence of UA on peripheral nerves, although a causative role has not yet established.

As image analysis expands into clinical and basic applications it is important that users be aware of opportunities and limitations. A common image analysis workflow involves the digitization of stained tissue sections into a red-green-blue (RGB) colour model for quantitative interpretation. Upstream of the digital image, quality and variability can be degraded at each step (tissue handling, fixation, sectioning, staining, image acquisition). Digital image analysis presents additional steps where variables can affect data quality. Image analysis platforms are not uniform. Aside from interface preferences, some introduce unintended variability due to their processing architecture that may not be obvious to the end-user. One important component of this is colour space representation: hue-saturation-intensity (HSI) vs. colour deconvolution (CD). A potential weakness of analyses within the HSI colour space is the mis-identification of darkly stained pixels, particularly when more than one stain is present. We were interested to discover whether HSI or CD provided greater fidelity in a typical immunoperoxidase/hematoxylin dataset.

Fifty-nine samples were processed using HSI- and CD-based analyses. Processed image pairs were compared with the original sample to determine which processed image provided a more accurate representation. CD proved superior to HSI in 94.9% of the analyzed image pairs. Where the option exists, CD-based image analysis is strongly recommended.

Measured nerve conduction velocity in the fibular nerve increases across the knee during hip flexion. This is due to stretching of sciatic and fibular nerves. We modeled the additional nerve length required for the sciatic nerve to course around the flexed hip, based upon distance between the hip and the sciatic nerve on magnetic resonance imaging (MRI). The median distance from the femoral head to the sciatic nerve was 41 mm. The model predicted that 64 mm of sciatic nerve is required for hip flexion. This impacts our understanding of lower limb nerve conduction studies and clinical straight leg raising tests.

Natalizumab is an efficacious disease modifying therapy (DMT) for relapsing remitting multiple sclerosis (RRMS), often limited by risk of progressive multifocal leukoencephalopathy. We describe the clinical course of RRMS patients switched from natalizumab to another DMT. We identified all RRMS patients treated with natalizumab ≥3 months with JC virus antibody positivity who switched to another DMT. Overall, 84 individuals switched DMT with 57 (68%) beginning fingolimod. On fingolimod, survival without a relapse was 74% (55.8–85.6%) at 36 months and survival without disease progression was 78% (62.6–87.6%) at 36 months. In conclusion, fingolimod is an effective therapy post-natalizumab.

We describe the case of an 11-month-old girl with a rare cerebellar glioblastoma driven by a NACC2-NTRK2 (Nucleus Accumbens Associated Protein 2-Neurotrophic Receptor Tyrosine Kinase 2) fusion. Initial workup of our case demonstrated homozygous CDKN2A deletion, but immunohistochemistry for other driver mutations, including IDH1 R132H, BRAF V600E, and H3F3A K27M were negative, and ATRX was retained. Tissue was subsequently submitted for personalized oncogenomic analysis, including whole genome and whole transcriptome sequencing, which demonstrated an activating NTRK2 fusion, as well as high PD-L1 expression, which was subsequently confirmed by immunohistochemistry. Furthermore, H3 and IDH demonstrated wildtype status. These findings suggested the possibility of treatment with either NTRK- or immune checkpoint- inhibitors through active clinical trials. Ultimately, the family pursued standard treatment that involved Head Start III chemotherapy and proton radiotherapy. Notably, at most recent follow upapproximately two years from initial diagnosis, the patient is in disease remission and thriving, suggesting favorable biology despite histologic malignancy. This case illustrates the value of personalized oncogenomics, as the molecular profiling revealed two actionable changes that would not have been apparent through routine diagnostics. NTRK fusions are known oncogenic drivers in a range of cancer types, but this is the first report of a NACC2-NTRK2 fusion in a glioblastoma.

Psychosurgery refers to the surgical interruption of the white matter fibres joining the frontal cortex to the remainder of the cortical mantle and to the thalamus, in an attempt to mitigate the manifestations of psychosis. It reached its heyday following World War Two and was abandoned with the introduction of major tranquilisers such as chlorpromazine. Wilder Penfield, unlike most of his contemporaries, had a jaundiced view of psychosurgery. This paper addresses Penfield’s early experience with experimental, penetrating brain trauma and with the surgical resection of frontal, epileptogenic lesions, which explain his antagonism towards psychosurgery.