A parcellation-based connectomic model of hemispatial neglect

BACKGROUND AND PURPOSE

Hemispatial neglect is characterized by a reduced awareness to stimuli on the contralateral side. Current literature suggesting that damage to the right parietal lobe and attention networks may cause hemispatial neglect is conflicting and can be improved by investigating a connectomic model of the "neglect system" and the anatomical specificity of regions involved in it.

METHODS

A meta-analysis of voxel-based morphometry magnetic resonance imaging (MRI) studies of hemispatial neglect was used to identify regions associated with neglect. We applied parcellation schemes to these regions and performed diffusion spectrum imaging (DSI) tractography to determine their connectivity. By overlaying neglect areas and maps of the attention networks, we studied the relationship between them.

RESULTS

The meta-analysis generated a list of 13 right hemisphere parcellations. These 13 neglect-related parcellations were predominantly linked by the superior longitudinal fasciculus (SLF) throughout a fronto-parietal-temporal network. We found that the dorsal and ventral attention networks showed partial overlap with the neglect system and included various other higher-order networks.

CONCLUSIONS

We provide an anatomically specific connectomic model of the neurobehavioral substrates underlying hemispatial neglect. Our model suggests a fronto-parietal-temporal network linked via the SLF supports the functions impaired in neglect and implicates various higher-order networks which are not limited to the attention networks.

Survival and quality of life after CSF diversion in adult patients with leptomeningeal metastasis-associated hydrocephalus: a systematic review and meta-analysis

OBJECTIVE

Leptomeningeal metastasis (LM) is associated with altered CSF flow dynamics in 50%-70% of patients. Approximately 1%-5% of patients develop symptomatic LM-associated hydrocephalus (LM-H), which adversely impacts quality of life (QOL), functional status, and overall survival (OS). There is equipoise for CSF diversion procedures in LM-H. This systematic review and meta-analysis aimed to assess the effect of CSF diversion on OS and QOL in this context.

METHODS

This systematic review was conducted according to the PRISMA guidelines. PubMed/Medline, Embase, Web of Science, and Scopus were searched for articles that evaluated the role of CSF diversion for LM-H due to systemic cancer in adult patients. A meta-analysis was conducted using random effects models, with mean differences and 95% CIs reported. Bias was assessed using the Risk of Bias in Nonrandomized Studies of Interventions (ROBINS-I) tool.

RESULTS

Ten eligible studies with a total of 494 patients were included. Two studies reported multivariate HRs for median OS, suggesting no significant effect of shunting on OS (pooled HR 0.42, 95% CI 0.09-1.94, p = 0.27). A difference between preoperative and postoperative Karnofsky Performance Status of mean 17.6 points (95% CI 10.44-24.68, p < 0.0001) was calculated from 4 studies. Across all studies, a symptomatic improvement rate of 67%-100% was observed, with high rates of improvement for headaches and nausea and lower rates for cranial nerve palsies. Complication rates across 9 studies ranged from 0% to 21.1%.

CONCLUSIONS

Based on the present findings, shunting does not improve OS but does relieve symptoms, suggesting that individuals who exhibit certain symptoms should be considered for CSF diversion. The present findings prompt the generation of a standardized decision-making tool and a critical analysis of the individual patient risk-benefit ratio. Implementation of these will optimize surgical management of LM-H patients.

The Phenotypic Spectrum of New-onset IBD in Canadian Children of South Asian Ethnicity: A Prospective Multi-Centre Comparative Study

BACKGROUND

Canadian-born children of South Asian [SA] ethnicity develop inflammatory bowel disease [IBD] at similar rates to those among Caucasian children. We evaluated the variation in phenotypic spectrum of IBD in SA and Caucasian children in a national paediatric inception cohort of new-onset IBD.

METHODS

Patients aged <17 years, enrolled in a Canadian nationwide inception cohort study, were included. Baseline demographic and IBD phenotypic features were compared between SA and Caucasian children. Longitudinal outcomes through 18 months of follow-up were compared matched by propensity scores.

RESULTS

Of 1156 children enrolled over 2014 to 2019, 623 were Caucasian [98% and 88% parents Canadian born] and 114 SA [79% Canadian born, 87% parents SA born]. Fewer SAs have a first-degree relative with IBD, 6% vs 19% in Caucasians, p = 0.002. SAs present at a younger age, median age 11.4 years (interquartile range [IQR] 9.2-14.3) vs 13 years [IQR 10.9-15 years], p = 0.03 and more commonly with a UC/IBD-U [ulcerative colitis/IBD-unclassified] subtype [ratio of UC/IBD-U to CD 1.2:1 vs 1:1.8 for Caucasians, p <0.001]. Additionally, a greater proportion of SA CD patients present with colonic-only disease [colonic-only CD/UC/IBD-U in SAs 67% vs 57% for Caucasians, p = 0.001], and among those with CD, colonic CD in SAs 31% vs 23% in Caucasians, p = 0.20]. Perianal fistulising disease was also numerically more common in SAs (14 [27%] vs 64 [18%], p = 0.06]. Adjusting for differences in phenotypic presentation, anti-tumour necrosis factor [TNF] exposure, and time to initiation was similar, and two-thirds of children, whether anti-TNF exposed or naïve, were in corticosteroid-free clinical remission at 18 months irrespective of ethnicity.

CONCLUSIONS

The phenotypic spectrum of new-onset IBD in SA children differs from that of Caucasian children, but treatment and clinical course are similar within phenotypic subgroups.

Phenotypic Variation in Paediatric Inflammatory Bowel Disease by Age: A Multicentre Prospective Inception Cohort Study of the Canadian Children IBD Network

BACKGROUND AND AIMS

Incidence of paediatric inflammatory bowel disease [IBD] in Canada is among the highest worldwide, and age of onset may be decreasing. In a multicentre nationwide inception cohort study, we examined variation in phenotype of IBD throughout the paediatric age spectrum.

METHODS

Children aged ≥2 years [y] and <17y [A1 age at diagnosis], with new onset IBD, were systematically evaluated at sites of the Canadian Children IBD Network. Prospectively recorded phenotypic data were compared between age groups.

RESULTS

Among 1092 children (70% Caucasian; 64% Crohn's disease [CD], 36% ulcerative colitis/inflammatory bowel disease unclassified [UC/IBD-U]; median age 13 y, interquartile range [IQR] 11-15 y), 210 [19%] were diagnosed before the age of age 10 y [Paris A1a] and 43 [4%] before age 6 y (very-early-onset [VEO-IBD]). CD was less common in younger children [42%, 56%, 66%, respectively, of VEO-IBD, A1a; A1b]. Colon-only IBD [UC/IBDU or CD-colon] was present in 81% of VEO-IBD and 65% of A1a; ileal disease increased progressively, reaching plateau at age 10 y. CD location was ileocolonic [L3] in 53% overall. Ileitis [L1] increased with age [6% of VEO-IBD; 13% of A1a; 21% of A1b], as did stricturing/penetrating CD [4% of A1a; 11% of A1b]. At all ages UC was extensive [E3/E4] in >85%, and disease activity moderate to severe according to Physician's Global Assessment [PGA] and weighted Paediatric Crohn's Disease Activity Index/Paediatric Ulcerative Colitis Activity Index [wPCDAI/PUCAI] in >70%. Heights were modestly reduced in CD [mean height z score -0.30 ± 1.23], but normal in UC/IBD-U.

CONCLUSIONS

Paris classification of age at diagnosis is supported by age-related increases in ileal disease until age 10 years. Other phenotypic features, including severity, are similar across all ages. Linear growth is less impaired in CD than in historical cohorts, reflecting earlier diagnosis.

Hepatic steatosis is highly prevalent across the paediatric age spectrum, including in pre-school age children

BACKGROUND

The prevalence of non-alcoholic fatty liver disease (NAFLD) in children is 8% in the general population, and 34% in the context of obesity. There is a paucity of data on the prevalence of hepatic steatosis in healthy children in Ontario.

AIMS

To determine the prevalence of hepatic steatosis using abdominal computed tomography (CT) scans in a cohort of previously healthy children across the paediatric age spectrum in Ontario, Canada, and to determine any association between measures of abdominal adiposity and hepatic steatosis.

METHODS

Retrospective review of the SickKids Trauma Database from 2004-2015. Previously healthy children ages 1-17 years having undergone an abdominal CT scan as a part of routine trauma assessment were included, and those with an intra-abdominal injury excluded. Steatosis was defined as a difference between liver and spleen attenuation ≤-25HU. The percentage of the total area occupied by abdominal subcutaneous adipose and visceral adipose tissue was measured. Anthropometrics and baseline demographics were collected.

RESULTS

A total of 503 (51% male) children with mean (±SD) age 9.5 ± 4.5 years and weight z-score of 0.37 ± 1.05 were studied. Seventy-seven (15%, 95% CI [12%-18%]) had hepatic steatosis; no differences found between sexes or across age quartiles. The abdominal subcutaneous adipose tissue area was greater in those with hepatic steatosis compared to those without (32% [22-42] vs 24% [17-36], P = 0.003). The visceral adipose tissue area was significantly greater in older children ≥9.8 years with hepatic steatosis (7.7% [5.1-10] vs 6.6% (4.9-8.5), P = 0.04).

CONCLUSION

Hepatic steatosis was highly prevalent in previously healthy children in Ontario, including children of pre-school age. We found an association between hepatic steatosis and abdominal subcutaneous adipose tissue, and in older children with visceral adipose tissue.

A201 PREVALENCE OF NONALCOHOLIC FATTY LIVER DISEASE IN A COHORT OF HEALTHY CHILDREN IN ONTARIO

Aims

To determine the prevalence of hepatic steatosis in a cohort of previously healthy children and adolescents, with the use of abdominal computer tomography (CT).

Methods

Retrospective review of the Sickkids trauma database from (year 2004 to 2015). Inclusion criteria: previously healthy children ages 1-17yr having undergone an abdominal CT scan as a part of routine trauma assessment. Exclusion criteria: Involvement of spleen and/or liver in the injury, known metabolic condition, concurrent use of medications that could predispose to hepatic steatosis. Steatosis was defined as a liver spleen attenuation index (L/S AI) of &lt;0.8. Anthropometrics and baseline demographics were collected. Statistical analyses were performed using Graphpad Prism 7.

Results

A total of 143 children were included in the analyses with a mean (SD) age of 7.12(4.26) years. 88 children were male (7.10(4.24) years old). The mean (SD) weight z score was 0.48 (0.97). Fifteen percent of the 137 children with a weight z-score between -2 to 2 had evidence of hepatic steatosis on imaging (using liver/spleen index &lt;0.8). Twenty seven percent (6/22) of children with weight z-scores less than the 33rd percentile had L/S AI &lt;0.8. An inverse correlation between weight z-scores and L/S AI was found in children &gt;10 years (P&lt;0.016) (Fig 1); however there was no correlation in pre-pubertal children (P&lt;0.374).

Conclusions

Hepatic steatosis is highly prevalent in this cohort of healthy children in Ontario. Larger population based studies are needed to investigate the prevalence of hepatic steatosis in children across Canada.

Funding Agencies

None

Treatment outcomes for eosinophilic esophagitis in children with esophageal atresia

Eosinophilic esophagitis (EoE) has been reported to be more prevalent in patients with esophageal atresia/tracheoesophageal fistula (EA-TEF). To date, there is limited data on the management of EoE in this group of patients. The aim of this study is to evaluate the treatment outcomes of EoE in children with EA-TEF. A retrospective chart review was performed on all EA-TEF children who were diagnosed with and treated for EoE between January 2000 and September 2013 at the Sydney Children's Hospital. Data collected included details of the patient's treatment, post-treatment endoscopy, symptoms and nutrition. Twenty patients were included in the study. Median age at diagnosis was 26 months (8-103 months), and median time from diagnosis to last follow-up was 23 months (2-132 months). Patients were treated with budesonide slurry, swallowed fluticasone, elimination diet alone or in combination. All patients were on proton pump inhibitors at time of diagnosis of EoE which was continued. Six out of seven patients who had furrowing/exudate in endoscopy at diagnosis had complete resolution at a median follow-up period of 26 months (P = 0.031). Median peak intraepithelial eosinophil count reduced significantly from 30/high-powered field (HPF) (19-80/HPF) to 8/HPF (0-85/HPF) (median time for improvement = 24 months) (P = 0.015). There was a significant reduction in symptoms of dysphagia and reflux post-treatment (P < 0.001). Prevalence of strictures significantly decreased (P = 0.016), as did need for dilatations (P = 0.004). In four out of six patients with gastrostomies at baseline, the feeding improved on treatment of EoE and the gastrostomy could be closed. There was also a nonsignificant trend towards improvement in weight and height 'z scores' of the patients. Treatment of EoE in children with EA-TEF was found to significantly reduce intraepithelial eosinophil count, symptoms, strictures and need for dilatations.

Auditory-cued sensorimotor task reveals disengagement deficits in rats exposed to the autism-associated teratogen valproic acid

Autism Spectrum Disorder (ASD) is often found to co-exist with non-core behavioral manifestations that include difficulties in disengagement of attention to sensory cues. Here we examined whether this behavioral abnormality can be induced in rats prenatally exposed to valproic acid (VPA), a well-established teratogen associated with ASD animal models. We tested rats using an auditory-cued sensorimotor task (ACST) based on the premise that ACST will be more sensitive to developmental changes in temporal association cortex (TeA) of the posterior attention system. We show that VPA rats learned the ACST markedly faster than control animals, but they exhibited a profound preoccupation with cues associated with the expectancy at the reward location such that disengagement was disrupted. Control rats on the other hand were able to disengage and utilize auditory cues for re-engagement. However, both control and VPA-treated rats performed similarly when tested on novel object recognition (NOR) and novel context mismatch (NOCM) behavioral tasks that are known to be sensitive to normal perirhinal and prefrontal network functioning respectively. Consistent with disrupted posterior rather than frontal networks, we also report that VPA can selectively act on deep-layer TeA cortical neurons by showing that VPA increased dendritic density in isolated deep-layer TeA but not frontal neurons. These results describe a useful approach to examine the role of cue-dependent control of attention systems in rodent models of autism and suggest that disengagement impairments may arise from an inability to modify behavior through the appropriate use of sensory cue associations.

Eosinophilic esophagitis in children with esophageal atresia

Eosinophilic esophagitis (EoE) has only rarely been reported in esophageal atresia (EA) patients. A retrospective case analysis of all EA patients born at our center between January 1999 and April 2012 was performed. A total of 113 of patients were identified; 10 patients were excluded as a result of inadequate data. Eighteen patients (17%) were diagnosed with EoE. The average number of eosinophilis was 30/high-power field (HPF) (19/HPF-80/HPF). The median age for diagnosis of EoE was 1 year and 6 months (8 months-8 years and 7 months). Children with EoE had a significantly greater incidence of reflux symptoms, dysphagia, tracheomalacia, and 'hypoxic spells' (P < 0.05). EoE patients also underwent significantly more surgery including fundoplication and aortopexy when compared with those without EoE (P < 0.0001). Although the incidence of gastrostomy was greater in the EoE group (33% vs. 13%), this was not statistically significant. Half of the EoE patients had a coexisting atopic condition at time of diagnosis. The commonest condition was asthma 7/18 (38%) followed by specific food allergy 6/18 (33%). EoE was treated in 11 patients with either swallowed fluticasone or budesonide slurry. All improved clinically. Histologically, five had complete resolution and six had partial improvement. Six children with EoE were treated with acid suppression alone. All improved clinically, and 5/6 had subsequent histological resolution. One child who received acid suppression and an exclusion diet also improved. Seven patients (38%) had an esophageal stricture at time of EoE diagnosis. Five were dilated at time of the initial endoscopy, prior to the diagnosis of EoE being available. Two patients had resolution of their strictures on medical treatment of their EoE alone and did not require further dilatation. EoE was seen in 17% of children with EA in this study. EoE should be considered in EA patients with persistent symptoms on standard reflux treatment, increasing dysphagia, and recurrent strictures.

Failures of the Dual Articular knee prosthesis due to fracture of the polyethylene post

The Dual Articular (DA) total knee replacement was designed for revision and complex primary knee arthroplasty. A number of these knees failed due to fracture of the polyethylene post. We aimed to identify the proportion of DA prostheses that failed in this manner in our hospital. The hospital database was interrogated to identify all patients undergoing revision total knee replacement under the care of one surgeon from 1995 to 2007. Case notes were then reviewed to collect information about the history surrounding the knee surgery, and determine the patient's weight at the time of surgery. Telephone follow-up was carried out to obtain complete contemporary data. Forty-eight prostheses were implanted into 39 patients (21 male, 18 female). Thirty-two of the prostheses were DA and of these, 7 underwent arthroscopy or arthrotomy to reveal a fracture of the polyethylene post (22%). T-tests showed no statistical difference in age (p=0.73) or weight (p=0.79) between the group of DA patients with fractured posts and those without. Six of the 7 fractures were in male patients (Chi-squared; p=0.01). Patients complained of pain, clicking and instability at a mean of 7 years post-surgery. Sixteen DA2000 prostheses were implanted, but none of these had failed due to a fractured polyethylene post. A high proportion of DA prostheses failed due to post fracture. We recommend that patients with DA prostheses be kept under review to detect failures early. Pain, clicking and instability should be investigated with arthroscopy and the tibial insert exchanged as appropriate.

Age-related trends in the timeliness and prediction of medical visits, hospitalizations and deaths due to pneumonia and influenza, British Columbia, Canada, 1998-2004

The influenza immunization program in North America has been primarily designed to provide direct benefit to vaccinated individuals at highest risk of serious influenza outcomes. Some evidence suggests that immunization of certain age groups may also extend indirect protective benefit to vulnerable populations. Our goal was to identify age groups associated earliest with seasonal influenza activity and who may have the greatest indirect impact at the population level. We examined age-based associations between influenza medical visits and population-wide hospitalization/mortality due to pneumonia & influenza (P&I) using administrative datasets in British Columbia, Canada. A peak week was identified for each age group based on the highest rates observed in a given week for that study year. Mean rates at the peak week were averaged over the study years per age group. Timeliness (T) was defined as the mean difference in days between the first peak in influenza medical visits and population-wide P&I hospitalizations/deaths. Poisson regression was applied to calculate prediction (Pr) as the average proportion of deviance in P&I explained by influenza medical visits. T and Pr were derived by age group, and the product (T x Pr) was used as a summary measure to rank potential indirect effects of influenza by age group. Young children (0-23 months) and the elderly (> or = 65 years) had the highest peak rates of P&I hospitalization. Children < 6m and the elderly had the highest peak rates of P&I mortality. We found no significant differences by age for influenza medical visits in predicting population-wide P&I hospitalizations or deaths. School-aged children (5-19 years) showed the best relative combination of T x Pr, followed by preschool-aged children (2-4 years). We conclude that the very young and old suffer the greatest morbidity due to P&I, and an indirect role for school-aged children in anticipating the risk to others warrants further evaluation.

Performance Evaluation of the Latest Fully Automated Hematology Analyzers in a Large, Commercial Laboratory Setting:A 4-Way, Side-by-Side Study

Gamma-Dynacare is a Canadian-based community laboratory partnership formed in the mid-1990s through the merger of 3 prominent Ontario medical diagnostic laboratories. Laboratory Corporation of America acquired an interest in the GD partnership in mid 2002. We service more than 10,000 community-based Canadian clinicians, hospital partners, and private clients with an integrated customer-focused system that includes specimen collection, transportation, and results reporting services. With more than 1,700 highly qualified medical, technical, and support staff and a network of laboratories, Gamma Dynacare aims to be at the forefront of technological innovation to better service the clinician base and ultimately deliver better patient care. We were looking for a hematology analyzer that would allow. (1) standardization throughout Ontario in our 4 largest sites and (2) better performance to effectively handle aged samples and minimize slide review. To select the best, most productive hematology analyzer for our environment, it was decided to perform a side-by-side comparison of the top hematology analyzers from Abbott (Cell-Dyn 3500), Beckman Coulter (LH 750), Bayer (Advia 120), and Sysmex (XE 2100), utilizing the same samples. CBC, differential and reticulocyte parameters were all evaluated according to CLSI (formerly NCCLS) and established hematology analyzer evaluation guidelines. We assessed each analyzer for precision, linearity, carryover, stability, differential capabilities, slide review rates, and throughput (clean bench studies). Two hundred samples were assessed for differential and morphology flagging on each analyzer using the reference 400 cell manual differential for comparison. Throughput was assessed by analyzing 700 consecutive samples representative of our workload mix. Stability studies at 24 hours showed that the Beckman Coulter LH 750 was least affected by EDTA, effect with minimal changes in the mean corpuscular volume (MCV) and hematocrit. Both the Bayer Advia 120 and Sysmex XE 2100 showed an elevation of the MCV (up to 5 fL) and Hematocrit over the 24 hours. Analysis of the 200 randomly selected patient samples showed that, while the false-negative rates on each of the instruments were comparable, there were significant differences in the false-positive rates. This has important implications for slide review rates. For our specimen mix, the Sysmex XE 2100 had the highest false-positive rate (15%), followed by the Cell-Dyn 3500 (8%), Advia 120 (6.5%) and the Beckman Coulter LH 750 (1.5%). Reticulocyte analysis performance was observed to be satisfactory with the Beckman Coulter LH 750, Cell-Dyn 3500, and XE 2100, while the Bayer Advia 120 showed a decrease in retic values after 12 hours. In conclusion, many laboratories will not be able to perform a 4-way evaluation such as described here due to time, space, and resource constraints. For our laboratories, result quality, sample stability performance, slide review rates, and efficiency were the primary criteria in selection of the most suitable hematology analyzer. Our 4-way evaluation resulted in selection of the Beckman Coulter LH 750 for Gamma-Dynacare Laboratories because it enabled the lowest slide review rate and handled aged samples better than the other analyzers.

Nasal T-cell lymphoma associated with Epstein-Barr virus infection

A case of nasal T-cell lymphoma in a Caucasian male is reported, in which the presence of Epstein-Barr virus within tumour cells was demonstrated by in situ hybridization to the Epstein-Barr virus encoded RNAs EBER-1 and EBER-2.