Faculty Bibliography

Nonhuman primates are frequently transported to a new location or temporarily relocated within their colony. Both transportation and relocation expose animals to new environments, causing them to undergo a stress response (before adapting). In our NHP colony, the mentioned situations are not infrequent for many reasons, including maintenance. The objective of this study was to determine whether abrupt changes consisting of relocation, housing, separation, and grouping could influence hematological and immunological parameters and thereby functional activity. The current study used squirrel monkeys as a model to investigate the stress-inducing effects of relocation within a facility, while animals acclimated to new situations (physical, housing). A detailed blood analysis revealed significant changes in lymphocytes, triglycerides, total protein, creatinine, and ALT. Flow cytometric analysis of peripheral blood showed reduction in CD3⁺, CD4⁺, and CD8⁺ T cells and monocytes, while B cells and natural killer (NK) cells changed with relocation. Simultaneously, changes in functional activity of immune cells altered proliferative responses and as shown by ELISpot (IFN γ). Though the parameters studied are not affected as severely as those in animals transported by road or air, stress responses induced by intrafacility relocation are significant and worth consideration. Our findings indicate that squirrel monkeys mimic the features seen in humans exposed to social stressors and may serve an important model for understanding the mechanisms of stress-induced immune dysfunction in humans.

Up to two-thirds of stroke survivors experience persistent sensorimotor impairments. Recovery relies on the integrity of spared brain areas to compensate for damaged tissue. Deep grey matter structures play a critical role in the control and regulation of sensorimotor circuits. The goal of this work is to identify associations between volumes of spared subcortical nuclei and sensorimotor behaviour at different timepoints after stroke. We pooled high-resolution T₁-weighted MRI brain scans and behavioural data in 828 individuals with unilateral stroke from 28 cohorts worldwide. Cross-sectional analyses using linear mixed-effects models related post-stroke sensorimotor behaviour to non-lesioned subcortical volumes (Bonferroni-corrected, P < 0.004). We tested subacute (≤90 days) and chronic (≥180 days) stroke subgroups separately, with exploratory analyses in early stroke (≤21 days) and across all time. Sub-analyses in chronic stroke were also performed based on class of sensorimotor deficits (impairment, activity limitations) and side of lesioned hemisphere. Worse sensorimotor behaviour was associated with a smaller ipsilesional thalamic volume in both early (n = 179; d = 0.68) and subacute (n = 274, d = 0.46) stroke. In chronic stroke (n = 404), worse sensorimotor behaviour was associated with smaller ipsilesional putamen (d = 0.52) and nucleus accumbens (d = 0.39) volumes, and a larger ipsilesional lateral ventricle (d = -0.42). Worse chronic sensorimotor impairment specifically (measured by the Fugl-Meyer Assessment; n = 256) was associated with smaller ipsilesional putamen (d = 0.72) and larger lateral ventricle (d = -0.41) volumes, while several measures of activity limitations (n = 116) showed no significant relationships. In the full cohort across all time (n = 828), sensorimotor behaviour was associated with the volumes of the ipsilesional nucleus accumbens (d = 0.23), putamen (d = 0.33), thalamus (d = 0.33) and lateral ventricle (d = -0.23). We demonstrate significant relationships between post-stroke sensorimotor behaviour and reduced volumes of deep grey matter structures that were spared by stroke, which differ by time and class of sensorimotor measure. These findings provide additional insight into how different cortico-thalamo-striatal circuits support post-stroke sensorimotor outcomes.

The human brain functions at the center of a network of systems aimed at providing a structural and immunological layer of protection. The cerebrospinal fluid (CSF) maintains a physiological homeostasis that is of paramount importance to proper neurological activity. CSF is largely produced in the choroid plexus where it is continuous with the brain extracellular fluid and circulates through the ventricles. CSF movement through the central nervous system has been extensively explored. Across numerous animal species, the involvement of various drainage pathways in CSF, including arachnoid granulations, cranial nerves, perivascular pathways, and meningeal lymphatics, has been studied. Among these, there is a proposed CSF clearance route spanning the olfactory nerve and exiting the brain at the cribriform plate and entering lymphatics. While this pathway has been demonstrated in multiple animal species, evidence of a similar CSF egress mechanism involving the nasal cavity in humans remains poorly consolidated. This review will synthesize contemporary evidence surrounding CSF clearance at the nose-brain interface, examining across species this anatomical pathway, and its possible significance to human neurodegenerative disease. Our discussion of a bidirectional nasal pathway includes examination of the immune surveillance in the olfactory region protecting the brain. Overall, we expect that an expanded discussion of the brain-nose pathway and interactions with the environment will contribute to an improved understanding of neurodegenerative and infectious diseases, and potentially to novel prevention and treatment considerations.

Critical illness and sepsis are commonly associated with subclinical seizures. COVID-19 frequently causes severe critical illness, but the incidence of electrographic seizures in patients with COVID-19 has been reported to be low. This retrospective case series assessed the incidence of and risks for electrographic seizures in patients hospitalized with COVID-19 who underwent continuous video electroencephalography monitoring (cvEEG) between March 1st, 2020 and June 30th, 2020. One hundred and twenty-two patients were initially identified who resulted SARS-CoV-2 nasopharyngeal RT-PCR swab positivity with any electroencephalography order placed in the EMR. Seventy-nine patients met study inclusion criteria: age ≥18 years, >1 h of cvEEG monitoring, and positive SARS-CoV-2 nasopharyngeal swab PCR. Six (8%) of the 79 patients suffered electrographic seizures (ES), three of whom suffered non-convulsive status epilepticus. Acute hyperkinetic movements were the most common reason for cvEEG in patients with ES (84%). None of the patients undergoing cvEEG for persistent coma (29% of all patients) had ES. Focal slowing (67 vs. 10%), sporadic interictal epileptiform discharges (EDs; 33 vs. 6%), and periodic/rhythmic EDs (67 vs. 1%) were proportionally more frequent among patients with electrographic seizures than those without these seizures. While 15% of patients without ES had generalized periodic discharges (GPDs) with triphasic morphology on EEG, none of the patients with ES had this pattern. Further study is required to assess the predictive values of these risk factors on electrographic seizure incidence and subsequent outcomes.

Objective/UNASSIGNED:The study objective was to examine predictors of sleep disturbance and strain among caregivers of persons living with dementia (PLWD). Methods/UNASSIGNED:This cross-sectional study utilized a sample of community-dwelling older adults and their family caregivers drawn from the 2017 National Health and Aging Trends Study and National Study of Caregiving. Multivariable logistic regression was used to assess the association between caregiver and PLWD characteristics and a composite measure of caregiving strain. High caregiving strain was defined as a total score of ≥ 5 on the 6 caregiving strain items (e.g., emotional difficulty, no time for self). We used multivariable proportional odds models to examine predictors of caregiver sleep-related outcomes (trouble falling back to sleep and interrupted sleep), after adjusting for other caregiver and PLWD factors. Results/UNASSIGNED:Of the 1,142 family caregivers, 65.2% were female, 15% were Black, and 14% were Hispanic. Average age was 60 years old. Female caregivers were more likely to report high level of strain compared to male caregivers (OR: 2.61, 95% CI = 1.56, 4.39). Compared to non-Hispanic Whites, non-Hispanic Black and Hispanic caregivers had reduced odds of reporting greater trouble falling back asleep [OR = 0.55, CI (0.36, 0.82) and OR = 0.56, CI (0.34, 0.91), respectively]. The odds of reporting greater trouble falling back asleep was significantly greater among caregivers with high blood pressure vs. caregivers without high blood pressure [OR = 1.62, CI (1.12, 2.33)]. Conclusion/UNASSIGNED:In this cross-sectional study, caregivers with greater sleep difficulty (trouble falling back asleep) were more likely to report having high blood pressure. We found no racial/ethnic differences in interrupted sleep among caregivers to PLWD. These results suggest that interventions to improve sleep among caregivers to PLWD may decrease poor cardiovascular outcomes in this group.

We reviewed data on the American diet from 1800 to 2019. Methods: We examined food availability and estimated consumption data from 1800 to 2019 using historical sources from the federal government and additional public data sources. Results: Processed and ultra-processed foods increased from <5 to >60% of foods. Large increases occurred for sugar, white and whole wheat flour, rice, poultry, eggs, vegetable oils, dairy products, and fresh vegetables. Saturated fats from animal sources declined while polyunsaturated fats from vegetable oils rose. Non-communicable diseases (NCDs) rose over the twentieth century in parallel with increased consumption of processed foods, including sugar, refined flour and rice, and vegetable oils. Saturated fats from animal sources were inversely correlated with the prevalence of NCDs. Conclusions: As observed from the food availability data, processed and ultra-processed foods dramatically increased over the past two centuries, especially sugar, white flour, white rice, vegetable oils, and ready-to-eat meals. These changes paralleled the rising incidence of NCDs, while animal fat consumption was inversely correlated.

The management of women with epilepsy (WWE) presents many challenges for physicians. The primary goal during pregnancy is to achieve the best possible control of seizures with the least adverse effects associated with exposure to antiseizure medications (ASMs). Even though the guidelines for managing pregnant WWE are expanding, no definitive guidelines exist for the treatment of status epilepticus (SE). Additionally, much of our data comes from the effect of generalized tonic clonic seizures on the fetus. There is very little data on the effect of focal seizures and even less on focal SE. Here we present two cases of pregnant WWE who presented in focal SE, who underwent simultaneous video-EEG monitoring and fetal heart tracing (FHT). During each focal seizure the FHT demonstrated a normal baseline heart rate with moderate variability. In the second case due to continuous seizures more aggressive treatment had to be started. This led to maternal relative autonomic instability as well as absent variability on FHT. These findings raise many questions on the management of focal SE during pregnancy including if the effect of treatment is worse than the seizures, and how do we balance our goals for both mother and fetus?

BACKGROUND:Patients with Parkinson's disease (PD) are at higher risk of vaccine-preventable respiratory infections. However, advanced, homebound individuals may have less access to vaccinations. In light of COVID-19, understanding barriers to vaccination in PD may inform strategies to increase vaccine uptake. OBJECTIVE:To identify influenza and pneumococcal vaccination rates, including barriers and facilitators to vaccination, among homebound and ambulatory individuals with PD and related disorders. METHODS:Cross-sectional US-based study among individuals with PD, aged > 65 years, stratified as homebound or ambulatory. Participants completed semi-structured interviews on vaccination rates and barriers, and healthcare utilization. RESULTS:Among 143 participants, 9.8% had missed all influenza vaccinations in the past 5 years, and 32.2% lacked any pneumococcal vaccination, with no between-group differences. Homebound participants (n = 41) reported difficulty traveling to clinic (p < 0.01) as a vaccination barrier, and despite similar outpatient visit frequencies, had more frequent emergency department visits (31.7% vs. 9.8%, p < 0.01) and hospitalizations (14.6% vs. 2.9%, p = 0.03). Vaccine hesitancy was reported in 35% of participants, vaccine refusal in 19%, and 13.3% reported unvaccinated household members, with no between-group differences. Nearly 13% thought providers recommended against vaccines for PD patients, and 31.5% were unsure of vaccine recommendations in PD. CONCLUSION/CONCLUSIONS:Among a sample of homebound and ambulatory people with PD, many lack age-appropriate immunizations despite ample healthcare utilization. Many participants were unsure whether healthcare providers recommend vaccinations for people with PD. In light of COVID-19, neurologist reinforcement that vaccinations are indicated, safe, and recommended may be beneficial.