Faculty Bibliography

The medial temporal lobe (MTL) is traditionally considered to be a system that is specialized for long-term memory. Recent work has challenged this notion by demonstrating that this region can contribute to many domains of cognition beyond long-term memory, including perception and attention. One potential reason why the MTL (and hippocampus specifically) contributes broadly to cognition is that it contains relational representations-representations of multidimensional features of experience and their unique relationship to one another-that are useful in many different cognitive domains. Here, we explore the hypothesis that the hippocampus/MTL plays a critical role in attention and perception via relational representations. We compared human participants with MTL damage to healthy age- and education-matched individuals on attention tasks that varied in relational processing demands. On each trial, participants viewed two images (rooms with paintings). On "similar room" trials, they judged whether the rooms had the same spatial layout from a different perspective. On "similar art" trials, they judged whether the paintings could have been painted by the same artist. On "identical" trials, participants simply had to detect identical paintings or rooms. Patients were significantly and selectively impaired on the similar room task. This work provides further evidence that the hippocampus/MTL plays a ubiquitous role in cognition by virtue of its relational and spatial representations and highlights its important contributions to rapid perceptual processes that benefit from attention.

OBJECTIVE:To investigate the incidence and spectrum of neuroimaging findings and their prognostic role in hospitalized COVID-19 patients in New York City. METHODS:This is a retrospective cohort study of 3218 COVID-19 confirmed patients admitted to a major healthcare system (three hospitals) in New York City between March 1, 2020 and April 13, 2020. Clinical data were extracted from electronic medical records, and particularly data of all neurological symptoms were extracted from the imaging reports. Four neuroradiologists evaluated all neuroimaging studies for acute neuroimaging findings related to COVID-19. RESULTS:14.1% of admitted COVID-19 patients had neuroimaging and this accounted for only 5.5% of the total imaging studies. Acute stroke was the most common finding on neuro-imaging, seen in 92.5% of patients with positive neuro-imaging studies, and present in 1.1% of hospitalized COVID-19 patients. Patients with acute large ischemic and hemorrhagic stroke had much higher mortality risk adjusted for age, BMI and hypertension compared to those COVID-19 patients without neuroimaging. (Odds Ratio 6.02 by LR; Hazard Ratio 2.28 by CRR). CONCLUSIONS:Our study demonstrates acute stroke is the most common neuroimaging finding among hospitalized COVID-19 patients. Detection of an acute stroke is a strong prognostic marker of poor outcome. Our study also highlights the fact there is limited use of neuroimaging in these patients due to multiple logistical constraints.

INTRODUCTION/BACKGROUND:In addition to neurogenic orthostatic hypotension (nOH), patients with synucleinopathies frequently have hypertension when supine. The long-term consequences of both abnormalities are difficult to disentangle. We aimed to determine if supine hypertension is associated with target organ damage and worse survival in patients with nOH. METHODS:Patients with nOH due to multiple system atrophy (MSA), Parkinson disease (PD), or pure autonomic failure (PAF) were classified into those with or without supine hypertension (systolic BP of at least 140 mmHg or diastolic BP of at least 90 mmHg). Organ damage was assessed by measuring cerebral white matter hyperintensities (WMH), left ventricular hypertrophy (LVH), and renal function. We prospectively followed patients for 30 months (range: 12-66 months) and recorded incident cardiovascular events and all-cause mortality. RESULTS:Fifty-seven patients (35 with probable MSA, 14 with PD and 8 with PAF) completed all evaluations. In addition to nOH (average fall 35 ± 21/17 ± 14 mmHg, systolic/diastolic, mean ± SD), 38 patients (67%) had supine hypertension (systolic BP > 140 mmHg). Compared to those without hypertension, patients with hypertension had higher blood urea nitrogen levels (P = 0.005), lower estimated glomerular filtration rate (P = 0.008), higher prevalence of LVH (P = 0.040), and higher WMH volume (P = 0.019). Longitudinal follow-up of patients for over 2 years (27.1 ± 14.5 months) showed that supine hypertension was independently associated with earlier incidence of cardiovascular events and death (HR = 0.25; P = 0.039). CONCLUSIONS:Supine hypertension in patients with nOH was associated with an increased risk for target organ damage, cardiovascular events, and premature death. Defining management strategies and safe blood pressure ranges in patients with nOH remains an important research question.

STUDY OBJECTIVES/OBJECTIVE:Pediatric insomnia is a widespread problem and especially difficult to manage in children with neurodevelopmental disorders. There are currently no US Food and Drug Administration-approved medications to use once first-line therapy fails. The objective of this study was to evaluate the efficacy and tolerability of doxepin in pediatric patients. METHODS:This is a retrospective single-center chart review of children and adolescents (2-17 years of age) whose sleep failed to improve with behavioral intervention and melatonin who were then trialed on doxepin. Treatment was initiated at a median starting dose of 2 mg and slowly escalated to a median maintenance dose of 10 mg. Improvement in sleep was recorded using a 4-point Likert scale reported by parents on follow-up visits. RESULTS:A total of 29 patients were included in the analysis. Mean follow-up duration was 6.5 ± 3.5 months. Of 29 patients, 4 (13.8%) patients discontinued doxepin because of lack of efficacy or side effects. Eight (27.6%) patients showed significant improvement of their insomnia, 8 (27.6%) showed moderate improvement, 10 (34.5%) showed mild improvement, and 3 (10.3%) showed minimal to no improvement on treatment with doxepin (P < .05) Only 2 patients (6.9%) experienced adverse effects in the form of behavioral side effects (aggression) and enuresis. CONCLUSIONS:Results of our studies suggest that low-dose doxepin is both effective and well tolerated in pediatric patients with insomnia.

Caregivers of individuals with intellectual and developmental disabilities and epilepsy such as Dravet syndrome (DS) must navigate a complex web of state and community services through the transition from child-centered to adult-oriented healthcare. This study examined barriers to successful transition from the caregivers' perspective. Primary caregivers of teenagers or adults with DS who had contemplated or completed transition to adult care were eligible. A three-week, asynchronous, web-based focus group was conducted on Facebook. Data were analyzed in an iterative process based on a Grounded Theory approach. Participants reviewed findings for accuracy. Transition success was defined by how well it ensured adequate care for the child when caregivers became unable to provide it. Existing transition programs were described as "not for our kids." All caregivers reported that transition programs began too late. Challenges to identifying suitable providers were formidable, with 71% of adult patients still being seen by pediatric neurologists. Many adult physicians lacked a general knowledge of DS, yet caregivers perceived that adult physicians were unwilling to listen to caregivers, and few were comfortable accommodating patients with intellectual disabilities and challenging behaviors. Community programs often excluded patients with DS, and rural healthcare disparities created additional barriers. Analysis produced recommendations for improving the transition process including the creation of a certified Transition Navigator position in the clinical setting. The limitations of this focus group analysis include possible selection bias, but our study identified key issues and pathways to improve the transition process for patients with DS and their caregivers.

The natural history of idiopathic Parkinson's disease (PD) varies considerably across patients. While PD is generally sporadic, there are known genetic influences: the two most common, mutations in the LRRK2 or GBA1 gene, are associated with slower and more aggressive progression, respectively. Here, we applied graph theory to metabolic brain imaging to understand the effects of genotype on the organization of previously established PD-specific networks. We found that closely matched PD patient groups with the LRRK2-G2019S mutation (PD-LRRK2) or GBA1 variants (PD-GBA) expressed the same disease networks as sporadic disease (sPD), but PD-LRRK2 and PD-GBA patients exhibited abnormal increases in network connectivity that were not present in sPD. Using a community detection strategy, we found that the location and modular distribution of these connections differed strikingly across genotypes. In PD-LRRK2, connections were gained within the network core, with the formation of distinct functional pathways linking the cerebellum and putamen. In PD-GBA, by contrast, the majority of functional connections were formed outside the core, involving corticocortical pathways at the network periphery. Strategically localized connections within the core in PD-LRRK2 may maintain PD network activity at lower levels than in PD-GBA, resulting in a less aggressive clinical course.

BACKGROUND/UNASSIGNED:Dietary intervention in multiple sclerosis carries potential therapeutic implications. While studies utilizing animal models of multiple sclerosis (MS) have demonstrated intriguing findings, well-designed clinical trials are few in number. OBJECTIVE/UNASSIGNED:The objective of this study is to review the animal model and clinical literature regarding dietary factors in experimental autoimmune encephalitis (EAE) and MS. METHODS/UNASSIGNED:This manuscript provides a comprehensive review of current animal model and clinical knowledge related to dietary factors in MS. RESULTS/UNASSIGNED:While there is currently little data for any specific diet in MS, there is growing evidence that certain dietary factors may influence the disease. CONCLUSIONS/UNASSIGNED:Definitive information regarding dietary factors as a modifiable risk factor in MS will require larger randomized clinical trials.

Although macroautophagy/autophagy deficiency causes degenerative diseases, the deletion of essential autophagy genes in adipocytes paradoxically reduces body weight. Brown adipose tissue (BAT) plays an important role in body weight regulation and metabolic control. However, the key cellular mechanisms that maintain BAT function remain poorly understood. in this study, we showed that global or brown adipocyte-specific deletion of pink1, a Parkinson disease-related gene involved in selective mitochondrial autophagy (mitophagy), induced BAT dysfunction, and obesity-prone type in mice. Defective mitochondrial function is among the upstream signals that activate the NLRP3 inflammasome. NLRP3 was induced in brown adipocyte precursors (BAPs) from pink1 knockout (KO) mice. Unexpectedly, NLRP3 induction did not induce canonical inflammasome activity. Instead, NLRP3 induction led to the differentiation of pink1 KO BAPs into white-like adipocytes by increasing the expression of white adipocyte-specific genes and repressing the expression of brown adipocyte-specific genes. nlrp3 deletion in pink1 knockout mice reversed BAT dysfunction. Conversely, adipose tissue-specific atg7 KO mice showed significantly lower expression of Nlrp3 in their BAT. Overall, our data suggest that the role of mitophagy is different from general autophagy in regulating adipose tissue and whole-body energy metabolism. Our results uncovered a new mitochondria-NLRP3 pathway that induces BAT dysfunction. The ability of the nlrp3 knockouts to rescue BAT dysfunction suggests the transcriptional function of NLRP3 as an unexpected, but a quite specific therapeutic target for obesity-related metabolic diseases.