Faculty Bibliography

Neurologists have long-recognized the importance of the visual system in the diagnosis and monitoring of neurological disorders. This is particularly true since approximately 50% of the brain's pathways subserve afferent and efferent aspects of vision. During the past 30 years, researchers and clinicians have further refined this concept to include investigation of the visual system for patients with specific neurologic diagnoses, including multiple sclerosis (MS), concussion, Parkinson's disease (PD) and conditions along the spectrum of Alzheimer's disease (AD, mild cognitive impairment [MCI] and subjective cognitive decline [SCD]). This review, highlights the visual "toolbox" that has been developed over the past three decades and beyond to capture both structural and functional aspects of vision in neurologic disease. While the efforts to accelerate the emphasis on structure-function relationships in neurological disorders began with MS during the early 2000's, such investigations have broadened to recognize the need for outcomes of visual pathway structure, function and quality of life for clinical trials of therapies across the spectrum of neurological disorders. This review begins with a patient case study highlighting the importance utilizing the most modern technologies for visual pathway assessment, including optical coherence tomography (OCT). We emphasize that both structural and functional tools for vision testing can be used in parallel to detect what might otherwise be sub-clinical events or markers of visual and, perhaps, more global neurological, decline. Such measures will be critical as clinical trials and therapies become more available across the neurological disease spectrum.

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a recently described CNS inflammatory disorder that may manifest with optic neuritis, myelitis, seizures, and/or acute disseminated encephalomyelitis. While MOG-specific antibodies in patients with MOGAD are IgG1, a T-cell-dependent antibody isotype, immunologic mechanisms of this disease are not fully understood. Thymic hyperplasia can be associated with certain autoimmune diseases. In this report we describe a case of MOGAD associated with thymic hyperplasia in a young adult.

BACKGROUND:The relationship between COVID-19 and epilepsy is uncertain. We studied the potential association between COVID-19 and seizures or epilepsy in the six months after infection. METHODS:We applied validated methods to an electronic health records network (TriNetX Analytics) of 81 million people. We closely matched people with COVID-19 infections to those with influenza. In each cohort, we measured the incidence and hazard ratios (HRs) of seizures and of epilepsy. We stratified data by age and by whether the person was hospitalized during the acute infection. We then explored time-varying HRs to assess temporal patterns of seizure or epilepsy diagnoses. RESULTS:We analyzed 860,934 electronic health records. After matching, this yielded two cohorts each of 152,754 patients. COVID-19 was associated with an increased risk of seizures and epilepsy compared to influenza. The incidence of seizures within 6 months of COVID-19 was 0.81% (95% CI, 0.75-0.88; HR compared to influenza 1.55 (1.39-1.74)). The incidence of epilepsy was 0.30% (0.26-0.34; HR compared to influenza 1.87 (1.54-2.28)). The HR of epilepsy after COVID-19 compared to influenza was greater in people who had not been hospitalized and in individuals aged under 16 years. The time of peak HR after infection differed by age and hospitalization status. CONCLUSIONS:The incidence of new seizures or epilepsy diagnoses in the six months following COVID-19 was low overall, but higher than in matched patients with influenza. This difference was more marked in people who were not hospitalized, highlighting the risk of epilepsy and seizures even in those with less severe infection. Children appear at particular risk of seizures and epilepsy after COVID-19 providing another motivation to prevent COVID-19 infection in pediatric populations. That the varying time of peak risk related to hospitalization and age may provide clues as to the underlying mechanisms of COVID-associated seizures and epilepsy.

BACKGROUND AND OBJECTIVES/OBJECTIVE:The validity of brain monitoring using electroencephalography (EEG), particularly to guide care in patients with acute or critical illness, requires that experts can reliably identify seizures and other potentially harmful rhythmic and periodic brain activity, collectively referred to as "ictal-interictal-injury continuum" (IIIC). Prior inter-rater reliability (IRR) studies are limited by small samples and selection bias. This study was conducted to assess the reliability of experts in identifying IIIC. METHODS:This prospective analysis included 30 experts with subspecialty clinical neurophysiology training from 18 institutions. Experts independently scored varying numbers of ten-second EEG segments as: "Seizure (SZ)", "Lateralized Periodic Discharges (LPD)", "Generalized Periodic Discharges (GPD)", "Lateralized Rhythmic Delta Activity (LRDA)", "Generalized Rhythmic Delta Activity (GRDA)", or "Other". EEGs were performed for clinical indications at Massachusetts General Hospital between 2006 to 2020. Primary outcome measures were pairwise IRR (average percent agreement (PA) between pairs of experts) and majority IRR (average PA with group consensus) for each class; and beyond chance agreement (κ). Secondary outcomes were calibration of expert scoring to group consensus, and latent trait analysis to investigate contributions of bias and noise to scoring variability. RESULTS:: 75 [59, 89]%). Thus, variation between experts is mostly attributable not to differences in expertise, but rather to variation in decision thresholds. DISCUSSION/CONCLUSIONS:Our results provide precise estimates of expert reliability from a large and diverse sample, and a parsimonious theory to explain the origin of disagreements between experts. The results also establish a standard for how well an automated IIIC classifier must perform to match experts. CLASSIFICATION OF EVIDENCE/METHODS:This study provides Class II evidence that independent expert review reliably identifies ictal-interictal injury continuum patterns on EEG compared to expert consensus.

An international consensus report in 2019 recommended a classification system for limbic-predominant age-related TDP-43 encephalopathy neuropathologic changes (LATE-NC). The suggested neuropathologic staging system and nomenclature have proven useful for autopsy practice and dementia research. However, some issues remain unresolved, such as cases with unusual features that do not fit with current diagnostic categories. The goal of this report is to update the neuropathologic criteria for the diagnosis and staging of LATE-NC, based primarily on published data. We provide practical suggestions about how to integrate available genetic information and comorbid pathologies [e.g., Alzheimer's disease neuropathologic changes (ADNC) and Lewy body disease]. We also describe recent research findings that have enabled more precise guidance on how to differentiate LATE-NC from other subtypes of TDP-43 pathology [e.g., frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS)], and how to render diagnoses in unusual situations in which TDP-43 pathology does not follow the staging scheme proposed in 2019. Specific recommendations are also made on when not to apply this diagnostic term based on current knowledge. Neuroanatomical regions of interest in LATE-NC are described in detail and the implications for TDP-43 immunohistochemical results are specified more precisely. We also highlight questions that remain unresolved and areas needing additional study. In summary, the current work lays out a number of recommendations to improve the precision of LATE-NC staging based on published reports and diagnostic experience.

BACKGROUND AND OBJECTIVE/OBJECTIVE:Neuromyelitis optica spectrum disorder (NMOSD) is a rare autoimmune condition, which can lead to significant disability, and up to 3% to 5% of the cases have a pediatric onset. There are limited studies to guide physicians in disease-modifying treatment (DMT) choices for children with NMOSD. METHODS:This retrospective cohort study evaluated children with NMOSD cases followed at 12 clinics in the US Network of Pediatric MS Centers. Cases were classified as Aquaporin-4 antibody positive (AQP4+) and double-seronegative (DS) when negative for AQP4+ and for myelin oligodendrocyte glycoprotein (MOG) antibody. Effect of initial DMTs including rituximab, mycophenolate, azathioprine, and intravenous immunoglobulin (IVIg) on annualized relapse rate (ARR) was assessed by negative binomial regression. Time to disability progression (EDSS increase ≥1.0 point) was modeled with a Cox proportional-hazards model. RESULTS:91 children with NMOSD were identified: 77 AQP4+ and 14 DS (85.7% females; 43.2% Caucasian, 46.6% African American). 81 patients were started on a DMT and 10 were treatment naïve at the time of the analysis. The ARR calculated in all serogroups was 0.25 (95% CI 0.13-0.49) for rituximab, 0.33 (95% CI 0.19-0.58) for mycophenolate, 0.40 (95% CI 0.13-1.24) for azathioprine and 0.54 (95% CI 0.28-1.04) for IVIg. The ARR in the AQP4+ subgroup was 0.28 (95% CI 0.14-0.55) for rituximab, 0.39 (95% CI 0.21-0.70) for mycophenolate, 0.41 (95% CI 0.13-1.29) for azathioprine and 0.54 (95% CI 0.23-1.26) for IVIg. The ARR in the treatment naïve group was 0.97 (95% CI 0.58-1.60) in all serogroups and 0.91 (95% CI 0.53-1.56) in the AQP4+ subgroup. None of the initial DMT had a statistically significant effect on EDSS progression. DISCUSSION/CONCLUSIONS:The use of DMTs, in particular rituximab, is associated with a lowered annualized relapse rate in children with NMOSD AQP4+. CLASSIFICATION OF EVIDENCE/METHODS:This study provides Class IV evidence that use of disease-modifying treatments is associated with a lowered annualized relapse rate in children with NMOSD AQP4+.

BACKGROUND AND OBJECTIVE/OBJECTIVE:GM2 gangliosidoses (Tay-Sachs and Sandhoff diseases) are rare, autosomal-recessive, neurodegenerative diseases with no available symptomatic or disease modifying treatments. This clinical trial investigated N-acetyl-L-leucine (NALL), an orally administered, modified amino acid in pediatric (≥ 6 years) and adult patients with GM2 gangliosidoses. METHODS:In this Phase IIb, multi-national, open-label, rater-blinded study (IB1001-202), male and female patients aged ≥6 years with a genetically confirmed diagnosis of GM2 gangliosidoses received orally-administered NALL for a 6-week treatment period (4 g/day in patients ≥13 years, weight-tiered doses for patients 6-12 years), followed by a 6-week post-treatment washout period. For the primary Clinical Impression of Change in Severity analysis, patient performance on a pre-determined primary anchor test (the 8-Meter Walk Test or the 9-Hole Peg Test) at baseline, after 6 weeks on NALL, and again after a 6-week washout period, was videoed and evaluated centrally by blinded raters. Secondary outcomes included assessments of ataxia, clinical global impression, and quality of life. RESULTS:30 patients between the age of 6 and 55 were enrolled. 29 had an on-treatment assessment and were included in the primary modified intention-to-treat analysis. The study met its CI-CS primary endpoint (mean difference 0.71, SD=2.09, 90% CI 0.00, 1.50, p=0.039), as well as secondary measures of ataxia and global impression. NALL was safe and well-tolerated, with no serious adverse reactions. CONCLUSIONS:Treatment with NALL was associated with statistically significant and clinically-relevant changes in functioning and quality of life in patients with GM2 gangliosidosis. NALL was safe and well-tolerated, contributing to an overall favourable risk: benefit profile. NALL is a promising, easily administered (oral) therapeutic option for these rare, debilitating diseases with immense unmet medical needs. CLASSIFICATION OF EVIDENCE/METHODS:This study provides Class IV evidence that NALL improves outcomes for patients with GM2 gangliosidoses. TRIAL REGISTRATION INFORMATION/UNASSIGNED:The trial is registered with ClinicalTrials.gov (NCT03759665; registered 30-Nov-2018), EudraCT (2018-004406-25), and DRKS (DRKS00017539). The first patient was enrolled 07-June-2019.

Phosphorylated tau is the main protein present in neurofibrillary tangles, the presence of which is a key neuropathological hallmark of Alzheimer's disease (AD). The toxic effects of phosphorylated tau are likely mediated by interacting proteins; however, methods to identify these interacting proteins comprehensively in human brain tissue are limited. Here, we describe a method that enables the efficient identification of hundreds of proteins that interact with phosphorylated tau (pTau), using affinity purification-mass spectrometry (AP-MS) on human, fresh-frozen brain tissue from donors with AD. Tissue is homogenized using a gentle technique that preserves protein-protein interactions, and co-immunoprecipitation of pTau and its interacting proteins is performed using the PHF1 antibody. The resulting protein interactors are then identified using label-free quantitative liquid chromatography-mass spectrometry (LC-MS)/MS. The Significance Analysis of INTeractome (SAINT) algorithm is used to determine which proteins significantly interact with pTau. This approach enables the detection of an abundance of all 6 isoforms of tau, 23 phosphorylated residues on tau, and 125 significant pTau protein interactors, in human AD brain tissue.

BACKGROUND:There is a well documented relationship between cardiovascular risk factors and the development of brain injury, which can lead to cognitive dysfunction. Hypertension (HTN) is a condition increasing the risk of silent and symptomatic ischemic brain lesions. Although benefits of hypertension treatment are indisputable, the target blood pressure value where the possibility of tissue damage is most reduced remains under debate. METHOD/METHODS:Our group performed a cross-sectional (n = 376) and longitudinal (n = 188) study of individuals without dementia or stroke (60% women n = 228, age 68.5 ± 7.4 years; men n = 148, age 70.7 ± 6.9 years). Participants were split into hypertensive (n = 169) and normotensive (n = 207) groups. MR images were obtained on a 3T system. Linear modeling was performed in hypertensive and normotensive cohorts to investigate the relationship between systolic (SBP) and diastolic (DBP) blood pressure, white matter lesion (WML), and brain volumes. RESULTS:Participants in the hypertensive cohort showed a quadratic relationship between SBP and WML, with the lowest amounts of WML being measured in participants with readings at approximately 124 mmHg. Additionally, the hypertensive cohort also exhibited a quadratic relationship between DBP and mean hippocampal volume; participants with readings at approximately 77 mmHg showing the largest volumes. Longitudinally, all groups experienced WML growth, despite different BP trajectories, further suggesting that WML expansion may occur despite or because of BP reduction in individuals with compromised vascular system. CONCLUSION/CONCLUSIONS:Overall, our study suggests that in the hypertensive group there is a valley of mid-range blood pressures displaying less pathology in the brain.