Faculty Bibliography

<p>Background: Salvador Dalí (1904-1989), the great Surrealist painter, developed a progressive parkinsonian syndrome during the last decade of his life that ended his artistic career and reduced him to near-total dependence. Multiple physicians documented tremor, rigidity, and progressive disability, yet no clinical account has been published in the neurological literature. Summary: Drawing on contemporaneous press reports, biographies based on primary sources, sworn medical testimony, and a published quantitative analysis of his paintings, this review compiles the chronological evolution of Dalí's neurological symptoms. Non-motor features (including nocturia without urological explanation and erectile dysfunction from at least 1974) were documented years before the onset of visible motor symptoms, a sequence consistent with, but not diagnostic of, prodromal synucleinopathy. The motor phase, beginning around 1980, was characterized by asymmetric resting tremor affecting the right upper extremity, rigidity, gait impairment, and progressive akinesia. Despite examinations by prominent neurologists including Lluís Barraquer Bordas and François Lhermitte, the diagnosis remained contested throughout Dalí's life. Drug-induced parkinsonism was implicated in the initial crisis, but the continued deterioration after drug withdrawal argues against a purely iatrogenic etiology. No autopsy was performed. Key Messages: This case illustrates a problem familiar to practicing neurologists: the difficulty of diagnosing parkinsonism in patients with complex premorbid personalities, where emerging neuropsychiatric symptoms are absorbed into longstanding behavioral patterns. Today, biomarkers detecting α-synuclein aggregates in peripheral tissues would greatly reduce such diagnostic uncertainty; these tools were not available in Dalí's lifetime. </p>.

BACKGROUND/UNASSIGNED:Although vertebral hemangiomas (VH) are relatively common, aggressive symptomatic VH are rarely reported (i.e. in up to 11% of cases). Multiple other benign and malignant primary bone tumors must be considered in the differential diagnosis. Here, we review the clinical diagnosis and surgical management for aggressive hemangiomas, while also presenting 2 patients with thoracic lesions requiring posterior surgical decompression/fusion, with/without vertebroplasty, embolization, and/or CyberKnife radiosurgery. METHODS/UNASSIGNED:The classification system for these tumors ranges from Types I-IV; I Occupy < 50% of a vertebral body (VB), II-Occupy > 50% VB (IIb Thoracolumbar - Symptomatic), III-Occupy 100% VB, and IV-Occupy 100% VB involved plus extension into the pedicles, laminae, spinous process, and epidural space. RESULTS/UNASSIGNED:Radiographically (i.e. X-rays, MR, CT) these lesions originate in the vertebral bodies, but aggressive VH extend into the pedicles, laminae, spinous processes, and epidural space causing both spinal cord/root (i.e., myelopathy/radiculopathy)) compression. Surgical options include anterior, posterior, or circumferential decompressions with/without fusions, percutaneous vertebroplasty, embolization, radiation, and/or chemotherapy. Early treatment maximizes neurological recovery and limits/avoids permanent injury. CONCLUSION/UNASSIGNED:Aggressive VH are rare lesions that most frequently occur in the thoracic spine. Notably, the subset of Type IV lesions that extend into the pedicles, laminae, spinous processes, and epidural space may cause symptomatic myelopathy/radiculopathy warranting early surgical intervention to optimize neurological outcomes.

Deep neural networks (DNNs) are promising computational models for understanding visual object recognition. Yet, whether DNNs use similar visual cues for object recognition as humans do remains unknown. We created an image set that systematically untangles global shape, internal parts, and texture information, and compared human recognition behavior against >200 DNNs spanning diverse architectures, training diets, and training objectives. No DNNs replicated humans' cue-reliance profile, including those with recurrence or specialized training. Fine-tuned text-image contrastive-trained models, regardless of architecture, were most human-like overall, but lost their human-alignment when the global shape was disrupted. Strikingly, all DNNs substantially underperformed humans when the global shape cue alone was critical to object recognition. Furthermore, alignment with ventral stream neural recordings in an existing database did not predict alignment to human behavior, and model performance does not always predict its human-alignment. Together, these findings reveal systematic and persistent differences between human and machine vision.

BACKGROUND AND PURPOSE/OBJECTIVE: MATERIALS AND METHODS/METHODS: RESULTS: CONCLUSIONS:The dynamics of the CVR response can reveal differential and previously occult temporal signatures in the pharmacologic response of white matter to ACZ, suggesting potential interactions between macrovascular and microvascular hemodynamic impairment.

Hyperhomocysteinemia (HHcy), a risk factor for cardiovascular, neurodegenerative, and metabolic dysfunctions in humans, has been recapitulated in murine models by genetic and dietary modifications. The relevance of HHcy in clinical and experimental settings has led to the development of various analytical techniques with varying sensitivity and sample volume requirements. This study uses a fit-for-purpose, small-volume LC-MS/MS workflow to quantify plasma homocysteine (Hcy), methionine (Met), and cysteine (Cys) in a diet-induced HHcy mouse model. Using these assays that overcome limitations imposed by sample availability in small animals, our study evaluated circulating levels of these amino acids in C57BL/6 mice fed a HHcy-inducing diet rich in Met and lacking vitamins B6, B9, and B12. The increased Hcy and decreased Cys plasma concentrations observed in these mice correlated with decreased glutathione concentrations in brain homogenates and concomitant increase in the activity of the antioxidant enzyme Glutathione-S-Transferase and in the levels of the lipid peroxidation marker malondialdehyde. Overall, our work links plasma HHcy to the induction of brain oxidative stress, supporting the role of dietary modifications as complementary therapeutic strategies for neurodegenerative conditions.

Sensory processing is fundamentally shaped by stimulation history. For example, in visual cortex, neural responses are reduced for repeated or sustained stimuli (adaptation). These phenomena are well characterized and effectively modeled by divisive normalization. We asked whether these same computational principles govern somatosensory processing. We used fMRI (6 participants, all female) and intracranial electroencephalography (iEEG, 2 participants, both male) to measure responses to time-varying vibrotactile stimuli in human somatosensory cortex. Stimuli consisted of single- and paired-pulses with durations and interstimulus intervals ranging from 0.05 to 1.2 s. We extracted BOLD time courses to capture neural response amplitudes, and high-frequency iEEG broadband envelopes to capture fast neural dynamics. In both experiments, we observed pronounced sub-additive temporal summation. Responses to longer or repeated stimuli were consistently lower than predicted by linear integration. Computational modeling revealed that divisive normalization models outperformed linear models in cross-validated accuracy across both datasets. These results demonstrate that somatosensory temporal dynamics closely mirror those in the visual system. Our findings suggest that the nervous system employs similar computational principles across modalities to encode sensory information across time.Significance statement How the brain integrates sensory information over time is a fundamental question in neuroscience. While nonlinear temporal integration is well documented in visual cortex, it has not been extensively mapped in the human somatosensory system. By combining fMRI with intracranial EEG in humans, we demonstrate that somatosensory responses to tactile stimulation exhibit subadditive temporal summation. This nonlinearity is accurately captured by a divisive normalization model, matching observations in the visual system. Our results suggest that normalization is a canonical computation shared across different modalities to manage temporal dynamics, providing a unified framework for understanding how the brain encodes dynamic sensory stimuli.

Biomarkers of cerebral amyloid angiopathy (CAA) are critically needed. We recently identified semaphorin 3G (SEMA3G) as a novel protein selectively enriched in CAA. Here, we aimed to determine if SEMA3G was a selective marker of CAA in a large cohort of human brain tissue spanning multiple neurodegenerative diseases and three brain regions, and to determine if SEMA3G directly interacts with amyloid beta (Aβ). Multiplexed immunofluorescence showed that SEMA3G significantly accumulated only in CAA⁺ blood vessels in the brain in all cases. We also showed that SEMA3G preferentially associated with Aβ₄₀, Aβ_pS8 and Aβ_pE3, but not Aβ₄₂. Thioflavin T assays and transmission electron microscopy showed that SEMA3G directly interacted with Aβ and slowed Aβ aggregation in vitro, and that this effect was more pronounced for Aβ₄₀ than Aβ₄₂. Together our results demonstrate that SEMA3G is a highly specific marker of CAA in the brain.

BACKGROUND:Visual evoked potential (VEP) P100 latency is routinely used to assess optic nerve demyelination. However, there is no established methodology for disentangling whether shifts in VEP P100 latency may reflect upstream changes in the visual pathway, such as the level of the retina, or whether these delays could be reflective of downstream disturbances in broader brain structure and functioning. OBJECTIVE:To determine the relationship between VEP-based P100 and MRI-based outcomes in people with MS (PwMS) after accounting for structural retinal changes assessed by spectral domain optical coherence tomography (OCT). METHODS:64 study participants underwent OCT, VEP, and MRI. Standardized VEP assessment derived monocular P100 latency for both eyes. Similarly, OCT performed on Heidelberg Spectralis hardware provided peripapillary retinal nerve fiber layer (pRNFL) thickness. Mediation analyses were performed to assess the relationship between P100 and MRI-based outcomes, adjusting for mediating effects of pRNFL and age. RESULTS:VEP-based P100 was significantly associated with lower whole brain volume (WBV) (p=0.0037), with 87.8% of the total effect being both direct and independent from RNFL and the significant age-WBV covariate effect. Similarly, greater VEP-based P100 latency was directly and independently predictive of lower gray matter volume (GMV) (p=0.015) and greater T2-FLAIR LV (p=0.0036) after adjusting for RNFL and age mediating effects. CONCLUSION/CONCLUSIONS:VEP-based P100 latency shows both age- and RNFL-independent associations with MRI-based MS outcomes. In addition to their established diagnostic utility, VEP measures may provide a neurophysiological, objective metric to assess neurodegeneration.

BACKGROUND:Family caregivers of people living with Lewy body dementia (PLBD) experience significant strain and adverse health outcomes that consequently affect the health of their loved ones with Lewy Body Dementia (LBD). Effective LBD caregiver interventions are needed. Building on pilot work, our objective is to test the effects of PERSEVERE (Peer Mentor Support and Caregiver Education)- a 12-week peer mentor-supported, LBD-specific educational intervention -on caregiver knowledge, attitudes, strain, and PLBD quality of life and healthcare utilization in a national, virtual, randomized controlled trial. METHODS:Partnering with LBD caregiver advisors and advocacy organizations, we are recruiting and enrolling 180 seasoned caregivers (having cared for a PLBD with ≥3 years of cognitive symptoms) and 502 novice LBD family caregivers (<3 years of cognitive symptoms). Seasoned caregivers train as Mentors. Novice caregivers are randomized 1:1 in cohorts of 100 to (1) the Mentee group receiving weekly Mentor calls covering a novel LBD curriculum focused on symptom management, future planning, and caregiver support, or (2) the attention-control group receiving pre-existing resources for self-directed learning. Primary outcomes include change from baseline in caregiver knowledge and attitudes at 12 weeks (post-intervention) and caregiver strain at nine months (follow-up). Secondary outcomes include engagement with materials and/or mentor, satisfaction, future interest, and change in PLBD quality of life and PLBD healthcare utilization at nine months. DISCUSSION/CONCLUSIONS:A peer mentor-delivered LBD-focused curriculum may improve caregiver and PLBD outcomes in a cost-effective, scalable manner. PERSEVERE has experienced robust national enrollment and retention within the first 18 months of recruitment, with outcomes forthcoming. Trial Registration https://clinicaltrials.gov/study/NCT06389032, registered on April 24, 2024.

BACKGROUND/UNASSIGNED:Atrial fibrillation (AF) is the most common cardiac arrhythmia worldwide and is associated with an increased risk of adverse outcomes. Age is an important risk factor for AF with a sharp rise in prevalence after the age of 60 years. Despite a rising share of older adults in Africa, there is a paucity of data regarding AF burden in this demographic. OBJECTIVE/UNASSIGNED:This study aimed to determine the prevalence, clinical characteristics, and associated factors of AF among adults 60 years and older attending noncardiac outpatient clinics at a tertiary hospital in Tanzania. METHODS/UNASSIGNED:We conducted a cross-sectional study among consenting adults aged 60 years and older at noncardiac outpatient clinics of Muhimbili National Hospital from June 2021 to February 2022. A structured questionnaire was used to collect sociodemographic and clinical characteristics of participants. They were screened for AF using a smartphone-connected single-lead electrocardiography (ECG) device (KardiaMobile, AliveCor). Probable AF was confirmed by 12-lead ECG. Multivariable logistic regression was used to determine factors associated with AF. Data analysis was performed using Stata version 13 (StataCorp LLC). RESULTS/UNASSIGNED:< .001) were independently associated with AF. CONCLUSION/UNASSIGNED:AF is common and underdiagnosed and carries a high stroke risk among elderly outpatients in Tanzania. Opportunistic screening of the elderly for AF in low-resource countries with 1-lead ECG is feasible and has the potential to reduce the burden of stroke.