About

Anthony Alexander is an Assistant Professor of Clinical Anesthesiology and Critical Care at the Perelman School of Medicine, University of Pennsylvania. He earned his MBBS degree from the University of the West Indies in 2012. His professional focus includes anesthesiology and critical care, with research contributions in perioperative adverse events, pediatric ventilation, and racial and ethnic disparities in anesthesiology care. He has authored multiple publications on these topics, including studies on risk factors in primary palatoplasty, heterogeneity in neonatal aeration, and controlled hypotension. His work emphasizes improving patient outcomes and addressing disparities within anesthesiology practice.

Research topics

• Medicine
• Audiology
• Developmental psychology
• Psychology
• Radiology
• Neuroscience
• Pathology

Selected publications

• Associations of Prenatal Cannabis Exposure and Neonatal Brain Development in the HBCD Cohort

  medRxiv · 2026-03-03

  articleOpen access

  Importance: Prenatal cannabis exposure is increasing in prevalence, yet its associations with early brain development-particularly how the timing and frequency of exposure relate to neonatal brain structure-remain insufficiently understood. Clarifying these associations is essential for informing early risk identification and guiding perinatal care. Objective: To examine associations between patterns of maternal prenatal cannabis exposure, including exposure presence, gestational timing, and frequency, and neonatal brain structure and microstructure during the first month of life. Design Setting and Participants: This cohort study included 1,782 mother-infant dyads (221 with PCE) from the HEALthy Brain and Child Development Study. Maternal cannabis use was assessed using the validated Timeline Follow-back method. Infants underwent natural-sleep magnetic resonance imaging, including T2-weighted structural imaging and diffusion imaging, within the first month of life. Main Outcomes and Measures: Associations between prenatal cannabis exposure and regional T2-weighted volumes and diffusion white matter microstructure metrics were examined as a function of (1) exposure presence, (2) gestational timing of exposure, and (3) frequency of exposure within exposed infants. Results: Prenatal cannabis exposure was associated with small but statistically significant differences in neonatal brain structure. Exposure was linked to volumetric variation in cerebellar and subcortical limbic regions, including smaller amygdala, thalamic, and cerebellar vermis volumes and larger caudate, hippocampal, and cerebellar cortex volumes. Timing-specific analyses revealed distinct patterns: first-trimester exposure was primarily associated with white matter microstructural alterations, particularly in cerebellar and association tracts, whereas sustained exposure throughout pregnancy was associated with volumetric differences across cerebellar and subcortical regions. Among exposed infants, higher exposure frequency was associated with larger cerebral white matter volume and lower fractional anisotropy in select regions. Effect sizes were modest, and regional findings varied in directionality. Conclusions and Relevance: Prenatal cannabis exposure was associated with timing-and frequency-dependent differences in neonatal brain structure within the first month of life. These differences likely reflect variation in early neurodevelopmental processes rather than uniformly adverse effects and may evolve with ongoing brain maturation and postnatal influences. Consideration of exposure timing and frequency, alongside broader clinical context and competing risks, may support more individualized, nonjudgmental counseling and longitudinal developmental monitoring. Key Points: The timing and frequency of prenatal cannabis exposure is associated with alterations in neonatal brain development, underscoring the importance of addressing cannabis use in pregnancy.

  PublisherOA PDFDOI

• Major Lifetime Discrimination Exposure Accelerates Brain Microstructural Aging: Diffusion MRI Evidence From MIDUS

  Biopsychosocial Science and Medicine · 2026-01-28

  articleOpen access

  OBJECTIVE: Experiencing discrimination is associated with faster biological aging, as reflected in telomere shortening and DNA methylation. However, the impact of discrimination on brain aging processes remains unclear. Here, we tested whether individuals who reported at least one major lifetime discrimination event would exhibit steeper age-related associations in microstructural metrics within whole-brain white matter and the hippocampus, consistent with accelerated brain microstructural aging, compared with those with no such experiences. METHODS: We analyzed multi-shell diffusion-weighted MRI data from the Midlife in the United States (MIDUS) cohort ( n =147, mean age=65 years, range: 48 to 95 years) to assess brain microstructure using complementary statistical and biophysical diffusion models. Diffusion kurtosis imaging representation was used to derive diffusion tensor imaging (DTI) and white matter tract integrity (WMTI) measures. Additional microstructural health indices were derived using the neurite orientation dispersion and density imaging (NODDI) model. Permutation analyses of linear models were run within the whole-brain white matter and bilateral hippocampi, adjusting for sex, race, and education. RESULTS: Participants who reported at least one major discriminatory experience during their lifetime exhibited accelerated age-associated changes in white matter microstructural measures, including higher mean and radial diffusivities, extra-axonal radial diffusivity, and free water fraction compared with those with no such experiences. CONCLUSIONS: These converging findings from complementary measures of brain microstructure suggest that major discrimination experiences may contribute to accelerated brain microstructural aging.

  PublisherOA PDFDOI

• 16 weeks of moderate intensity resistance exercise improves strength but is insufficient to alter brain structure in Gulf War Veterans with chronic musculoskeletal pain: a randomized controlled trial

  Frontiers in Neuroscience · 2025-04-16

  articleOpen access

  Introduction Chronic widespread musculoskeletal pain (CMP) is a primary condition of Veterans who were deployed to the Persian Gulf War. The mechanisms that underlie CMP in these Veterans are unknown and few efficacious treatment options exist. This study tested the effects of 16 weeks of resistance exercise training (RET) on gray matter (GM) volume and white matter (WM) microstructure in Gulf War Veterans (GWVs) with CMP compared to GWV waitlist controls (WLC). Methods Fifty-four GWVs were randomly assigned to 16 weeks of RET ( n = 28) or WLC ( n = 26). Training involved 10 resistance exercises to involve the whole body, was supervised and individually tailored, and progressed slowly to avoid symptom exacerbation. Outcomes assessed at baseline, 6, 11 and 17 weeks and 6- and 12-months post-intervention included GM volume (voxel-based morphometry), WM microstructure (diffusion tensor imaging), pain [short form McGill Pain Questionnaire (SF-MPQ) and 0–100 visual analog scale (VAS)], fatigue (0–100 VAS), and mood (Profile of Mood States). Muscular strength was assessed at baseline, 8 and 16 weeks, and training volume was tracked throughout the 16-week intervention. Primary analyses used linear mixed effects models with Group, Time, and the Group*Time interaction as fixed factors and subject and slope as random factors to test the differential effects of RET and WLC on brain structure and symptoms. All neuroimaging analyses used the False Discovery Rate to correct for multiple comparisons at an alpha of 0.05. Results Strength increased significantly across the trial for the RET group ( p < 0.001). There were significant Group*Time interaction effects for pain ratings (SF-MPQ total; p < 0.01) and the Profile of Mood States total mood disturbance score ( p < 0.01). There were no Group or Group*Time effects for GM volume or WM microstructure. There were no significant associations between strength, symptoms, and brain structure ( p > 0.05). Conclusion Sixteen weeks of low-to-moderate intensity RET (i) improved musculoskeletal strength and (ii) did not exacerbate symptoms, but (iii) was insufficient to alter brain structure in GWVs with CMP.

  PublisherOA PDFDOI

• Separable, symptom specific alterations in brain microstructure associated with early-stage Parkinson’s Disease

  medRxiv · 2025-07-14

  preprintOpen access

  Abstract Introduction Parkinson’s Disease (PD) is diagnosed based on motor symptoms (bradykinesia, resting tremor, rigidity); yet non-motor symptoms such as sleep abnormalities, autonomic dysfunction, and cognitive changes often precede motor signs, fulfilling the criteria for prodromal PD. How motor and non-motor symptoms emerge from dopamine depletion and whether they involve separable neural substrates remains unclear. Methods We applied correlational tractography based on multi-shell, diffusion-weighted magnetic resonance imaging in early-stage PD to assess microstructural changes throughout the brain. Eight participants with early-stage PD and 5 healthy controls underwent motor, cognitive, and mood assessments, followed by structural and multi-shell, diffusion-weighted magnetic resonance imaging. Their groupwise differences in white matter integrity associated with PD status were quantified using correlational tractography, with and without age correction. Results Correlational tractography delineated both microstructural changes that held either a significant positive or negative association with PD status, where the statistical maps of these changes linked differentially to motor and non-motor symptoms. Quantitative anisotropy (QA) extracted from positively associated fibers significantly correlated with cognitive function, while QA of negatively associated fibers correlated with motor function—independent of the effect of age. Of note, QA of positively associated fibers correlated with depressive mood only in the age-uncorrected analyses, suggesting a strong age-related effect. Conclusion In early-stage PD, motor and non-motor symptoms are mapped to anatomically distinct pathways, suggesting separable pathophysiological mechanisms. These findings further suggest that correlational tractography is appropriate to evaluate changes in structural connectivity in neurodegenerative diseases and, potentially, their therapeutic interventions.

  PublisherOA PDFDOI

• Cartesian MPnRAGE for Efficient Simultaneous Multi-Contrast and Quantitative Relaxometry Imaging

  Proceedings on CD-ROM - International Society for Magnetic Resonance in Medicine. Scientific Meeting and Exhibition/Proceedings of the International Society for Magnetic Resonance in Medicine, Scientific Meeting and Exhibition · 2025-09-16

  article

  Motivation: Quantitative T1 (qT1) values help diagnose and examine progression of disease and characterization of brain development, yet long scan times diminish use in clinic and research settings. Faster, accurate qT1 sequences would have great benefit. Goal(s): To create a sequence with multiple image contrasts suitable for diagnostic evaluation and accurate qT1 maps in a short scan time. Approach: We created a novel 3D Cartesian MPnRAGE sequence with 10 inversion times and under-sampling to obtain qT1 values across the brain. Results: This method generated 10 T1-weighted images across the inversion recovery curve, and B1 and inversion efficiency corrected quantitative T1 maps with high accuracy. Impact: Cartesian MPnRAGE provides an accurate way for efficient qT1 mapping to facilitate applications in research or clinical scanning sessions with limited scan time.

  PublisherDOI

• Evaluating and Predicting Non-linear Acoustics Using Multi-Axis Gradient Variations and Convolutional Neural Networks

  Proceedings on CD-ROM - International Society for Magnetic Resonance in Medicine. Scientific Meeting and Exhibition/Proceedings of the International Society for Magnetic Resonance in Medicine, Scientific Meeting and Exhibition · 2025-09-16

  article

  Motivation: MRI scanners produce substantial acoustic noise that may affect sensitive groups. Traditional acoustic models, assuming linear sound pressure level (SPL) scale and combine linearly along three separate axes, may oversimplify system dynamics. Goal(s): To evaluate SPL linearity and develop a predictive model that improves accuracy over traditional methods. Approach: We implemented a custom pulse sequence design to test gradient amplitudes and frequencies and used a convolutional neural network(CNN) to predict SPL changes on an ultra-high performance head-only system. Results: Non-linear SPL responses were observed; our CNN more accurately predicted SPL compared to linear models, demonstrating potential for improved patient comfort and image quality. Impact: This study challenges existing linear acoustic models in MRI, offering a more complex and accurate understanding of SPL dynamics. With improved acoustic noise estimation, more informed choices can be made when developing pulse sequences with reduced SPL.

  PublisherDOI

• Diffusion MRI Processing in the HEALthy Brain and Child Development Study: Innovations and Applications

  bioRxiv (Cold Spring Harbor Laboratory) · 2025-11-11 · 3 citations

  preprintOpen access

  ABSTRACT The landmark ongoing HEALthy Brain and Cognitive Development (HBCD) study will longitudinally chart brain development in a large sample (projected n =7,200) of infants through age 10 years with multimodal neuroimaging that includes an advanced diffusion MRI (dMRI) acquisition. Here, we detail advances in dMRI image processing developed for HBCD, incorporated into the widely used QSIPrep pipeline. Major changes to preprocessing include improvements in infant brain extraction, distortion correction, and normalization to infant-specific templates. Additionally, we describe a new software package – QSIRecon – that yields rich derived data including diverse maps of tissue microstructure as well as person-specific white matter bundles. Using dMRI data from a subset of the HBCD 1.0 release where age information was available ( n =529 sessions across two time points), we observe critical improvements in data quality with preprocessing and see expected developmental patterns. Moving forward, the publicly-available data from HBCD will rapidly grow to become the largest study of brain development in infancy and early childhood using dMRI. QSIPrep and QSIRecon are openly available and can be applied to other infant and pediatric dMRI datasets.

  PublisherOA PDFDOI

• Burden of Intracranial Hypertension and Patterns of Brain Injury on MRI: Secondary Analysis of the 2014–2017 “Approaches and Decisions for Acute Pediatric TBI” Study

  Pediatric Critical Care Medicine · 2025-09-10

  article

  OBJECTIVES: Elevated intracranial pressure (ICP) is a complication of severe traumatic brain injury (TBI) that carries a risk of secondary brain injury. This study investigated the association between ICP burden and brain injury patterns on MRI in children with severe TBI. DESIGN, SETTING, AND PATIENTS: Secondary analysis of the Approaches and Decisions in Acute Pediatric TBI (ADAPT) study, which included children with severe TBI (Glasgow Coma Scale score < 9) who received a clinical MRI within 30 days of injury. We excluded patients who had ICP monitoring less than 24 hours, were missing ICP data for greater than 40% of monitoring time, or who underwent craniectomy. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: ICP burden was defined as the trapezoidal area under the curve of hourly ICP greater than 20 mm Hg. ICP was standardized to total monitoring time, and patients were categorized to four levels of ICP burden. MRI was evaluated for number of diffuse axonal injury (DAI) microhemorrhages, intracerebral hemorrhage (ICH) volume, contusion volume, and number of regions with ischemia. Fisher exact or chi-square tests were used to test the independence between ICP burden and MRI injury amount. Of the 220 patients, 156 (71%) had DAI, 31 (14%) had ICH, 161 (73%) had contusions, and 70 (32%) had ischemia on MRI. Most patients (180, 82%) experienced episodes of ICP greater than 20 mm Hg. Contusion volume ( p = 0.02) and number of regions with ischemia ( p = 0.007) were associated with ICP burden, but we failed to identify such an association for DAI or ICH. Severe (but not mild or moderate) ICP burden was associated with presence of ischemia (odds ratio, 4.64 [95% CI, 1.30-19.5]; p = 0.02). CONCLUSIONS: Elevated ICP was prevalent in the ADAPT cohort. Ischemia and contusion were associated with the burden of ICP. Further research is needed to determine temporal relationships between elevated ICP and ischemia.

  PublisherDOI

• Neural Correlates of Inhibitory Control in Children: Evidence Using MRI and fNIRS

  Brain Topography · 2025-07-26 · 1 citations

  articleOpen access

  Inhibitory control (IC) develops in stages from infancy through adolescence and is associated with numerous developmental disorders and learning outcomes. This study examined how neural architecture - in particular myelination - underlies brain activation patterns observed during IC tasks in a sample of 28 children aged 4-10 years old. IC was observed using reaction times during go/no-go and flanker IC tasks. Myelination was measured using quantitative longitudinal relaxation rate (R1) mapping obtained from selected white matter regions of interest (ROIs). Brain activation was defined as task-related changes in hemoglobin oxygenation as measured by functional near-infrared spectroscopy (fNIRS) averaged within ROIs. Results indicated that myelination in ROIs was higher in older children and fNIRS activation in frontal channels was significantly and positively associated with go/no-go mean reaction time. Myelination in the corona radiata and superior longitudinal fasciculus was positively associated with frontal fNIRS activation, while myelination was negatively associated with go/no-go and flanker mean reaction times across white matter ROIs. Overall, significance level notably varied across models. Independently of inhibitory control constructs, these regions may be of interest in future structure-function studies across development.

  PublisherOA PDFDOI

• Hypothalamic Estrogen Receptor α Is Essential for Female Marmoset Sexual Behavior Without Protecting From Obesity

  Journal of the Endocrine Society · 2025-02-04

  articleOpen access

  Context: ) regulation of sexual behavior, reproductive neuroendocrinology, and metabolic function. In female nonhuman primates (NHPs) and women, however, its hypothalamic counterpart remains unknown. Objective: We hypothesized that knockdown (KD) of ERα expression in the hypothalamic VMN and ARC of female marmosets would diminish sexual receptivity, while simultaneously disrupting gonadotropic and metabolic homeostasis. Methods: at midcycle levels, and approximately 1 month later assigned monkeys to diet-induced obesity (DIO) within group (1) control, receiving scrambled short hairpin RNA (shRNA), or (2) ERαKD, receiving selective ERα gene silencing shRNA. Magnetic resonance imaging-guided neural surgery enabled hypothalamic infusion of viral vector shRNA and subsequent brain immunohistochemistry enabled observer-validated, NIS-elements computer software quantification of ERα knockdown. Results: ERα expression was significantly diminished in the VMN and ARC, but not the preoptic area (POA), of ERαKD females coincident with elimination of timely female sexual responses, more than 80% loss of female receptivity, modestly elevated gonadotropin levels, hyperglycemia, and diminished calorie consumption. Density and intensity of ERα-expressing cells in the VMN correlated positively with female sexual receptivity and calorie consumption, negatively with timeliness of female sexual responses, and in the ARC, correlated negatively with calorie consumption. Conclusion: ERα activation in the female NHP MBH is critically important for female sexual behavior and modestly contributes to gonadotropic and metabolic control.

  PublisherDOI

Recent grants

• Waisman Center Intellectual and Developmental Disabilities Research Center

  NIH · $12.3M · 2021–2027

• NIH Grant R21DA015879

  NIH · $437k · 2006

• NIH Grant R01NS092870

  NIH · $2.2M · 2022

• NIH Grant P50MH100031

  NIH · $20.8M · 2020

• NIH Grant R21HD078119

  NIH · $401k · 2017

Frequent coauthors

• Sterling C. Johnson

  Temple University

  204 shared

• Barbara B. Bendlin

  University of Wisconsin–Madison

  177 shared

• Sanjay Asthana

  Geriatric Research Education and Clinical Center

  123 shared

• Nagesh Adluru

  University of Wisconsin–Madison

  115 shared

• Erin D. Bigler

  Brigham Young University

  81 shared

• Cynthia M. Carlsson

  University of Wisconsin–Madison

  76 shared

• Douglas Dean

  73 shared

• Richard J. Davidson

  University of Wisconsin–Madison

  72 shared

Education

• PhD, Optical Sciences

  The University of Arizona

  1994

• B.S., Electrical Engineering

  University of Maine

  1987