Ahmed Negida, MD, PhD

Ahmed Negida

MD, PhD

Postdoctoral Scholar, Parkinson's and Movement Disorders Center
Department of Neurology, Virginia Commonwealth University, Richmond, VA

I develop multimodal MRI and EEG biomarkers to select patients with Parkinson's disease (PD), dementia with Lewy bodies (DLB), and Alzheimer's disease (AD) for therapeutic trials and to track disease progression. My work centers on degeneration of the cholinergic nucleus basalis of Meynert (Ch4).

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Updated October 2026

Research Program

Cholinergic vulnerability and cognitive resilience in Lewy body disorders and Alzheimer’s disease

I develop scalable multimodal imaging biomarkers of cholinergic degeneration to predict cognitive outcomes and select patients for therapeutic trials in Parkinson’s disease, dementia with Lewy bodies, and Alzheimer’s disease.

  1. Problem

    Cholinergic degeneration is a convergent, therapeutically relevant feature of Parkinson’s disease, dementia with Lewy bodies, and Alzheimer’s disease, although its regional pattern differs across disorders. Cholinesterase inhibitors remain the symptomatic mainstay, but their benefits are modest and heterogeneous, likely reflecting differences in the severity and stage of cholinergic degeneration between individuals.

    The cholinergic pipeline is expanding to muscarinic agonists (e.g., xanomeline–trospium), Ch4 neuromodulation, and trophic or regenerative strategies. These approaches share one requirement: an impaired but not irreversibly lost cholinergic substrate. Whereas amyloid- and tau-targeted trials enroll biomarker-confirmed patients, the cholinergic field lacks a scalable biomarker that identifies cholinergic degeneration and stages the remaining Ch4 substrate.

  2. Target: Ch4 and its cortical connections

    Ch4 (the nucleus basalis of Meynert) supplies most cortical cholinergic input and degenerates in these diseases. I measure its structure, microstructure, and cortical connectivity to capture degeneration and preservation that volume alone does not reveal.

    ↓

    Cognitive resilience

    Some patients keep better cognition than their Ch4 degeneration would predict. I study whether regional cholinergic preservation and network connectivity explain this resilience.

  3. Approach

    • Multimodal MRI. Structural, diffusion, and functional imaging of Ch4 integrity and cortical connectivity.
    • Cholinergic PET benchmarking. Relating MRI signatures to regional cholinergic innervation.
    • Complementary EEG. Network dysfunction and cognitive fluctuations.
    • Subtyping and longitudinal modeling. Patient subgroups, deviations from normative trajectories, and prediction of cognitive decline and dementia.

  4. Applications

    Validated imaging biomarkers for patient stratification in cholinergic trials, with secondary goals of refining prognosis and testing whether baseline cholinergic status explains differences in treatment response.

    Longer term: assessing residual target integrity before Ch4 stimulation or restorative therapies.

Contributions

1. In vivo imaging of cholinergic integrity

Ch4 is small and difficult to delineate with conventional MRI volumetry. Using probabilistic cytoarchitectonic maps, I quantified Ch4 integrity from standard MRI and identified a subtype of PD mild cognitive impairment (PD-MCI) defined by MRI evidence of Ch4 degeneration. I then added diffusion MRI, estimating Ch4 free water with the regularized bi-tensor model of Pasternak et al. (2009). In resting-state fMRI, Ch4 connectivity with the attention-related cingulo-opercular network mediated the relationship between Ch4 degeneration and cognition, a candidate circuit link to cognitive impairment.

Papers
Parkinsonism Relat Disord, 2025medRxiv, 2026
Tools
Ch4 SubtyperCh4 Subtyping Tool

2. EEG signature of Lewy body dementia

EEG is inexpensive, repeatable, and widely available, and cognitive fluctuations in Lewy body dementia are commonly attributed to cholinergic degeneration. In the NIH R21 AG077469 study, I analyzed resting-state EEG in patients with Lewy body disease and built a machine-learning model that detects cognitive fluctuations. Building on this work, I contributed pilot data and the multimodal Ch4 MRI pipeline to a funded mechanistic R01 on cholinergic degeneration and cognitive fluctuations, which currently supports my position.

Papers
Alzheimer's Res Ther, 2026
Tools
EEG feature toolbox

3. Modeling disease progression

Heterogeneity in progression also complicates disease-modifying trials. Using PPMI, I modeled ten-year progression milestones across clinical, pathological, and data-driven PD subtypes; diffuse-malignant PD progressed fastest. To identify these patients prospectively, I developed disease-duration–specific percentiles for the first five years after diagnosis, released an open-source subtype calculator, and characterized the genetic associations of these subtypes. This work converges with my imaging research: patients with PD-MCI and MRI evidence of Ch4 degeneration overlap with those classified as diffuse-malignant PD.

Papers
npj Parkinson's Dis, 2026Mov Disord Clin Pract, 2026Genes, 2026
Tools
Percentile calculatorPD Subtyping Tool

I leverage existing human brain imaging data from more than 40,000 MRIs obtained under data use agreements from large multisite consortia: A4, ADNI, ADNI-DoD, AIBL, AMP-PD, Critical Path for Parkinson's (CPP), NACC, OASIS-3, PDBP, PPMI, and U.S. POINTER.

Education and Training

NIA
2025

IMPACT-AD Fellowship

Institute on Methods and Protocols for Advancement of Clinical Trials in ADRD · NIA and Alzheimer's Association

UoP
2022

Ph.D. in Biomedical Sciences

University of Portsmouth · United Kingdom

ZU
2018

M.B.B.Ch. in Medicine and Surgery (equivalent to MD)

Zagazig University Faculty of Medicine · Egypt

Academic and Research Appointments

VCU
2023 – present

Postdoctoral Scholar

VCU Parkinson's and Movement Disorders Center, Department of Neurology · Richmond, VA

  • Built a multimodal Ch4 MRI signature (T1-weighted gray-matter density and diffusion free water), now extended with resting-state fMRI across PD, DLB, and AD, and identified a PD-MCI subtype with MRI evidence of cholinergic nucleus 4 degeneration
  • Developed EEG-based biomarkers for cognitive fluctuations in Lewy body dementia, combining NASA's Psychomotor Vigilance Test with resting-state and task-based EEG
  • Led PPMI, NACC, and PDBP database studies stratifying PD, LBD, and AD patients, including 10-year progression patterns across PD subtypes
  • Built structural, functional, and diffusion MRI pipelines, including DTI-ALPS and white matter hyperintensity quantification for glymphatic–vascular studies
  • Generated pilot data and contributed study design, biostatistical planning, and the multimodal Ch4 MRI pipeline to the funded NIH/NINDS R01 NS142622
HMS
2021 – 2023

Research Fellow

Harvard Medical School, Department of Global Health and Social Medicine · Boston, MA

  • Assessed global neurological care delivery systems through systematic data collection
  • Quantified social and environmental determinants of neurological health disparities
  • Applied external validation methods for financial risk prediction tools in low-income settings
  • Led the development of CHYSPR guidelines in LMICs (first author, www.chyspr.org)
  • Produced peer-reviewed outputs informing WHO and regional health policy decisions
BAU
2019

Research Fellow

Bahçeşehir University, Department of Neurological Surgery · Istanbul, Turkey

  • Evaluated deep brain stimulation outcomes in Parkinson's and Huntington's disease patients
  • Analyzed clinical and neuropsychological endpoints using advanced statistical methods
ELRI
2015

Clinical Research Assistant

Epidemiology Department, Egyptian Liver Research Institute and Hospital · Mansoura, Egypt

Research Support

Postdoctoral Salary Support (PI: Matthew J. Barrett, MD, MS)

R01 · Active (2025–2030)
NIH / National Institute of Neurological Disorders and Stroke (R01 NS142622)
"Elucidating the Role of Cholinergic Degeneration in Cognitive Fluctuations in Lewy Body Dementia"

Role: Postdoctoral Researcher

Contribution: Generated pilot data; contributed to study design, biostatistical planning, and the EEG/neuroimaging analysis sections, including the multimodal Ch4 MRI pipeline; drafted portions of the application.

R21 · Completed (2022–2025)
NIH / National Institute on Aging (R21 AG077469)
"Development and Characterization of EEG Signature of Cognitive Fluctuations in Lewy Body Dementia"

Role: Postdoctoral Researcher

Contribution: EEG and neuroimaging analysis; manuscript preparation.

Independent Projects

Approved ancillary study · 2026–2027
U.S. POINTER · NIA / Alzheimer's Association
"Brain Age Gap as a Novel Endpoint for Evaluating Lifestyle Intervention Effects on Brain Health" (approved ancillary proposal #26-2049)

Role: Chair of the writing group for this secondary analysis (not the parent trial), in collaboration with Ai-Ling Lin, PhD (University of Missouri)

Scope: Approved access to U.S. POINTER trial imaging data. No funding is attached to this approval.

Data Resources

Data use agreements · more than 40,000 MRIs from multisite consortia

A4, ADNI (2–5), ADNI-DoD, AIBL, AMP-PD (Tier 1), Critical Path for Parkinson's (CPP), NACC, OASIS-3, PDBP, PPMI, and U.S. POINTER (imaging secondary analysis); plus the VCU multimodal discovery cohort (n = 111).

Publications

2026

First authorParkinson's disease

Negida A, Mukhopadhyay N, Berman BD, Fereshtehnejad SM, Barrett MJ. Disease-Duration–Specific Percentiles for Prospective Subtyping of Parkinson’s Disease: A PPMI-Based Study. Movement Disorders Clinical Practice (Impact Factor = 3.4). 2026. doi:10.1002/mdc3.70740

First authorParkinson's disease

Negida A, Mukhopadhyay N, Berman BD, Barrett MJ. Comparative analysis of progression milestones across Parkinson’s disease clinical, pathological, and data-driven subtypes: a 10-year follow-up. npj Parkinson's Disease (Impact Factor = 8.5). 2026. PMID: 42286020

First authorParkinson's disease

Negida A, Abouelmagd ME, Hamed BM, et al. Genetic Associations of Parkinson’s Disease Clinical, Pathological, and Data-Driven Subtypes. Genes (Basel) (Impact Factor = 3.1; Q2). 2026;17(4):449. PMID: 42074567

First authorLewy body dementia

Negida A, Lageman SK, Ono K, Ahsan MM, Mukhopadhyay N, Barrett MJ. Resting-State EEG Features of Cognitive Fluctuations Across the Lewy Body Disease Spectrum. Alzheimer's Research & Therapy (Impact Factor = 8.9). 2026. doi:10.1186/s13195-026-02148-8

First authorParkinson's diseasePreprint

Negida A, Zaman A, Wyman-Chick KA, Hallak R, Miller-Patterson C, Berman BD, et al. Multimodal MRI characterization of nucleus basalis of Meynert degeneration: structural atrophy and free-water diffusion in Parkinson's disease cognitive impairment. medRxiv. 2026. doi:10.64898/2026.06.08.26355183

Co-principal investigatorTraumatic brain injury

Nugent JG, Tan H, Stedelin B, et al.; Negida A, Raslan AM; on behalf of the GNS-I Collaborators. Traumatic brain injury outcomes across human development index strata in 29 countries. Nature Medicine (Impact Factor = 52.5). 2026. doi:10.1038/s41591-026-04600-6

Senior authorParkinson's disease

Abouelmagd ME, Abbas A, Yousef O, et al.; Negida A. Efficacy and safety of apomorphine in the treatment of Parkinson's disease: a systematic review and meta-analysis of randomized controlled trials. Therapeutic Advances in Neurological Disorders (Impact Factor = 4.0). 2026;19:17562864261436541. PMID: 42027696

Senior authorParkinson's diseaseNeuromodulation

Abbas AW, Al-Qiami A, Sarhan K, et al.; Negida A. The potential of utilizing Local Field Potential (LFP) in diagnosis and management of Parkinsonism's hallmark symptoms: a comprehensive review. Neurological Sciences (Impact Factor = 2.7). 2026;47(5). PMID: 41957306

Senior authorParkinson's disease

Messak M, Abdelmageed A, Khattab YA, Mandour Y, Shaker O, Negida A. Bright light therapy for depression and excessive daytime sleepiness in Parkinson's disease: a systematic review and meta-analysis of randomized controlled trials with dose-response meta-regression. Neurodegenerative Disease Management (Impact Factor = 2.8; Q2). 2026:1-16. PMID: 42217222

Senior authorParkinson's disease

Messak M, Abdelmageed A, Abbas AN, Mandour Y, Talkhan A, Eltohami MF, Kanaan D, Alfahmi FK, Saeed HT, Hamzeh LH, Taman L, Negida A. Therapeutic effects of cannabinoids on Parkinson's disease: an updated systematic review and meta-analysis of randomized controlled trials. Acta Neurologica Belgica (Impact Factor = 2.0). 2026. PMID: 42138778

Senior authorNeuroprotection

Hawas Y, Abouzid M, Gadelmawla AF, Ewis DK, Khatatbeh A, Negida Y; Negida A. The Neuroprotective Potentials of Dual GIP/GLP1-RA (Tirzepatide): From Preclinical Experiments to Clinical Trials: A Scoping Review. Brain and Behavior (Impact Factor = 2.8). 2026;16(8):e71702. PMID: 42608956

Dementia

Heo RJ, Negida A, Barrett MJ, et al. Cholinesterase inhibitors for patients with dementia: Patterns of prescribing and disparities in treatment. Journal of Alzheimer's Disease (Impact Factor = 3.1). 2026;109(4):1917-1924. PMID: 41527747

2025

First authorParkinson's disease

Negida A, Vohra HZ, Lageman SK, et al. Parkinson's disease mild cognitive impairment with MRI evidence of cholinergic nucleus 4 degeneration: A new subtype? Parkinsonism & Related Disorders (Impact Factor = 4.3). 2025;141:108072. PMID: 41106089

First authorParkinson's diseaseBook chapter

Negida A, et al. Chapter 14: Epidemiology and Risk Factors of Parkinson’s Disease. Essential Guide to Neurodegenerative Disorders (Academic Press). 2025:225-234.

Senior authorDementia

Abouelmagd ME, Almosilhy NA, Makhlouf HA, et al.; Negida A. Comparative safety of cholinesterase inhibitors and memantine for dementia: a protocol for a network meta-analysis of randomized controlled trials. Systematic Reviews (Impact Factor = 5.7). 2025;14(1):213. PMID: 41188985

Senior authorParkinson's disease

Serag I, Azzam AY, Hassan AK, et al.; Negida A. Multimodal diagnostic tools and advanced data models for detection of prodromal Parkinson's disease: a scoping review. BMC Medical Imaging (Impact Factor = 3.9). 2025;25(1):103. PMID: 40155878

Senior authorAlzheimer's disease

Mansour MEM, Ali AHG, Ibrahim MHM, Mousa AIA, Negida AS. Safety and efficacy of sodium benzoate for patients with mild Alzheimer's disease: a systematic review and meta-analysis. Nutritional Neuroscience (Impact Factor = 3.1; Q2). 2025;28(6):763-772. PMID: 39450675

Senior authorEpilepsyNeuromodulation

Hawas Y, Abbas A, Alkhawaldeh IM, et al.; Negida A. Efficacy and safety of transcranial direct current stimulation (tDCS) in treatment of refractory epilepsy: an updated systematic review and meta-analysis of randomized sham-controlled trials. Neurological Sciences (Impact Factor = 2.7). 2025;46(2):671-687. PMID: 39532798

Senior authorStroke

Alkhawaldeh IM, Abdelhady M, Aljabali A, et al.; Negida A. Rates of discontinuation and non-publication of endovascular stroke clinical studies: A cross-sectional analysis. Journal of Clinical Neuroscience (Impact Factor = 1.9). 2025;135:111122. PMID: 40043330

Senior authorParkinson's disease

Mady A, Kashbour M, Abu-Qare'e O, et al.; Barrett MJ, Negida A. Rheumatoid arthritis drugs and the risk of Parkinson's disease: a meta-analysis. NeuroImmune Pharmacology and Therapeutics. 2025. doi:10.1515/nipt-2024-0023

Dementia with Lewy bodies

Heo RJ, Negida A, Wyman-Chick KA, et al. Patterns and predictors of cholinesterase inhibitor use in dementia with Lewy bodies. Alzheimer's & Dementia: TRCI (Impact Factor = 7.4). 2025;11(3):e70136. PMID: 40687401

Parkinson's diseaseNeuromodulation

Abbas A, Sabet H, Hawas Y, ..., Negida A, ..., Raslan AM. Impact of Subthalamic Nucleus Deep Brain Stimulation on Gastrointestinal Symptoms and Gastric Emptying in Parkinson's Disease: A Systematic Review and Meta-Analysis. Neuromodulation (Impact Factor = 3.7). 2025. PMID: 40910967

EpilepsyNeuromodulation

Pichardo-Rojas PS, Pichardo-Rojas D, Zarate-Duran CA, ..., Negida A, ..., Milanese V. Stereoelectroencephalography-guided radiofrequency thermocoagulation for drug-resistant epilepsy: A meta-analysis. Epilepsia. 2025;66(10):3602-3620. PMID: 40569267

DystoniaNeuromodulation

Yousef O, Abbas A, Abdelmeseh M, ..., Negida A, ..., Berman BD. Subthalamic nucleus versus globus pallidus internus deep brain stimulation in the treatment of dystonia: A systematic review and meta-analysis of safety and efficacy. Journal of Clinical Neuroscience (Impact Factor = 1.9). 2025;132:110958. PMID: 39647323

Dystonia

Heo RJ, Mukhopadhyay N, Dintino C, Negida A, Barrett MJ, Berman BD. Oral medication treatment patterns in blepharospasm and Meige syndrome: a multi-institutional TriNetX study. Dystonia (Impact Factor = 1.6). 2025;4:15368. doi:10.3389/dyst.2025.15368

2024

First authorParkinson's disease

Negida A, Hassan NM, Aboeldahab H, et al. Efficacy of the iron-chelating agent, deferiprone, in patients with Parkinson’s disease: a systematic review and meta-analysis. CNS Neuroscience & Therapeutics (Impact Factor = 6.6). 2024;30(2):e14607. PMID: 38334258

Senior authorParkinson's disease

Mady A, Nabil Y, Daoud A, et al.; Negida A. Determining the role of statins in Parkinson's disease risk reduction and disease modification: A comprehensive meta-analysis of 4 million participants' data. CNS Neuroscience & Therapeutics (Impact Factor = 6.6). 2024;30(8):e14888. PMID: 39097909

Senior authorStroke

Ghaith HS, Gabra MD, Ebada MA, et al.; Negida A. Tranexamic acid for patients with aneurysmal subarachnoid hemorrhage: a systematic review and meta-analysis of 2991 patients. International Journal of Neuroscience (Impact Factor = 1.7). 2024;134(7):763-776. PMID: 36463556

Huntington's disease

Barrett MJ, Negida A, Mukhopadhyay N, et al. Optimizing Screening for Intrastriatal Interventions in Huntington's Disease Using Predictive Models. Movement Disorders (Impact Factor = 7.7; Q1). 2024;39(5):855-862. PMID: 38465778

Lewy body dementia

Desai N, Nawaz H, Mukhopadhyay ND, ..., Negida A, ..., Barrett MJ. Neuropsychological Determinants of Impairment in Activities of Daily Living in Patients With Lewy Body Dementia. Cureus. 2024;16(10):e70762. PMID: 39493124

Alzheimer's disease

Saleh O, Albakri K, Altiti A, ..., Negida A, ..., Kamal MA. The Role of Non-coding RNAs in Alzheimer's Disease: Pathogenesis, Novel Biomarkers, and Potential Therapeutic Targets. CNS & Neurological Disorders - Drug Targets. 2024;23(6):731-745. PMID: 37211844

2023

Senior authorParkinson's disease

Shahien M, Elaraby A, Gamal M, et al.; Negida A. Physical therapy interventions for the management of hand tremors in patients with Parkinson's disease: a systematic review. Neurological Sciences (Impact Factor = 2.7). 2023;44(2):461-470. PMID: 36205810

Senior authorDementia

Hussein AS, Shawqi M, Bahbah EI, et al.; Negida A. Do cerebral microbleeds increase the risk of dementia? A systematic review and meta-analysis. IBRO Neuroscience Reports (Impact Factor = 2.9). 2023;14:86-94. PMID: 36632242

Senior authorStroke

Hassanein ME, Fayad J, Shabana JA, et al.; Negida A. Efficacy and safety of intravenous mesenchymal stem cells for ischemic stroke patients, a systematic review and meta-analysis. Frontiers in Stroke (Impact Factor = 1.2). 2023;2:1339331. PMID: 41541094

StrokePreprint

Aljabali A, Abdelhady M, Altal MK, Negida A, Masadeh MM, Alrabadi NS. The efficacy and safety of the sphingosine-1-phosphate receptor agonist fingolimod in cerebrovascular stroke: a systematic review and meta-analysis. Research Square. 2023. doi:10.21203/rs.3.rs-2680622/v1

2022

First authorParkinson's diseasePhD thesis

Negida A. The Hope and the Hype in Parkinson’s Disease Treatments. PhD thesis, University of Portsmouth. 2022.

Senior authorStroke

Ghaith HS, Elfil M, Gabra MD, et al.; Negida A. Intravenous thrombolysis before mechanical thrombectomy for acute ischemic stroke due to large vessel occlusion; should we cross that bridge? A systematic review and meta-analysis of 36,123 patients. Neurological Sciences (Impact Factor = 2.7). 2022;43(11):6243-6269. PMID: 35871179

Traumatic brain injury

Ghaith HS, Nawar AA, Gabra MD, ..., Negida A, ..., Barreto GE. A Literature Review of Traumatic Brain Injury Biomarkers. Molecular Neurobiology (Impact Factor = 5.5). 2022;59(7):4141-4158. PMID: 35499796

2021

First authorParkinson's disease

Negida A, Ghaith HS, Fala SY, et al. Mavoglurant (AFQ056) for the treatment of levodopa-induced dyskinesia in patients with Parkinson's disease: a meta-analysis. Neurological Sciences (Impact Factor = 2.7). 2021;42(8):3135-3143. PMID: 34014397

First authorStroke

Negida A, Ghaith HS, Gabra MD, et al. Should the direct aspiration first pass technique be advocated over the stent-retriever technique for acute ischemic stroke? A systematic review and meta-analysis of 7692 patients. Surgical Neurology International. 2021;12:597. PMID: 34992914

First authorTraumatic brain injury

Negida A, Teton Z, Stedelin B, Nerison C, Al-Shami H, Hegazy A, Raslan AMT. Determining the global outcomes of traumatic brain injury in low-, middle- and high-income countries: a prospective, global neurosurgery, multicentre cohort study (GNS-1) protocol. Journal of Surgical Protocols and Research Methodologies. 2021. doi:10.1093/jsprm/snab002

Stroke

Yassin A, Ghzawi A, Al-Mistarehi AH, ..., Negida A, ..., Abdelmonem M. Mortality rate and biomarker expression within COVID-19 patients who develop acute ischemic stroke: a systematic review and meta-analysis. Future Science OA (Impact Factor = 2.5). 2021;7(7):FSO713. PMID: 34254031

2019

First authorTraumatic brain injury

Negida A, Raslan AM. Invitation to the GNS-I Study; a Global Evaluation of Traumatic Brain Injury in Low-, Middle-, and High- income Countries. Advanced Journal of Emergency Medicine. 2019;3(3):e21. PMID: 31410398

Senior authorParkinson's disease

Ebada MA, Alkanj S, Ebada M, et al.; Negida A. Safety and Efficacy of Levetiracetam for the Management of Levodopa- Induced Dyskinesia in Patients with Parkinson's Disease: A Systematic Review. CNS & Neurological Disorders - Drug Targets. 2019;18(4):317-325. PMID: 30868968

Senior authorAlzheimer's disease

Bahbah EI, Fathy S, Negida A. Is Alzheimer's disease linked to Herpes simplex virus type 1 infection? A mini‐review of the molecular correlation and the possible disease connections. Clinical and Experimental Neuroimmunology. 2019;10(3):192-196. doi:10.1111/cen3.12518

Stroke

Najmi E, Bahbah EI, Negida A, Afifi A, Baratloo A. Diagnostic Value of Serum Neuron-Specific Enolase Level in Patients With Acute Ischemic Stroke; A Systematic Review and Meta-Analysis. International Clinical Neuroscience Journal. 2019;6(2):36-41. doi:10.15171/icnj.2019.08

2018

First authorParkinson's diseaseNeuromodulation

Negida A, Elminawy M, El Ashal G, Essam A, Eysa A, Abd Elalem Aziz M. Subthalamic and Pallidal Deep Brain Stimulation for Parkinson's Disease. Cureus. 2018;10(2):e2232. PMID: 29713577

Senior authorParkinson's diseaseNeuromodulation

Elgebaly A, Elfil M, Attia A, Magdy M, Negida A. Neuropsychological performance changes following subthalamic versus pallidal deep brain stimulation in Parkinson's disease: a systematic review and metaanalysis. CNS Spectrums (Impact Factor = 4.6; Q1). 2018;23(1):10-23. PMID: 28236811

Parkinson's disease

Abushouk AI, Negida A, Elshenawy RA, et al. C-Abl Inhibition; A Novel Therapeutic Target for Parkinson's Disease. CNS & Neurological Disorders - Drug Targets. 2018;17(1):14-21. PMID: 28571531

2017

First authorParkinson's disease

Negida A, Elfil M, Attia, et al. Caffeine; the Forgotten Potential for Parkinson's Disease. CNS & Neurological Disorders - Drug Targets. 2017;16(6):652-657. PMID: 27823571

Senior authorParkinson's disease

Attia, Ahmed H, Gadelkarim M, et al.; Negida A. Meta-Analysis of Creatine for Neuroprotection Against Parkinson's Disease. CNS & Neurological Disorders - Drug Targets. 2017;16(2):169-175. PMID: 27823574

Senior authorParkinson's disease

Abushouk AI, El-Husseny MWA, Magdy M, et al.; Negida A. Evidence for association between hepatitis C virus and Parkinson's disease. Neurological Sciences (Impact Factor = 2.7). 2017;38(11):1913-1920. PMID: 28780707

Parkinson's disease

Ahmed H, Abushouk AI, Gabr M, Negida A, Abdel-Daim MM. Parkinson's disease and pesticides: A meta-analysis of disease connection and genetic alterations. Biomedicine & Pharmacotherapy (Impact Factor = 7.5). 2017;90:638-649. PMID: 28412655

Parkinson's disease

Awad K, Abushouk AI, AbdelKarim AH, Mohammed M, Negida A, Shalash AS. Bee venom for the treatment of Parkinson's disease: How far is it possible? Biomedicine & Pharmacotherapy (Impact Factor = 7.5). 2017;91:295-302. PMID: 28477460

Parkinson's disease

Abushouk AI, Negida A, Ahmed H, Abdel-Daim MM. Neuroprotective mechanisms of plant extracts against MPTP induced neurotoxicity: Future applications in Parkinson's disease. Biomedicine & Pharmacotherapy (Impact Factor = 7.5). 2017;85:635-645. PMID: 27890431

2016

First authorParkinson's disease

Negida A, Menshawy A, El Ashal G, et al. Coenzyme Q10 for Patients with Parkinson's Disease: A Systematic Review and Meta-Analysis. CNS & Neurological Disorders - Drug Targets. 2016;15(1):45-53. PMID: 26553164

First authorParkinson's diseaseNeuromodulation

Negida A, Attia D. Comments on the paper "Efficacies of globus pallidus stimulation and subthalamic nucleus stimulation for advanced Parkinson's disease: a meta-analysis of randomized controlled trials". Clinical Interventions in Aging (Impact Factor = 4.1). 2016;11:1599-1600. PMID: 27877029

Senior authorNeurogenic orthostatic hypotension

Elgebaly A, Abdelazeim B, Mattar O, Gadelkarim M, Salah R, Negida A. Meta-analysis of the safety and efficacy of droxidopa for neurogenic orthostatic hypotension. Clinical Autonomic Research (Impact Factor = 4.6). 2016;26(3):171-80. PMID: 26951135

Senior authorStroke

Baratloo A, Forouzanfar MM, Hashemi B, et al.; Negida A. Tissue Plasminogen Activator: A Literature Review. Archives of Neuroscience (Impact Factor = 0.5). 2016;3(1). doi:10.5812/archneurosci.30452

Full record: Google Scholar · ORCID

Code & Tools

Cholinergic Imaging and EEG

PD-MCI Ch4 Subtyping Tool

Parkinsonism & Related Disorders, 2025

Imaging-based subtype tool for PD-MCI using cholinergic nucleus 4 (NBM) gray matter density. Helps identify patients with cholinergic vulnerability markers for treatment selection.

Paper → Online Tool → Ch4 Subtyper (open source) → Source on GitHub →

Ch4 Normative Calculator

Structural MRI · Research demonstrator

Converts an individual’s Ch4 gray-matter volume (CAT12, Julich-Brain Ch4) into a W-score relative to cognitively healthy adults of the same age, sex, and head size. Runs in the browser; research and educational use only.

Online Tool →

Negida-FE-Toolbox

EEG Analysis · Open Source

MATLAB toolbox for dominant frequency-based EEG feature extraction, released from the NIH R21 AG077469 study of cognitive fluctuations in Lewy body disease. Automated spectral analysis and biomarker pipelines for AD, LBD, and PD cohorts.

GitHub →

Disease Subtyping and Progression

PD Subtyping Tool

Mov Disord Clin Pract, 2026 · npj Parkinson's Disease, 2026

Clinical, pathological, and data-driven subtyping of Parkinson's disease. Disease-duration–specific percentiles (PPMI, N = 1,030) classify patients as diffuse-malignant, intermediate, or mild motor-predominant for real-time trial stratification.

Percentile Calculator → Online Tool → Percentiles paper → Milestones paper →

Neuroimaging Methods

Negida-DTI-ALPS

Diffusion MRI · Open Source

DTI-ALPS pipeline for perivascular (glymphatic) diffusivity that uses ANTs SyN and T1-based boundary-based registration to correct ROI misplacement under high head rotation. Validated against the reference alps.sh toolbox in 106 diffusion-MRI datasets (r = 0.96 for mean ALPS); MIT-licensed.

GitHub →

CNN-PD-3D

Deep Learning · Open Source

Convolutional neural network for automated Parkinson's Disease detection from structural 3D T1-weighted MRI. End-to-end pipeline from preprocessing to classification with interpretability visualization.

GitHub →

Vol-HD

Movement Disorders, 2024

Online calculator for predicting striatal volumes in Huntington's Disease patients using demographic and clinical variables, enabling pre-screening for clinical trials of intrastriatal gene therapies.

Paper → Online Tool →

Evidence Synthesis

Meta-Analysis Accelerator

BMC Medical Research Methodology, 2024 · 12,000+ Users

Comprehensive statistical conversion tool for systematic reviews with 21 conversion functions including median/IQR to mean/SD, SEM to SD, and CI to SD for one and two groups.

Online Tool →

Meta-analysis.io

Comprehensive Meta-Analysis Platform

Full-featured platform for meta-analyses with statistical analysis and visualization. Supports standard meta-analysis, DTA, meta-regression, subgroup analysis, and publication bias assessment.

Online Tool →

Invited Lectures and Presentations

Invited Lectures (Selected)

07/2025
PD-MCI with MRI Evidence of Cholinergic Nucleus 4 Degeneration: A New Subtype?
VCU Parkinson's Center Symposium, VA
08/2024
Using Advanced Data Models to Study Neurodegenerative Diseases
VCU Education Conference, VA
12/2023
T1 MRI Characteristics of Parkinson's Disease Dementia
VCU Education Conference, VA
05/2022
Disease Modification and Neuroprotection in Neurodegenerative Disorders
IBRO Neuroscience School, Tunisia
05/2022
Basic Mechanisms of Neurodegeneration: A Critical Update
IBRO Neuroscience School, Tunisia

Teaching and Mentorship

Mentorship Track Record

I have mentored 50+ junior researchers to first-author publications in peer-reviewed journals, using a model built around staged project scoping, weekly writing accountability, and graduated independence, and have supervised graduate and undergraduate students in neuroimaging analysis, machine learning, and systematic reviews.

Named mentees: Hazem Ghaith, MD (Postdoctoral Scholar, Department of Neurological Surgery, Oregon Health & Science University) and Hussien Abdelgawad, MD (Research Scientist, University of Arizona; Assistant Research Professor, Mayo Clinic Arizona). Further mentees have first-authored peer-reviewed papers across academic medical centers in Europe and the Middle East.

Negida Research Academy

Founded in 2014, Negida Research Academy is a global virtual training platform in clinical research methods: study design, biostatistics, systematic reviews, meta-analysis, scientific writing, and grant preparation. It runs two structured cohort-based training camps each year, each training approximately 1,200 researchers over 8–12 weeks. Author of the Negida Handbook of Clinical Research.

35,000+ total trainees  ·  20+ countries  ·  2,500+ active members

Visit Negida Academy →

Global Research Training

Most Academy trainees work in low- and middle-income countries in the Middle East, Africa, and South Asia. I developed the first neuroimaging analysis course in Arabic (MRI preprocessing, VBM, and fMRI with MATLAB/SPM12/CAT12), and in 2022 I provided free, specialized training to African medical students affected by the war in Ukraine; their work resulted in a peer-reviewed publication (PMID: 38087277). In the Global NeuroSurg Research Collaborative, investigators from low- and middle-income countries hold authorship and leadership roles.

Courses Developed & Prepared to Teach

  • Neuroscience: Systems neuroscience, cognitive neuroscience, neurodegenerative diseases
  • Neuroimaging and EEG Methods: Neuroimaging methods, EEG signal processing, multimodal data integration
  • Clinical Research Methods: Study design, biostatistics, systematic reviews, meta-analysis, clinical trials
  • Scientific Writing: Grant writing, manuscript preparation, peer review

Honors, Leadership, and Service

Honors and Awards

2025
IMPACT-AD Fellowship — Institute on Methods and Protocols for Advancement of Clinical Trials in ADRD (NIA / Alzheimer's Association)
2021
Sigma Xi Scientific Honor Society — Membership by nomination
2020
Best Paper Award — Asian Australasian Society of Stereotactic and Functional Neurosurgery
2017
EAN Young Investigators Award — European Academy of Neurology, 3rd Congress
2014–2026
International Travel Grants — MDS (2026, 2024, 2017), IAPRD (2026), EANS (2022, 2021), IBRO-ARC (2022, 2018), WSO (2020), WSSFN (2019), WPC (2019, 2016), EAN (2017), APAO (2017)

Media: the PD-MCI Ch4 subtype study was covered by Neurology Today (2024).

Research Network Leadership

Co-Founder & Global Research Lead Coordinator, Global NeuroSurg Research Collaborative, Oregon Health & Science University (2018–present). International network of 2,000+ investigators in 50+ countries; co-principal investigator, steering committee, and writing group of GNS-I, a prospective study of 2,165 patients with traumatic brain injury at 100 hospitals in 29 countries (Nature Medicine, 2026). Network PI: Ahmed M.T. Raslan, MD.

Regional Lead, North African Countries, Global PaedSurg Study, King's College London (2018–2020)

National Lead, Egypt, GlobalSurg-I Study, Royal College of Surgeons, London (2014–2015); 27 hospitals

Professional Service

Guidelines Development

Member, Education, Research, and Guidelines Development Committees, North American Neuromodulation Society (2023–present)

Member, European Association of Neurosurgical Societies Guidelines Committee

Lead Author, Global CHYSPR guidelines for spina bifida and hydrocephalus in low- and middle-income countries (chyspr.org), endorsed by 30+ global institutions

Grant Review

Ad hoc reviewer, VCU Parkinson's and Movement Disorders Center Internal Pilot Grants (2025)

Ad hoc reviewer, Wright Center for Clinical and Translational Research Pilot Grants (2025)

Editorial Service

Editorial Boards: Therapeutic Advances in Neurological Disorders; Frontiers in Neurology (Dementia, Neurodegenerative Diseases, Neurotrauma, Experimental Therapeutics); PLOS ONE; Current Neuropharmacology; Frontiers in Pain Research; Frontiers in Pediatrics; Medicine; Pain Research and Management

Ad-hoc Reviewer: Nature Scientific Reports, BMJ JNNP, BMC Neurology, BMC Public Health, Frontiers in Medicine/Neuroscience/Pharmacology, World Neurosurgery, and more (150+ verified reviews on Web of Science)

Conference Service

Session Chair, “Global Research Collaboratives,” XVII World Congress of Neurosurgery (WFNS), Bogotá, Colombia (2022)

Professional Memberships

International Parkinson and Movement Disorder Society · American Academy of Neurology · International Neuromodulation Society · North American Neuromodulation Society · Sigma Xi Scientific Honor Society · European Association of Neurosurgical Societies · WFNS Global Neurosurgery Committee (Secretariat)

Methods and Technical Skills

Structural MRI
T1-weighted (MPRAGE), T2-weighted, FLAIR; voxel-based morphometry, cortical thickness, ROI-based morphometry, white matter hyperintensity quantification
Diffusion MRI
Diffusion microstructure (Free Water, DKI, NODDI, multi-tissue multi-compartment and fixel-based analyses); DTI-ALPS; tract-based spatial statistics; tractography
Functional MRI
Resting-state and task-based (including the Psychomotor Vigilance Task)
Imaging software
SPM12, CAT12, FreeSurfer, FSL, ANTs, fMRIPrep, CONN, QSIPrep, MRtrix3, DSI Studio
EEG
EEGLAB (familiar with FieldTrip, MNE-Python, Brainstorm); resting-state and task-based paradigms; spectral power, functional connectivity, event-related potentials
Statistics
Generalized linear and mixed-effects models; survival analysis (Cox regression, competing risks, Kaplan–Meier); meta-analysis (standard, network, diagnostic test accuracy); propensity-score methods. With biostatisticians: Bayesian models, longitudinal trajectory modeling
Programming
Python and MATLAB

Additional Information

Certifications
CITI Program, Research Security (2026); American Board of Artificial Intelligence in Medicine (ABAIM) course and certification (2024); CITI Program, Responsible Conduct of Research, Stage 1 (2024)
Consulting
Methods and biostatistics consultant (2017–2025) for contract research organizations and pharmaceutical companies in the Middle East and North Africa: trial design, sample-size calculation, statistical analysis plans, and clinical study reports. Outside activities are disclosed and managed under institutional conflict-of-interest and outside-activity policies
Languages
English (fluent), Arabic (native), French (intermediate)