Yashar Rahimpour

All Publications

• DTI-Derived Evaluation of Glymphatic System Function in Veterans with Chronic Multisymptom Illness. AJNR. American journal of neuroradiology Zhang, Y., Moore, M. S., Rahimpour, Y., Clark, J. D., Bayley, P. J., Ashford, J. W., Furst, A. J. 2025

  Abstract

  Chronic Multisymptom Illness includes symptoms of fatigue, pain, sleep difficulties, as well as neurological, respiratory, and gastrointestinal problems and is particularly common in veterans from the 1990-91 Gulf War and the Afghanistan and Iraq Wars. Glymphatic system function may play an important role in the etiopathology of Chronic Multisymptom Illness but has not been addressed. DTI-derived analysis along the perivascular space provides a promising proxy for glymphatic system function by evaluating the status of perivascular space fluid flow. The objective of this study was to compare this DTI-derived glymphatic index in veterans with CMI and healthy controls, and to reveal possible correlations between this index and the severity of CMI symptoms.DTI-derived indices were extracted from imaging data of 203 veterans who met clinical diagnostic criteria for Chronic Multisymptom Illness, and 224 age-matched healthy control subjects from multiple public research databases. Severity of Chronic Multisymptom Illness, sleep difficulty, pain intensity, and the degree of chronic fatigue were based on self-report measures. MRI scanner and site variations were harmonized. Statistical analyses were performed adjusting for demographic confounding factors.Both healthy controls and veterans showed significantly reduced glymphatic indices associated with increased age. Compared to controls, veterans showed bilaterally lower indices (Cohen's d = -.47; p < .001) after adjusting for age, sex, and education. Across the entire sample of veterans, negative correlations were observed between glymphatic indices and pain intensities (r = -.17; p = .01), sleep disturbances (r = -.17; p = .02), degree of fatigue (r = -.20; p = .006), severity of Chronic Multisymptom Illness (r = -.17; p = .02), and the indices were positively correlated with medullar volumes (r = -.19; p = .007). Note, these results showing significant outcomes for a group of patients do not guarantee the same outcome for individual patients.This study suggests that impaired glymphatic functions are strongly associated with Chronic Multisymptom Illness. These findings improve our understanding of the pathological mechanism underlying Chronic Multisymptom Illness and point to DTI-based metrics as a potential biomarker for disease severity in this condition.CMI＝ Chronic multisymptom illness; GWI＝ Gulf War Illness; PVS＝ perivascular space; DTI-ALPS＝ DTI-analysis along the perivascular space; HC＝ healthy control; TBI＝ traumatic brain injury; PTSD＝ post-traumatic stress disorder; PSQI＝ Pittsburgh sleep quality index; BPI＝ brief pain inventory; CFS＝ chronic fatigue syndrome.

  View details for DOI 10.3174/ajnr.A8901

  View details for PubMedID 40579044

• Association of Loneliness with Functional Connectivity MRI, Amyloid-β PET, and Tau PET Neuroimaging Markers of Vulnerability for Alzheimer's Disease. Journal of Alzheimer's disease : JAD Zhao, A., Balcer, L. J., Himali, J. J., O'Donnell, A., Rahimpour, Y., DeCarli, C., Gonzales, M. M., Aparicio, H. J., Ramos-Cejudo, J., Kenney, R., Beiser, A., Seshadri, S., Salinas, J. 2024; 99 (4): 1473-1484

  Abstract

  Loneliness has been declared an "epidemic" associated with negative physical, mental, and cognitive health outcomes such as increased dementia risk. Less is known about the relationship between loneliness and advanced neuroimaging correlates of Alzheimer's disease (AD).To assess whether loneliness was associated with advanced neuroimaging markers of AD using neuroimaging data from Framingham Heart Study (FHS) participants without dementia.In this cross-sectional observational analysis, we used functional connectivity MRI (fcMRI), amyloid-β (Aβ) PET, and tau PET imaging data collected between 2016 and 2019 on eligible FHS cohort participants. Loneliness was defined as feeling lonely at least one day in the past week. The primary fcMRI marker was Default Mode Network intra-network connectivity. The primary PET imaging markers were Aβ deposition in precuneal and FLR (frontal, lateral parietal and lateral temporal, retrosplenial) regions, and tau deposition in the amygdala, entorhinal, and rhinal regions.Of 381 participants (mean age 58 [SD 10]) who met inclusion criteria for fcMRI analysis, 5% were classified as lonely (17/381). No association was observed between loneliness status and network changes. Of 424 participants (mean age 58 [SD = 10]) meeting inclusion criteria for PET analyses, 5% (21/424) were lonely; no associations were observed between loneliness and either Aβ or tau deposition in primary regions of interest.In this cross-sectional study, there were no observable associations between loneliness and select fcMRI, Aβ PET, and tau PET neuroimaging markers of AD risk. These findings merit further investigation in prospective studies of community-based cohorts.

  View details for DOI 10.3233/JAD-231425

  View details for PubMedID 38820017

  View details for PubMedCentralID PMC11191473

• White matter signal abnormalities in former National Football League players. Alzheimer's & dementia (Amsterdam, Netherlands) Alosco, M. L., Koerte, I. K., Tripodis, Y., Mariani, M., Chua, A. S., Jarnagin, J., Rahimpour, Y., Puzo, C., Healy, R. C., Martin, B., Chaisson, C. E., Cantu, R. C., Au, R., McClean, M., McKee, A. C., Lin, A. P., Shenton, M. E., Killiany, R. J., Stern, R. A. 2018; 10: 56-65

  Abstract

  Later-life brain alterations in former tackle football players are poorly understood, particularly regarding their relationship with repetitive head impacts (RHIs) and clinical function. We examined white matter signal abnormalities (WMSAs) and their association with RHIs and clinical function in former National Football League (NFL) players.Eighty-six clinically symptomatic former NFL players and 23 same-age reportedly asymptomatic controls without head trauma exposure underwent magnetic resonance imaging and neuropsychological testing. FreeSurfer calculated WMSAs. A cumulative head impact index quantified RHIs.In former NFL players, increased volume of WMSAs was associated with higher cumulative head impact index scores (P = .043) and worse psychomotor speed and executive function (P = .015). Although former NFL players had greater WMSA volume than controls (P = .046), these findings are inconclusive due to recruitment of controls based on lack of clinical symptoms and head trauma exposure.In former NFL players, WMSAs may reflect long-term microvascular and nonmicrovascular pathologies from RHIs that negatively impact cognition.

  View details for DOI 10.1016/j.dadm.2017.10.003

  View details for PubMedID 29201991

  View details for PubMedCentralID PMC5699890