Longitudinal changes in motor network activity and connectivity in patients with suspected Transcient Ischemic Attack: an exploratory fMRI study
- 1Universite Marie et Louis Pasteur, INSERM, UMR 1322 LINC, F-25000 Besancon, France
Abstract
Background and ObjectivesTransient ischemic attack (TIA) diagnosis is challenging because it relies mainly on clinical assessment and exclusion of common differential. Functional MRI (fMRI) may provide a diagnostic biomarker by detecting transient brain dysfunction not visible on conventional imaging. This pilot study aimed to characterize acute motor-task BOLD activation in patients with suspected DWI-negative TIA and compare functional patterns between confirmed TIA and alternative diagnoses. Secondary objectives were to assess longitudinal changes in activation and connectivity at 3 months.
MethodsIn this prospective single-center study, adults presenting within 24 h of transient anterior-circulation neurological symptoms underwent conventional MRI and additional motor-task fMRI. Patients with acute DWI lesions were excluded. Final diagnosis was established after 3-month follow-up. Whole-brain analyses, individualized motor cortex region-of-interest (ROI) analyses, and generalized psychophysiological interaction (gPPI) connectivity analyses were performed during the acute phase and at 3 months.
ResultsEight patients were enrolled; six had complete longitudinal imaging data and were included in the final analyses. Final diagnoses were TIA (n=2), migraine aura (n=2), functional neurological disorder (n=1), and hypoglycemia (n=1). Whole-brain and ROI analyses showed reduced bilateral motor-related BOLD responses during the acute phase in both TIA patients and in the patient with hypoglycemia. In contrast, patients with migraine and functional neurological disorder exhibited less marked longitudinal changes. In TIA patients, motor cortex activation increased at 3 months, tending to normalize toward values observed in non-TIA participants. Connectivity analyses revealed heterogeneous patterns, but the 2 TIA patients demonstrated increased longitudinal connectivity between the motor cortex contralateral to symptoms and other sensorimotor regions, including supplementary motor, premotor, parietal, and postcentral cortices.
DiscussionThese preliminary findings suggest that TIA may be associated with transient bilateral reductions in motor-network activity. Functional abnormalities appeared to improve over time, supporting the hypothesis of reversible network dysfunction. Although limited by the very small sample size, this study provides the first longitudinal assessment of emergency task-based fMRI in rigorously defined TIA and supports further investigation of acute functional MRI as a potential biomarker of transient cerebral dysfunction.
Related
- Prehospital qSOFA Is Associated with 30-Day Mortality Within Emergency Department Triage Strata in Ambulance-Transported Adults with Suspected Infection: An Exploratory Three-Year Retrospective Cohort Study
- Genotypes and Longitudinal Change in the Cardiac Function in Patients with Suspected Idiopathic Cardiomyopathy
- Longitudinal quantitative streamline tractography: Robust estimation of white matter connectivity differences.
- Effectiveness of physical activity and sedentary behaviour interventions delivered following cancer screening or suspected cancer referral: a systematic review and meta-analysis protocol
- Case Report: BARD1 p.Val507Met in two relatives with ER-positive breast cancer: cascade testing and exploratory longitudinal cfDNA dynamics
BibTeX
@misc{charbonnier2026longitudinal,
title = {{Longitudinal changes in motor network activity and connectivity in patients with suspected Transcient Ischemic Attack: an exploratory fMRI study}},
author = {G. Charbonnier and L. Bonnet and A. Comte and E. Medeiros de Bustos and M. Lesourd},
howpublished = {medRxiv},
year = {2026},
month = oct,
doi = {10.64898/2026.10.13.26365278},
url = {https://www.medrxiv.org/content/10.64898/2026.10.13.26365278v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Longitudinal changes in motor network activity and connectivity in patients with suspected Transcient Ischemic Attack: an exploratory fMRI study
AU - G. Charbonnier
AU - L. Bonnet
AU - A. Comte
AU - E. Medeiros de Bustos
AU - M. Lesourd
PY - 2026
DA - 2026/10/13
PB - medRxiv
DO - 10.64898/2026.10.13.26365278
UR - https://www.medrxiv.org/content/10.64898/2026.10.13.26365278v1
AB - Background and ObjectivesTransient ischemic attack (TIA) diagnosis is challenging because it relies mainly on clinical assessment and exclusion of common differential. Functional MRI (fMRI) may provide a diagnostic biomarker by detecting transient brain dysfunction not visible on conventional imaging. This pilot study aimed to characterize acute motor-task BOLD activation in patients with suspected DWI-negative TIA and compare functional patterns between confirmed TIA and alternative diagnoses. Secondary objectives were to assess longitudinal changes in activation and connectivity at 3 months. MethodsIn this prospective single-center study, adults presenting within 24 h of transient anterior-circulation neurological symptoms underwent conventional MRI and additional motor-task fMRI. Patients with acute DWI lesions were excluded. Final diagnosis was established after 3-month follow-up. Whole-brain analyses, individualized motor cortex region-of-interest (ROI) analyses, and generalized psychophysiological interaction (gPPI) connectivity analyses were performed during the acute phase and at 3 months. ResultsEight patients were enrolled; six had complete longitudinal imaging data and were included in the final analyses. Final diagnoses were TIA (n=2), migraine aura (n=2), functional neurological disorder (n=1), and hypoglycemia (n=1). Whole-brain and ROI analyses showed reduced bilateral motor-related BOLD responses during the acute phase in both TIA patients and in the patient with hypoglycemia. In contrast, patients with migraine and functional neurological disorder exhibited less marked longitudinal changes. In TIA patients, motor cortex activation increased at 3 months, tending to normalize toward values observed in non-TIA participants. Connectivity analyses revealed heterogeneous patterns, but the 2 TIA patients demonstrated increased longitudinal connectivity between the motor cortex contralateral to symptoms and other sensorimotor regions, including supplementary motor, premotor, parietal, and postcentral cortices. DiscussionThese preliminary findings suggest that TIA may be associated with transient bilateral reductions in motor-network activity. Functional abnormalities appeared to improve over time, supporting the hypothesis of reversible network dysfunction. Although limited by the very small sample size, this study provides the first longitudinal assessment of emergency task-based fMRI in rigorously defined TIA and supports further investigation of acute functional MRI as a potential biomarker of transient cerebral dysfunction.
ER -