P3.07. GUT–BRAIN AXIS MODULATION OF SYMPTOMS IN EARLY PARKINSON’S DISEASE: EVIDENCE FROM A PILOT STUDY
Karolina Lorek1, Katarzyna Markowska2, Andrzej Bereza2, Sławomir Budrewicz2, Ewa Koziorowska-Gawron2, Karolina Stankowska1, Tomasz Ściepuro1, Jarosław Marusiak1
1 Wroclaw University of Health and Sport Sciences, Faculty of Physiotherapy, Department of Physiotherapy in Movement System Dysfunctions and Kinesiology
2 Wroclaw Medical University, Department of Neurology
INTRODUCTION: Growing evidence indicates that gastrointestinal (GI) dysfunction in Parkinson’s disease (PD) can impact central nervous system function through the microbiota–gut–brain axis. However, the underlying mechanisms remain poorly understood.
AIM(S): To investigate whether GI symptoms in early PD are associated with changes in cortical activity, and whether this activity mediates the manifestation of PD symptoms.
METHOD(S): We examined 28 patients with early PD. GI symptoms were assessed using the Polish version of the Gastrointestinal Symptom Rating Scale (GSRS), clinical severity with the Unified Parkinson’s Disease Rating Scale (UPDRS), and resting cortical bioelectrical activity using electroencephalography (EEG) with source analysis (eLORETA).
RESULTS: Source analysis revealed a significant negative correlation (r = – 0.42, p < 0.05) between GI symptom severity and alpha-band (8–12 Hz) activity, with the source localized in the bilateral occipital cortex (Brodmann Areas 17 and 18), as well as the posterior parietal cortex (BA 7). Mediation analysis of the relationship between GI symptoms (GSRS) and PD symptoms (UPDRS), with cortical activity (EEG in alpha bands) as the mediator, indicated distinct pathways: EEG activity significantly mediated the associations between GI symptoms and non-motor features such as speech disturbances (p = 0.021) and daytime sleepiness (p = 0.019). In contrast, motor symptoms like freezing of gait showed a direct relationship with GI severity (p < 0.001), suggesting separate pathophysiological mechanisms.
CONCLUSIONS: Our findings suggest that GI dysfunction may influence resting-state cortical activity in early PD. This relationship may modulate distinct pathophysiological pathways, contributing to different symptom manifestations via the gut–brain axis.
FINANCIAL SUPPORT: Internal grant awarded by the University School of Physical Education in Wrocław in 2024, titled: "Does interval training on a cycle ergometer affect gut microbiota, gut-brain axis mechanisms, brain bioelectrical activity, and psychomotor functions in patients with Parkinson's disease?"