New Brain Imaging Techniques Illuminate Variability in Parkinson's Treatment

Recent advancements in brain imaging have unveiled critical insights into why patients with Parkinson's disease exhibit varying responses to levodopa, the cornerstone of dopamine replacement therapy. A collaborative study led by researchers from Simon Fraser University (SFU) and the Karolinska Institute in Sweden has utilized magnetoencephalography (MEG) to analyze brain activity in Parkinson's patients, revealing previously unrecognized 'off-target' effects of the medication.

Parkinson's disease, the second most prevalent neurodegenerative disorder globally, is characterized by the progressive degeneration of dopamine-producing neurons in the substantia nigra, leading to symptoms such as tremors, stiffness, and balance issues. According to Dr. Alex Wiesman, Assistant Professor of Biomedical Physiology and Kinesiology at SFU, understanding the variability in treatment response is essential for developing personalized treatment plans. "Treating this disease, both in terms of helping people with their symptoms and trying to find ways to reverse the effects, is becoming more crucial," stated Dr. Wiesman in a press release dated June 30, 2025.

The study, published in the journal *Movement Disorders*, involved 17 patients with Parkinson's disease. Researchers employed MEG, a sophisticated non-invasive technology that measures the magnetic fields generated by neural electrical activity, to observe brain signals before and after administering levodopa. Dr. Wiesman emphasized that this method allows for real-time tracking of drug effects on specific brain regions, thereby facilitating more tailored therapeutic approaches.

"What we found was that there are 'off-target' effects of the drug, meaning it sometimes activates brain regions that may hinder its beneficial impacts," Dr. Wiesman explained. This discovery could potentially lead to adjustments in medication types and dosages based on individual brain activity patterns, enhancing treatment efficacy.

The implications of this research extend beyond Parkinson's disease. The MEG analysis developed by the SFU team can be utilized for studying the effects of various medications that impact brain signaling. The SFU’s ImageTech Lab, which houses the only MEG in Western Canada, is at the forefront of this innovative research approach. Dr. Wiesman noted, "We can use this technology moving forward to study Parkinson’s disease in ways that have never been done before worldwide."

The next phase of research aims to apply this technique to a larger cohort of patients and to develop more accessible imaging methods, such as electroencephalography (EEG). Dr. Wiesman concluded, "Ultimately, we want to ensure this technology is useful for a diverse population and more widely accessible to patients with Parkinson’s disease."

This study not only underscores the potential for personalized medicine in treating neurodegenerative disorders but also highlights the importance of continued innovation and research in understanding complex brain conditions. As the field progresses, the hope is to refine treatment strategies that maximize therapeutic benefits for each individual patient.

### References - Wiesman AI, Vinding MC, Tsitsi P, Svenningsson P, Waldthaler J, Lundqvist D. Cortical effects of dopamine replacement account for clinical response variability in Parkinson’s disease. *Mov Disord*. 2025. doi: 10.1002/mds.30200. - Simon Fraser University Press Release, June 30, 2025. - Movement Disorders Journal, 2025.