TMS-evoked potentials unveil occipital network involvement in patients diagnosed with Parkinson's disease within 5 years of inclusion

Summary

This study looked at whether network responses to magnetic stimulation can help distinguish subgroups of patients with Parkinson's disease (PD). TMS-evoked potentials (TEPs) from three brain networks were compared between patients diagnosed within the previous five years and healthy controls of similar age.

Study design

• Participants: 62 patients with PD (age 69.9 ± 7.5) and 76 healthy controls (age 69.2 ± 4.3).
• Stimulation sites: bilateral primary motor cortex (M1), dorsolateral prefrontal cortex (DLPFC) and visual cortex (V1).
• Patients were divided into tremor-dominant (TD), non-tremor-dominant (NTD) and rapid disease progression (RDP) subgroups.
• Analysis: two-way ANCOVA adjusted for MoCA score.

Key findings

• Patients with PD showed lower wide-waveform adherence (p = 0.025) and lower interhemispheric connectivity (p < 0.001) than healthy controls.
• Lower occipital interhemispheric connectivity correlated with a more advanced disease stage (r = −0.37, p = 0.0039).
• The RDP and NTD subgroups showed lower wide-waveform adherence in response to occipital stimulation than the TD subgroup (p = 0.005).
• Occipital TEP measures identified RDP patients with 85% accuracy.

Authors' conclusions

The authors conclude that the findings show occipital network involvement in early stages of PD and suggest that TEP measures may offer insight into the altered networks of PD subgroups.

Read the full article

Zifman N, Levy-Lamdan O, Hiller T, Thaler A, Dolev I, Mirelman A, Fogel H, Hallett M, Maidan I. TMS-evoked potentials unveil occipital network involvement in patients diagnosed with Parkinson's disease within 5 years of inclusion. npj Parkinson's Disease. 2024;10:182. doi:10.1038/s41531-024-00793-0

Summary prepared by QuantalX from the published abstract. All results are as reported by the authors. The full text is available from the publisher.