Bocci Tommaso, Ferrara Rosanna, Albizzati Tommaso, Averna Alberto, Guidetti Matteo, Marceglia Sara, Priori Alberto
'Aldo Ravelli' Research Center for Neurotechnology and Experimental Neurotherapeutics, Department of Health Sciences, University of Milan, 20142 Milan, Italy.
III Neurology Clinic, ASST-Santi Paolo e Carlo University Hospital, 20142 Milan, Italy.
Brain Commun. 2024 Jun 11;6(3):fcae201. doi: 10.1093/braincomms/fcae201. eCollection 2024.
The role of brain asymmetries of dopaminergic neurons in motor symptoms of Parkinson's disease is still undefined. Local field recordings from the subthalamic nucleus revealed some neurophysiological biomarkers of the disease: increased beta activity, increased low-frequency activity and high-frequency oscillations. Phase-amplitude coupling coordinates the timing of neuronal activity and allows determining the mechanism for communication within distinct regions of the brain. In this study, we discuss the use of phase-amplitude coupling to assess the differences between the two hemispheres in a cohort of 24 patients with Parkinson's disease before and after levodopa administration. Subthalamic low- (12-20 Hz) and high-beta (20-30 Hz) oscillations were compared with low- (30-45 Hz), medium- (70-100 Hz) and high-frequency (260-360 Hz) bands. We found a significant beta-phase-amplitude coupling asymmetry between left and right and an opposite-side-dependent effect of the pharmacological treatment, which is associated with the reduction of motor symptoms. In particular, high coupling between high frequencies and high-beta oscillations was found during the OFF condition ( < 0.01) and a low coupling during the ON state ( < 0.0001) when the right subthalamus was assessed; exactly the opposite happened when the left subthalamus was considered in the analysis, showing a lower coupling between high frequencies and high-beta oscillations during the OFF condition ( < 0.01), followed by a higher one during the ON state ( < 0.01). Interestingly, these asymmetries are independent of the motor onset side, either left or right. These findings have important implications for neural signals that may be used to trigger adaptive deep brain stimulation in Parkinson's and could provide more exhaustive insights into subthalamic dynamics.
多巴胺能神经元的脑不对称性在帕金森病运动症状中的作用仍不明确。来自丘脑底核的局部场记录揭示了该疾病的一些神经生理生物标志物：β活动增加、低频活动增加和高频振荡。相位-振幅耦合协调神经元活动的时间，并有助于确定大脑不同区域之间的通信机制。在本研究中，我们讨论了使用相位-振幅耦合来评估24例帕金森病患者在左旋多巴给药前后两个半球之间的差异。将丘脑底核的低（12 - 20Hz）和高β（20 - 30Hz）振荡与低（30 - 45Hz）、中（70 - 100Hz）和高频（260 - 360Hz）频段进行比较。我们发现左右两侧之间存在显著的β相位-振幅耦合不对称，以及药物治疗的对侧依赖性效应，这与运动症状的减轻有关。具体而言，在评估右侧丘脑底核时，发现关期（<0.01）高频与高β振荡之间的耦合较高，而开期（<0.0001）耦合较低；当分析左侧丘脑底核时情况正好相反，即关期（<0.01）高频与高β振荡之间的耦合较低，随后开期（<0.01）耦合较高。有趣的是，这些不对称性与运动起始侧（左侧或右侧）无关。这些发现对于可用于触发帕金森病适应性深部脑刺激的神经信号具有重要意义，并可为丘脑底核动力学提供更详尽的见解。
