scholarly journals Deep brain stimulation in the subthalamic nucleus for Parkinson's disease can restore dynamics of striatal networks

2021 ◽  
Author(s):  
Elie M Adam ◽  
Emery N. Brown ◽  
Nancy Kopell ◽  
Michelle M McCarthy
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Deep Brain Stimulation ◽  
Subthalamic Nucleus ◽  
Brain Stimulation ◽  
Gamma Oscillations ◽  
Medium Spiny Neuron ◽  
Beta Oscillations ◽  
Movement Disability ◽  
Deep Brain

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is highly effective in alleviating movement disability in patients with Parkinson's disease (PD). However, its therapeutic mechanism of action is unknown. The healthy striatum exhibits rich dynamics resulting from an interaction of beta, gamma and theta oscillations. These rhythms are at the heart of selection, initiation and execution of motor programs, and their loss or exaggeration due to dopamine (DA) depletion in PD is a major source of the behavioral deficits observed in PD patients. Interrupting abnormal rhythms and restoring the interaction of rhythms as observed in the healthy striatum may then be instrumental in the therapeutic action of DBS. We develop a biophysical networked model of a BG pathway to study how abnormal beta oscillations can emerge throughout the BG in PD, and how DBS can restore normal beta, gamma and theta striatal rhythms. Our model incorporates STN projections to the striatum, long known but understudied, that were recently shown to preferentially target fast spiking interneurons (FSI) in the striatum. We find that DBS in STN is able to normalize striatal medium spiny neuron (MSN) activity by recruiting FSI dynamics, and restoring the inhibitory potency of FSIs observed in normal condition. We also find that DBS allows the re-expression of gamma and theta rhythms, thought to be dependent on high DA levels and thus lost in PD, through cortical noise control. Our study shows how BG connectivity can amplify beta oscillations, and delineates the role of DBS in disrupting beta oscillations and providing corrective input to STN efferents to restore healthy striatal dynamics. It also suggests how gamma oscillations can be leveraged to enhance or supplement DBS treatment and improve its effectiveness.

scholarly journals Cross-frequency coupling between gamma oscillations and deep brain stimulation frequency in Parkinson’s disease

Brain ◽  
2020 ◽  
Vol 143 (11) ◽  
pp. 3393-3407
Author(s):  
Muthuraman Muthuraman ◽  
Manuel Bange ◽  
Nabin Koirala ◽  
Dumitru Ciolac ◽  
Bogdan Pintea ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Deep Brain Stimulation ◽  
Subthalamic Nucleus ◽  
Brain Stimulation ◽  
Gamma Oscillations ◽  
Stimulation Frequency ◽  
Frequency Coupling ◽  
Cross Frequency Coupling ◽  
Deep Brain

Abstract The disruption of pathologically enhanced beta oscillations is considered one of the key mechanisms mediating the clinical effects of deep brain stimulation on motor symptoms in Parkinson’s disease. However, a specific modulation of other distinct physiological or pathological oscillatory activities could also play an important role in symptom control and motor function recovery during deep brain stimulation. Finely tuned gamma oscillations have been suggested to be prokinetic in nature, facilitating the preferential processing of physiological neural activity. In this study, we postulate that clinically effective high-frequency stimulation of the subthalamic nucleus imposes cross-frequency interactions with gamma oscillations in a cortico-subcortical network of interconnected regions and normalizes the balance between beta and gamma oscillations. To this end we acquired resting state high-density (256 channels) EEG from 31 patients with Parkinson’s disease who underwent deep brain stimulation to compare spectral power and power-to-power cross-frequency coupling using a beamformer algorithm for coherent sources. To show that modulations exclusively relate to stimulation frequencies that alleviate motor symptoms, two clinically ineffective frequencies were tested as control conditions. We observed a robust reduction of beta and increase of gamma power, attested in the regions of a cortical (motor cortex, supplementary motor area, premotor cortex) and subcortical network (subthalamic nucleus and cerebellum). Additionally, we found a clear cross-frequency coupling of narrowband gamma frequencies to the stimulation frequency in all of these nodes, which negatively correlated with motor impairment. No such dynamics were revealed within the control posterior parietal cortex region. Furthermore, deep brain stimulation at clinically ineffective frequencies did not alter the source power spectra or cross-frequency coupling in any region. These findings demonstrate that clinically effective deep brain stimulation of the subthalamic nucleus differentially modifies different oscillatory activities in a widespread network of cortical and subcortical regions. Particularly the cross-frequency interactions between finely tuned gamma oscillations and the stimulation frequency may suggest an entrainment mechanism that could promote dynamic neural processing underlying motor symptom alleviation.

scholarly journals Average beta burst duration profiles provide a signature of dynamical changes between the ON and OFF medication states in Parkinson’s disease

2021 ◽  
Vol 17 (7) ◽  
pp. e1009116
Author(s):  
Benoit Duchet ◽  
Filippo Ghezzi ◽  
Gihan Weerasinghe ◽  
Gerd Tinkhauser ◽  
Andrea A. Kühn ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Deep Brain Stimulation ◽  
Subthalamic Nucleus ◽  
Brain Stimulation ◽  
Motor Impairment ◽  
Burst Duration ◽  
Motor Symptoms ◽  
Beta Oscillations ◽  
Deep Brain

Parkinson’s disease motor symptoms are associated with an increase in subthalamic nucleus beta band oscillatory power. However, these oscillations are phasic, and there is a growing body of evidence suggesting that beta burst duration may be of critical importance to motor symptoms. This makes insights into the dynamics of beta bursting generation valuable, in particular to refine closed-loop deep brain stimulation in Parkinson’s disease. In this study, we ask the question “Can average burst duration reveal how dynamics change between the ON and OFF medication states?”. Our analysis of local field potentials from the subthalamic nucleus demonstrates using linear surrogates that the system generating beta oscillations is more likely to act in a non-linear regime OFF medication and that the change in a non-linearity measure is correlated with motor impairment. In addition, we pinpoint the simplest dynamical changes that could be responsible for changes in the temporal patterning of beta oscillations between medication states by fitting to data biologically inspired models, and simpler beta envelope models. Finally, we show that the non-linearity can be directly extracted from average burst duration profiles under the assumption of constant noise in envelope models. This reveals that average burst duration profiles provide a window into burst dynamics, which may underlie the success of burst duration as a biomarker. In summary, we demonstrate a relationship between average burst duration profiles, dynamics of the system generating beta oscillations, and motor impairment, which puts us in a better position to understand the pathology and improve therapies such as deep brain stimulation.

Coronal Gradient Echo MRI to Visualize the Zona Incerta for Deep Brain Stimulation Targeting in Parkinson’s Disease

2021 ◽  
pp. 1-8
Author(s):  
Ashesh A. Thaker ◽  
Kartik M. Reddy ◽  
John A. Thompson ◽  
Pamela David Gerecht ◽  
Mark S. Brown ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Deep Brain Stimulation ◽  
Subthalamic Nucleus ◽  
Brain Stimulation ◽  
Regions Of Interest ◽  
Zona Incerta ◽  
Gradient Echo ◽  
Noise Ratio ◽  
Deep Brain

<b><i>Introduction:</i></b> Deep brain stimulation of the zona incerta is effective at treating tremor and other forms of parkinsonism. However, the structure is not well visualized with standard MRI protocols making direct surgical targeting unfeasible and contributing to inconsistent clinical outcomes. In this study, we applied coronal gradient echo MRI to directly visualize the rostral zona incerta in Parkinson’s disease patients to improve targeting for deep brain stimulation. <b><i>Methods:</i></b> We conducted a prospective study to optimize and evaluate an MRI sequence to visualize the rostral zona incerta in patients with Parkinson’s disease (<i>n</i> = 31) and other movement disorders (<i>n</i> = 13). We performed a contrast-to-noise ratio analysis of specific regions of interest to quantitatively assess visual discrimination of relevant deep brain structures in the optimized MRI sequence. Regions of interest were independently assessed by 2 neuroradiologists, and interrater reliability was assessed. <b><i>Results:</i></b> Rostral zona incerta and subthalamic nucleus were well delineated in our 5.5-min MRI sequence, indicated by excellent interrater agreement between neuroradiologists for region-of-interest measurements (&#x3e;0.90 intraclass coefficient). Mean contrast-to-noise ratio was high for both rostral zona incerta (6.39 ± 3.37) and subthalamic nucleus (17.27 ± 5.61) relative to adjacent white matter. There was no significant difference between mean signal intensities or contrast-to-noise ratio for Parkinson’s and non-Parkinson’s patients for either structure. <b><i>Discussion/Conclusion:</i></b> Our optimized coronal gradient echo MRI sequence delineates subcortical structures relevant to traditional and novel deep brain stimulation targets, including the zona incerta, with high contrast-to-noise. Future studies will prospectively apply this sequence to surgical planning and postimplantation outcomes.

scholarly journals Electrode Location in a Microelectrode Recording-Based Model of the Subthalamic Nucleus Can Predict Motor Improvement After Deep Brain Stimulation for Parkinson’s Disease

2019 ◽  
Vol 9 (3) ◽  
pp. 51 ◽  
Author(s):  
Rens Verhagen ◽  
Lo Bour ◽  
Vincent Odekerken ◽  
Pepijn van den Munckhof ◽  
P. Schuurman ◽  
...  
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Deep Brain Stimulation ◽  
Subthalamic Nucleus ◽  
Brain Stimulation ◽  
Anatomical Variation ◽  
Patient Specific ◽  
One Year ◽  
Motor Improvement ◽  
Deep Brain

Motor improvement after deep brain stimulation (DBS) in the subthalamic nucleus (STN) may vary substantially between Parkinson’s disease (PD) patients. Research into the relation between improvement and active contact location requires a correction for anatomical variation. We studied the relation between active contact location relative to the neurophysiological STN, estimated by the intraoperative microelectrode recordings (MER-based STN), and contralateral motor improvement after one year. A generic STN shape was transformed to fit onto the stereotactically defined MER sites. The location of 43 electrodes (26 patients), derived from MRI-fused CT images, was expressed relative to this patient-specific MER-based STN. Using regression analyses, the relation between contact location and motor improvement was studied. The regression model that predicts motor improvement based on levodopa effect alone was significantly improved by adding the one-year active contact coordinates (R2 change = 0.176, p = 0.014). In the combined prediction model (adjusted R2 = 0.389, p < 0.001), the largest contribution was made by the mediolateral location of the active contact (standardized beta = 0.490, p = 0.002). With the MER-based STN as a reference, we were able to find a significant relation between active contact location and motor improvement. MER-based STN modeling can be used to complement imaging-based STN models in the application of DBS.

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