scholarly journals The Effect of Deep Brain Stimulation on High Frequency Oscillations in a Chronic Epilepsy Model

2020 ◽  
Vol 93 (2) ◽  
pp. 63-70
Author(s):  
Mihály István ◽  
Bod Réka-Barbara ◽  
Orbán-Kis Károly ◽  
Berki Ádám-József ◽  
Szilágyi Tibor

Abstract Temporal lobe epilepsy (TLE) is a severe neurological disease which is often pharmacoresistant. Deep brain stimulation (DBS) is a novel method for treating epilepsy; however, its mechanism of action is not fully understood. We aimed to study the effect of amygdala DBS in the pilocarpine model of TLE. Status epilepticus was induced by pilocarpine in male Wistar rats, and spontaneous seizures occurred after a latency period. A stimulating electrode was inserted into the left basolateral amygdala and two recording electrodes into the left and right hippocampus. A stimulus package consisted of 0.1 ms-long biphasic pulses applied regularly at 4 Hz for 50 seconds. This package was repeated four times a day, with 5-minute pauses, for 10 days. We also used an age-matched healthy control group of stimulated animals and another one of sham-operated rats. From the hippocampal local field potentials high frequency oscillations (HFOs) were analyzed as these are promising epilepsy biomarkers. HFOs are short oscillatory events between 80-600 Hz which were detected offline using an open-source application of MATLAB, the RIPPLELAB system. We found that the HFO rate was significantly higher in pilocarpine-treated rats compared to the control groups (0.41 ± 0.14 HFO/min vs. 0.006 ± 0.003 in the stimulated control group and no HFO in the sham-operated group). In the pilocarpine group an instantaneous decrease in HFO rate was observed while the stimulation was on (0.44 ± 0.15 HFO/min vs 0.07 ± 0.03 HFO/min, p=0.017). The effect was short-lived because the frequency of HFOs did not change significantly in the time windows between stimulus packages or during the ten-day stimulation period. The difference of HFO rates between epileptic and control groups could be used in the electrographic assessment of epilepsy. The decreased frequency of HFOs during stimulation may be useful to study the efficacy of DBS.

Author(s):  
Gusta van Zwieten ◽  
Mark J. Roberts ◽  
Frédéric LVW Schaper ◽  
Jasper V Smit ◽  
Yasin Temel ◽  
...  

The thalamic medial geniculate body (MGB) is uniquely positioned within the neural tinnitus networks. Deep brain stimulation (DBS) of the MGB has been proposed as a possible novel treatment for tinnitus, yet mechanisms remain elusive. The aim of this study was to characterize neurophysiologic hallmarks in the MGB after noise-exposure and to assess the neurophysiological effects of electrical stimulation of the MGB. Fourteen male Sprague Dawley rats were included. Nine subjects were unilaterally exposed to a 16 kHz octave-band noise at 115 dB for 90 minutes, five received sham exposure. Single units were recorded from the contralateral MGB where spontaneous firing, coefficient of variation, response type, rate-level functions and thresholds were determined. Local field potentials and electroencephalographical (EEG) recordings were performed before and after high frequency DBS of the MGB. Thalamocortical synchronization and power were analyzed. In total, 214 single units were identified (n = 145 in noise-exposed group, n = 69 in control group). After noise-exposure, fast-responding neurons become less- or non-responsive without change to their spontaneous rate, while sustained and suppressed type neurons exhibit enhanced spontaneous activity without change to their stimulus driven activity. MGB DBS suppressed thalamocortical synchronization in the beta and gamma bands, supporting suppression of thalamocortical synchronization as an underlying mechanism of tinnitus suppression by high frequency DBS. These findings contribute to our understanding of the neurophysiologic consequences of noise-exposure and the mechanism of potential DBS therapy for tinnitus.


TecnoLógicas ◽  
2020 ◽  
Vol 23 (49) ◽  
pp. 11-32
Author(s):  
Sarah Valderrama-Hincapié ◽  
Sebastián Roldán-Vasco ◽  
Sebastián Restrepo-Agudelo ◽  
Frank Sánchez-Restrepo ◽  
William D. Hutchison ◽  
...  

Deep Brain Stimulation (DBS) has been successfully used to treat patients with Parkinson’s Disease. DBS employs an electrode that regulates the oscillatory activity of the basal ganglia, such as the subthalamic nucleus (STN). A critical point during the surgical implantation of such electrode is the precise localization of the target. This is done using presurgical images, stereotactic frames, and microelectrode recordings (MER). The latter allows neurophysiologists to visualize the electrical activity of different structures along the surgical track, each of them with well-defined variations in the frequency pattern; however, this is far from an automatic or semi-automatic method to help these specialists make decisions concerning the surgical target. To pave the way to automation, we analyzed three frequency bands in MER signals acquired from 11 patients undergoing DBS: beta (13-40 Hz), gamma (40-200 Hz), and high-frequency oscillations (HFO – 201-400 Hz). In this study, we propose and assess five indexes in order to detect the STN: variations in autoregressive parameters and their derivative along the surgical track, the energy of each band calculated using the Yule-Walker power spectral density, the high-to-low (H/L) ratio, and its derivative. We found that the derivative of one parameter of the beta band and the H/L ratio of the HFO/gamma bands produced errors in STN targeting like those reported in the literature produced by image-based methods (<2 mm). Although the indexes introduced here are simple to compute and could be applied in real time, further studies must be conducted to be able to generalize their results.


2020 ◽  
Vol 7 (4) ◽  
Author(s):  
Mina Mokhtari Hashtjini ◽  
Gila Pirzad Jahromi ◽  
Seyed Shahabeddin Sadr ◽  
Ali Khaleghi ◽  
Boshra Hatef ◽  
...  

Background: The study of the biological basis of fear in animal models has progressed considerably because of the energy and space that the brain devotes to this basic emotion. Electrical stimulation targets several structures of the brain to examine its behavioral effects and to understand the role of different regions in underlying mechanisms of fear processing and anxiety in preclinical models. Objectives: In this study, the effects of high-frequency deep brain stimulation (DBS) of the basolateral amygdala (BLA) and prelimbic (PL) sub-region of the prefrontal cortex were evaluated on the extinction process of conditioned fear. Methods: This study was performed on 35 male Wistar rats in the weight range of 220 – 250 g. After selecting the animals, they were separated into five groups. Then, we did stereotactic surgery on rats for electrode implantation. After recovery, some rats were conditioned, followed by a 10-day treatment schedule via high-frequency DBS in the BLA or PL. Next, freezing behavior was measured as a predicted response dedicated to extinction, without shock (re-exposure). In addition, we used ELISA and Western blot to estimate blood serum corticosterone levels and c-Fos protein expression. Results: The mean freezing time recorded for the PL group was significantly lower than that of both the BLA group and the PC group (P < 0.01). The BLA group and PC group were also significantly different (P < 0.001). Corticosterone results indicated that the PL group had significantly higher serum corticosterone levels compared with both the BLA group and the PC group (P < 0.01). In addition, the BLA group revealed a significant reduction in c-Fos expression compared with the PC (P < 0.001). Conclusions: This study provides further evidence for the contribution of the prelimbic cortex and amygdala both in acquisition and extinction processes during contextual fear conditioning. However, the PL stimulation by high-frequency DBS might be more involved in the extinction process and play a more important role as an enhancer.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Estefanía Hernandez-Martin ◽  
Enrique Arguelles ◽  
Yifei Zheng ◽  
Ruta Deshpande ◽  
Terence D. Sanger

AbstractHigh-frequency peripheral nerve stimulation has emerged as a noninvasive alternative to thalamic deep brain stimulation for some patients with essential tremor. It is not known whether such techniques might be effective for movement disorders in children, nor is the mechanism and transmission of the peripheral stimuli to central brain structures understood. This study was designed to investigate the fidelity of transmission from peripheral nerves to thalamic nuclei in children with dystonia undergoing deep brain stimulation surgery. The ventralis intermediate (VIM) thalamus nuclei showed a robust evoked response to peripheral high-frequency burst stimulation, with a greatest response magnitude to intra-burst frequencies between 50 and 100 Hz, and reliable but smaller responses up to 170 Hz. The earliest response occurred at 12–15 ms following stimulation onset, suggesting rapid high-fidelity transmission between peripheral nerve and thalamic nuclei. A high-bandwidth, low-latency transmission path from peripheral nerve to VIM thalamus is consistent with the importance of rapid and accurate sensory information for the control of coordination and movement via the cerebello-thalamo-cortical pathway. Our results suggest the possibility of non-invasive modulation of thalamic activity in children with dystonia, and therefore the possibility that a subset of children could have beneficial clinical response without the need for invasive deep brain stimulation.


2021 ◽  
Vol 11 (5) ◽  
pp. 639
Author(s):  
David Bergeron ◽  
Sami Obaid ◽  
Marie-Pierre Fournier-Gosselin ◽  
Alain Bouthillier ◽  
Dang Khoa Nguyen

Introduction: To date, clinical trials of deep brain stimulation (DBS) for refractory chronic pain have yielded unsatisfying results. Recent evidence suggests that the posterior insula may represent a promising DBS target for this indication. Methods: We present a narrative review highlighting the theoretical basis of posterior insula DBS in patients with chronic pain. Results: Neuroanatomical studies identified the posterior insula as an important cortical relay center for pain and interoception. Intracranial neuronal recordings showed that the earliest response to painful laser stimulation occurs in the posterior insula. The posterior insula is one of the only regions in the brain whose low-frequency electrical stimulation can elicit painful sensations. Most chronic pain syndromes, such as fibromyalgia, had abnormal functional connectivity of the posterior insula on functional imaging. Finally, preliminary results indicated that high-frequency electrical stimulation of the posterior insula can acutely increase pain thresholds. Conclusion: In light of the converging evidence from neuroanatomical, brain lesion, neuroimaging, and intracranial recording and stimulation as well as non-invasive stimulation studies, it appears that the insula is a critical hub for central integration and processing of painful stimuli, whose high-frequency electrical stimulation has the potential to relieve patients from the sensory and affective burden of chronic pain.


2018 ◽  
Vol 10 (2) ◽  
Author(s):  
Candace Borders ◽  
Frank Hsu ◽  
Alexander J. Sweidan ◽  
Emily S. Matei ◽  
Robert G. Bota

Studies suggest deep brain stimulation (DBS) as a treatment modality for the refractory obsessive-compulsive disorder (OCD). It is unclear where to place the DBS. Various sites are proposed for placement with the ventral capsule/ventral striatum (VC/VS) among the most studied. Herein, we aim to summarize both quantitative Yale-Brown Obsessive-Compulsive Scale (YBOCS) data and qualitative descriptions of the participants’ symptoms when given. A literature search conducted via PubMed yielded 32 articles. We sought to apply a standard based on the utilization of YBOCS. This yielded 153 distinct patients. The outcome measure we focused on in this review is the latest YBOCS score reported for each patient/cohort in comparison to the location of the DBS. A total of 32 articles were found in the search results. In total, 153 distinct patients’ results were reported in these studies. Across this collection of papers, a total of 9 anatomic structures were targeted. The majority of studies showed a better response at the last time point as compared to the first time point. Most patients had DBS at nucleus accumbens followed by VC/VS and the least patients had DBS at the bilateral superolateral branch of the median forebrain bundle and the bilateral basolateral amygdala. The average YBOCS improvement did not seem to directly correlate with the percentile of patients responding to the intervention. Well-controlled, randomized studies with larger sample sizes with close follow up are needed to provide a more accurate determination for placement of DBS for OCD.


2021 ◽  
Vol 15 ◽  
Author(s):  
Lila H. Levinson ◽  
David J. Caldwell ◽  
Jeneva A. Cronin ◽  
Brady Houston ◽  
Steve I. Perlmutter ◽  
...  

Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a clinically effective tool for treating medically refractory Parkinson’s disease (PD), but its neural mechanisms remain debated. Previous work has demonstrated that STN DBS results in evoked potentials (EPs) in the primary motor cortex (M1), suggesting that modulation of cortical physiology may be involved in its therapeutic effects. Due to technical challenges presented by high-amplitude DBS artifacts, these EPs are often measured in response to low-frequency stimulation, which is generally ineffective at PD symptom management. This study aims to characterize STN-to-cortex EPs seen during clinically relevant high-frequency STN DBS for PD. Intraoperatively, we applied STN DBS to 6 PD patients while recording electrocorticography (ECoG) from an electrode strip over the ipsilateral central sulcus. Using recently published techniques, we removed large stimulation artifacts to enable quantification of STN-to-cortex EPs. Two cortical EPs were observed – one synchronized with DBS onset and persisting during ongoing stimulation, and one immediately following DBS offset, here termed the “start” and the “end” EPs respectively. The start EP is, to our knowledge, the first long-latency cortical EP reported during ongoing high-frequency DBS. The start and end EPs differ in magnitude (p &lt; 0.05) and latency (p &lt; 0.001), and the end, but not the start, EP magnitude has a significant relationship (p &lt; 0.001, adjusted for random effects of subject) to ongoing high gamma (80–150 Hz) power during the EP. These contrasts may suggest mechanistic or circuit differences in EP production during the two time periods. This represents a potential framework for relating DBS clinical efficacy to the effects of a variety of stimulation parameters on EPs.


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