Deep Brain Stimulation, a Neurosurgical Approach for Neuromodulation.pptx

**Deep Brain Stimulation (DBS): A Neurosurgical Approach for Neuromodulation**

This SlideShare presentation delves into the transformative field of Deep Brain Stimulation (DBS), a cutting-edge neurosurgical procedure that has revolutionized the treatment of various neurological disorders. Presented by MD. Ziual Hasan, MD. Jahid Hasan, and Nusrat Jahan Usha from the Department of Biomedical Engineering, CUET, this comprehensive overview highlights the essential aspects of DBS, from its foundational principles to its real-world applications.

### **Introduction**

DBS is a neurosurgical intervention designed to deliver electrical stimulation to targeted brain regions via an implanted pacemaker-like device. This approach has proven effective in managing conditions such as Parkinson's disease (PD) and dystonia by suppressing excessive neural activity, thus alleviating symptoms like tremor, rigidity, and impaired mobility. Over the past three decades, DBS has emerged as a long-term, adjustable alternative to medications for treating various neurological and psychiatric disorders, significantly enhancing patients' quality of life.

### **Key Components of DBS**

The presentation meticulously outlines the components of a DBS system:

1. **Electrodes**:
- Implanted through a small hole in the skull and positioned in the targeted brain region.

2. **Connecting Wires**:
- Routed beneath the scalp, neck, and shoulder tissue to connect the electrodes to the pacemaker.

3. **Pacemaker (Implantable Pulse Generator - IPG)**:
- Located beneath the skin near the collarbone, this device transmits electrical impulses to regulate brain activity.

### **Working Principle**

The DBS system works by placing electrodes in brain regions responsible for abnormal neural signals. The procedure involves:

- Preoperative evaluations, including MRI scans and neuropsychological testing.
- Electrode placement using intraoperative microelectrode mapping.
- High-frequency electrical stimulation to recondition faulty signals without damaging healthy tissue.

This process enables the modulation of neural activity, offering symptom relief for various conditions.

### **Design of DBS Sensors**

The presentation explores two primary DBS system designs: open-loop and closed-loop systems.

- **Open-Loop DBS**:
- Requires manual adjustments by a neurologist every 3-12 months.
- Continuous stimulation, irrespective of the brain state.

- **Closed-Loop DBS**:
- Automatically adapts stimulation based on biomarkers.
- Deactivates stimulation when the brain returns to a normal state, ensuring precise modulation.

Additionally, the design of electrodes, including configurations and stimulation patterns, is discussed. Various stimulation techniques such as unipolar, bipolar, interleaving, and directional stimulation are covered, showcasing the versatility of DBS systems.

### **Innovative Waveform Designs**

DBS systems use diverse waveform designs to tailor therapy for patient

1. Department of BME,CUET 23 /02/2025 Presented by MD. Ziual Hasan(1911001) MD. Jahid Hasan(1911018) Nusrat Jahan Usha(1911014) ‹#› Deep Brain Stimulation (DBS) “ A Neurosurgical Approach for Neuromodulation” Ref: What Is Deep Brain Stimulation? Benefits, Cost, Risks | HealthyPlace

2. Table of Contents Introduction. Components . Working Principle. Design of a sensor. An implantable Sensor. Body Sensor Network. Application. Commercial Product. Conclusion. ‹#› Department of BME,CUET 23/02/2025

3. Introduction A neurosurgical procedure with an implanted pacemaker to deliver electrical stimulation to deep brain regions. Treats Parkinson’s disease(PD) and dystonia by suppressing excessive neural activity. Decreases symptoms like tremor, rigidity, slowness of movement, and impairment of walking. Long-term, adjustable alternative to medication to manage neurological and psychiatric disorders. Over 30 years of improving patients' quality of life. ‹#› Department of BME,CUET P arkinson's Patients May Live Longer After Deep Brain Stimulation 23/02/2025

4. Components of DBS Electrodes Inserted through a small hole in the skull. Positioned in the targeted region of the brain. Connecting Wires Directed beneath the scalp , neck, and shoulder tissue . Connect electrodes to the pacemaker. Pacemaker (Implantable Pulse Generator - IPG) Positioned just below the skin near the collarbone. Transmits electrical impulses to maintain brain activity within bounds. ‹#› Department of BME,CUET Ref: 3D Software to improve success of DBS surgery 23/02/2025

5. Working Principle ‹#› Department of BME,CUET Ref: Understanding Deep Brain Stimulation (DBS) 23/02/2025

6. Working Principle The electrodes are placed inside the targeted region of the brain that is responsible for the abnormal signals. Preoperative evaluation includes MRI scans, neuropsychological testing, and gait analysis. Electrode placement is done with MRI and intraoperative microelectrode mapping. Electrodes are implanted on a neurostimulator (battery-powered), placed under the skin just below the collarbone. High-frequency electrical stimulation reconditions faulty signals, enhancing symptoms without injuring healthy tissue. ‹#› Department of BME,CUET 23/02/2025

7. Design of the sensor Open Loop and Closed Loop DBS ‹#› Department of BME,CUET Ref: Advances in closed-loop deep brain stimulation devices - Scientific Figure on ResearchGate. Open-Loop DBS (a) - Manual adjustments by neurologist - Parameters adjusted every 3-12 months Closed-Loop DBS (b) - Automatic programming based on biomarkers - No manual intervention required Brain State Response - Open-Loop DBS: Continues stimulation regardless of brain state - Closed-Loop DBS: Gets deactivated when brain enters normal state 23/02/2025

8. Dark grey regions illustrate electrode contacts, which can be activated to deliver current. Common electrode configurations for DBS: Electrode designs vary in contact spacing and number/shape of contacts. Greater contact spacing: expands neural target range Smaller contact spacing: facilitates precise stimulation control which can be activated to deliver current. Types of DBS stimulation: Unipolar stimulation: current flows from battery to contact or vice versa Bipolar stimulation: current flows between electrode contacts Interleaving stimulation: alternation of different stimulation settings Multiple level stimulation: stimulates multiple neural targets along electrode trajectory Directional stimulation: current can be directed based on local anatomy or clinical symptoms ‹#› Department of BME,CUET Design of the sensor DBS electrode configurations Ref: https://pmc.ncbi.nlm.nih.gov/articles/PMC7116699/figure/F2/ 23/02/2025

9. Conventional asymmetric biphasic DBS waveform with a short-duration cathodic phase followed by an interphase delay and a long-duration anodic (recharge) phase. Symmetric biphasic DBS waveform with equal-duration cathodic and anodic phases. Symmetric biphasic DBS waveform with zero interphase delay. Reversal of the standard pulse phase order of a symmetric biphasic DBS waveform. Regular temporal pattern of stimulation with fixed interpulse intervals (typically ~7.7 ms or ~130 Hz). Non-regular temporal pattern of stimulation with random interpulse intervals. Burst pattern of stimulation with several pulses at short interpulse intervals followed by a long interpulse interval. Stimulation pattern for coordinated reset with bursts of stimulation distributed across four different electrode contacts, with each row corresponding to the stimulation pattern delivered to each electrode contact. ‹#› Design of the sensor Stimulation waveform shapes and temporal stimulation patterns Ref: https://pmc.ncbi.nlm.nih.gov/articles/PMC7116699/figure/F3/ Department of BME,CUET 23/02/2025

10. DBS and local field potential activity: Beta activity (~20 Hz) in the off-levodopa phase High-frequency DBS delivered when amplitude threshold is crossed DBS intensity proportional to beta amplitude as an alternative approach DBS and electrocorticographic (ECOG) activity: Gamma activity (~70 Hz) in the on-levodopa and dyskinetic phase DBS stopped or reduced when ECOG amplitude threshold is crossed ‹#› Design of the sensor Adaptive DBS in Parkinson disease Ref: https://pmc.ncbi.nlm.nih.gov/articles/PMC7116699/figure/F4/ Department of BME,CUET 23/02/2025

11. Is DBS an In-body or On-body Sensor? In-body Sensor – DBS electrodes are implanted inside the brain to regulate neural activity. DBS in the Perspective of Body Sensor Network (BSN) In a BSN,multiple sensors work together to monitor and control body functions. DBS is part of this network as it: Monitors neural activity in the brain. Sends electrical signals to regulate abnormal brain activity. Communicates wirelessly with an external controller for adjustments. ‹#› Department of BME,CUET https://neurosurgery.wustl.edu/wp-content/uploads/2021/09/deep-brain-stimulation_feature. 23/02/2025

12. DBS in Body Sensor Networks: Wearable Perspectives Not a traditional wearable (like smartwatches or ECG patches). Implanted Sensor: Electrodes and pulse generator are inside the body. Wearable Component: The external controller allows adjustments by the patient or doctor. Hybrid Nature: Implanted system + Wearable control unit. . ‹#› Department of BME,CUET 23/02/2025

13. Application ‹#› Department of BME,CUET 23/02/2025

14. Commercial Product Activa™ RC – DBS System Treats Parkinson’s disease, essential tremor, and dystonia . Implantation : Placed in chest/abdomen , with leads in the brain . Features : Rechargeable (15-year battery life). Dual-channel stimulation for precise treatment. MRI-compatible & wireless recharging . Function : Delivers controlled electrical pulses to regulate brain activity. Benefit : Improves motor function & quality of life. ‹#› Department of BME,CUET https://neurosurgery.wustl.edu/wp-content/uploads/2021/09/deep-brain-stimulation_feature. 23/02/2025

15. Conclusion DBS has been shown to be a safe and effective surgical option for a number of movement disorders including essential tremor, PD, and the dystonias. Advances in the neuroscience will to drive the application of DBS Finally,innovations in biomedical engineering and technology will continue to be applied to DBS The ideal platform for the development of this innovation is the active collaboration between basic scientists,engineer and clinicians. ‹#› Department of BME,CUET 23/02/2025

16. References [1] A. Pasquarelli, Biosensors and Biochips , 1st ed. Ulm, Germany: Ulm University, Institute of Electron Devices and Circuits, Faculty of Engineering, Computer Science and Psychology, Springer Nature Switzerland AG, 2021. doi: 10.1007/978-3-030-76469-2. [2] HealthyPlace, "What Is Deep Brain Stimulation? Benefits, Cost, Risks," HealthyPlace , [Online]. Available: https://www.healthyplace.com . [Accessed: 14-Feb-2025]. [3] Brain Institute, "Understanding Deep Brain Stimulation (DBS)," Oregon Health & Science University (OHSU) , [Online]. Available: https://www.ohsu.edu/brain-institute. [Accessed: 14-Feb-2025]. [4] Parkinsons NSW, "3D Software to Improve Success of DBS Surgery," Parkinsons NSW , [Online]. Available: https://www.parkinsonsnsw.org.au . [Accessed: 14-Feb-2025]. [5] How Does Deep Brain Stimulation Work? Northwestern Medicine , 2025. [Online]. Available: https://www.nm.org/healthbeat/medical-advances/how-does-deep-brain-stimulation-work . [Accessed: 14-Feb-2025]. [6] Advances in closed-loop deep brain stimulation devices - Scientific Figure on ResearchGate, ResearchGate , Available: https://www.researchgate.net/figure/Overview-of-open-loop-DBS-a-versus-closed-loop-DBS-b-In-open-loop-DBS-a-neurologist_fig3_319068029 . [Accessed: Feb. 15, 2025]. ‹#› Department of BME,CUET 23/02/2025

17. Thank You!!! Any Question? ‹#› Department of BME,CUET 23/02/2025