scholarly journals Electro-Quasistatic Simulations in Bio-Systems Engineering and Medical Engineering

2005 ◽  
Vol 3 ◽  
pp. 39-49 ◽  
Author(s):  
U. van Rienen ◽  
J. Flehr ◽  
U. Schreiber ◽  
S. Schulze ◽  
U. Gimsa ◽  
...  
Keyword(s):  
Deep Brain Stimulation ◽  
Systems Engineering ◽  
Brain Stimulation ◽  
Medical Engineering ◽  
Morbus Parkinson ◽  
Electric Activity ◽  
Surrounding Tissue ◽  
Auditory Nerves ◽  
Major Interest ◽  
Deep Brain

Abstract. Slowly varying electromagnetic fields play a key role in various applications in bio-systems and medical engineering. Examples are the electric activity of neurons on neurochips used as biosensors, the stimulating electric fields of implanted electrodes used for deep brain stimulation in patients with Morbus Parkinson and the stimulation of the auditory nerves in deaf patients, respectively. In order to simulate the neuronal activity on a chip it is necessary to couple Maxwell's and Hodgkin-Huxley's equations. First numerical results for a neuron coupling to a single electrode are presented. They show a promising qualitative agreement with the experimentally recorded signals. Further, simulations are presented on electrodes for deep brain stimulation in animal experiments where the question of electrode ageing and energy deposition in the surrounding tissue are of major interest. As a last example, electric simulations for a simple cochlea model are presented comparing the field in the skull bones for different electrode types and stimulations in different positions.

scholarly journals The Active Electrode in the Living Brain: The Response of the Brain Parenchyma to Chronically Implanted Deep Brain Stimulation Electrodes

2020 ◽  
Author(s):  
Judith Evers ◽  
Madeleine Lowery
Keyword(s):  
Deep Brain Stimulation ◽  
Brain Stimulation ◽  
Foreign Body Response ◽  
Surrounding Tissue ◽  
Active Electrode ◽  
Fibrous Sheath ◽  
Tissue Impedance ◽  
Implanted Electrodes ◽  
Postmortem Studies ◽  
Deep Brain

Abstract BACKGROUND Deep brain stimulation is an established symptomatic surgical therapy for Parkinson disease, essential tremor, and a number of other movement and neuropsychiatric disorders. The well-established foreign body response around implanted electrodes is marked by gliosis, neuroinflammation, and neurodegeneration. However, how this response changes with the application of chronic stimulation is less well-understood. OBJECTIVE To integrate the most recent evidence from basic science, patient, and postmortem studies on the effect of such an “active” electrode on the parenchyma of the living brain. METHODS A thorough and in-part systematic literature review identified 49 papers. RESULTS Increased electrode-tissue impedance is consistently observed in the weeks following electrode implantation, stabilizing at approximately 3 to 6 mo. Lower impedance values are observed around stimulated implanted electrodes when compared with unstimulated electrodes. A temporary reduction in impedance has also been observed in response to stimulation in nonhuman primates. Postmortem studies from patients confirm the presence of a fibrous sheath, astrocytosis, neuronal loss, and neuroinflammation in the immediate vicinity of the electrode. When comparing stimulated and unstimulated electrodes directly, there is some evidence across animal and patient studies of altered neurodegeneration and neuroinflammation around stimulated electrodes. CONCLUSION Establishing how stimulation influences the electrical and histological properties of the surrounding tissue is critical in understanding how these factors contribute to DBS efficacy, and in controlling symptoms and side effects. Understanding these complex issues will aid in the development of future neuromodulation systems that are optimized for the tissue environment and required stimulation protocols.

Nicht-medikamentöse Optionen zur Behandlung pharmakoresistenter Epilepsien

2018 ◽  
Vol 75 (7) ◽  
pp. 448-454
Author(s):  
Thomas Grunwald ◽  
Judith Kröll
Keyword(s):  
Deep Brain Stimulation ◽  
Brain Stimulation ◽  
Tiefe Hirnstimulation ◽  
Ketogene Diät ◽  
Deep Brain

Zusammenfassung. Wenn mit den ersten beiden anfallspräventiven Medikamenten keine Anfallsfreiheit erzielt werden konnte, so ist die Wahrscheinlichkeit, dies mit anderen Medikamenten zu erreichen, nur noch ca. 10 %. Es sollte dann geprüft werden, warum eine Pharmakoresistenz besteht und ob ein epilepsiechirurgischer Eingriff zur Anfallsfreiheit führen kann. Ist eine solche Operation nicht möglich, so können palliative Verfahren wie die Vagus-Nerv-Stimulation (VNS) und die tiefe Hirnstimulation (Deep Brain Stimulation) in eine bessere Anfallskontrolle ermöglichen. Insbesondere bei schweren kindlichen Epilepsien stellt auch die ketogene Diät eine zu erwägende Option dar.

The Effect of Deep Brain Stimulation for Movement Disorders on Emotions

2008 ◽  
Author(s):  
Jonathan D. Richards ◽  
Paul M. Wilson ◽  
Pennie S. Seibert ◽  
Carin M. Patterson ◽  
Caitlin C. Otto ◽  
...  
Keyword(s):  
Deep Brain Stimulation ◽  
Brain Stimulation ◽  
Movement Disorders ◽  
Deep Brain

Deep Brain Stimulation Improves Medication Related Addictive Behavior and Associated Quality of Life

2009 ◽  
Author(s):  
Hunter Covert ◽  
Pennie S. Seibert ◽  
Caitlin C. Otto ◽  
Missy Coblentz ◽  
Nicole Whitener ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Deep Brain Stimulation ◽  
Brain Stimulation ◽  
Addictive Behavior ◽  
Deep Brain
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