scholarly journals Diffusion geometry approach to efficiently remove electrical stimulation artifacts in intracranial electroencephalography

2019 ◽  
Vol 16 (3) ◽  
pp. 036010 ◽  
Author(s):  
Sankaraleengam Alagapan ◽  
Hae Won Shin ◽  
Flavio Fröhlich ◽  
Hau-tieng Wu
Keyword(s):  
Electrical Stimulation ◽  
Diffusion Geometry ◽  
Intracranial Electroencephalography

scholarly journals Distinction of Physiologic and Epileptic Ripples: An Electrical Stimulation Study

2021 ◽  
Vol 11 (5) ◽  
pp. 538
Author(s):  
Jan Schönberger ◽  
Anja Knopf ◽  
Kerstin Alexandra Klotz ◽  
Matthias Dümpelmann ◽  
Andreas Schulze-Bonhage ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Slow Wave Sleep ◽  
Focal Epilepsy ◽  
Epileptic Activity ◽  
Interictal Spikes ◽  
Seizure Onset ◽  
Receiver Operating Characteristic Curves ◽  
Seizure Onset Zone ◽  
Intracranial Electroencephalography ◽  
Better Than

Ripple oscillations (80–250 Hz) are a promising biomarker of epileptic activity, but are also involved in memory consolidation, which impairs their value as a diagnostic tool. Distinguishing physiologic from epileptic ripples has been particularly challenging because usually, invasive recordings are only performed in patients with refractory epilepsy. Here, we identified ‘healthy’ brain areas based on electrical stimulation and hypothesized that these regions specifically generate ‘pure’ ripples not coupled to spikes. Intracranial electroencephalography (EEG) recorded with subdural grid electrodes was retrospectively analyzed in 19 patients with drug-resistant focal epilepsy. Interictal spikes and ripples were automatically detected in slow-wave sleep using the publicly available Delphos software. We found that rates of spikes, ripples and ripples coupled to spikes (‘spike–ripples’) were higher inside the seizure-onset zone (p < 0.001). A comparison of receiver operating characteristic curves revealed that spike–ripples slightly delineated the seizure-onset zone channels, but did this significantly better than spikes (p < 0.001). Ripples were more frequent in the eloquent neocortex than in the remaining non-seizure onset zone areas (p < 0.001). This was due to the higher rates of ‘pure’ ripples (p < 0.001; median rates 3.3/min vs. 1.4/min), whereas spike–ripple rates were not significantly different (p = 0.87). ‘Pure’ ripples identified ‘healthy’ channels significantly better than chance (p < 0.001). Our findings suggest that, in contrast to epileptic spike–ripples, ‘pure’ ripples are mainly physiological. They may be considered, in addition to electrical stimulation, to delineate eloquent cortex in pre-surgical patients. Since we applied open source software for detection, our approach may be generally suited to tackle a variety of research questions in epilepsy and cognitive science.

The “KIMWIPE” Effect in Ultra-Thin Cryosections

1985 ◽  
Vol 43 ◽  
pp. 458-459
Author(s):  
I. Taylor ◽  
P. Ingram ◽  
J.R. Sommer
Keyword(s):  
Skeletal Muscle ◽  
Electrical Stimulation ◽  
Muscle Fibers ◽  
Ice Crystals ◽  
Crystal Formation ◽  
Ice Crystal ◽  
Thin Sections ◽  
Skeletal Muscle Fibers ◽  
Freeze Dried ◽  
Ice Crystal Formation

In studying quick-frozen single intact skeletal muscle fibers for structural and microchemical alterations that occur milliseconds, and fractions thereof, after electrical stimulation, we have developed a method to compare, directly, ice crystal formation in freeze-substituted thin sections adjacent to all, and beneath the last, freeze-dried cryosections. We have observed images in the cryosections that to our knowledge have not been published heretofore (Figs.1-4). The main features are that isolated, sometimes large regions of the sections appear hazy and have much less contrast than adjacent regions. Sometimes within the hazy regions there are smaller areas that appear crinkled and have much more contrast. We have also observed that while the hazy areas remain still, the regions of higher contrast visibly contract in the beam, often causing tears in the sections that are clearly not caused by ice crystals (Fig.3, arrows).

1372: The Effect of Tolterodine on Sensations Evoked by Electrical Stimulation and Bladder Filling Sensations

2006 ◽  
Vol 175 (4S) ◽  
pp. 442-442
Author(s):  
Sönke Boy ◽  
Brigitte Schurch ◽  
Gudrun Mehring ◽  
Peter A. Knapp ◽  
Gilles Karsenty ◽  
...  
Keyword(s):  
Electrical Stimulation ◽  
Bladder Filling

Transcranial Electrical Stimulation in Post-Stroke Cognitive Rehabilitation

2016 ◽  
Vol 21 (1) ◽  
pp. 55-64 ◽  
Author(s):  
Silvia Convento ◽  
Cristina Russo ◽  
Luca Zigiotto ◽  
Nadia Bolognini
Keyword(s):  
Electrical Stimulation ◽  
Cognitive Rehabilitation ◽  
Cognitive Disorders ◽  
Spatial Neglect ◽  
Transcranial Electrical Stimulation ◽  
Clinical Settings ◽  
Post Stroke ◽  
Neuropsychological Disorders ◽  
Current State ◽  
Stimulation Technique

Abstract. Cognitive rehabilitation is an important area of neurological rehabilitation, which aims at the treatment of cognitive disorders due to acquired brain damage of different etiology, including stroke. Although the importance of cognitive rehabilitation for stroke survivors is well recognized, available cognitive treatments for neuropsychological disorders, such as spatial neglect, hemianopia, apraxia, and working memory, are overall still unsatisfactory. The growing body of evidence supporting the potential of the transcranial Electrical Stimulation (tES) as tool for interacting with neuroplasticity in the human brain, in turn for enhancing perceptual and cognitive functions, has obvious implications for the translation of this noninvasive brain stimulation technique into clinical settings, in particular for the development of tES as adjuvant tool for cognitive rehabilitation. The present review aims at presenting the current state of art concerning the use of tES for the improvement of post-stroke visual and cognitive deficits (except for aphasia and memory disorders), showing the therapeutic promises of this technique and offering some suggestions for the design of future clinical trials. Although this line of research is still in infancy, as compared to the progresses made in the last years in other neurorehabilitation domains, current findings appear very encouraging, supporting the development of tES for the treatment of post-stroke cognitive impairments.

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