Association Between Burst-Suppression Latency and Burst-Suppression Ratio Under Isoflurane or Adjuvant Drugs With Isoflurane Anesthesia in Mice

The same doses of anesthesia may yield varying depths of anesthesia in different patients. Clinical studies have revealed a possible causal relationship between deep anesthesia and negative short- and long-term patient outcomes. However, a reliable index and method of the clinical monitoring of deep anesthesia and detecting latency remain lacking. As burst-suppression is a characteristic phenomenon of deep anesthesia, the present study investigated the relationship between burst-suppression latency (BSL) and the subsequent burst-suppression ratio (BSR) to find an improved detection for the onset of intraoperative deep anesthesia. The mice were divided young, adult and old group treated with 1.0% or 1.5% isoflurane anesthesia alone for 2 h. In addition, the adult mice were pretreated with intraperitoneal injection of ketamine, dexmedetomidine, midazolam or propofol before they were anesthetized by 1.0% isoflurane for 2 h. Continuous frontal, parietal and occipital electroencephalogram (EEG) were acquired during anesthesia. The time from the onset of anesthesia to the first occurrence of burst-suppression was defined as BSL, while BSR was calculated as percentage of burst-suppression time that was spent in suppression periods. Under 1.0% isoflurane anesthesia, we found a negative correlation between BSL and BSR for EEG recordings obtained from the parietal lobes of young mice, from the parietal and occipital lobes of adult mice, and the occipital lobes of old mice. Under 1.5% isoflurane anesthesia, only the BSL calculated from EEG data obtained from the occipital lobe was negatively correlated with BSR in all mice. Furthermore, in adult mice receiving 1.0% isoflurane anesthesia, the co-administration of ketamine and midazolam, but not dexmedetomidine and propofol, significantly decreased BSL and increased BSR. Together, these data suggest that BSL can detect burst-suppression and predict the subsequent BSR under isoflurane anesthesia used alone or in combination with anesthetics or adjuvant drugs. Furthermore, the consistent negative correlation between BSL and BSR calculated from occipital EEG recordings recommends it as the optimal position for monitoring burst-suppression.

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Gyral window mapping of typical cortical folding using MRI

Translational Neuroscience ◽

10.2478/s13380-011-0018-1 ◽

2011 ◽

Vol 2 (2) ◽

Cited By ~ 1

Author(s):

Brynn Dombroski ◽

Andrew Switala ◽

Ayman El-Baz ◽

Manuel Casanova

Keyword(s):

Right Hemisphere ◽

Occipital Lobe ◽

Data Repository ◽

Age Difference ◽

Developmental Studies ◽

Cortical Folding ◽

Parietal Lobes ◽

Gyral Window ◽

Corticocortical Projections ◽

Occipital Lobes

AbstractUsing the NIH Pediatric MRI Data Repository for normative developmental studies, white matter depth within the gyri of the frontal, temporal, parietal, and occipital lobes, and of the left and right hemisphere was identified for 312 typically developing children and young adults (168 male and 144 female) between 4 and 23 years of age. There was no significant age difference between male and female groups overall (F 1,867 = 0.0002; p = 0.99) or per-visit (F 2,867 = 2.18; p = 0.86). There was significant dependence of gyral window upon age (F 1,6544 = 115, p < 0.0001), lobe (F 3,6544 = 229, p < 0.0001), hemisphere (F 1,6544 = 5.23, p = 0.022), age*sex (F 1,6544 = 13.8, p = 0.0002), age*lobe (F 3,6544 = 120, p = 0.0001), and age*hemisphere (F 1,6544 = 4.41, p = 0.036). Gyrification increased with age in both males and females in the frontal, temporal and parietal lobes with opposite effects observed in the occipital lobe. Relative gyral depth, as measured in this study, was significantly (p < 0.0001) inversely correlated with gyrification index. Previous studies relate gyral window measurements to the differential expression of short and long corticocortical projections. Our results therefore suggest that the pattern of corticocortical connections is malleable during the first two decades of development.

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Basal Forebrain Histaminergic Transmission Modulates Electroencephalographic Activity and Emergence from Isoflurane Anesthesia

Anesthesiology ◽

10.1097/aln.0b013e3181b061a0 ◽

2009 ◽

Vol 111 (4) ◽

pp. 725-733 ◽

Cited By ~ 45

Author(s):

Tao Luo ◽

L Stan Leung

Keyword(s):

Respiratory Rate ◽

Receptor Antagonist ◽

Basal Forebrain ◽

Suppression Ratio ◽

Power Spectra ◽

Burst Suppression ◽

Nucleus Basalis ◽

H2 Receptor Antagonist ◽

Isoflurane Anesthesia ◽

Electroencephalographic Activity

Background The tuberomammillary histaminergic neurons are involved in the sedative component of anesthetic action. The nucleus basalis magnocellularis (NBM) in the basal forebrain receives dense excitatory innervation from the tuberomammillary nucleus and is recognized as an important site of sleep-wake regulation. This study investigated whether NBM administration of histaminergic drugs may modulate arousal/emergence from isoflurane anesthesia. Methods Microinjections of histaminergic agonists and antagonists were made into the NBM of rats anesthetized with isoflurane. The changes in electroencephalographic activity, including electroencephalographic burst suppression ratio and power spectra, as well as respiratory rate, were recorded under basal conditions and after NBM injection. Time to resumption of righting reflex was recorded as a measure of emergence from anesthesia. Results The rats displayed a burst suppression electroencephalographic pattern at inhaled isoflurane concentrations of 1.4-2.1%. Application of histamine (1 microg/0.5 microl) to the NBM reversed the electroencephalographic depressant effect of isoflurane; i.e., electroencephalographic activity shifted from the burst suppression pattern toward delta activity at 1.4% isoflurane, and the burst suppression ratio decreased at 2.1% isoflurane. Histamine-evoked activation of electroencephalography was blocked by NBM pretreatment with a H1 receptor antagonist, triprolidine (5 microg/1 microl), but not by a H2 receptor antagonist, cimetidine (25 microg/1 microl). The respiratory rate was significantly increased after histamine injection. NBM application of histamine facilitated, while triprolidine delayed, emergence from isoflurane anesthesia. Conclusions Histamine activation of H1 receptors in the NBM induces electroencephalographic arousal and facilitates emergence from isoflurane anesthesia. The basal forebrain histaminergic pathway appears to play a role in modulating arousal/emergence from anesthesia.

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Burst-Suppression Ratio on Electrocorticography Depends on Interelectrode Distance

Journal of Clinical Neurophysiology ◽

10.1097/wnp.0000000000000248 ◽

2016 ◽

Vol 33 (2) ◽

pp. 127-132 ◽

Cited By ~ 3

Author(s):

Mihai Moldovan ◽

Alexandru Calin ◽

Vishakhadatta M. Kumaraswamy ◽

Diana Braver ◽

Mirela V. Simon

Keyword(s):

Suppression Ratio ◽

Burst Suppression ◽

Interelectrode Distance

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The Topography of Degeneration in the Cortex of Paralytics in relation to Flechsig's Association Centres [Die Topographie der paralytischen Rinden Degeneration und deren Verhältniss zu Flechsigs Associations-Centrern]. (Neur. Cbl., No. 2, 1902.) Schaffer, Karl

Journal of Mental Science ◽

10.1192/bjp.48.202.583 ◽

1902 ◽

Vol 48 (202) ◽

pp. 583-584

Author(s):

William W. Ireland

Keyword(s):

Original Study ◽

Visual Area ◽

Motor Area ◽

Nerve Fibres ◽

General Paralysis ◽

Posterior Median ◽

Parietal Lobes ◽

Born Child ◽

Calcarine Fissure ◽

Occipital Lobes

Dr. Karl Schaffer, of Budapest, gives the results of his examination of the brains of three general paralytics. His paper is illustrated with five lithographs, showing sections of brain stained by Weigerts-Wolter's method. The degenerated parts take on the stain poorly. Schaffer finds the most degenerated parts in general paralysis to be the anterior and basal portions of the frontal lobes, the whole parietal lobes, the posterior median convolutions, the insula, and the temporal gyri, and the occipital lobes and the upper surface of the cerebellum. Less affected were the anterior median gyrus, the margins of the calcarine fissure, and the inferior occipito-gyri. This showed that degenerative process most affected the association centres of Flechsig, his sensory spheres being very much less touched. Schaffer holds that the degeneration of the cortex in general paralysis is not haphazard but selective. He upholds Flechsig's views, and considers that they have been confirmed by the recent researches of Ramon y Cajal, who has made an original study of the nerve-tissues in the foetus and in the newly-born child. The latter describes a specific plexus of centripetal nerve-fibres, which terminate in the motor area of the cortex, in the sphere of bodily sensibility, and in the visual area. It is significant that this plexus does not pass into Flechsig's association centres, confirming Schaffer's observation of the posterior median convolution being, in general paralysis, much more degenerated than the anterior. These considerations induce Schaffer to think that the posterior median gyrus belongs rather to the association centres than to the sensory areas.

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Investigation of Delayed Response during Real-Time Cursor Control Using Electroencephalography

Journal of Healthcare Engineering ◽

10.1155/2020/1418437 ◽

2020 ◽

Vol 2020 ◽

pp. 1-9

Author(s):

Hyeonseok Kim ◽

Natsue Yoshimura ◽

Yasuharu Koike

Keyword(s):

Real Time ◽

High Accuracy ◽

Delayed Response ◽

Cursor Control ◽

Parietal Lobes ◽

Delay Times ◽

Cortical Regions ◽

Occipital Lobes ◽

Response Classification ◽

The Brain

Error-related brain activation has been investigated for advanced brain-machine interfaces (BMI). However, how a delayed response of cursor control in BMI systems should be handled is not clear. Therefore, the purpose of this study was to investigate how participants responded to delayed cursor control. Six subjects participated in the experiment and performed a wrist-bending task. For three distinct delay intervals (an interval where participants could not perceive the delay, an interval where participants could not be sure whether there was a delay or not, and an interval where participants could perceive the delay), we assessed two types of binary classifications (“Yes + No” vs. “I don’t know” and “Yes” vs. “No”) based on participants’ responses and applied delay times (thus, four types of classification, overall). For most participants, the “Yes vs. No” classification had higher accuracy than “Yes + No” vs. “I don’t know” classification. For the “Yes + No” vs. “I don’t know” classification, most participants displayed higher accuracy based on response classification than delay classification. Our results demonstrate that a class only for “I don’t know” largely contributed to these differences. Many independent components (ICs) that exhibited high accuracy in “Yes + No” vs. “I don’t know” response classification were associated with activation of areas from the frontal to parietal lobes, while many ICs that showed high accuracy in the “Yes vs. No” classification were associated with activation of an area ranging from the parietal to the occipital lobes and were more broadly localized in cortical regions than was seen for the “Yes + No” vs. “I don’t know” classification. Our results suggest that small and large delays in real-time cursor control differ not only in the magnitude of the delay but should be handled as distinct information in different ways and might involve differential processing in the brain.

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Hemianopia and Features of Bálint Syndrome following Occipital Lobe Hemorrhage: Identification and Patient Understanding Have Aided Functional Improvement Years after Onset

Case Reports in Ophthalmological Medicine ◽

10.1155/2019/3864572 ◽

2019 ◽

Vol 2019 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Nicola McDowell ◽

Gordon N. Dutton

Keyword(s):

Dorsal Stream ◽

Visual Field Loss ◽

Occipital Lobe ◽

Visual Assessment ◽

Active Management ◽

Homonymous Hemianopia ◽

Functional Improvement ◽

Posterior Parietal ◽

Eeg Recordings ◽

The Impact

Introduction. Cerebral visual impairment (CVI) can present around birth or any time thereafter. Homonymous hemianopia is a common feature. The concept that functional improvement is unattainable augurs against active management. Dorsal stream dysfunction (or Bálint syndrome when severe) results from bilateral posterior parietal dysfunction but may go undetected, especially in children. Case Presentation. At 16 the patient suffered spontaneous left occipital lobe brain hemorrhage from a ruptured arteriovenous malformation. This was surgically excised. Short lived right upper limb intermittent jerking, with additional left sided weakness, ensued. Anomalous EEG recordings, with right-sided bias, arose from the posterior temporoparietal area. A right homonymous hemianopia was evident. During the ensuing 17 years she experienced multiple complex difficulties, until, at a lecture describing how to identify and support children with CVI, she realized she herself had many of the difficulties described. Visual assessment identified hemianopia and dorsal stream dysfunction. Discussion. Following identification, characterization, and explanation of the impact of her visual difficulties, she both gained greater awareness of her visual difficulties and their impact and developed a range of strategies leading to functional improvement of her visual field loss and amelioration of her dorsal stream dysfunction, with great improvement in quality of life.

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Dynamic Cortical Connectivity during General Anesthesia in Healthy Volunteers

Anesthesiology ◽

10.1097/aln.0000000000002656 ◽

2019 ◽

Vol 130 (6) ◽

pp. 870-884 ◽

Cited By ~ 23

Author(s):

Duan Li ◽

Phillip E. Vlisides ◽

Max B. Kelz ◽

Michael S. Avidan ◽

George A. Mashour ◽

...

Keyword(s):

Functional Connectivity ◽

General Anesthesia ◽

Healthy Volunteers ◽

Transition Probabilities ◽

Burst Suppression ◽

Occurrence Rate ◽

Connectivity Pattern ◽

Phase Lag ◽

Cortical Connectivity ◽

Isoflurane Anesthesia

Abstract Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New Background Recent studies of anesthetic-induced unconsciousness in healthy volunteers have focused on functional brain connectivity patterns, but the protocols rarely parallel the depth and duration of surgical anesthesia. Furthermore, it is unknown whether there is a single functional connectivity pattern that correlates with general anesthesia for the duration of prolonged anesthetic exposure. Methods The authors analyzed electroencephalographic data in 30 healthy participants who underwent induction of anesthesia with propofol followed by 3 h of isoflurane anesthesia at age-adjusted 1.3 minimum alveolar concentration. Functional connectivity was assessed by frequency-resolved weighted phase lag index between frontal and parietal channels and between prefrontal and frontal channels, which were classified into a discrete set of states through k-means cluster analysis. Temporal dynamics were evaluated by the occurrence rate and dwell time distribution for each state as well as the transition probabilities between states. Results Burst suppression was present, with mean suppression ratio reducing from 44.8 ± 32.3% to 14.0 ± 20.2% (mean ± SD) during isoflurane anesthesia (P < 0.001). Aside from burst suppression, eight connectivity states were classified by optimizing the reproducibility of clustering solutions, with each characterized by distinct properties. The temporal progression of dominant states revealed a successive shifting trajectory from the state associated with alpha frontal-parietal connectivity to those associated with delta and alpha prefrontal-frontal connectivity during induction, which was reversed during emergence. Cortical connectivity was dynamic during maintenance period, and it was more probable to remain in the same state (82.0 ± 8.3%) than to switch to a different state (P < 0.001). However, transitions to other states were structured, i.e., occurred more frequently than expected by chance. Conclusions Anesthesia-induced alterations of functional connectivity are dynamic despite the stable and prolonged administration of isoflurane, in the absence of any noxious stimuli. Changes in connectivity over time will likely yield more information as a marker or mechanism of surgical anesthesia than any single pattern.

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5. Notes more especially on the Bridging Convolutions in the Brain of the Chimpanzee

Proceedings of the Royal Society of Edinburgh ◽

10.1017/s0370164600041432 ◽

1866 ◽

Vol 5 ◽

pp. 578-587 ◽

Cited By ~ 2

Author(s):

Wm. Turner

Keyword(s):

Differential Diagnosis ◽

Occipital Lobe ◽

Great Weight ◽

Late Professor ◽

The Third ◽

Occipital Lobes ◽

The Brain

The late Professor Gratiolet, in his elaborate and beautifully illustrated memoir, “Sur les Plis Cérébraux de l'Homme et des Primates,” attaches great weight in his differential diagnosis of their cerebral characters to the presence or absence of one or more members of a series of convolutions, which he designates as the plis de passage. When present, these convolutions bridge over the external perpendicular fissure of the hemisphere, and connect the parietal and temporal with the occipital lobes. By various anatomists in this country they are called bridging, connecting, or annectent convolutions. In the brain of the Chimpanzee M. Gratiolet states that the first bridging convolution is altogether wanting; that the second is present, but concealed under the operculum of the occipital lobe; that the third and fourth are superficial.

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