scholarly journals Normalized Power Variance: A New Field Orthogonal to Power in EEG Analysis

2021 ◽  
Author(s):  
Yasunori Aoki ◽  
Hiroaki Kazui ◽  
Roberto D. Pascual-Marqui ◽  
Ricardo Bruña ◽  
Kenji Yoshiyama ◽  
...  
Keyword(s):  
Electrical Activity ◽  
Power Analysis ◽  
Estimation Method ◽  
Normal Pressure ◽  
Information Geometry ◽  
Csf Shunt ◽  
Shunt Operation ◽  
Disturbance Of Consciousness ◽  
Cortical Electrical Activity ◽  
Power Variance

Abstract To date, electroencephalogram (EEG) has been used in the diagnosis of epilepsy, dementia, and disturbance of consciousness via the inspection of EEG waves. In addition, EEG power analysis combined with a source estimation method like exact-low-resolution-brain-electromagnetic-tomography (eLORETA), which calculates the power of cortical electrical activity from EEG data, has been widely used to investigate cortical electrical activity in both healthy individuals and neuropsychiatric patients. However, the recently developed field of mathematics “information geometry” indicates that EEG has another dimension orthogonal to power dimension — that of normalized power variance (NPV). By also introducing the idea of information geometry, a significantly faster convergent estimator of NPV was obtained. In this study, we applied this NPV analysis of eLORETA to idiopathic normal pressure hydrocephalus (iNPH) patients prior to a cerebrospinal fluid (CSF) shunt operation, where traditional power analysis could not detect any difference associated with CSF shunt operation outcome. NPV analysis detected significantly higher NPV values at the high convexity area in the beta frequency band between 17 shunt responders and 19 non-responders. Our findings demonstrated that EEG has another dimension — that of NPV, which contains a great deal of information about cortical electrical activity that can be useful in clinical practice.

scholarly journals Manajemen Perioperatif Gejala Ekstrapiramidal (EPS) pada Hidrocephalus Tekanan Normal (NPH)

2020 ◽  
Vol 9 (2) ◽  
pp. 183-190
Author(s):  
Agus Baratha Suyasa ◽  
◽  
Ni Putu Dharmi Lestari ◽  
Keyword(s):  
Dopamine Receptor ◽  
Normal Pressure Hydrocephalus ◽  
Normal Pressure ◽  
Extrapyramidal Symptoms ◽  
Medical Rehabilitation ◽  
Long Term Results ◽  
Shunt Operation ◽  
Receptor Blocking

Extrapyramidal symptoms (EPS) are movement disorders due to side effects of dopamine receptor blocking agents. Symptoms of EPS include dystonia, akathisia, and parkinsonism. Symptoms of EPS in this case are found in normal pressure hydrocephalus (NPH) which does not consume dopamine receptor blocking drugs. Normal pressure hydrocephalus is hydrocephalus which does not coincide with intracranial pressure (ICT) elevation. Reported a case of a 57-year-old male with decreased consciousness and extrapyramidal symptoms and Normo pressure hydrocephalus (NPH), a V-P Shunt operation was performed. The operation was carried out under general anesthesia, using a non-kinking ETT no. 7.5, controlled ventilation. Premedication given midazolam 2 mg iv, Co induction with oxycodon 10 mg iv. Induction with propofol 150 mg iv, intubation facilities with rocketuronium 30 mg iv, maintenance with O2: Air (50: 50), sevoflurane, propofol continuous 100 mg/hour, rokuronium 20 mg/hour. Stable hemodynamics, SBP 130–150 mmHg, DBP 80–90 mmHg, HR 50–70 x/min, O2 saturation 99–100%, etCO2 35–37. After surgery the patient was treated in the intensive care unit (ICU) for monitoring blood pressure and extrapyramidal symptoms. The main goal of treatment should not be solely for the treatment of acute symptoms of EPS but also for the management of basic disease causing EPS related to morbidity and maintaining quality of life. Multidisciplinary management (neurosurgery, neurosurgery, intensive anesthesia and medical rehabilitation) are needed for better long-term results.

scholarly journals Normalized power variance of eLORETA at high-convexity area predicts shunt response in idiopathic normal pressure hydrocephalus

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Yasunori Aoki ◽  
Hiroaki Kazui ◽  
Ricardo Bruña ◽  
Roberto D. Pascual-Marqui ◽  
Kenji Yoshiyama ◽  
...  
Keyword(s):  
Normal Pressure Hydrocephalus ◽  
Normal Pressure ◽  
Idiopathic Normal Pressure Hydrocephalus ◽  
Power Variance ◽  
Shunt Response

Experiments on the Prolongation of Induced Epileptiform Convulsions in the Cat

1952 ◽  
Vol 98 (412) ◽  
pp. 454-456 ◽  
Author(s):  
Hugo Ruf
Keyword(s):  
Electrical Activity ◽  
Intravenous Injection ◽  
Experimental Research ◽  
Electric Stimulation ◽  
List Type ◽  
Type Number ◽  
Convulsive Activity ◽  
Cortical Electrical Activity ◽  
Epileptiform Convulsions

THE present paper offers a brief summary of work which has been published in German journals dealing with the prolongation of induced convulsions. In the course of my experimental research the following phenomena were demonstrated:(1)Continuousconvulsionslastingup to oneand a half hours were produced by the administration of oxygen and adrenaline, preceded by the injection of phenyl-methyl-aminopropane.(2)Prolonged convulsions of 33 minutes were produced by the intravenous injection of 2 ml. of a io per cent. metrazol solution and continuous oxygen in suffiation.(3)Isolated continuous convulsive activity of the cerebellum was produced lasting 30 minutes after cessation of respiration and of all cortical electrical activity. This was achieved by continuous insuffiation of oxygen together with the injection of adrenaline and strychnine.(4)Activation of a prolonged convulsion up to 11 minutes, without further electric stimulation, was effected via the thalamus by the injection of adrenaline after administration of phenyl-methyl-aminopropane and continuous oxygen in sufflation.

The role of diffusion tensor imaging in idiopathic normal pressure hydrocephalus: A literature review

2020 ◽  
pp. 197140092097515
Author(s):  
Irene Grazzini ◽  
Duccio Venezia ◽  
Gian Luca Cuneo
Keyword(s):  
Diffusion Tensor Imaging ◽  
Normal Pressure Hydrocephalus ◽  
Clinical Symptoms ◽  
Diffusion Tensor ◽  
Clinical History ◽  
Normal Pressure ◽  
Idiopathic Normal Pressure Hydrocephalus ◽  
Csf Shunt ◽  
Magnetic Resonance Imaging Mri

Idiopathic normal pressure hydrocephalus (iNPH) is a syndrome that comprises a triad of gait disturbance, dementia and urinary incontinence, associated with ventriculomegaly in the absence of elevated intraventricular cerebrospinal fluid (CSF) pressure. It is important to identify patients with iNPH because some of its clinical features may be reversed by the insertion of a CSF shunt. The diagnosis is based on clinical history, physical examination and brain imaging, especially magnetic resonance imaging (MRI). Recently, some papers have investigated the role of diffusion tensor imaging (DTI) in evaluating white matter alterations in patients with iNPH. DTI analysis in specific anatomical regions seems to be a promising MR biomarker of iNPH and could also be used in the differential diagnosis from other dementias. However, there is a substantial lack of structured reviews on this topic. Thus, we performed a literature search and analyzed the most recent and pivotal articles that investigated the role of DTI in iNPH in order to provide an up-to-date overview of the application of DTI in this setting. We reviewed studies published between January 2000 and June 2020. Thirty-eight studies and four reviews were included. Despite heterogeneity in analysis approaches, the majority of studies reported significant correlations between DTI and clinical symptoms in iNPH patients, as well as different DTI patterns in patients with iNPH compared to those with Alzheimer or Parkinson diseases. It remains to be determined whether DTI could predict the success after CSF shunting.

An Estimation of Generalized Bradley-Terry Models Based on the em Algorithm

2011 ◽  
Vol 23 (6) ◽  
pp. 1623-1659 ◽  
Author(s):  
Yu Fujimoto ◽  
Hideitsu Hino ◽  
Noboru Murata
Keyword(s):  
Em Algorithm ◽  
Estimation Method ◽  
Pairwise Comparison ◽  
Information Geometry ◽  
Point Of View ◽  
Ranking Data ◽  
Statistical Representation ◽  
Comparison Results ◽  
The Em Algorithm ◽  
Probability Simplex

The Bradley-Terry model is a statistical representation for one's preference or ranking data by using pairwise comparison results of items. For estimation of the model, several methods based on the sum of weighted Kullback-Leibler divergences have been proposed from various contexts. The purpose of this letter is to interpret an estimation mechanism of the Bradley-Terry model from the viewpoint of flatness, a fundamental notion used in information geometry. Based on this point of view, a new estimation method is proposed on a framework of the em algorithm. The proposed method is different in its objective function from that of conventional methods, especially in treating unobserved comparisons, and it is consistently interpreted in a probability simplex. An estimation method with weight adaptation is also proposed from a viewpoint of the sensitivity. Experimental results show that the proposed method works appropriately, and weight adaptation improves accuracy of the estimate.

Effects of memory-modulating neuropeptides on spontaneous and evoked cortical electrical activity in rabbits

1983 ◽  
Vol 14 (6) ◽  
pp. 419-424
Author(s):  
V. I. Medvedev ◽  
V. D. Bakharev ◽  
S. A. Avdyushenko ◽  
V. N. Nezavibat'ko ◽  
M. A. Ponomareva-Stepnaya ◽  
...  
Keyword(s):  
Electrical Activity ◽  
Cortical Electrical Activity

Cine-MR Imaging of Aqueductal CSF Flow in Normal Pressure Hydrocephalus Syndrome before and after CSF Shunt

1993 ◽  
Vol 34 (6) ◽  
pp. 586-592 ◽  
Author(s):  
M. Mascalchi ◽  
G. Arnetoli ◽  
D. Inzitari ◽  
G. Dal Pozzo ◽  
F. Lolli ◽  
...  
Keyword(s):  
Normal Pressure Hydrocephalus ◽  
Normal Pressure ◽  
Csf Shunt ◽  
Communicating Hydrocephalus ◽  
Csf Flow ◽  
Cine Mr ◽  
Csf Shunting ◽  
Before And After ◽  
Flow Void ◽  
Central Flow

Reproducibility of the aqueductal CSF signal intensity on a gradient echo cine-MR sequence exploiting through plane inflow enhancement was tested in 11 patients with normal or dilated ventricles. Seven patients with normal pressure hydrocephalus (NPH) syndrome were investigated with the sequence before and after CSF shunting. Two patients exhibiting central flow void within a hyperintense aqueductal CSF improved after surgery and the flow void disappeared after shunting. One patient with increased maximum and minimum aqueductal CSF signal as compared to 18 healthy controls also improved and the aqueductal CSF signal was considerably decreased after shunting. Three patients with aqueductal CSF values similar to those in the controls did not improve, notwithstanding their maximum aqueductal CSF signals decreasing slightly after shunting. No appreciable aqueductal CSF flow related enhancement consistent with non-communicating hydrocephalus was found in the last NPH patient who improved after surgery. Cine-MR with inflow technique yields a reproducible evaluation of flow-related aqueductal CSF signal changes which might help in identifying shunt responsive NPH patients. These are likely to be those with hyperdynamic aqueductal CSF or aqueductal obstruction.

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