Search results for "brain"

Increased Connexin 43 Expression as a Potential Mediator of the Neuroprotective Activity of the Corticotropin-Releasing Hormone

2009

CRH is a major central stress mediator, but also a potent neuroprotective effector. The mechanisms by which CRH mediates its neuroprotective actions are largely unknown. Here, we describe that the gap junction molecule connexin43 (Cx43) mediates neuroprotective effects of CRH toward experimentally induced oxidative stress. An enhanced gap junction communication has been reported to contribute to neuroprotection after neurotoxic insults. We show that CRH treatment up-regulates Cx43 expression and gap junctional communication in a CRH receptor-dependent manner in IMR32 neuroblastoma cells, primary astrocytes, and organotypic hippocampal slice cultures. MAPKs and protein kinase A-cAMP response…

Endoscope-assisted Craniotomy

1995

We describe a surgical technique to improve visualization of deep brain structures during craniotomy. The technique, developed in a cadaveric model, combines the use of an operating microscope and a solid-rod lens endoscope. Addition of the endoscope during craniotomy allows the operator to visualize structures that otherwise might not have been seen. An approach to the brain stem is demonstrated.

Brainstem Auditory Evoked Potentials and Visual Potentials in Kawasaki Disease: An Observational Monocentric Study

2020

Background: Kawasaki Disease is a systemic vasculitis, particularly involving coronary arteries. Rare involvement of other vascular districts is described, as central nervous system arteries, leading to a vasculitic neuropathy. Sensorineural hearing loss and alterations of evoked potentials are uncommonly reported complications.Methods: In an observational monocentric study, 59 children (37 males; 22 females; mean age: 2.7 ± 2.2 years) with documented Kawasaki Disease were enrolled. No risk factors for hearing loss and/or neurological impairment were identified in the cohort. Brainstem auditory evoked potentials and visual evoked potentials were correlated with clinical, hamatological and r…

Mapping symbols to sounds: electrophysiological correlates of the impaired reading process in dyslexia

2012

Dyslexic and control first-grade school children were compared in a Symbol-to-Sound matching test based on a non-linguistic audiovisual training which is known to have a remediating effect on dyslexia. Visual symbol patterns had to be matched with predicted sound patterns. Sounds incongruent with the corresponding visual symbol (thus not matching the prediction) elicited the N2b and P3a event-related potential (ERP) components relative to congruent sounds in control children. Their ERPs resembled the ERP effects previously reported for healthy adults with this paradigm. In dyslexic children, N2b onset latency was delayed and its amplitude significantly reduced over left hemisphere whereas P…

The so-called one-and-a-half syndrome, type II: a new syndrome?

1999

Objective: The term one-and-a-half syndrome, type II, was recently coined and has been applied to two somewhat different eye movement disorders: the loss of voluntary horizontal eye movements except for adduction in one eye (one patient with two lesions, one in the cerebral hemisphere and the other in the cavernous sinus) and the loss of all voluntary horizontal eye movements with adduction nystagmus in the right eye on attempted gaze to the left and preserved abduction in both eyes with the doll’s head maneuver (one patient with infarction of the midbrain). The justification of the term ‘one-and-a-half syndrome, type II’ is questioned. Design: Retrospective analysis of 9000 consecutive ele…

Visual mismatch negativity for changes in orientation - a sensory memory-dependent response

2008

It remains unclear whether the mismatch negativity of event-related potentials (ERPs) in vision resembles its auditory counterpart in terms of memory relatedness. We recorded ERPs to visual bars in adult humans engaged in an auditory task. In one condition, a bar ('standard') repeated at 400- or 1100-ms non-stimulated intervals was rarely (P = 0.1) replaced by another bar of a different orientation ('deviant'). In the other condition (400-ms intervals), the occurrences of the standards were replaced by 10 (P = 0.1 each) bars of different orientations, including that of the deviant ('control-deviant'). Deviants shifted ERPs towards negative polarity relative to standards in occipital electro…

Mapping of the human visual cortex using image-guided transcranial magnetic stimulation

2002

We describe a protocol using transcranial magnetic stimulation (TMS) to systematically map the visual sensations induced by focal and non-invasive stimulation of the human occipital cortex. TMS is applied with a figure of eight coil to 28 positions arranged in a 2x2-cm grid over the occipital area. A digitizing tablet connected to a PC computer running customized software, and audio and video recording are used for detailed and accurate data collection and analysis of evoked phosphenes. A frameless image-guided neuronavigational device is used to describe the position of the actual sites of the stimulation coils relative to the cortical surface. Our results show that TMS is able to elicit p…

A Look into Liver Mitochondrial Dysfunction as a Hallmark in Progression of Brain Energy Crisis and Development of Neurologic Symptoms in Hepatic Enc…

2020

Background: The relationship between liver disease and neuropathology in hepatic encephalopathy is well known, but the genesis of encephalopathy in liver failure is yet to be elucidated. Conceptually, the main cause of hepatic encephalopathy is the accumulation of brain ammonia due to impaired liver detoxification function or occurrence of portosystemic shunt. Yet, as well as taking up toxic ammonia, the liver also produces vital metabolites that ensure normal cerebral function. Given this, for insight into how perturbations in the metabolic capacity of the liver may be related to brain pathology, it is crucial to understand the extent of ammonia-related changes in the hepatic metabolism th…

Obstructive Sleep Apnea and the Brain

2018

Brain Oedema and Intracranial Pressure in Superior Sagittal Sinus Balloon Occlusion. An Experimental Study in Pigs

1990

About 2/3 of all patients with thrombosis of the superior sagittal sinus (SSS) develop signs of increased ICP and/or brain oedema (BE). The time of onset and the spectrum of symptoms in SSS thrombosis vary extremely. This variability might be caused by differences in pathomechanism like BE and rise of ICP, parameters studied in the present contribution.