Search results for "Sensory system"
showing 10 items of 1266 documents
Imaging of Vestibular Schwannoma With Prevalent Cystic Component
2009
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15. Functional mapping of monaural auditory brainstem responses
2012
Background and aims: The pedunculopontine nucleus (PPN) is a new deep brain stimulation (DBS) target, thought to be particularly for useful in ameliorating gait disturbance in Parkinson’s disease. Recent evidence shows a prominent theta (4–7 Hz) rhythm in the PPN (Tsang et al., Neurology, 2010; Simon et al., J. Neurophysiol., 2010; Shimamoto et al., JNNP, 2010). Given that theta activity is modulated by vestibular signals elsewhere in the brain, e.g. hippocampus, (Shin, Synapse, 2010; Chen et al., Neuroimage, 2010), we assessed whether vestibular signals modulate PPN theta activity. Methods: We recorded local field potentials (LFPs) in three patients with implanted bilateral subthalamic nuc…
P13. Dendato-thalamo-cortical pathways in association with otolith dysfunction
2015
Introduction The processing of otolith information within the human cortex is still poorly understood (Lopez and Blanke, 2011). Two distinct anatomical otolith pathways within the thalamo-cortical vestibular network were proposed in patients with thalamic infarctions who presented with contra- or ipsiversive tilts of the subjective visual vertical (SVV) (Dieterich and Brandt, 1993; Baier et al., submitted for publication). Aim of this study was to investigate the dendato-thalamo-cortical pathways in association with otolith dysfunction by means of DTI (diffusion tensor imaging) based on the regions found in a recent patient study using statistical lesion-behavior mapping (Baier et al., subm…
Functional brain imaging of peripheral and central vestibular disorders.
2008
This review summarizes our current knowledge of multisensory vestibular structures and their functions in humans. Most of it derives from brain activation studies with PET and fMRI conducted over the last decade. The patterns of activations and deactivations during caloric and galvanic vestibular stimulations in healthy subjects have been compared with those in patients with acute and chronic peripheral and central vestibular disorders. Major findings are the following: (1) In patients with vestibular neuritis the central vestibular system exhibits a spontaneous visual-vestibular activation–deactivation pattern similar to that described in healthy volunteers during unilateral vestibular sti…
Textbook of Vertigo: Diagnosis and Management
2013
Following you will find a brief description of the book done, as accorded with Alessandro De Stefano, to publish in Int Tinnitus J Vertigo: Diagnosis and Management of Jaypee Brother Publisher, is a new book in the field of vestibular disorders. This publication includes several topics ranging from anatomy of vestibular system to the rehabilitation after a vestibular disease. The book, edited by Dr. Francesco Dispenza and Dr. Alessandro De Stefano, had the contribution of about 30 Professors worldwide, experts in the fields of vertigo. The first part of the book includes the information about anatomy, physiology of vestibular system and general approach to the dizzy patients, with a window …
Sensory system interactions during simultaneous vestibular and visual stimulation in PET
2002
The patterns of regional cerebral blood flow (rCBF) increases and decreases in PET were compared for unimodal vestibular, unimodal visual, and for simultaneous vestibular and visual stimulation. Thirteen healthy volunteers were exposed to a) caloric vestibular stimulation, b) small-field visual motion stimulation in roll, c) simultaneous caloric vestibular and visual pattern stimulation. Unimodal vestibular stimulation led to activations of vestibular cortex areas, in particular the parieto-insular vestibular cortex (PIVC), and concurrent deactivations of visual cortical areas [Brodmann area (BA) 17-19]. Unimodal visual motion stimulation led to activations of the striate visual cortex and …
The role of the thalamus in the human subcortical vestibular system1
2014
Most of our knowledge concerning central vestibular pathways is derived from animal studies while evidence of the functional importance and localization of these pathways in humans is less well defined. The termination of these pathways at the thalamic level in humans is even less known. In this review we summarize the findings concerning the central subcortical vestibular pathways in humans and the role of these structures in the central vestibular system with regard to anatomical localization and function. Also, we review the role of the thalamus in the pathogenesis of higher order sensory deficits such as spatial neglect, pusher syndrome or thalamic astasia and the correlation of these p…
Threshold-based vestibular adaptation to cross-coupled canal stimulation
2008
Prior experiments have demonstrated that people are able to adapt to cross-coupled accelerations associated with head movements while spinning at high rotation rates (e.g., 23 rpm or 138°/s). However, while adapting, subjects commonly experience serious side effects, such as motion sickness, non-compensatory eye movements, and strong and potentially disorienting illusory body tilt or tumbling sensations. In the present study, we investigated the feasibility of adaptation using a threshold-based method, which ensured that the illusory tilt sensations remained imperceptible or just barely noticeable. This was achieved by incrementally increasing the angular velocity of the horizontal centrifu…
FV 2. Modulation of the cortical vestibular network by means of rTMS and its neural correlate
2016
Repetitive transcranial magnetic stimulation (rTMS) has been applied to sensory research and for the treatment of disorders in psychiatry and neurology since 1993 ( Wassermann and Zimmermann, 2012 ). The widespread cortical vestibular system, however, has to date not been targeted. Aim of our study was to manipulate vestibular regions in the human cortex by temporary virtual lesioning through rTMS and analyse the changes in the perception of a galvanic vestibular stimulation (GVS) as well as the differing activation patterns in functional neuroimaging. The effects of rectangular and sinusoidal bimastoidal GVS were studied in 16 healthy volunteers (8 F; mean age 23 years) in a 3T scanner. Da…
Posterior insular cortex - a site of vestibular-somatosensory interaction?
2013
Background In previous imaging studies the insular cortex (IC) has been identified as an essential part of the processing of a wide spectrum of perception and sensorimotor integration. Yet, there are no systematic lesion studies in a sufficient number of patients examining whether processing of vestibular and the interaction of somatosensory and vestibular signals take place in the IC. Methods We investigated acute stroke patients with lesions affecting the IC in order to fill this gap. In detail, we explored signs of a vestibular tone imbalance such as the deviation of the subjective visual vertical (SVV). We applied voxel-lesion behaviour mapping analysis in 27 patients with acute unilate…