Search results for "Cerebellar Vermi"

Anatomical correlates of ocular motor deficits in cerebellar lesions

2009

Humans are able to stabilize the images of moving targets on the retina by means of smooth pursuit eye movements. After the pontine level, all smooth pursuit pathways pass through the cerebellum. Previous animal studies gave evidence that two specific lesion sites within the cerebellum cause smooth pursuit disorders: those of the flocculus/paraflocculus and the vermis including lobule VI, VII, the uvula and the deep cerebellar nuclei. To date, there have been only a few lesion studies in patients with smooth pursuit disorders that do not allow direct comparison with a control group. In the present study, new lesion mapping techniques determined which cerebellar structures were involved in p…

Changes in cerebellar activation pattern during two successive sequences of saccades

2002

The changes in the cerebellar activation pattern of two successive fMRI scanning runs were determined for visually guided to‐and‐fro saccades in 12 healthy volunteers familiar with the study paradigm. Group and single subject‐analyses revealed a constant activation of the paramedian cerebellar vermis (uvula, tonsils, tuber, folium/declive), which reflects constant ocular motor activity in both runs. A significant decrease in activation of the cerebellar hemispheres found in the second run is best explained by either a decrease in attention or the effects of motor optimization and learning. The significant, systematic changes of the cerebellar activation pattern in two successive runs were n…

Surgical Treatment in Symptomatic Chiari Malformation Type I: A Series of 25 Adult Patients Treated with Cerebellar Tonsil Shrinkage

2019

Background: The variety of symptoms and radiological findings in patients with Chiari malformation type I makes both the indication for surgery and the technical modality controversial. We report our 5-year experience, describing our technique and critically evaluating the clinical results. Methods: Between 2012 and 2016, 25 patients (15 female and 10 male; mean age 39.2 years) underwent posterior fossa decompression for Chiari malformation type I. Their clinical complaints included headache, nuchalgia, upper limb weakness or numbness, instability, dizziness and diplopia. Syringomyelia was present in 12 patients (48%). Suboccipital craniectomy was completed in all cases with C1 laminectomy …

Cognitive and social impairments in patients with superficial siderosis

2005

Superficial siderosis of the CNS is a rare condition, caused by deposition of haemosiderin in the superficial layers of the CNS due to repeated chronic subarachnoid or intraventricular haemorrhage. Typically, the hindbrain structures, especially the cerebellum, are most affected. There is a surprising lack of studies investigating in detail the behavioural functioning of patients with such a condition. In this study, we document for the first time the cognitive, social and emotional processing of six patients with a confirmed clinical diagnosis of superficial siderosis. They were aged between 40 and 62 years, with a mean age of 50.2 years; four were male. We administered a comprehensive bat…

Functional MRI of galvanic vestibular stimulation with alternating currents at different frequencies.

2004

Abstract Functional MRI was performed in 28 healthy volunteers to study the effects of galvanic vestibular stimulation with alternating currents (AC-GVS) of different frequencies on brain activation patterns. The aims of this study were (1) to identify specific areas within the vestibular cortical network that are involved in the processing of frequency-specific aspects by correlation analyses, (2) to determine the optimal frequency for stimulation of the vestibular system with respect to perception, and (3) to analyze whether different frequencies of AC-GVS are mediated in different cortical areas or different sites within the vestibular cortex. AC-GVS was performed using sinusoidal stimul…

Examination of the fetal brain by transabdominal three-dimensional ultrasound: potential for routine neurosonographic studies

2006

Objective To evaluate the role of transabdominal three-dimensional (3D) ultrasound in the assessment of the fetal brain and its potential for routine neurosonographic studies. Methods We studied prospectively 202 consecutive fetuses between 16 and 24 weeks' gestation. A 3D ultrasound volume of the fetal head was acquired transabdominally. The entire brain anatomy was later analyzed using the multiplanar images by a sonologist who was expert in neonatal cranial sonography. The quality of the conventional planes obtained (coronal, sagittal and axial, at different levels) and the ability of the 3D multiplanar neuroscan to visualize properly the major anatomical structures of the brain were eva…

23. Resting state functional magnetic resonance imaging analysis of the brain of pathological gamblers

2018

Purpose Gambling disorder has been recently reclassified under the category “substance-related and addictive disorders”. Recent studies performed through functional MRI (fMRI) have shown that the perseverance of some behaviors can alter brain activation [1] , [2] . In this work we aim at investigating functional connectivity changes in pathological gamblers (PGs) in comparison to healthy controls (HCs) by means of resting state functional Magnetic Resonance Imaging (rs-fMRI). Methods and materials Thirteen HCs and fourteen PGs were recruited (all right handed males; drugs free; mean age 36 ± 10 yrs). All acquisitions were performed through a 1,5 T MRI scanner using a 8-channels phased-array…

2020

In this paper a comprehensive system-level computational model of oculomotor pathways is presented. This model shows the necessity of embedding internal models of muscles biomechanics in the cerebellar Vermis to realize fast saccadic eye movements based on predicting the changes in muscles lengths. First, the eye biomechanics are described by nonlinear equations during “slow” and “fast” movements. Afterward, by analyzing these equations, a computational model, is deduced. Furthermore, each part of this model is interpreted as a possible function of an element in the oculomotor pathways based on physiological and anatomical pieces of evidence. In this model, two internal feedback loops compe…

OC2.01: Examination of the fetal brain by three-dimensional ultrasound: potential for routine neurosonographic studies

2005

Objective: To evaluate the role of three-dimensional (3D) ultrasound in the assessment of the fetal brain and its potential for routine neurosonographic studies. Methods: We studied prospectively 202 consecutive brain fetuses between 16 and 24 weeks’ gestation. A 3D-ultrasound volume of the fetal head was acquired transabdominally. The entire brain anatomy was later analyzed by a sonologist expert in neonatal cranial sonography using the multiplanar images. The quality of the conventional planes obtained (coronal, sagittal and axial, at different levels) and the ability to visualize properly the major brain anatomic structures were evaluated. Results: Acceptable rendered cerebral volumes we…