Search results for "brain stem"
showing 10 items of 86 documents
Somatosensory evoked potentials in Arnold-Chiari malformation.
2002
Abstract Nearly all patients with repaired myelomeningoceles have an Arnold–Chiari (AC) malformation and about 20% of these patients develop clinical signs of brainstem dysfunction. The management of symptomatic AC malformation is still controversial and techniques are needed to provide an objective assessment of brainstem function. We recorded somatosensory evoked potentials (SEPs) in 52 patients aged between 8 months and 20 years (median 7.3 years) with AC malformation, to determine whether the SEPs discriminate patients with symptomatic AC malformation from those without symptoms. The subcortical far-field components P13, P14 and N18, which are generated within the brainstem, were record…
Early auditory evoked potentials: developmental aspects and validity in neuropaediatric and audiologic disorders.
1984
Auditory evoked potentials and in this context especially five waves in the first 10 ms (early auditory evoked potentials = EAEP) are a diagnostic aid in topodiagnosis of posterior fossa diseases. This is due to waves I to V which arise along the acoustic nerve and in brain stem structures such as medulla, pons and mid-brain. Besides an indication about the site of a lesion in the posterior fossa, wave V allows an objective threshold determination. The present results were gained in normal children aged 1-3 years and in children with neuropaediatric and audiologic disorders.
Bickerstaff brainstem encephalitis. A case report
1992
A 33-year-old woman three weeks after a febrile illness presented with a syndrome of ophthalmoplegia, ataxia and areflexia (SOAA) that characterizes clinically both Bickerstaff and Miller Fisher syndromes. The normality of the electrophysiological tests performed, the CSF findings and the magnetic resonance images proved that the syndrome stemmed from brainstem pathology.
Brainstem reflex circuits revisited
2004
Our current understanding of brainstem reflex physiology comes chiefly from the classic anatomical-functional correlation studies that traced the central circuits underlying brainstem reflexes and establishing reflex abnormalities as markers for specific areas of lesion. These studies nevertheless had the disadvantage of deriving from post-mortem findings in only a few patients. We developed a voxel-based model of the human brainstem designed to import and normalize MRIs, select groups of patients with or without a given dysfunction, compare their MRIs statistically, and construct three-plane maps showing the statistical probability of lesion. Using this method, we studied 180 patients with…
The brainstem efferent acoustic chiasm in pigmented and albino rats
2015
Abstract The present study examined whether structural peculiarities in the brain-efferent pathway to the organ of Corti may underlie functional differences in hearing between pigmented and albino individuals of the same mammalian species. Pigmented Brown-Norway rats and albino Wistar rats received unilateral injections of an aqueous solution of the retrograde neuronal tracer Fluorogold (FG) into the scala tympani of the cochlea to identify olivocochlear neurons (OCN) in the brainstem superior olivary complex. After five days, brains were perfusion-fixed and brainstem sections were cut and analyzed with respect to retrogradely labeled neurons. Intrinsic neurons of the lateral system were lo…
The Oculo-auricular Phenomenon in Brain-Stem Disease
1993
The oculo-auricular phenomenon (OAP), as described by Wilson in 1908 [26], consists of bilateral coactivation of external ear muscles during lateral gaze. Two ear muscles are innervated by motoneurons of the medial part of the facial nucleus [9, 25]: the transverse auricular muscle (TAM) (Fig. 1), which adducts and curls the helix of the auricle, and the posterior auricular muscle (Fig. 2), which moves the whole auricle backwards [3, 16, 22].
A low repeat length in oligodendrocyte chromatin
1985
Abstract: The behavior of oligodendrocyte chromatin after micrococcal nuclease digestion of nuclei was assayed in brains of rats of four different ages. During oligodendrocyte differentiation, a decreasing sensitivity of the chromatin to enzymatic attack was observed. On the other hand, the nucleosomal repeat length showed a slight tendency to increase during development. It is worth noting that even the highest values reported here for “oligodendrocyte’ chromatin repeat lengths are significantly lower than 200 base pairs, the value previously reported by others for “non‐astrocytic glia.” Copyright © 1985, Wiley Blackwell. All rights reserved
Determination of Brain Death/Death by Neurologic Criteria
2020
Importance: There are inconsistencies in concept, criteria, practice, and documentation of brain death/death by neurologic criteria (BD/DNC) both internationally and within countries. Objective: To formulate a consensus statement of recommendations on determination of BD/DNC based on review of the literature and expert opinion of a large multidisciplinary, international panel. Process: Relevant international professional societies were recruited to develop recommendations regarding determination of BD/DNC. Literature searches of the Cochrane, Embase, and MEDLINE databases included January 1, 1992, through April 2020 identified pertinent articles for review. Because of the lack of high-quali…
Natural Course, Clinical Profile, and Treatment Strategies for Cerebral Cavernous Malformations
2022
A large body of evidence has suggested that the natural biology for symptomatic cerebral cavernous malformations (CCMs) is dynamic. These lesions exhibit a temporal clustering epiphenomenon and usually manifest with multispectral clinical patterns, the most relevant being hemorrhagic and seizurogenic events. Most patients with cerebral cavernous malformations are asymptomatic, and the lesions are detected as incidentalomas. However, association with the CCM3 gene, Zabramski type I and II lesions, and brainstem location have the propensity to increase the bleeding events. The rebleeding risk is 20%/year per lesion, which supports the need for surgical strategies for brainstem cavernous malfo…
A critical role for the cholesterol-associated proteolipids PLP and M6B in myelination of the central nervous system.
2012
The formation of central nervous system myelin by oligodendrocytes requires sterol synthesis and is associated with a significant enrichment of cholesterol in the myelin membrane. However, it is unknown how oligodendrocytes concentrate cholesterol above the level found in nonmyelin membranes. Here, we demonstrate a critical role for proteolipids in cholesterol accumulation. Mice lacking the most abundant myelin protein, proteolipid protein (PLP), are fully myelinated, but PLP-deficient myelin exhibits a reduced cholesterol content. We therefore hypothesized that "high cholesterol" is not essential in the myelin sheath itself but is required for an earlier step of myelin biogenesis that is f…