ISSN:1350-7540    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Purpose of reviewVestibular symptoms occur frequently in patients with migraine. This review refines recently proposed diagnostic criteria for migraine-related vestibular symptoms, and develops a pathophysiological model for the interface between migraine and the vestibular system.Recent findingsThe epidemiological link between migraine and vestibular symptoms and signs suggests shared pathogenetic mechanisms. Links between the vestibular nuclei, the trigeminal system, and thalamocortical processing centers provide the basis for the development of a pathophysiological model of migraine-related vertigo. During the last year, several studies have increased understanding of the relationship between migraine and vestibular symptoms. A study of motion sickness and allodynia in migraine patients supports the importance of central mechanisms of sensitization for migraine-related vestibular symptoms. A study has demonstrated effective treatment of vertigo with migraine therapy. The identification of migrainous vertigo, however, is hampered by a lack of standardized assessment criteria for both clinical and research practices. The application of published criteria for the diagnosis of migrainous vertigo allows the development of a standardized, structured assessment interview.SummaryAn understanding of the relationship between migraine and the vestibular system increases knowledge of the pathogenesis of both migraine and vertigo. In addition, studies have identified successful treatment, with standard migraine therapies, of vestibular symptoms in patients with both migraine and vertigo. The use of a standardized assessment tool to identify this unique population of patients will help future studies to test both the pathological model and effective treatment options.

ISSN:1350-7540    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Purpose of reviewFalls among elderly persons create immense social problems because of their association with physical decline, serious psychosocial consequences, negative impact on the quality of life, and markedly reduced survival. In addition, falls pose high costs to the public health service. For these reasons, falls remain a popular topic for research. Here, we review several interesting developments that have been published during the past year.Recent findingsConsiderable attention has been focused on early identification of fallers and prevention strategies for falls or injuries. A remaining challenge is to implement such strategies into daily clinical practice, at acceptable costs and with good acceptance. New evidence has been generated to suggest the importance of high-level processing for postural control, but it remains difficult to predict falls based upon a simple dual tasking test. Neuroimaging studies are now beginning to provide new insights into the role of cortical structures in balance regulation, and how cortical dysfunction might contribute to falls. Posturography studies using multidirectional moving platforms or computer models of balance have provided new insights into falling mechanisms, in particular the role of abnormal protective responses (stepping or grasping) and the negative effects of stiffening. Other studies have shown how a fear of falling, a common sequel to falls, may lead to secondary degeneration of postural control, thus completing a vicious loop.SummaryWhile these examples illustrate that falls research is very much ongoing, one cannot speak of true progress until the scientific evidence can be implemented into real life, with falls being prevented effectively in individual cases.

ISSN:1350-7540    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Purpose of reviewRecent clinical and molecular research on neurofibromatosis 2 (NF2) is reviewed, and the implications for clinical practice and research are discussed.Recent findingsNF2 patients who are treated in specialty centers have a significantly lower risk of mortality than those who are treated in non-specialty centers. Vestibular schwannoma growth rates in NF2 are generally higher in younger people but are highly variable, even among multiple NF2 patients of similar ages in the same family. Radiation therapy is best reserved for NF2 patients who have particularly aggressive tumors, those who are poor surgical risks, those who refuse surgery, or those who are elderly. In-vivo studies have demonstrated that leptomeningeal cell activation ofNf2in mice results in leptomeningeal hyperplasia and meningioma formation. In-vitro studies have identified molecules that interact with theNF2product (merlin or schwannomin), some of which (e.g., CD44 and paxillin) may play critical roles in merlin growth regulation.SummaryNF2 patients should be referred to specialty treatment centers for optimal care. Clinical management of multiple patients in NF2 families cannot be based on the expectation of similar vestibular schwannoma growth rates, even when other clinical aspects of disease severity are similar. The availability of accurate mouse models of human NF2-associated tumors and the identification of molecules involved in merlin growth regulation now provide an opportunity to design targeted treatments for schwannomas and meningiomas.

ISSN:1350-7540    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Purpose of reviewTo review recent data on mitochondrial diseases with emphasis on their neuro-ophthalmic manifestations.Recent findingsNumerous studies have associated mitochondrial diseases with neuro-ophthalmic manifestations. Although there has been an explosion of studies on the genetics of mitochondrial diseases over the past few years, pathogenesis is only partly understood and therapy remains very limited. Over the past year, new mutations in Leber's hereditary optic neuropathy have been reported, and at least three genes associated with autosomal dominant chronic progressive external ophthalmoplegia have been described. These findings allow a better definition of the specific genetic mutations and gene products as well as pathophysiology of Leber's hereditary optic neuropathy and chronic progressive external ophthalmoplegia. The current development of animal models allows a better understanding of the pathophysiology of human mitochondrial diseases.SummaryThe afferent and efferent visual pathways within the central nervous system are frequently involved in mitochondrial diseases. Neuro-ophthalmic signs figure prominently and may be the presenting or even sole manifestation of these disorders. The four most common neuro-ophthalmic abnormalities seen in mitochondrial disorders are bilateral optic neuropathy, ophthalmoplegia with ptosis, pigmentary retinopathy, and retrochiasmal visual loss.

ISSN:1350-7540    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Purpose of reviewAll functional classes of eye movements require exquisite coordination between cortical, basal ganglia and brainstem centers involved in ocular motor control. Vertebrobasilar stroke may produce a wide spectum of isolated or combined eye-movement disorders. The intent of this article is to summarize the curent knowledge of eye-movement disorders occurring in infarcts involving the different arterial territories of the vertebrobasilar circulation.Recent findingsIn the last few years there has been an improvement in our understanding of pathophysiological mechanisms that are related mainly to abnormal vergence disorders due to thalamic-subthalamic infarcts, as well as of the peculiar symptoms resulting from otolith pathway involvement occurring in lateral medullary infarcts. Moreover, progress in neuroimaging technology has implicated neurovascular contact of the trochlear nerve in instances of superior oblique myokimia.SummaryEye-movement disorders commonly occur in vertebrobasilar stroke, although they are often unappreciated. They may make it possible to establish specific anatomical correlates, as well as the probable nature of the underlying pathology.

ISSN:1350-7540    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Purpose of reviewA greater understanding of the underlying component mechanisms of normal visual search provides explanations for disturbances seen in certain neurological conditions. This review focuses on recent advances in this field which bear on the neurology of visual search in health and disease.Recent findingsForemost, visual search requires a normal apparatus for the application of attentional resources to the visual environment and, with that facility lost in hemispatial neglect, search becomes uselessly stuck within one portion of the field. New evidence suggests that loss of normal registration of where the eyes have been compounds the problem. Even if attention can be deployed flexibly, its parameters must be chosen strategically, in terms of saccade amplitude, size of attentional window at each fixation and search path taken. Evidence is growing that the prefrontal cortex plays a complex role in this strategic control. Rehabilitation strategies of the future may be tailored according to which component functions have been lost in different patient groups.SummaryVisual search is a dominant human activity and provides not only a window into how brain function is deranged after structural damage, but also offers the prospect of an ideal modality through which to deliver future behavioural therapies. New techniques have advanced our understanding of the physiology of visual search enormously in the past few decades. The time is now ripe in which to begin to integrate these findings into our understanding of the pathophysiology and treatment prospects of neurological disorders like hemispatial neglect, hemianopia and other deficits after stroke.

ISSN:1350-7540    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Purpose of reviewClassical and modern computed tomography imaging techniques, including conventional computed tomography, perfusion-computed tomography and computed tomography-angiography for acute stroke are reviewed.Recent findingsThrombolysis has become an approved therapy for acute stroke. However, many stroke patients do not benefit from such treatment, since the presently used criteria are very restrictive, notably with respect to the accepted time-window. Even so, a significant rate of intracranial hemorrhage still occurs. Conventional cerebral computed tomography has been proposed as a selection tool for acute stroke patients. Recently, more modern computed tomography techniques, referred to as functional computed tomography or perfusion-computed tomography, have been introduced. Such perfusion-computed tomography techniques are competing favorably with diffusion-weighted/perfusion-weighted magnetic resonance imaging in the delineation of the penumbra. They are more easy to perform, because they are readily available and accessible in emergency settings, and less time-consuming. Furthermore, perfusion-computed tomography combined with computed tomography-angiography affords a comprehensive non-invasive survey of acute stroke patients as early as at the time of their emergency admission, with accurate demonstration of the site of arterial occlusion and its hemodynamic and pathophysiological repercussions for the brain parenchyma.SummaryA renewal of computed tomography in the field of stroke has been afforded by the introduction of functional techniques such as perfusion-computed tomography, which provides promising insights into cerebral tissue viability and can be used as a guidance tool for therapy when combined with computed tomography-angiography.

ISSN:1350-7540    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Purpose of reviewThis review covers experimental developments in the laboratory and their translation to clinical stroke trials over the year from 3 August 2001 to 2002.Recent findingsRecent findings include novel observations in the areas of excitotoxicity, free radical injury, neuro-inflammation and apoptosis. A key clinical finding this year has been the translation of the effects of hypothermia in global ischemia to two successful trials in cardiac arrest with patients cooled within 4-8 h following resuscitation achieving good neurological outcomes, as compared with their normothermic controls. An era of molecular imaging in stroke research is presaged by the first reports of enhanced magnetic resonance or labelingin vivowith supramagnetic contrast agents.SummaryAlthough none of the drugs in focal ischemia has translated from experimental models, for the first time there is evidence of cytoprotection for the brain that has been translated from the laboratory to man.

ISSN:1350-7540    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

Purpose of reviewStroke thrombolysis is in the process of moving from academic centers into community-based standard therapy in experienced centers. Recently published data on patient selection, imaging and other technical or organizational advances are reviewed in order to improve the safety and efficacy of stroke thrombolysis and identify areas in which more study is needed.Recent findingsDuring the past year, several open series were published on the application of thrombolysis in community-based settings, which have mostly reproduced the outcome described in randomized, placebo-controlled recombinant tissue plasminogen activator cohorts. New information has been produced to identify the clinical parameters that are associated with good and adverse outcomes after stroke thrombolysis. Elevated blood glucose decreases the likelihood of a good outcome and increases that of cerebral hemorrhagic change, but the effect of early glucose reduction needs to be investigated. Non-contrast computed tomography still prevails as the standard imaging method in patient selection, but computed tomography angiography can be added within a reasonable time to furnish vascular diagnosis. Perfusion-weighted imaging is used to quantify the fraction of brain tissue salvaged by intravenous thrombolysis, and may be used in the future to select patients with still viable penumbral brain tissue, even beyond a 3-h time-window, if efficacy can be proved.SummaryThrombolysis with recombinant tissue plasminogen activator is well tolerated and effective within 3 h of symptoms, and new trials will determine if extension of this time-window or new target populations for thrombolysis, such as children with stroke, can be substantiated. An unfinished task remains in the education of health personnel; imperatives stemming from pathophysiology need to penetrate attitudes on acute stroke at all levels before acute therapies such as thrombolysis can have an impact on stroke outcome in general.

ISSN:1350-7540    

出版商:OVID    

年代:2003

数据来源: OVID