Clinical Neuroscience

[Functional magnetic resonance imaging in neurology (in English language)]

AUER Tibor, SCHWARCZ Attila, HORVÁTH Réka A., BARSI Péter, JANSZKY József

JANUARY 22, 2008

Clinical Neuroscience - 2008;61(01-02)

[The present contribution discusses the clinical use of functional MRI (fMRI) and its role in the most common neurological diseases. FMRI was found a reliable and reproducible examination tool resulting in a wide distribution of fMRI methods in presurgical evaluation of epilepsy in determining the relationship of eloquent areas and the epileptic focus. Preliminary data suggest that fMRI using memory paradigms can predict the postoperative memory decline in epilepsy surgery by determining whether a reorganization of memory functions took place. Speech-activated fMRI became the most used tool in determining hemispheric dominance. Visual and senso-motor cortex can also be routinely investigated by fMRI which helps in decision on epilepsy surgery. FMRI combined with EEG is a new diagnostic tool in epilepsy and sleep disorders. FMRI can identify the penumbra after stroke and can provide an additional information on metabolic state of the threatened brain tissue. FMRI has a predictive role in poststroke recovery. In relapsing-remitting MS an adaptive reorganization can be demonstrated by fMRI affecting the visual, motor, and memory systems, despite preserved functional performance. Much more extensive reorganization can be demonstrated in secondary progressive MS. These findings suggest that the different stages of MS are related to different stages of the reorganization and MS becomes progressive when there is no more reserve capacity in the brain for reorganization. FMRI offers the capability of detecting early functional hemodynamic alterations in Alzheimer’s disease before morphological changes. FMRI can be a valuable tool to test and monitor treatment efficacy in AD. FMRI can also provide information about the mechanisms of different therapeutic approaches in Parkinson disorder including drug treatment and deep brain stimulation.]

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[Background - Dementia is an increasing problem of the society. The underlying cause of dementia may be difficult to diagnose during life. Only neuropathological examination gives definite diagnosis. Differences in the reported frequency may be related to factors such as the age or gender of subjects with dementia. Materials and methods - In our neuropathology-based study we examined 156 consecutive subjects clinically diagnosed with dementia during a 3-year period. Using histopathological criteria we calculated the frequencies of various disorders causing dementia. We studied the effect of age and gender on these frequencies. Results - Alzheimer’s disease was the most frequent pathologic finding (57.7%) followed by vascular dementia (43%); diffuse Lewy body disease (15.4%); argyrophilic grain dementia (12.1%), various forms of frontotemporal dementia (5.7%); and other (4.5%). The latter comprise prion disease, alcoholic encephalopathy, and hippocampal sclerosis. Mixed pathology was common: concomitant Alzheimer’s disease was present in 41.6% of diffuse Lewy body disease cases and in 49.2% of vascular dementia patients. Pure disease forms are rare: Alzheimer’s disease: 26.3%, vascular dementia: 17.3%, diffuse Lewy body disease: 5.1%, argyrophilic grain dementia: 2.5%. Females were overrepresented among those with Alzheimer’s disease with age at death above 75 years (p <0.02), while males were overrepresented in patients below 75 years with vascular dementia (p <0.05). Conclusions - Our study indicates that the frequency of neurodegenerative dementias is high in the examined patients, but vascular pathology frequently influences the clinical course.]

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[Objective - To survey the role of pattern electroretinography (PERG) and pattern visual evoked potentials (VEPs) in the process of clinical evaluation of neuro-ophthalmological cases. The study is illustrated with the electrophysiological findings of 231 patients sent to our laboratory in 2005 because of the suspicion of damage in the optic pathway. Methods - The RETIport program of the ROLAND equipment (Wiesbaden - Germany) was used to record PERGs and VEPs. The recordings were done according to the recommendations of the International Society for Clinical Electrophysiology of Vision. Results - The combined application of PERG and VEP provided useful data on the retino-cortical conduction time and hence demyelinisation. The comparison of the N35/P50 and P50/N90 amplitudes of the PERG recordings greatly promoted the diagnostic procedure. Conclusions - The combined application of PERG and VEP methods is recommended in the assessment of optic nerve function of neuro-ophthalmological patients.]

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