Background And Purpose: In multiple sclerosis (MS) the individual disease courses are very heterogeneous among patients and biomarkers for setting the diagnosis and the estimation of the prognosis for individual patients would be very helpful. For this purpose, we are developing a multidisciplinary method and workflow for the quantitative, spatial, and spatiotemporal analysis and characterization of MS lesion patterns from MRI with geostatistics.
Methods: We worked on a small data set involving three synthetic and three real-world MS lesion patterns, covering a wide range of possible MS lesion configurations.
Available pharmacological treatments for Alzheimer disease (AD) have limited effectiveness, are expensive, and sometimes induce side effects. Therefore, alternative or complementary adjuvant therapeutic strategies have gained increasing attention. The development of novel noninvasive methods of brain stimulation has increased the interest in neuromodulatory techniques as potential therapeutic tool for cognitive rehabilitation in AD.
View Article and Find Full Text PDFDiagnosis of patients with a disorder of consciousness is very challenging. Previous studies investigating resting state networks demonstrate that 2 main features of the so-called default mode network (DMN), metabolism and functional connectivity, are impaired in patients with a disorder of consciousness. However, task-induced deactivation--a third main feature of the DMN--has not been explored in a group of patients.
View Article and Find Full Text PDFMild cognitive impairment (MCI) is considered a transitional stage between normal aging and a diagnosis of clinically probable Alzheimer disease (AD). The role of the cholinergic system in MCI is not clearly defined and needs to be further investigated. A transcranial magnetic stimulation (TMS) protocol, the short latency afferent inhibition (SAI), may give direct information about the function of some cholinergic pathways in the human motor cortex.
View Article and Find Full Text PDFFunctional brain imaging in mild cognitive impairment (MCI) reveals differences in activation of task-relevant brain areas between patients and age-matched healthy controls. However, some studies reported hyperactivation and others hypoactivation in MCI compared with controls. The inconsistencies may be explained by compensatory mechanisms due to high complexity of the applied tasks.
View Article and Find Full Text PDFNumerical processing involves either number magnitude processing, which has been related to spatial abilities and relies on superior parietal regions, or arithmetic fact retrieval, which has been related to verbal abilities and involves the inferior parietal lobule. Since men score better in spatial and women in verbal tasks, we assume that women have advantages in fact retrieval, while men have benefits in number magnitude processing. According to findings on menstrual cycle variations in spatial and verbal abilities, fact retrieval should improve during the luteal phase and magnitude processing during the follicular phase.
View Article and Find Full Text PDFLittle attention has been given to the fetal-type posterior circle of Willis (FTP) in the literature; also symptomatic basilar artery (BA) hypoplasia has been rarely reported. We aimed to illustrate that the association of a hypoplastic vertebrobasilar system (VBS) with the FTP may lead to posterior circulation ischemia. Magnetic resonance imaging and three-dimensional time-of-flight magnetic resonance angiography were performed in 88 consecutive patients with ischemic stroke or TIA in the VBS.
View Article and Find Full Text PDFWe conducted a retrospective controlled study to assess the safety and effectiveness of intravenous thrombolysis via videoconferencing, followed by patient transport to a specialized stroke unit. Between 2006 and 2009, 47 stroke patients were treated in peripheral hospitals in the county of Salzburg in Austria by intravenous thrombolysis via telemedicine; 304 patients who were treated with intravenous thrombolysis at a stroke unit served as the control group. The mean age of the patients was 67 years in the telemedicine group and 71 years in the control group.
View Article and Find Full Text PDFCentral cholinergic circuits of human brain can be tested non-invasively by coupling electrical peripheral stimulation with transcranial magnetic stimulation (TMS) of the motor cortex. The short-latency afferent inhibition (SAI) is reduced in cholinergic forms of dementia, such as Alzheimer disease (AD) and dementia with Lewy bodies, while it is normal in non-cholinergic forms of dementia, such as frontotemporal dementia. This finding suggests that this method can be used as a non-invasive additional tool for discriminating between cholinergic and non-cholinergic forms of dementia.
View Article and Find Full Text PDFThere has been little investigation on the association between cognitive impairment and the microbleeds (MBs) frequently seen in subcortical vascular dementia (SVaD). One possible mechanism of cognitive decline in individuals with SVaD could be disruption of cholinergic fibers by vascular lesions. Central cholinergic circuits in human brain can be tested non-invasively by means of a transcranial magnetic stimulation (TMS) protocol named short latency afferent inhibition (SAI) of motor cortex.
View Article and Find Full Text PDFIn previous studies event-related potentials and oscillations in response to subject's own name have been analyzed extensively on group-level in healthy subjects and in patients with a disorder of consciousness. Subject's own name as a deviant produces a P3. With equiprobable stimuli, non-phase-locked alpha oscillations are smaller in response to subject's own name compared to other names or subject's own name backwards.
View Article and Find Full Text PDFObjective: The diagnostic validity of non-phase-locked oscillations (NPLOs) and mismatch negativity (MMN) in an oddball task for assessing attentional reactivity in patients with disordered consciousness was examined.
Methods: Patients in a minimally conscious (MCS, n = 6) or vegetative (VS, n = 16) state and healthy controls (n = 15) were assessed. MMN and NPLOs were analyzed with single-subject, non-parametric statistics.
Spinal subdural hematoma (SSDH) with no underlying pathology is a very rare condition and has been rarely reported. Our patient presented with severe occipital headache as isolated symptom during the first 4 days. SSDH slowly enlarges with time, and first determines tension of the pain-sensitive dural membrane, resulting in cervicogenic-like headache.
View Article and Find Full Text PDFAlthough different lesion and neuroimaging studies had highlighted the importance of the dorsolateral prefrontal cortex (DLPFC) in language switching, the nature of this higher cortical disorder of communication and its neural correlates have not been clearly established. To further investigate the functional involvement of the DLPFC, we used transcranial magnetic stimulation (TMS) given as theta burst stimulation (TBS) in a bilingual patient showing pathologic language switching after an ischemic stroke involving the left frontal lobe. Inhibitory and excitatory TBS were applied to the left DLPFC, to the right DLPFC, or to an occipital cortical control site.
View Article and Find Full Text PDFObjective: Although many animal and human studies have been performed, the exact mechanisms of action whereby modafinil promotes wakefulness are still not completely understood. We aimed to investigate the functional effects of modafinil on motor cortex excitability in patients with narcolepsy by means of transcranial magnetic stimulation (TMS) techniques.
Methods: In a double-blind and placebo-controlled design, 24 drug-naive narcoleptic patients with cataplexy and 20 control subjects were administered modafinil or placebo over a period of 4 weeks.
We report a patient with clinical and neuroimaging findings of spontaneous intracranial hypotension (SIH) who developed cerebral venous thrombosis (CVT). An association between SIH and CVT has rarely been observed. Anticoagulation therapy was administered.
View Article and Find Full Text PDFBackground: We used fMRI to examine functional brain abnormalities of German-speaking dyslexics who suffer from slow effortful reading but not from a reading accuracy problem. Similar to acquired cases of letter-by-letter reading, the developmental cases exhibited an abnormal strong effect of length (i.e.
View Article and Find Full Text PDFThis study examined functional brain abnormalities in dyslexic German readers who - due to the regularity of German in the reading direction - do not exhibit the reading accuracy problem of English dyslexic readers, but suffer primarily from a reading speed problem. The in-scanner task required phonological lexical decisions (i.e.
View Article and Find Full Text PDFObjective: The neuronal response to hearing a subject's own (SON) compared with other names has been examined in healthy subjects as well as in patients with disorders of consciousness. So far, on electroencephalographic data, only event-related potentials (ERPs) were considered. In this study, we examined the frequency properties of SON.
View Article and Find Full Text PDFTo better understand the development of hydrocephalus of different origins, we evaluated cytokine and growth factor concentration in cerebrospinal fluid from patients with hydrocephalus. CSF was collected from patients developing hydrocephalus following hemorrhage (n = 15), patients with normal pressure hydrocephalus (n = 10), and following the embolization of unruptured intracranial aneurysms (n = 9). Myelography patients (n = 15) served as controls.
View Article and Find Full Text PDFSex differences in human brain structure have repeatedly been described, but results are inconsistent. However, these studies hardly controlled for cycle phase of women or the use of hormonal contraceptives. Our study shows that these factors are not negligible, but have a considerable influence on human brain structure.
View Article and Find Full Text PDFAcute ischemic stroke remains a condition of high morbidity and mortality. Until now, the only established therapy has been intravenous (IV) tissue-type plasminogen activator (tPA). Only 3-10% of patients with acute ischemic stroke receive this treatment.
View Article and Find Full Text PDFBecause in the early phases of spinal cord ischemia magnetic resonance imaging (MRI) can be normal, its clinical diagnosis is often difficult. We aimed to explore if motor-evoked potentials (MEPs) recordings may contribute to earlier diagnosis of spinal cord stroke. The clinical, MRI, and MEP findings in one case each of cervical and lumbar spinal cord infarction were reported.
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