44 research outputs found
Multiple sclerosis impairs regional functional connectivity in the cerebellum
AbstractResting-state functional magnetic resonance imaging (rs-fMRI) has been used to study changes in long-range functional brain connectivity in multiple sclerosis (MS). Yet little is known about how MS affects functional brain connectivity at the local level. Here we studied 42 patients with MS and 30 matched healthy controls with whole-brain rs-fMRI at 3T to examine local functional connectivity. Using the Kendall's Coefficient of Concordance, regional homogeneity of blood-oxygen-level-dependent (BOLD)-signal fluctuations was calculated for each voxel and used as a measure of local connectivity. Patients with MS showed a decrease in regional homogeneity in the upper left cerebellar hemisphere in lobules V and VI relative to healthy controls. Similar trend changes in regional homogeneity were present in the right cerebellar hemisphere. The results indicate a disintegration of regional processing in the cerebellum in MS. This might be caused by a functional disruption of cortico-ponto-cerebellar and spino-cerebellar inputs, since patients with higher lesion load in the left cerebellar peduncles showed a stronger reduction in cerebellar homogeneity. In patients, two clusters in the left posterior cerebellum expressed a reduction in regional homogeneity with increasing global disability as reflected by the Expanded Disability Status Scale (EDSS) score or higher ataxia scores. The two clusters were mainly located in Crus I and extended into Crus II and the dentate nucleus but with little spatial overlap. These findings suggest a link between impaired regional integration in the cerebellum and general disability and ataxia
Gray matter imaging in multiple sclerosis: what have we learned?
At the early onset of the 20th century, several studies already reported that the gray matter was implicated in the histopathology of multiple sclerosis (MS). However, as white matter pathology long received predominant attention in this disease, and histological staining techniques for detecting myelin in the gray matter were suboptimal, it was not until the beginning of the 21st century that the true extent and importance of gray matter pathology in MS was finally recognized. Gray matter damage was shown to be frequent and extensive, and more pronounced in the progressive disease phases. Several studies subsequently demonstrated that the histopathology of gray matter lesions differs from that of white matter lesions. Unfortunately, imaging of pathology in gray matter structures proved to be difficult, especially when using conventional magnetic resonance imaging (MRI) techniques. However, with the recent introduction of several more advanced MRI techniques, the detection of cortical and subcortical damage in MS has considerably improved. This has important consequences for studying the clinical correlates of gray matter damage. In this review, we provide an overview of what has been learned about imaging of gray matter damage in MS, and offer a brief perspective with regards to future developments in this field
Decreasing incidence of peptic ulcer complications after the introduction of the proton pump inhibitors, a study of the Swedish population from 1974–2002
<p>Abstract</p> <p>Background</p> <p>Despite a decreasing incidence of peptic ulcer disease, most previous studies report a stabile incidence of ulcer complications. We wanted to investigate the incidence of peptic ulcer complications in Sweden before and after the introduction of the proton pump inhibitors (PPI) in 1988 and compare these data to the sales of non-steroid anti-inflammatory drugs (NSAID) and acetylsalicylic acid (ASA).</p> <p>Methods</p> <p>All cases of gastric and duodenal ulcer complications diagnosed in Sweden from 1974 to 2002 were identified using the National hospital discharge register. Information on sales of ASA/NSAID was obtained from the National prescription survey.</p> <p>Results</p> <p>When comparing the time-periods before and after 1988 we found a significantly lower incidence of peptic ulcer complications during the later period for both sexes (p < 0.001). Incidence rates varied from 1.5 to 7.8/100000 inhabitants/year regarding perforated peptic ulcers and from 5.2 to 40.2 regarding peptic ulcer bleeding. The number of sold daily dosages of prescribed NSAID/ASA tripled from 1975 to 2002. The number of prescribed sales to women was higher than to males. Sales of low-dose ASA also increased. The total volume of NSAID and ASA, i.e. over the counter sale and sold on prescription, increased by 28% during the same period.</p> <p>Conclusion</p> <p>When comparing the periods before and after the introduction of the proton pump inhibitors we found a significant decrease in the incidence of peptic ulcer complications in the Swedish population after 1988 when PPI were introduced on the market. The cause of this decrease is most likely multifactorial, including smoking habits, NSAID consumption, prevalence of Helicobacter pylori and the introduction of PPI. Sales of prescribed NSAID/ASA increased, especially in middle-aged and elderly women. This fact seems to have had little effect on the incidence of peptic ulcer complications.</p
The detrimental effects of iron on the joint : a comparison between haemochromatosis and haemophilia
Joint damage due to (recurrent) joint bleeding in haemophilia causes major morbidity. Although the exact pathogenesis has not been fully elucidated, a central role for iron is hypothesised. Likewise, in hereditary haemochromatosis joint destruction is caused by iron overload. A comparison between these types of arthropathy could provide more insight in the influence of iron in inducing joint damage. A literature review was performed to compare both disorders with respect to their clinical and histological characteristics, and preclinical studies on the influence of iron on different joint components were reviewed. Similarities in the features of arthropathy in haemochromatosis and haemophilia are cartilage degeneration, subchondral bone changes with osteophyte and cyst formation, and osteoporosis. In both disorders synovial inflammation and proliferation are seen, although this is much more explicit in haemophilia. Other substantial differences are the age at onset, the occurrence of chondrocalcinosis radiographically and calcium pyrophosphate dihydrate deposition disease in haemochromatosis, and a rapid progression with joint deformity and neovascularisation in haemophilia. Preclinical studies demonstrate detrimental effects of iron to all components of the joint, resulting in synovial inflammation and hyperplasia, chondrocyte death, and impaired osteoblast function. These effects, particularly the synovial changes, are aggravated in the presence of a pro-inflammatory signal, which is prominent in haemophilic arthropathy and minimal in haemochromatosis. Additional research is needed to further specify the role of iron as a specific target in treating these types of arthropathy