Non-communicating syringomyelia: a feature of spinal cord involvement in multiple sclerosis

In patients with multiple sclerosis (MS) non-communicating syringomyelia (NCS) has been described as an incidental finding in case studies and small case series. NCS in MS patients commonly leads to uncertainty particularly as the clinical picture of NCS is variable and surgical therapy may be considered. Up to date little is known about the prevalence and clinical importance of NCS in MS. We report the imaging and clinical characteristics of NCS formations in nine MS patients from a 1 year follow-up study in a representative group of 202 MS (4.5%) patients. Brain and spinal cord MRI was performed as part of a genetic study. NCS did commonly extend the central canal and the cord was slightly distended at the level of the syrinx. The cord and syrinx showed no tendency to change in size or shape over 1 year. Despite thorough search into the clinical history and current clinical status no definite but only minimal indications of symptoms potentially related to the NCS were found. We confirm that NCS may occur in MS patients with spinal cord pathology. It can be a subtle finding without clinical correlates. Syrinx formations are more likely to be a consequence of MS cord pathology than a coincidental findin

Evaluation of a new approach for semi-automatic segmentation of the cerebellum in patients with multiple sclerosis

Cerebellar dysfunction is an important contributor to disability in patients with multiple sclerosis (MS), however, few in vivo studies focused on cerebellar volume loss so far. This relates to technical challenges regarding the segmentation of the cerebellum. In this study, we evaluated the semi-automatic ECCET software for performing cerebellar volumetry using high-resolution 3D T1-MR scans in patients with MS and healthy volunteers. We performed test-retest as well as inter-observer reliability testing of cerebellar segmentation and compared the ECCET results with a fully automatic cerebellar segmentation using the FreeSurfer software pipeline in 15 MS patients. In a pilot matched-pair analysis with another data set from 15 relapsing-remitting MS patients and 15 age- and sex-matched healthy controls (HC), we assessed the feasibility of the ECCET approach to detect MS-related cerebellar volume differences. For total normalized cerebellar volume as well as grey and white matter volumes, intrarater (intraclass correlation coefficient (ICC)=0.99, 95% CI=0.98-0.99) and interobserver agreement (ICC=0.98, 95% CI=0.74-0.99) were strong. Comparison between ECCET and FreeSurfer results likewise yielded a good intraclass correlation (ICC=0.86, 95% CI=0.58-0.95). Compared to HC, MS patients had significantly reduced normalized total brain, total cerebellar, and grey matter volumes (p≤0.05). ECCET is a suitable tool for cerebellar segmentation showing excellent test-retest and inter-observer reliability. Our matched-pair analysis between MS patients and healthy volunteers suggests that the method is sensitive and reliable in detecting cerebellar atrophy in M

Eine vergleichende Studie zur zerebralen Repräsentation des Spiegelneuronensystems und der Deutschen Gebärdensprache bei Normalprobanden sowie Gehörlosen

The mirror neuron system is an observation-execution matching system activated, in humans, during action observation, motor learning, and imitation of action. Furthermore it is hypothesized that the mirror neuron system plays a key role during the evolution of language and provides the necessary link between manual gestures as an early step in communication preceding vocalization. This theory is based on a functional overlap between cerebral systems involved in action observation and those mediating linguistic processing. However, observation of manual actions and decoding of oral linguistic information are bound to different modalities thus not allowing for systematic investigation of network overlap. In the present study we investigated sign language, a natural language sharing both manual output and visual input with action observation, in deaf signers and hearing controls using functional magnetic resonance imaging. We identified a common network for sign language lexem comprehension and action observation in deaf signers and hearing controls involving bilateral frontal and inferior parietal areas including classic language regions. In contrast, differential activations between deaf signers and hearing controls were observed within bilateral posterior temporal and adjacent parietal regions both for the linguistic and the action observation task. The integration of posterior temporal and parietal regions in the dorsal stream for visual spatial and linguistic processing indicates cross-modal plasticity due to auditory deprivation. The data of the present study demonstrated an overlap between functional representations of the mirror neuron system and the language network when tested within the same modality

Rapid Automatic Segmentation of the human Cerebellum And its Lobules (RASCAL)

Reliable and fast segmentation of the human cerebellum with its complex architecture of lobes and lobules has been a challenge for the past decades. Emerging knowledge of the functional integration of the cerebellum in various sensori-motor and cognitive-behavioural circuits demands new automatic segmentation techniques, with accuracies similar to manual segmentations, but applicable to large subject numbers in a reasonable time frame. This article presents the development and application of a novel pipeline for rapid automatic segmentation of the human cerebellum and its lobules (RASCAL) combining patch-based label-fusion and a template library of manually labeled cerebella of 16 healthy controls from the International Consortium for Brain Mapping (ICBM) database. Leave-one-out experiments revealed a good agreement between manual and automatic segmentations (Dice kappa = 0.82). Intraclass correlation coefficients (ICC) were calculated to test reliability of segmented volumes and were highest (ICC > 0.9) for global measures (total and hemispherical grey and white matter) followed by larger lobules of the posterior lobe (ICC>0.8). Further we applied the pipeline to all 152 young healthy controls of the ICBM database to look for hemispheric and gender differences. The results demonstrated larger native space volumes in men then women (mean (± SD) total cerebellar volume in women = 217cm3 (± 26), men = 259cm3 (± 29); p<0.001). Significant gender-by-hemisphere interaction was only found in stereotaxic space volumes for white matter core (men>women) and anterior lobe volume (women>men). This new method shows great potential for the precise and efficient analysis of the cerebellum in large patient cohorts

A semi-automatic method for the quantification of spinal cord atrophy

Due to its high flexibility, the spinal cord is a particularly challenging part of the central nervous system for the quantification of nervous tissue changes. In this paper, a novel semi-automatic method is presented that reconstructs the cord surface from MR images and reformats it to slices that lie perpendicular to its centerline. In this way, meaningful comparisons of cord cross-sectional areas are possible. Furthermore, the method enables to quantify the complete upper cervical cord volume. Our approach combines graph cut for presegmentation, edge detection in intensity profiles for segmentation refinement, and the application of starbursts for reformatting the cord surface. Only a minimum amount of user input and interaction time is required. To quantify the limits and to demonstrate the robustness of our approach, its accuracy is validated in a phantom study and its precision is shown in a volunteer scan–rescan study. The method’s reproducibility is compared to similar published quantification approaches. The application to clinical patient data is presented by comparing the cord cross-sections of a group of multiple sclerosis patients with those of a matched control group, and by correlating the upper cervical cord volumes of a large MS patient cohort with the patients’ disability status. Finally, we demonstrate that the geometric distortion correction of the MR scanner is crucial when quantitatively evaluating spinal cord atrophy

The Role of the Cerebellum in Multiple Sclerosis

In multiple sclerosis (MS), cerebellar signs and symptoms as well as cognitive dysfunction are frequent and contribute to clinical disability with only poor response to symptomatic treatment. The current consensus paper highlights the broad range of clinical signs and symptoms of MS patients, which relate to cerebellar dysfunction. There is considerable evidence of cerebellar involvement in MS based on clinical, histopathological as well as structural and functional magnetic resonance imaging (MRI) studies. The review of the recent literature, however, also demonstrates a high variability of results. These discrepancies are, at least partially, caused by the use of different techniques and substantial heterogeneity among the patient cohorts in terms of disease duration, number of patients, and progressive vs. relapsing disease courses. Moreover, the majority of studies were cross-sectional, providing little insight into the dynamics of cerebellar involvement in MS. Some links between the histopathological changes, the structural and functional abnormalities as captured by MRI, cerebellar dysfunction, and the clinical consequences are starting to emerge and warrant further study. A consensus is formed that this line of research will benefit from advances in neuroimaging techniques that allow to trace cerebellar involvement at higher resolution. Using a prospective study design, multimodal high-resolution cerebellar imaging is highly promising, particularly in patients who present with radiologically or clinically isolated syndromes or newly diagnosed MS