[Driving ability with multiple sclerosis]. / Fahreignung bei Multipler Sklerose.

Driving is an important issue for young patients, especially for those whose walking capacity is impaired. Driving might support the patient's social and vocational participation. The question as to whether a patient with multiple sclerosis (MS) is restricted in the ability to drive a car depends on neurological and neuropsychological deficits, self-awareness, insight into deficits and ability to compensate for loss of function. Because of the enormous variability of symptoms in MS the question is highly individualized. A practical driving test under supervision of a driving instructor (possibly accompanied by a neuropsychologist) might be helpful in providing both patient and relatives adequate feedback on driving abilities.

Combined space and alertness related therapy of visual hemineglect: effect of therapy frequency.

The combined efficacy of space- and alertness related training in chronic hemineglect was tested behaviorally and in a longitudinal fMRI study. Earlier results had shown that both space as well as alertness related training as single intervention methods lead to short term improvement which, however, is not stable for longer time periods. The neurobiological data obtained in these studies revealed differential cortical reorganization patterns for the two training approaches thereby leading to the hypothesis that a combination of both trainings might result in stronger and longer lasting effects. The results of our current study, however, - at least at first glance - do not clearly corroborate this hypothesis, because neither alertness training alone nor the combination with OKS on the group level led to significant behavioral improvement, although four of the six patients after alertness and even more after combined training showed a higher percentage of behavioral improvement than during baseline. Despite the lack of clearcut behavioral training induced improvement we found right parietal or fronto-parietal increase of activation in the imaging data immediately after combined training and at follow-up 3 weeks later. The study design had called for splitting up training time between the two training approaches in order to match total training time with our earlier single training studies. The results of our current study are discussed as a possible consequence of reduced training time and intensity of both training measures under the combined training situation.

Bidirectional alterations of interhemispheric parietal balance by non-invasive cortical stimulation.

Transcranial direct current stimulation is a painless, non-invasive brain stimulation technique that allows one to induce polarity-specific excitability changes in the human brain. Here, we investigated, for the first time in a 'proof of principle' study, the behavioural effect of transcranial direct current stimulation on visuospatial attention in both healthy controls and stroke patients suffering from left visuospatial neglect. We applied anodal, cathoP:dal or sham transcranial direct current stimulation (57 microA/cm(2), 10 min) to the left or right posterior parietal cortex. Using a visual detection task in a group of right-handed healthy individuals (n = 20), we observed that transcranial direct current stimulation enhanced or impaired performance depending on stimulation parameters (i.e. current polarity) and stimulated hemisphere. These results are in good accordance with classic models of reciprocal interhemispheric competition ('rivalry'). In a second experiment, we investigated the potential of transcranial direct current stimulation to ameliorate left visuospatial neglect (n = 10). Interestingly, both the inhibitory effect of cathodal transcranial direct current stimulation applied over the unlesioned posterior parietal cortex and the facilitatory effect of anodal transcranial direct current stimulation applied over the lesioned posterior parietal cortex reduced symptoms of visuospatial neglect. Taken together, our findings suggest that transcranial direct current stimulation applied over the posterior parietal cortex can be used to modulate visuospatial processing and that this effect is exerted by influencing interhemispheric reciprocal networks. These novel findings also suggest that a transcranial direct current stimulation-induced modulation of interhemispheric parietal balance may be used clinically to ameliorate visuospatial attention deficits in neglect patients.

Alertness-training in neglect: behavioral and imaging results.

PURPOSE: It has been proposed that the right hemisphere alerting network co-activates, either directly or via the brainstem, the spatial attention system in the parietal cortex. The observation that measures of impaired alertness and sustained attention can be used to predict the outcome of neglect might suggest such a relationship, too. The aim of the present study was to investigate the effects of alertness training on hemispatial neglect. METHOD: A three-week computerised alertness training was applied to patients with chronic (> 3 months) stable visuospatial hemineglect. Training effects were investigated both in a single case and in a group of 7 patients by means of neuropsychological tests and functional magnetic resonance imaging (fMRI). RESULTS: After the training, the patients showed a significant improvement in a neglect test battery above any natural fluctuation during a three-week baseline phase. Improvements in the neglect tasks were accompanied by an increase of both right and left hemisphere frontal, anterior cingulate and superior parietal activation, areas known to be associated with both alertness and spatial attention. Four weeks after the end of the training, the patients' neglect test performance had mostly returned to baseline. Despite decreases of activation in some of the initially reactivated areas, increases in neural activity bilaterally in frontal areas, in the right anterior cingulate cortex, the right angular gyrus and in the left temporoparietal cortex remained. An Optokinetic Stimulation Training (OKS) in a control group of another 7 neglect patients led to comparable behavioral results. After the training, however, there was a reactivation mainly in posterior parts of both hemispheres suggesting training specific functional reorganization. CONCLUSION: The limited stability of the behavioral and reactivation results over time demonstrates that a three-week alertness or OKS training alone does not result in long lasting behavioral improvements and stable reactivation patterns in every patient. We rather suggest that combining alertness and spatial attention oriented training procedures might lead to a more stable amelioration of neglect symptoms.

Impact of alertness training on spatial neglect: a behavioural and fMRI study.

The effects of a 3-week computerised alertness training on chronic (>3 months) visuospatial hemineglect were investigated prospectively in seven patients by means of neuropsychological tests and functional magnetic resonance imaging (fMRI). Following the alertness training, the group showed improved alertness and a significant improvement in the performance of a neglect test battery over and above any improvement during a 3-week baseline phase. Improvements in the neglect tasks were accompanied by an increase of right hemisphere neural activity in frontal cortex, anterior cingulate cortex, precuneus, cuneus and angular gyrus. These areas have previously been associated with alertness and spatial attention. A similar pattern of increased neural activity was found for the left hemisphere. Four weeks after the end of the training, the patients' neglect test performance had mostly returned to baseline, while the increases in neural activity bilaterally in frontal areas, in the right anterior cingulate cortex, the right angular gyrus and the left temporoparietal cortex remained. The data show that a 3-week computerised alertness training can improve performance both in alertness and neglect tests and that these behavioural improvements are associated with reactivation in areas associated with alerting and visuospatial attention. The limited stability of these effects over time suggests that a 3-week alertness training alone does not result in long lasting improvements in every patient, but refining the treatment protocol may lead to a more stable amelioration of neglect symptoms.

[Interactive driving simulation--a new approach to diagnosis and rehabilitation of driving skills]. / Interaktive Fahrsimulation--ein neuer Weg zur Diagnose und Rehabilitation der Fahrtauglichkeit.

Until recently, major methodological problems were faced in the assessment and rehabilitation of driving ability in neurological patients, concerning practical driving lessons and driving tests as well as neuropsychological tests and therapies. The use of highly-advanced driving simulators may solve parts of this problem. However, a basic requirement for effective rehabilitation is the patients' acceptance of this method. In a semi-standardized interview with 56 patients we found that the driving simulator recently installed in the Neurological Rehabilitation Centre "Godeshöhe" was rated mainly positively. Also, patients experienced the simulator to be motivating, effective and informative. Hence, a very important prerequisite for successful use of driving simulators in neurological rehabilitation is given.