[Multiple sclerosis treatment consensus group (MSTCG): position paper on disease-modifying treatment of multiple sclerosis 2021 (white paper)]. / Multiple Sklerose Therapie Konsensus Gruppe (MSTKG): Positionspapier zur verlaufsmodifizierenden Therapie der Multiplen Sklerose 2021 (White Paper).

Multiple sclerosis is a complex, autoimmune-mediated disease of the central nervous system characterized by inflammatory demyelination and axonal/neuronal damage. The approval of various disease-modifying therapies and our increased understanding of disease mechanisms and evolution in recent years have significantly changed the prognosis and course of the disease. This update of the Multiple Sclerosis Therapy Consensus Group treatment recommendation focuses on the most important recommendations for disease-modifying therapies of multiple sclerosis in 2021. Our recommendations are based on current scientific evidence and apply to those medications approved in wide parts of Europe, particularly German-speaking countries (Germany, Austria, Switzerland).

Visual half-field experiments are a good measure of cerebral language dominance if used properly: evidence from fMRI.

Traditional neuropsychology employs visual half-field (VHF) experiments to assess cerebral language dominance. This approach is based on the assumption that left cerebral dominance for language leads to faster and more accurate recognition of words in the right visual half-field (RVF) than in the left visual half-field (LVF) during tachistoscopic presentation. Information in the RVF is directly projected to the left hemisphere, whereas information presented in the LVF needs interhemispheric transfer to reach the left half of the brain. This interpretation of the RVF superiority for word recognition lacks direct evidence however, and a multitude of studies have lead to contradictory findings. To investigate this matter further we try to establish the ideal parameters for VHF experiments to measure language dominance, and subsequently compare laterality indices (LIs) obtained from RT patterns in bilateral VHF tasks to those LIs acquired in the same individuals during a mental word generation task in the fMRI scanner. Our results reveal a direct link between VHF advantages and individual language lateralization. Differences in behavioral performance between left-hemisphere dominant and right-hemisphere dominant individuals suggest that carefully designed VHF tests can be used as a reliable predictor of cerebral language dominance.

Foveal word reading requires interhemispheric communication.

The left cerebral hemisphere is dominant for language processing in most individuals. It has been suggested that this asymmetric language representation can influence behavioral performance in foveal word-naming tasks. We carried out two experiments in which we obtained laterality indices by means of functional imaging during a mental word-generation task, using functional transcranial Doppler sonography and functional magnetic resonance imaging, respectively. Subsequently, we administered a behavioral word-naming task, where participants had to name foveally presented words of different lengths shown in different fixation locations shifted horizontally across the screen. The optimal viewing position for left language dominant individuals is located between the beginning and the center of a word. It is shifted toward the end of a word for right language dominant individuals and, to a lesser extent, for individuals with bilateral language representation. These results demonstrate that interhemispheric communication is required for foveal word recognition. Consequently, asymmetric representations of language and processes of interhemispheric transfer should be taken into account in theoretical models of visual word recognition to ensure neurological plausibility.