Contributions
Abstract: EP1534
Type: Poster Sessions
Abstract Category: Pathology and pathogenesis of MS - Neuropsychology
Multiple sclerosis (MS) patients are rarely referred to a neuropsychologist and their cognitive deficits remain undetected until they grow to an alarming extent. Relying exclusively on a brief clinical examination is not suitable for identifying patients who should be referred to a more elaborate neuropsychological examination. A more precise, inexpensive as well as easy to apply screening tool is urgently required. We employed the sound-induced flash illusion (SiFi), a multisensory perceptual illusion, where a single visual flash is presented together with an auditory beep. If shortly thereafter (< 150 ms stimulus onset asynchrony, SOA) a second auditory beep is presented, most of the subjects perceive two instead of one visual flash, e.g. the inputs from the two different sensory modalities fuse and the subjects perceive a second, non-existing visual flash. Healthy subjects usually perceive this illusion if the SOA is less than 150 ms. For SOAs > 150 ms the illusion is less frequently or not perceived at all. However, patients with mild cognitive impairment report seeing the second visual flash even at SOAs up to 300 ms (Chan et al., 2015). Therefore, we performed the SiFi task as well as an extensive neuropsychological testing in 95 subjects (39 patients with relapse-remitting MS (RRMS), 16 subjects with progressive multiple sclerosis (PMS) and 40 healthy control subjects (HC)). MS patients reported more frequently the SiFi as compared to HC as well as compared to control, non-illusion conditions (ANOVA interaction, p < 0.05). Essentially, patients with progressive type of MS continued to perceive the SiFi even at SOAs up to 300 and 500 ms. Furthermore, MS patients' performance on cognitive measurement was significantly lower as compared to HC in tests measuring working memory, attention, concentration, speed of information processing as well as visuospatial memory and constructional ability. A linear regression demonstrated that the number of failed neuropsychological tests in MS patients was predicted by their performance in the SiFi task for the longest SOA of 500 ms but not by age or years or education. These findings support the notion that similar mechanisms of cognition and multisensory perception are impaired in MS, most prominently in progressive MS. One possible mechanism is the disruption of brain connectivity in MS due to neuroinflammatory processes. SiFi could be used as a surrogate marker for cognitive impairment in MS.
Disclosure: Yavor Yalachkov was supported by travel grants from Novartis and Genzyme and received honoraria for active participation in advisory boards as well as speaking honoraria by Genzyme and Roche. Johannes Gehrig was supported by travel grant from Novartis. Christian Förch received speaking honoraria and honoraria for active participation in advisory boards from TEVA, Roche, and Genzyme.
Abstract: EP1534
Type: Poster Sessions
Abstract Category: Pathology and pathogenesis of MS - Neuropsychology
Multiple sclerosis (MS) patients are rarely referred to a neuropsychologist and their cognitive deficits remain undetected until they grow to an alarming extent. Relying exclusively on a brief clinical examination is not suitable for identifying patients who should be referred to a more elaborate neuropsychological examination. A more precise, inexpensive as well as easy to apply screening tool is urgently required. We employed the sound-induced flash illusion (SiFi), a multisensory perceptual illusion, where a single visual flash is presented together with an auditory beep. If shortly thereafter (< 150 ms stimulus onset asynchrony, SOA) a second auditory beep is presented, most of the subjects perceive two instead of one visual flash, e.g. the inputs from the two different sensory modalities fuse and the subjects perceive a second, non-existing visual flash. Healthy subjects usually perceive this illusion if the SOA is less than 150 ms. For SOAs > 150 ms the illusion is less frequently or not perceived at all. However, patients with mild cognitive impairment report seeing the second visual flash even at SOAs up to 300 ms (Chan et al., 2015). Therefore, we performed the SiFi task as well as an extensive neuropsychological testing in 95 subjects (39 patients with relapse-remitting MS (RRMS), 16 subjects with progressive multiple sclerosis (PMS) and 40 healthy control subjects (HC)). MS patients reported more frequently the SiFi as compared to HC as well as compared to control, non-illusion conditions (ANOVA interaction, p < 0.05). Essentially, patients with progressive type of MS continued to perceive the SiFi even at SOAs up to 300 and 500 ms. Furthermore, MS patients' performance on cognitive measurement was significantly lower as compared to HC in tests measuring working memory, attention, concentration, speed of information processing as well as visuospatial memory and constructional ability. A linear regression demonstrated that the number of failed neuropsychological tests in MS patients was predicted by their performance in the SiFi task for the longest SOA of 500 ms but not by age or years or education. These findings support the notion that similar mechanisms of cognition and multisensory perception are impaired in MS, most prominently in progressive MS. One possible mechanism is the disruption of brain connectivity in MS due to neuroinflammatory processes. SiFi could be used as a surrogate marker for cognitive impairment in MS.
Disclosure: Yavor Yalachkov was supported by travel grants from Novartis and Genzyme and received honoraria for active participation in advisory boards as well as speaking honoraria by Genzyme and Roche. Johannes Gehrig was supported by travel grant from Novartis. Christian Förch received speaking honoraria and honoraria for active participation in advisory boards from TEVA, Roche, and Genzyme.