Altered individual behavioral and EEG parameters are related to the EDSS score in relapsing-remitting multiple sclerosis patients

Abstract

Functional neuroanatomy of cognitive impairment in multiple sclerosis is currently still a challenge. During the progression of the disease, several cognitive mechanisms deteriorate thus diminishing the patient’s quality of life. A primary objective in the cognitive assessment of multiple sclerosis (MS) patients is to find reliable measures utilizing diverse neuroimaging techniques. Moreover, especially relevant in the clinical environment is finding technical approaches that could be applied to individual participants and not only for group analysis. A 64-channel electroencephalographic recording (EEG) was made with thirty participants divided into three groups of equivalent size (N = 10) (healthy control, low-EDSS (1–2.5) and moderate-EDSS (4–6)). Correlation analysis was applied to multiple measures: behavior, neuropsychological tests (Paced Auditory Serial Addition Test, 3 seconds (PASAT-3s) and the Symbol Digit Modality Test (SDMT)), Expanded Disability Status Scale (EDSS), even-related potential (P3) and event-related desynchronization (ERD) parameters and the correlation scores between individual participant’s P3/ERD maps and the healthy grand average P3/ERDmaps. Statistical analysis showed that diverse parameters exhibited significant correlations. A remarkable correlation was the moderate score found between SDMT and EDSS (r = −0.679, p = 0.0009). However, the strongest correlation was between the value of integrated measures (reaction time, P3 and ERD latency) and EDSS (r = 0.699, p = 0.0006). In regard to correlations for grand average maps between groups, the P3 component exhibited a lower score according to a more deteriorated condition (higher EDSS). In contrast, ERD maps remained stable with an increase of EDSS. Lastly, a Z-transformation of individual values of all variables included in the study exhibited heterogeneity in cognitive alterations in the multiple sclerosis participants.

Electroencephalographic evidence of gray matter lesions among multiple sclerosis patients

“…More disabilities were evident among patients with PDR frequencies lower than 4 Hz. Functional disabilities partly include the cognitive domain that is negatively associated with the progression of MS disease as indicated by functional imaging techniques [29] . Therefore, the PDR frequency correlates with cognitive function and speed of processing as indicators of cortical and subcortical lesions among MS patients.…”

Deficits in Early Sensory and Cognitive Processing Are Related to Phase and Nonphase EEG Activity in Multiple Sclerosis Patients

“…Some studies have applied the visual oddball task in patients with MS [ 5 , 6 , 9 , 10 , 12 , 49 ]. Few authors have compared the performance between MS patients and healthy controls [ 9 , 10 , 49 ]. In two of these previous studies, no differences in reaction time in the visual oddball paradigm were observed between MS patients and healthy controls [ 9 , 10 ].…”

“…Some studies have applied the visual oddball task in patients with MS [5,6,9,10,12,49]. Few authors have compared the performance between MS patients and healthy controls [9,10,49].…”

Effects of brain-computer interface with functional electrical stimulation for gait rehabilitation in multiple sclerosis patients: preliminary findings in gait speed and event-related desynchronization onset latency

“…ERD could be detected in persons with motor sequelae due to brain injury like stroke [21][22][23] or MS [24,25]. Furthermore, it has been shown that pwMS with moderate impairment evidence a delayed upper limb ERD-onset compared to healthy subjects [24,25]. To our knowledge, there are no reports about similar time-course analysis in lower limb ERD of pwMS.…”

“…This phenomenon is known as event-related desynchronization (ERD) [20]. ERD could be detected in persons with motor sequelae due to brain injury like stroke [21][22][23] or MS [24,25]. Furthermore, it has been shown that pwMS with moderate impairment evidence a delayed upper limb ERD-onset compared to healthy subjects [24,25].…”