Contributions
Abstract: EP1568
Type: ePoster
Abstract Category: Pathology and pathogenesis of MS - 23 Neurophysiology
Multiple sclerosis (MS) is a neurological disorder characterized by progressive and extensive lesions in the brain and spinal cord, contemplating motor, cognitive and neuropsychiatric symptoms. Cognitive symptoms comprise between 40 and 70% of MS patients, affecting their functionality in both early and late stages of the disease. Memory impairment is one of the most common cognitive deficits in these patients. This cognitive ability is essential to guide behavior toward achieving goals. As part of short-term memory; Working Memory (WM) plays an important role in the cognitive process of multiple cognitive functions. The evidence about MS is scarce and contradictory regarding the nature of its cognitive impairment and its evolution.
The aim of the present research is to study the WM using the modification of the Steinberg Paradigm and electrophysiological recording during the requested tasks. Two groups were measured; one of MS patients without the manifest of cognitive alteration and another controlled group of well-matching healthy people. Participants watched arrays of 2, 4 or 6 consonants that had to be memorized. Then a black screen was shown and finally an objective stimulus was displayed (a consonant). The subjects had to respond quickly whether the consonant in the objective stimulus was either present on the array initially shown. We found significant differences in the reaction timing and correct responses in relation to the load of working memory for both the control group and the MS group. However, no significant differences between both groups were found. Regarding to Event-Related Potencials (ERPs), we found modulation in amplitudes of late potentials by memory load in both groups; showing significantly higher amplitudes on the control group. In time-frequency analyses, the both groups showed a reduction in the alpha activity in the end of codification and the beginning of the maintenance. This alpha activity modulation was significantly higher for control group. Furthermore, MS patients showed increased alpha and beta activity in the maintenance stage while, in the recovery stage, patients demonstrated an increase in alpha activity for higher load conditions. Differences in late potentials and in cortical oscillations alfa y beta, electrophysiological variables would be useful in early detecting of alterations in the WM in patients with MS.
Disclosure:
Alejandra Figueroa V: nothing to reveal
Francisco Zamorano M: nothing to reveal
Claudia Carcamo R: nothing to reveal
Ethel Ciampi: nothing to reveal
Reinaldo Uribe: nothing to reveal
Macarena Vásquez: nothing to reveal
Francisco Aboitiz D: nothing to reveal
Pablo Billeke B: nothing to reveal
Abstract: EP1568
Type: ePoster
Abstract Category: Pathology and pathogenesis of MS - 23 Neurophysiology
Multiple sclerosis (MS) is a neurological disorder characterized by progressive and extensive lesions in the brain and spinal cord, contemplating motor, cognitive and neuropsychiatric symptoms. Cognitive symptoms comprise between 40 and 70% of MS patients, affecting their functionality in both early and late stages of the disease. Memory impairment is one of the most common cognitive deficits in these patients. This cognitive ability is essential to guide behavior toward achieving goals. As part of short-term memory; Working Memory (WM) plays an important role in the cognitive process of multiple cognitive functions. The evidence about MS is scarce and contradictory regarding the nature of its cognitive impairment and its evolution.
The aim of the present research is to study the WM using the modification of the Steinberg Paradigm and electrophysiological recording during the requested tasks. Two groups were measured; one of MS patients without the manifest of cognitive alteration and another controlled group of well-matching healthy people. Participants watched arrays of 2, 4 or 6 consonants that had to be memorized. Then a black screen was shown and finally an objective stimulus was displayed (a consonant). The subjects had to respond quickly whether the consonant in the objective stimulus was either present on the array initially shown. We found significant differences in the reaction timing and correct responses in relation to the load of working memory for both the control group and the MS group. However, no significant differences between both groups were found. Regarding to Event-Related Potencials (ERPs), we found modulation in amplitudes of late potentials by memory load in both groups; showing significantly higher amplitudes on the control group. In time-frequency analyses, the both groups showed a reduction in the alpha activity in the end of codification and the beginning of the maintenance. This alpha activity modulation was significantly higher for control group. Furthermore, MS patients showed increased alpha and beta activity in the maintenance stage while, in the recovery stage, patients demonstrated an increase in alpha activity for higher load conditions. Differences in late potentials and in cortical oscillations alfa y beta, electrophysiological variables would be useful in early detecting of alterations in the WM in patients with MS.
Disclosure:
Alejandra Figueroa V: nothing to reveal
Francisco Zamorano M: nothing to reveal
Claudia Carcamo R: nothing to reveal
Ethel Ciampi: nothing to reveal
Reinaldo Uribe: nothing to reveal
Macarena Vásquez: nothing to reveal
Francisco Aboitiz D: nothing to reveal
Pablo Billeke B: nothing to reveal