Poster C21, Wednesday, August 21, 2019, 10:45 am – 12:30 pm, Restaurant Hall
Phonologically related EEG as a more reliable diagnostic tool in the recovery of aphasia in the different stages after stroke.
Miet De Letter1, Elissa-Marie Cocquyt1, Nils Knockaert1, Pieter van Mierlo2, Arnaud Szmalec3,4, Wouter Duyck3, Patrick Santens5;1Department of Rehabilitation Sciences, Ghent University, 2Medical Image and Signal Processing Group, Department of Electronics and Information Systems, Ghent University, 3Faculty of Psychology and Educational Sciences, Department of Experimental Psychology, Ghent University, 4Psychological Sciences Research Institute, Université catholique de Louvain, 5Department of Neurology, Ghent University Hospital
Introduction Phonologically evoked potentials seem to give more information about neural plasticity than behavioral investigation in people with aphasia after stroke1. Ongoing research on semantic and grammatical evaluation yields similar results. In order to validate the role of EEG in clinical aphasia diagnosis and rehabilitation, the current study investigates if phonologically evoked potentials 1. are more sensitive than behavioral data for detecting impairments in phonological input 2. can be considered as a prognostic and therapeutic indicator for people with aphasia in the different stages after stroke. Methods Eight right-handed, Dutch individuals with aphasia after stroke (6 men, 2 women, age 46;6-71;4) were included in this study. Four patients were evaluated in the subacute stage, 4 in the recovery stage. Both a behavioral and an electrophysiological language registration of phonological input were acquired at two evaluation moments (T1 and T2). Between T1 and T2, all patients received phonologically based therapy during three weeks with a maximum of two therapy sessions of 30 minutes a week. Neurophysiological findings in all patients were compared to the previously developed2 normative data. Peak amplitudes and latencies, both at T1 and T2, were compared to the normative values based on their age groups. Effect sizes were calculated to estimate the difference between the values of the patients and the normative values. Results The results of the current study confirm that neurophysiological evaluation (EEG) is more sensitive than behavioral evaluation for detecting phonological input impairments, especially when ceiling effects were reached in behavioral testing. Neurophysiological and/or behavioral indicators predicting the recovery of aphasia cannot be determined from our data, but the amplitudes and latencies of the EP’s can be helpful in guiding and monitoring therapeutic interventions. Conclusion The current results confirm previous results1,3 on the added value of EEG in the follow-up of patients with aphasia. We advocate to use EEG as a standard tool in aphasia diagnosis and follow-up. Therefore the development of a user friendly EEG device would be welcomed. 1. Aerts, Annelies, Batens, K., Santens, P., van Mierlo, P., Hartsuiker, R., Hemelsoet, D., Duyck, W., Raedt, R., Van Roost, D., & De Letter, M. (2015). Aphasia therapy early after stroke : behavioural and neurophysiological changes in the acute and post-acute phases. APHASIOLOGY, 29(7), 845–871. 2. Aerts, Annelies, van Mierlo, P., Hartsuiker, R., Hallez, H., Santens, P., & De Letter, M. (2013). Neurophysiological investigation of phonological input: aging effects and development of normative data. BRAIN AND LANGUAGE, 125(3), 253–263. 3. Khachatryan, E., De Letter, M., Vanhoof, G., Goeleven, A., & Van Hulle. (2017). Sentence context prevails over word association in aphasia patients with spared comprehension : evidence from N400 event-related potential. FRONTIERS IN HUMAN NEUROSCIENCE, 10.
Themes: Language Therapy, Phonology and Phonological Working Memory
Method: Electrophysiology (MEG/EEG/ECOG)