transcranial direct current stimulation & aphasia (tea): a
TRANSCRIPT
transcranial Direct Current Stimulation & aphasia
(TEA):
a neuroimaging study
Marieke Blom-Smink
Kerstin Spielmann (RoNeRes)
Dr. Carolina Mendez Orellana (Pontificia Universidad Católica de Chile, Santiago)
Prof. Dr. Gerard Ribbers (RoNeRes)
Dr. Marion Smits (Erasmus MC)
Dr. Jenny Crinion (Institute of Cognitive Neuroscience, Londen)
Dr. Mieke van de Sandt-Koenderman (RoNeRes)
R o t t e r d a m N e u r o r e h a b i l i t a t i o n R e s e a r c h
RoNeRes
Overview
� tDCS and aphasia recovery
� tDCS and aphasia recovery > neural mechanisms
� TEA-imaging study
� aim
� protocol
� outcome measures
� analyses
� current status
� conclusions
transcranial Direct Current Stimulation
� www.neuroconn.de
� - non-invasive brain stimulation
� - weak electric current (1-2 mA)
� - anode > facilitates cell firing
Nitsche & Paulus, J Physiol (2000)
aphasia recovery
Saur et al., Brain 2006
tDCS and aphasia recovery
Schlaug et al., Arch Neurol 2008
tDCS and aphasia: neural mechanisms
� Ulm et al. (2015):
� A-tDCS over Broca’s area
> increased activity in Broca’s area during A-tDCS as compared
to sham-tDCS (n = 1; chronic stage)
� Meinzer et al. (2016):
� A-tDCS over primary motor cortex in left hemisphere
> reduced activity in domain-general regions
> increased language network activity as compared to sham-
tDCS (n = 16; chronic stage)
Aim of TEA-imaging study
� What is the effect of anodal tDCS, targeting Broca’s area, on the neural
reorganization of language in stroke patients with subacute aphasia,
specifically in the context of word finding therapy?
Spielmann et al., Trials 2016 http://news.mit.edu
Design of TEA study (n = 58)
(functional) Magnetic Resonance Imaging
Structural MRI:
� brain anatomy
� brain lesions
Functional MRI:
� brain activity
� increase in oxygen-rich blood
flow to active brain areas
� change in blood oxygenation is
imaged
(f)MRI protocol
� Before treatment:
� Structural MRI scan
Structural MRI scan
� L R
Structural MRI scan
� L R
Structural MRI scan
� L R
Structural MRI scan
� L R
Structural MRI scan
� L R
Structural MRI scan
� L R
Structural MRI scan
� L R
Structural MRI scan
� L R
(f)MRI protocol
� Before treatment:
� Structural MRI scan
� Functional MRI scan:
� Auditory comprehension task
� After treatment:
� Functional MRI scan:
� Auditory comprehension task
fMRI scan – auditory comprehension
Before treatment: R L
After treatment: R L
(f)MRI protocol
� Before treatment:
� Structural MRI scan
� Functional MRI scan:
� Auditory comprehension task
� After treatment:
� Functional MRI scan:
� Auditory comprehension task
� Picture naming task
fMRI scan – picture naming
After treatment: R L
Outcome measures – TEA-imaging study
� Structural scan:
� lesion location
� lesion volume
� Functional scans:
� activated brain regions > auditory comprehension (pre / post
treatment)
> picture naming (post treatment)
� lateralization indices > auditory comprehension (pre / post
treatment)
> picture naming (post treatment)
Lateralization Index
� LI = (LH – RH) / (LH + RH)
� 0.1 < LI < 1.0 left hemispheric dominance
� -1.0 < LI < -0.1 right hemisphere dominance
� -0.1 < LI < 0.1 bilateral activation
Outcome measures – TEA-behavioral study
� Language measures
� Boston Naming Test
� Amsterdam-Nijmegen Everyday Language Test
� Aphasia Severity Rating Scale
Analyses – TEA-imaging study
� Lesion site and lesion size
� LI auditory comprehension pre / post: tDCS <> sham
� LI picture naming post: tDCS <> sham
� Activated brain regions auditory comprehension pre / post
� Activated brain regions picture naming post
� Language measures
Current status
� Participants: n = 13 (8 men, age 49-73)
� Lesions:
� site: under review by neuroradiologist
� size: M = 36.04 ml (range = 5.57 - 154.57)
� LIs: extracted last Monday ☺
Conclusions
� Results:
� will improve understanding of roles of LH and RH in neural
reorganization of language in aphasia in subacute stage after
stroke
� will contribute to the ongoing investigation of tDCS as adjunct
intervention to language therapy
Thank you for your attention