CORTICAL STIMULATION IN APHASIA Richard L. Harvey, MD Rehabilitation Institute of Chicago, Chicago,...
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Transcript of CORTICAL STIMULATION IN APHASIA Richard L. Harvey, MD Rehabilitation Institute of Chicago, Chicago,...
CORTICAL STIMULATION IN APHASIA
Richard L. Harvey, MDRehabilitation Institute of Chicago, Chicago, USA
Northwestern University, Feinberg School of Medicine, Chicago, USA
LANGUAGE NETWORK
Left Hemisphere Right Hemisphere
Hickok & Poeppel 2007
STROKE
Three phases of language reorganisation
Saur D et al. Brain 2006;129:1371-1384
9/2/112 A Neural Interface for Artificial Limbs: Targeted Muscle Reinnervation
INTERHEMISPHERIC INHIBITION IN LANGUAGE
Theory: Rebalancing cortical excitability may improve outcome
• High freq. rTMS• Anodal tDCS• Intermittant TBS
• Low freq. rTMS• Cathodal tDCS• Continuous TBS
Naeser MA, et al. Brain and Language. 2005; 93:95-105
LOW FREQUENCY RTMS TO NON-INJURED HEMISPHERE
4 chronic stroke patients with non-fluent aphasia
LOW FREQUENCY RTMS TO NON-INJURED HEMISPHERE
1 Hz rTMS to right pars triangularis 20 minute sessions 5 days a week for 2 weeks (10 sessions) Outcome
• Boston Diagnostic Aphasia Examination• Boston Naming Test• Snodgrass and Vanderwart Picture Naming
Naeser MA, et al. Brain and Language. 2005; 93:95-105
LOW FREQUENCY RTMS TO NON-INJURED HEMISPHERE
Naeser MA, et al. Brain and Language. 2005; 93:95-105
LOW FREQUENCY RTMS TO NON-INJURED HEMISPHERE
Naeser MA, et al. Brain and Language 2011; 119: 206-213
OPTIMAL STIMULATION SITE FOR RTMS RIGHT HEMISPHERE
OPTIMAL STIMULATION SITE FOR RTMS RIGHT HEMISPHERE
Naeser MA, et al. Brain and Language 2011; 119: 206-213
OPTIMAL STIMULATION SITE FOR RTMS RIGHT HEMISPHERE
Naeser MA, et al. Brain and Language 2011; 119: 206-213
Naeser MA, et al. Arch Phys Med Rehabil.2012; 93:S26-S34
CRITICAL ROLE OF PARS OPERCULARIS IN APHASIA RECOVERY
LOW FREQUENCY RTMS TO NON-INJURED HEMISPHERE
Randomized double-blind study N=12 1 Hz rTMS to right pars triangularis vs sham stimulation 20 minute session 5 days a week for 2 weeks (10 sessions) Outcome
• Boston Diagnostic Aphasia Examination• Boston Naming Test• Snodgrass and Vanderwart Picture Naming
Results showed improved picture naming, spontaneous speech and auditory comprehension in intervention group persisting at 2 months post-treatment
Barwood CH, et al. Eur J Neurol. 2011; 18: 935-943.
INDIVIDUALIZED RTMS THERAPY – BASED ON LANGUAGE DOMINANCE
Kakuda et al. Int J Neurosci. 2010; 120: 60-66
Kakuda et al. Int J Neurosci. 2010; 120: 60-66
INDIVIDUALIZED RTMS THERAPY
10 sessions of 1200 pulses 1 Hz rTMS to homologous region of maximal activation over 2 weeks.
Scores improved in all four patients on the following measures:• Western Aphasia Battery (WAB)• Standard Language Test of Aphasia (SLTA, SLTA-ST)
Benefits persisted for 4 weeks
HIGH FREQUENCY RTMS FOR APHASIA
Chronic stroke patients with moderate to severe aphasia
N=8 10 sessions over 2 weeks Excitatory theta-burst stimulation (iTBS) to brocas
area. 6 of 8 patients showed improved verbal fluency
(semantic fluency test; p=0.028) Subjects showed a shift in signal toward left
hemisphere (LI change sig. p=0.018)
Szaflarski JP, et al. Med Scit Monitor. 2011; 25: 132-139
Szaflarski JP, et al. Med Scit Monitor. 2011; 25: 132-139
HIGH FREQUENCY RTMS FOR APHASIA
tDCS APPLICATION
TRANSCRANIAL DIRECT CURRENT STIMULATION FOR APHASIA
Chronic non-fluent aphasic patients N=8 4 patients received anodal tDCS and sham tDCS over
left fronto-temporal region in random order with one week apart.
4 patients received cathodal tDCS and sham tDCS similarly
Outcome• Picture naming
Monti A et al. J Neurol Neurosurg Psychiatry 2008;79:451-453
TRANSCRANIAL DIRECT CURRENT STIMULATION FOR APHASIA
Monti A et al. J Neurol Neurosurg Psychiatry 2008;79:451-453
ANODAL TDCS ON OVER INJURED LEFT HEMISPHERE WITH NAMING PRACTICE
Chronic fluent aphasia N=8 Anodal tDCS targeted to perilesional (left) brain areas showing
greatest activation on pre-treatment fMRI during naming task 5 sessions daily over a week with A tDCS and 5 sessions with
Sham separated by 3 weeks Treatment combined with computerized naming practice Outcome: pre-, post-, and 3 weeks post
• Trained naming task• Untrained naming task
Fridriksson J et al. Stroke. 2011;42:819-821
Reduction in RT after A-tDCS (light gray) and S-tDCS (dark gray).
Fridriksson J et al. Stroke. 2011;42:819-821
ANODAL TDCS ON OVER INJURED LEFT HEMISPHERE WITH NAMING PRACTICE
TDCS WITH APHASIA THERAPY
Chronic Non-Fluent Aphasia N=12 Randomized to anodal, cathodal or sham stimulation Randomization stratified by severity of aphasia
• Less severe aphasia (AQ>55) 2 subjects receive anodal stimulation 2 subjects receive cathodal stimulation 2 subjects receive sham stimulation
• More severe aphasia (AQ<55) 2 subjects receive anodal stimulation 2 subjects receive cathodal stimulation 2 subjects receive sham stimulation
TREATMENT PROCEDURES
5-point gain on WAB AQ and LQ and a 12-point gain on CETI are considered to be clinically significant.Note the increase in WAB scores between post-treatment and f/up for anodal and cathodal groups – which contrasts with decline for sham group
MEAN PERFORMANCE ON TRAINED PROBES (ORAL READING OF SENTENCES - % ACCURACY)
0
10
20
30
40
50
60
70
80
90
100
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
% A
ccur
acy
Week
4 participants per condition (n=12)
Pre-treatment Treatment Post-treatment Maintenance
MEAN PERFORMANCE ON TRAINED PROBES (ORAL READING OF SENTENCES – RATE WPM)
0
10
20
30
40
50
60
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Wor
ds p
er m
inut
e
Week
4 participants per condition (n=12)
Pre-treatment Treatment Post-treatment Maintenance
IMPLANTED HIGH FREQUENCY EPIDURAL STIMULATION COMBINED WITH SPEECH THERPAPY
8 subjects with non-fluent aphasia Six weeks of intensive daily aphasia therapy for all subjects Four subjects received implants and epidural cortical stimulation
during therapy (50Hz, 6.5mA or 50% of motor threshold, 3s pulse train)
Raters blinded (all subjects had head covers)
Randomization
Control Arm (4 subjects)
Investigational Arm (4 subjects)
Device Implant
Rehab w/o Stimulation
6 & 12 Wk Follow-Up
Post Tx Assmnt
Device Removal
Post Tx Assmnt
Rehab and Stimulation
Cherney LR, et al. J Neurol Neurosurg Psych. 2010; 81:1014-1021
IMPLANTED EPIDURAL CORTICAL STIMULATOR
• fMRI used to identify activation site • Epidural electrode (2x3 grid; 2.6 x 2.7 cm) placed over cortical target
indicated by fMRI (ventral precentral gyrus) • Implantable pulse generator
• Overnight hospital stay
Cherney LR, et al. J Neurol Neurosurg Psych. 2010; 81:1014-1021
ANATOMIC LOCALIZATION OF STIMULATION SITE
Activation in ventral portion of precentral gyrus or sulcus
Intersection between
1. imitation and observation tasks
OR
2. imitation and oral reading tasks
Cherney LR, et al. J Neurol Neurosurg Psych. 2010; 81:1014-1021
SAFETY OUTCOMES
No occurrences of wound infection Post-operative pain well tolerated No seizures occurred Neurological function remained stable (NIH
Stroke scale; Box and Blocks; subtests of the Behavioral Inattention Test)
Cherney LR, et al. J Neurol Neurosurg Psych. 2010; 81:1014-1021
RESULTS
35
Cherney LR, et al. J Neurol Neurosurg Psych. 2010; 81:1014-1021
CONCLUSIONS
Cortical stimulation (CS) has the potential to improve language function post stroke
Both non-invasive and invasive CS may improve long-term language function when combined with speech therapy training
CS targets include sites in both left and right hemisphere and optimal stimulation site may be patient specific
rTMS, tDCS and Epidural stimulation each have advantages and disadvantages
Large, well designed clinical trials are warreted.