CORTICAL STIMULATION IN APHASIA Richard L. Harvey, MD Rehabilitation Institute of Chicago, Chicago, USA Northwestern University, Feinberg School of Medicine,

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


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 2011; 119: 206-213

OPTIMAL STIMULATION SITE FOR RTMS RIGHT HEMISPHERE





Naeser MA, et al. Arch Phys Med Rehabil.2012; 93:S26-S34

CRITICAL ROLE OF PARS OPERCULARIS IN APHASIA RECOVERY


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)

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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)

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

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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


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


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)


RESULTS

35


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.

Documents

CORTICAL STIMULATION IN APHASIA Richard L. Harvey, MD Rehabilitation Institute of Chicago, Chicago, USA Northwestern University, Feinberg School of Medicine,