Transcranial Direct Current Stimulation and Aphasia Language Therapy
| Status: | Active, not recruiting |
|---|---|
| Conditions: | Neurology |
| Therapuetic Areas: | Neurology |
| Healthy: | No |
| Age Range: | 21 - Any |
| Updated: | 4/21/2016 |
| Start Date: | March 2010 |
| End Date: | December 2016 |
The purpose of this study is to evaluate the effectiveness of small amounts of electrical
current, applied without surgery to the brain, in combination with speech-language
treatment, on the language outcome of study subjects with nonfluent aphasia (i.e. difficulty
with the comprehension and expression of spoken and written language) following a stroke.
current, applied without surgery to the brain, in combination with speech-language
treatment, on the language outcome of study subjects with nonfluent aphasia (i.e. difficulty
with the comprehension and expression of spoken and written language) following a stroke.
Stroke is the third leading cause of death and the most common cause of disability in the
United States. According to the American Stroke Association, the prevalence of stroke in the
U.S. is approximately 4.8 million with approximately 700,000 additional strokes occurring
annually. Approximately 150,000 to 250,000 stroke survivors becoming severely and
permanently disabled each year.
A common neurological deficit among stroke survivors, and thus a substantial contributor to
post-stroke disability, is aphasia. The loss of, or difficulty with language is extremely
debilitating and has enormous social and economic impact on quality of life. Presently, the
only treatment available for persons with aphasia is speech-language rehabilitation.
With rehabilitation only, however, many patients achieve a less than satisfactory
improvement in speech-language function, and thus are left with significant disability.
Enhancing stroke recovery by facilitating brain plasticity with the direct application of
stimulation to the cerebral cortex is a new area of investigation and shows promise for
improving language recovery in stroke-induced aphasia, most probably when it is combined
with intense learning. There are several methods of delivering cortical brain stimulation to
modulate cortical excitability, each of which have been studied in animal models with
promising results, and subsequently applied to the rehabilitation of motor deficits after
stroke. Applications to language problems after stroke are only emerging. Nevertheless,
results suggest a potential role for cortical stimulation as an adjuvant strategy in aphasia
rehabilitation.
Of the cortical stimulation methods available, transcranial direct current stimulation
(tDCS) has the greatest potential for clinical use in view of its non-invasive application,
ease of administration and relatively low cost. tDCS is a method of delivering weak
polarizing electrical currents to the cortex via two electrodes placed on the scalp. The
nature of the effect depends on the polarity of the current. Anodal tDCS has an excitatory
effect; cathodal tDCS induces inhibition.
This study proposes to evaluate the safety, feasibility, and effectiveness of anodal and
cathodal tDCS in study subjects with Broca's aphasia after stroke, delivered concurrent with
speech-language rehabilitation.
Subjects will receive speech and language therapy combined with either anodal, cathodal, or
sham stimulation applied to the lesioned left hemisphere. The polarity conditions will be
compared with each other and with sham stimulation, to determine safety, the degree to which
improvements in language performance occur, and the degree to which they are maintained over
time.
The protocol is single-blind. Neither the subjects nor the outcomes assessor will know what
stimulation the subject received until the study's conclusion; the investigator applying the
stimulation will know.
United States. According to the American Stroke Association, the prevalence of stroke in the
U.S. is approximately 4.8 million with approximately 700,000 additional strokes occurring
annually. Approximately 150,000 to 250,000 stroke survivors becoming severely and
permanently disabled each year.
A common neurological deficit among stroke survivors, and thus a substantial contributor to
post-stroke disability, is aphasia. The loss of, or difficulty with language is extremely
debilitating and has enormous social and economic impact on quality of life. Presently, the
only treatment available for persons with aphasia is speech-language rehabilitation.
With rehabilitation only, however, many patients achieve a less than satisfactory
improvement in speech-language function, and thus are left with significant disability.
Enhancing stroke recovery by facilitating brain plasticity with the direct application of
stimulation to the cerebral cortex is a new area of investigation and shows promise for
improving language recovery in stroke-induced aphasia, most probably when it is combined
with intense learning. There are several methods of delivering cortical brain stimulation to
modulate cortical excitability, each of which have been studied in animal models with
promising results, and subsequently applied to the rehabilitation of motor deficits after
stroke. Applications to language problems after stroke are only emerging. Nevertheless,
results suggest a potential role for cortical stimulation as an adjuvant strategy in aphasia
rehabilitation.
Of the cortical stimulation methods available, transcranial direct current stimulation
(tDCS) has the greatest potential for clinical use in view of its non-invasive application,
ease of administration and relatively low cost. tDCS is a method of delivering weak
polarizing electrical currents to the cortex via two electrodes placed on the scalp. The
nature of the effect depends on the polarity of the current. Anodal tDCS has an excitatory
effect; cathodal tDCS induces inhibition.
This study proposes to evaluate the safety, feasibility, and effectiveness of anodal and
cathodal tDCS in study subjects with Broca's aphasia after stroke, delivered concurrent with
speech-language rehabilitation.
Subjects will receive speech and language therapy combined with either anodal, cathodal, or
sham stimulation applied to the lesioned left hemisphere. The polarity conditions will be
compared with each other and with sham stimulation, to determine safety, the degree to which
improvements in language performance occur, and the degree to which they are maintained over
time.
The protocol is single-blind. Neither the subjects nor the outcomes assessor will know what
stimulation the subject received until the study's conclusion; the investigator applying the
stimulation will know.
Inclusion Criteria:
- A single unilateral left-hemisphere infarct that is confirmed by CT scan or MRI
- Nonfluent aphasia, with a mean length of utterance of 0-4 words and an Aphasia
Quotient score on the Western Aphasia Battery of 25-70
- Age 21 or older
- At least 6 months post-stroke
- Premorbidly right-handed, as determined by the Edinburgh Handedness Inventory
- Premorbidly literate in English
- Completed at least an eighth grade education
- Visual acuity no worse than 20/100 corrected in the better eye
- Auditory acuity, aided in the better ear, no worse than 30 dB HL on a pure tone
hearing screening (conducted at 500, 1000, 2000, and 4000 Hz.)
Exclusion Criteria:
- Any other neurological condition (other than cerebral vascular disease) that could
potentially affect cognition or speech, such as Parkinson's Disease, Alzheimer's
Dementia, traumatic brain injury
- Any significant psychiatric history prior to the stroke, such as severe major
depression or psychotic disorder requiring hospitalization; subjects with mood
disorders who are currently stable on treatment will be considered
- Active substance abuse
- Seizure disorder that precludes safe participation in this trial
- Absence of left hemisphere activation during two of the three fMRI tasks
- Presence of lesions that encompass premotor cortex from the Sylvian fissure to a
point high on the convexity
We found this trial at
1
site
Chicago, Illinois 60611
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