The overall goal of the following experiment is to use transcranial magnetic stimulation on chronic stroke patients with non fluent aphasia in order to facilitate language recovery. This is achieved by administering a battery of standardized language tests in order to obtain a valid baseline of patient language abilities as a second step. The site of stimulation in the right inferior frontal lobe is determined using a picture naming task and is then stimulated on separate days using low frequency repetitive TMS or sham TMS.
The stimulation is delivered 10 times in a 12 day period in order to elicit persistent changes in language performance. In measures made two and six months following treatment, improvement in language function can be observed from the patient's performance on standardized language measures. This method can help answer key questions in the fields of neurology and neuro rehabilitation.
It also addresses central topics in the neuroscience of aphasia recovery, like the debated role of the right hemisphere in language recovery after stroke. The implications of this technique extend toward therapy for patients with chronic aphasia after stroke. Current behavioral treatments for patients with this condition are limited in their efficacy, but the technique that we present here offers a promising new avenue of therapy for this common and often debilitating condition.
To assess the extent of each patient's language, impairment and deficits in other cognitive domains, administer a battery of standardized tests on three separate days. These tests include the cookie theft, picture description, subtest of the BDAE, the second edition, BDAE, subtest for word comprehension with subtests for basic word discrimination and for commands. Also administer the Boston naming test, the cognitive linguistic quick test, and sets of 40 line drawing stimuli taken from the Snodgrass and Vander wart picture database.
After conducting the initial battery of tests, initiate a baseline bold FMRI study in which the patient performs a picture naming task with an oral response. Collect high resolution whole brain T one weighted images with a MP rage sequence using the specified parameters. Then acquire functional volumes using a whole brain T two weighted bold echo planer sequence.
In order to target RTMS to cortical sites in a precise and accurate manner, use a neuro navigational system to coregister high resolution whole brain T one weighted images with the location of the patient and coil. For the RTMS group, determine the resting motor threshold via stimulation to the right motor cortex and subsequent visual inspection. During real RTMS, orient the coil with the handle in a posterior and inferior direction, approximately 45 degrees clockwise from the downward position for the sham group, administer STMS with the coil perpendicular to the head so that only the outer rim of the lateral wing of the coil contacts the head With the handle.
In this orientation, the peak magnetic field runs parallel to the skull and thus does not produce cortical stimulation. Now, over the next five days, conduct six separate TMS sessions, two of which are conducted on the final day with a 45 minute break in between sessions, either administer 10 minutes of RTMS at stimulation sites in a randomized order, or STMS to the right inferior frontal lobe. These sites include the primary motor cortex corresponding to the mouth, the pars ulis, the anterior pars triangulars, the dorsal posterior pars triangulars, the ventral posterior pars triangulars, and the parse orbitals.
In conducting these stimulations, be sure to randomize the order of the stimulated sites between patients. Have the patients perform a 40 item picture naming task immediately before and each TMS session. The 40 item lists must be matched with respect to word length, frequency, and semantic category.
Also, 20 items can be novel while 20 are repeated throughout the testing sessions. To assess for practice effects when scoring, any utterance should be counted as correct if it differs from the target by no more than one phoneme. Lara Liger lo.
Be sure that the word list order is randomized across the subjects and that each subject receives a different word list at every visit. Is it Now Determine the optimal site of stimulation by comparing the change in picture naming performance to the variability in pre stimulation naming performance for all sites. Use the variance of performance across all six pre RTMS sessions.
As a comparison for Sham site finding Administer STMS over the pars triangulars, this location acts as the optimal site for the sham arm of the treatment phase. During the treatment phase, administer RTMS or STMS to the optimal stimulation site for 10 days out of a 12 day period, taking the weekend off on the first day of stimulation. The order of events is as follows.
Have the patient undergo an FMRI with concurrent picture naming as in baseline. Administer the 40 item naming task. Stimulate the optimal site using 20 minutes of either one Hertz RTMS at 90%RMT or STMS.
Then administer the naming task again. And lastly, have the patient undergo a second FMRI with concurrent picture naming on days two through nine, the protocol consists of a 20 minute RTMS session using one hertz RTMS at 90%RMT or using STMS. Then on day 10, stimulate the optimal site for 20 minutes with one hertz.
RTMS preceded and followed by the picture naming task. Be certain that the picture item lists shown on days one and 10 are different, but matched for frequency, word length, and semantic category to follow up. Two and six month visits should be performed on each patient in the site finding phase of this investigation, most, but not all patients responded optimally on the picture naming task to stimulation of the right pars triangulars.
Patient's performance on picture naming was most consistently facilitated by stimulation of the ventral posterior aspect of the pars triangulars in the long term improvement in performance on the standardized language assessments was observed. This data from one patient shows improved accuracy. In picture naming on the BNT and the naming and categories section of the BDAE, this accuracy increased over time with RTMS treatment.
After watching this video, you should have a good understanding of how to perform A TMS study on a patient population with chronic non fluent aphasia in order to induce and assess performance in language production After its development. This technique paved the way for researchers in the fields of neurology and physiology to explore the use of non-invasive brain stimulation techniques, both TMS and transcranial direct current stimulation for facilitating language recovery in patients with acquired aphasia.
