Non-invasive brain stimulation can help stroke patients recover from chronic speech-language impairment, according to new research.
That was the initial result of a study by Dr. Roy Hamilton, the co-director of the Laboratory for Cognition and Neural Stimulation at the University of Pennsylvania Medical School.
His study was published in the Journal of Visualized Experiments, which issued a press release on his work.
Hamilton did lab research on a “well-curated” population of stroke patients and demonstrated long-term improvement in language production after transcranial magnetic stimulation, or TMS.
“The heart of our work is to use non-invasive brain stimulation… to modulate cortical networks that we think are in flux,” he said. “We think that those circuits in the brain do remodel and that we can tweak them further using non-invasive stimulation.”
According to Hamilton, “For most people the left hemisphere plays a dominant role in our language capacity. The brain does have the capacity to reorganize itself and rework some of the network and geography that represents specific cognitive skills.”
Strokes take place when a clot blocks blood flow to parts of the brain, denying groups of neurons of oxygen, which is necessary for normal function.
Nearly 130,000 of the 795,000 strokes Americans suffer annually result in death, accounting for roughly 5 percent of U.S. deaths, according to the press release. The other 665,000 stroke patients suffer of side effects including loss of motor function and speech, and even going into a catatonic state.
Seeking to get improvements in these patients, researchers have been working on the prevention, rehabilitation and restoration of function for stroke victims.
As part of these efforts, TMS has been used to improve language function in stroke patients with chronic aphasia, a language disorder that The Wall Street Journal, in a story Tuesday, defined as an “impairment to process and understand language, including speaking, reading and writing, while leaving intelligence unaffected.”
Patients who received TMS in the study had previously “reached a plateau in their ability to produce fluent language, despite signs of understanding and frustration at their inability to communicate,” the press release said.
TMS works through an aspect of the Biot-Savart Law, which states that a current running through a wire generates a magnetic field.
“Because neurons act like electric wires in the brain, targeting populations of neurons with a magnetic field can modulate their function, making them either more or less reactive,” the press release said.
TMS has only recently been used to treat stroke patients.
“Using our technique, we can take patients who are in the theoretical plateau period (in recovery) and cause continued improvement,” Hamilton said. “We like to think about it as enhancing their language plasticity.”
Patients who were administered TMS saw an extended recovery, where they not only experienced immediate improvement, but they also gained continued development of their language capacity months after treatment.
The Wall Street Journal Tuesday did an extensive story about therapy to treat stroke patients who suffer from aphasia. The story echoed Hamilton research, saying that stroke patients can see improvements, that the brain can adapt, over long periods of time.
“Encouraging new evidence is emerging to suggest the brain’s plasticity … may last many years after injury — far longer than the commonly assumed plateau for speech therapy of about six months to a year after a stroke,” The Journal wrote.
The story discusses a number of approaches to therapy for aphasia, including group programs that include craft classes. The Journal article, “Language Lost and Found,” is worth a read.