Brain Stimulation Seems to Boost Language Skills in Alzheimer's Patients

25 june 2010-- People with Alzheimer's who are losing their language skills may see some improvement by using a technique called repetitive transcranial magnetic stimulation (rTMS), early research by an Italian team suggests.

The noninvasive procedure delivers a series of rapid magnetic pulses at frequencies up to 100 Hz to the brain. Earlier studies have found that these pulses can change brain activity, depending on the frequency, the researchers explained.

Though "preliminary," the new findings "hold considerable promise, not only for advancing our understanding of brain plasticity mechanisms, but also for designing new rehabilitation strategies in patients with neurodegenerative disease," according to lead researcher Maria Cotelli, from IRCCS Centro San Giovanni di Dio Fatebenefratelli in Brescia.

The report is published in the June 24 online edition of the Journal of Neurology, Neurosurgery and Psychiatry.

For the study, Cotelli's team tried rTMS in 10 patients with moderate Alzheimer's disease. The researchers randomly assigned the patients to four weeks of rTMS at 20 Hz or two weeks of a dummy treatment followed by two weeks of rTMS. Pulses were delivered to the prefrontal lobes of the brain.

The people in the study had their memory, executive functions and language tested at the start of the study, after two and four weeks of treatment, and again after eight weeks.

After two weeks, the researchers found a significant difference between the two test groups in terms of their ability to understand spoken language.

Among people who underwent rTMS, the number of correct answers on a comprehension test went from 66 percent to more than 77 percent, while among those who did not receive the treatment the scores remained unchanged.

After the last two weeks of treatment, those who had not received rTMS initially showed improvement in language comprehension, the researchers noted.

Moreover, the improvement among those in both groups remained two months after the treatments.

rTMS did not change other language abilities or cognitive functions, including memory. This suggests that in this context rTMS is specifically related to language comprehension, Cotelli's group says.

How rTMS might work is not clear, the researchers noted. This stimulation may change activity in the brain and readjust unhealthy patterns caused by disease or damage, they speculated.

There is some evidence for this theory. Imaging studies of people with congenital or acquired brain damage show certain areas of the brain seem to be plastic and cortical activity can be "reorganized," Cotelli's group added.

"Our findings provide initial evidence for the persistent beneficial effects of rTMS on sentence comprehension in Alzheimer's disease patients," Cotelli said. "Rhythmic rTMS, in conjunction with other therapeutic interventions, may represent a novel approach to the treatment of language dysfunction in Alzheimer's disease patients."

One expert believes the findings are interesting, but they need to be replicated and extended before their value can truly be known.

Catherine M. Roe, a research instructor in neurology at the Washington University School of Medicine in St. Louis, called it "an intriguing study."

The results do seem to suggest that two to four weeks of rTMS treatment improved scores on a sentence-comprehension test among people with Alzheimer's disease, at least in the short term, she said.

However, "before concluding that the effects of the treatment are long-lasting, I think it would be important to also include in a study like this a group of participants who only received placebo treatment," Roe said.

As with all new research, it is also important to see whether the results can be shown in a larger, and different, group of people to see whether the effect is reliable, she added.

"We also need to keep in mind that we don't know whether improvement in scores on a sentence test will translate into improvement in day-to-day language comprehension," Roe said.