By Will Boggs, MDNEW YORK (Reuters Health) Aug 22 - Transcranial direct current stimulation (tDCS) improves recognition in patients with Alzheimer disease, according to a report in the August 12th issue of Neurology.
"Our preliminary data on Alzheimer's disease patients are promising as we observed beneficial effects after a single tDCS session, suggesting that chronic daily application might induce even greater improvement," Dr. Alberto Priori from the University of Milan told Reuters Health. "Our studies encourage broader research programs using different stimulation protocols and longer clinical follow-up to clarify the impact therapy might have on patients' daily functional activities."
Dr. Priori and colleagues investigated whether anodal tDCS (which generally increases the function of the underlying areas of the cerebral cortex) applied over the temporoparietal cortex could improve recognition memory in 10 patients with Alzheimer's disease.
Anodal tDCS significantly improved word recognition memory accuracy, the authors report, whereas cathodal tDCS (which generally suppresses the function of the underlying cerebral cortex) significantly worsened it. Sham tDCS had no impact on memory.
The results were similar after correcting memory performance for guessing, the report indicates.
Neither anodal tDCS nor cathodal tDCS induced specific changes in the attention task, compared with sham tDCS, the researchers note.
"Interestingly," the investigators say, "the tDCS-induced improvement in the word recognition test we observed in patients with Alzheimer's disease is comparable to the 16% improvement induced by long-term pharmacologic treatment with cholinesterase inhibitors."
"We are assessing possible long-lasting effects of tDCS in Alzheimer's disease patients using repeated session protocols in a larger sample with longer clinical follow-up," Dr. Priori said.
"We believe that the best results, especially in Alzheimer's disease patients, could be obtained by combining tDCS with cognitive rehabilitation," Dr. Priori added.
Neurology 2008;71:493-498.
