FRIDAY, Feb. 20 (HealthDay News) -- An experimental laser treatment of damaged brain areas failed to significantly reduce disability in stroke patients, researchers report.

The trial was the first major clinical study of "transcranial" laser therapy for stroke.

In the trial, the researchers at the University of California, San Diego used the NeuroThera laser system within 24 hours of stroke onset, with the average time to treatment being 14.6 hours. The system uses low-energy infrared radiation that targets areas in and around stroke-damaged brain tissue.

While the impact of the laser therapy didn't reach statistical significance, it did appear to offer some improvement in patients who'd suffered moderate to moderately severe strokes, said the authors of the study, which was funded by the manufacturer, PhotoThera Inc.

The study included 660 patients in four countries. Overall, 36 percent of patients treated with the laser system improved to mild or no [disability] on a disability rating scale within 90 days, compared to 30.9 percent of patients in a control group who didn't receive laser therapy.

Among patients with moderate to severe stroke impairment, 51.6 percent of those treated with the laser system improved to the mild or no disability range in 90 days, compared to 41.9 percent of control group patients.

The findings appear in the journal Stroke and were to be presented Friday at the American Stroke Association's International Stroke Conference in San Diego.

More information

The National Stroke Association has more about the effects of stroke.