Medial Areas Of Primary Auditory Cortex Are Stimulated By Ultrasound

Hearing Loss

Date: 4/16/2001

2001 APR 16 - (NewsRx.com & NewsRx.net) -- by Deborah W. Heinrich, staff medical writer - Researchers at the University of Tokyo in Japan report that ultrasound can stimulate medial areas of the primary auditory cortex even in the profoundly deaf.

S. Imazumi and colleagues measured cortical activation after stimulation with bone-conducted ultrasound, air-conducted, bone-conducted, and vibro-tactile hearing aids, using three dimensional positron emission tomography scan. Results were published in the March 2001 issue of Neuroreport.

Imazumi et al. observed that the medial primary auditory cortex was activated by the aforementioned hearing aids in both normal hearing and profoundly deaf subjects. However, reduced regional cerebral blood flow was noted in the profoundly deaf.

"Extra-cochlear routes convey information to the primary auditory cortex and can therefore produce detectable sound sensation even in the profoundly deaf subjects," Imazumi et al. concluded ("Ultrasound activates the auditory cortex of profoundly deaf subjects," Neuroreport, March 2001;12(3):583-586).

The corresponding author for this study is S. Imazumi, University of Tokyo, Graduate School of Medicine, Department of Speech & Cognitive Science, Bunkyo Ku, 7-3-1 Hongo, Tokyo 1130033, Japan.

A search at www.NewsRx.net using the search term "deafness" yielded 43 articles in nine specialized reports.

Key points reported in this study include:

* The medial primary auditory cortex was activated by extra-cochlear stimuli in normal hearing and profoundly deaf subjects

* Profoundly deaf subjects had reduced cerebral blood flow

* Extra-cochlear stimuli can produce detectable sound sensation in the profoundly deaf

This article was prepared by Health & Medicine Week editors from staff and other reports.