Although Parkinson's disease (PD) is most commonly understood as a
movement disorder, scientists have found that the disease also
causes widespread abnormalities in touch and vision Ð effects.
Scientists at the Emory University School of Medicine and Zhejiang
University Medical School in Hangzhou China have verified
abnormalities in touch and vision by using magnetic resonance
imaging (fMRI) of the brain.

Although scientists studying Parkinson's disease (PD) previously
have focused on the brain's motor and premotor cortex, they haven't
looked at the somatosensory or the visual cortex.

But Emory neurologist Krish Sathian, MD, PhD, and colleagues had
earlier discovered, through tests of tactile ability, that PD
patients have sensory problems with touch.

They designed a study using fMRI to investigate the brain changes
underlying these sensory abnormalities.

After conducting a number of fMRI scans of people suffering with
Parkinson's disease, it was found that that the PD patients had much
less activation of the somatosensory areas in the brain's cortex
than did the healthy controls.

"Our finding that the visual cortex is affected in Parkinson's
disease, while surprising, makes sense given that our laboratory and
many others have shown previously that areas of the brain's visual
cortex are intimately involved in the sense of touch," Dr. Sathian
said.

"Although the reasons for this are uncertain, they may involve a
process of mental visualization of the tactile stimuli and may also
reflect a multisensory capability of the visual cortex," he added.

10/19/06(ZEENEWS.COM) -