November 13, 2013

Lasers and Dot Tests for Alzheimer's and Parkinson's

I left last month’s World Parkinson Congress in Montreal a bit depressed. The top researchers who spoke to us seemed to agree: there was nothing on the horizon that offered any real hope for a cure. Other WPC participants I know left Canada with the same impression. It seems there's a similar lack of promise in the Alzheimer's arena, too, although research there always seems intense.

This past week brought some brighter news. One research report offered a glimmer of hope for finding cures for both diseases; another suggested an interesting new approach for treating Parkinson's

"Photo Therapy May Someday Cure Brain Diseases"
That was the headline on one of the stories.

Researchers at Chalmers University in Sweden and Wroclaw University of Technology in Poland discovered they could use multi-photon laser techniques to distinguish between aggregations of proteins believed to cause brain diseases and properly functioning proteins.

Diseases like AD and PD develop when amyloid beta proteins aggregate to the extent they inhibit proper cellular processes. If the protein aggregates are removed, the disease is cured . . . in principle. Until now, the issue has been detecting and removing those aggregates.

Researchers hope that photoacoustic therapy -- already used for tomography (using waves to image by sections) -- could identify and remove malfunctioning proteins. Now, scientists use chemicals to detect and remove amyloid protein aggregates, but those chemicals are toxic and harmful. Multi photon laser treatment avoids those dangers, and leaves surrounding healthy brain tissue unharmed.

One of the lead researchers, Piotr Hanczyc at Chalmers University of Technology, said:
Nobody has talked about using light to treat these diseases until now. This is a totally new approach and we believe this might become a breakthrough in research of diseases such as Alzheimer’s, Parkinson’s, and Creutzfeldt-Jakob (“mad cow”) disease, We have found a totally new way of discovering these structures just using laser light.
More News: A Simple Dot Test To Assess Dopamine Loss in PD?
This report comes from a research team at Georgetown University, just five minutes from my house. My neurologist and physical therapist are both affiliated with Georgetown Hospital.

A team there reports that a simple dot test may provide a non-invasive way to evaluate the level of dopamine deficiency in people with Parkinson's. Lead author Katherine R. Gamble, a psychology PhD student, said:
It is very difficult now to assess the extent of dopamine loss—a hallmark of Parkinson's disease—in people with the disease. Use of this test, called the Triplets Learning Task (TLT), may provide some help for physicians who treat people with Parkinson's disease, but we still have much work to do to better understand its utility.
The TLT testing is described this way in a Medical Express website article
The test is a sequential learning task that does not require complex motor skills, which tend to decline in people with PD. In the TLT, participants see four open circles, see two red dots appear, and are asked to respond when they see a green dot appear. Unbeknownst to them, the location of the first red dot predicts the location of the green target. Participants learn implicitly where the green target will appear, and they become faster and more accurate in their responses. 
Previous studies have shown that the caudate region in the brain underlies implicit learning. In the study, PD participants implicitly learned the dot pattern with training, but a loss of dopamine appears to negatively impact that learning compared to healthy older adults.

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