TORONTO -- A CT scan is usually used to diagnose a problem, not treat it.

But Canadian scientists are using CT scans to test out a provocative theory: could low doses of radiation from the scans actually help treat Alzheimer's?

Results from a small pilot study found that patients who received repeated doses of low-dose radiation displayed an improvement in cognition, speech and movement, with some being able to share moments with family that they hadn鈥檛 been able to in years.

Dr. Morris Freedman, head of the division of neurology at Baycrest Rotman Research Institute and one of the researchers behind the study, said the concept sounded far-fetched to him initially.

鈥淔irst reaction is that 鈥榯his does not sound like it would be a very effective treatment for Alzheimer's disease鈥,鈥 he told 麻豆影视. 鈥淏ut when I looked deeper and looked at the background for this suggestion, I thought that it was worth doing a small pilot, to see if there was any effect.鈥

In what is believed to a be a world first, researchers in the clinical pilot study gave four seniors who had severe Alzheimer鈥檚 disease three treatments of low-dose radiation over a period of six weeks.

The amount of radiation in each dose was no more than a person would receive in a clinical scan.

Three of the four patients improved after just one dose, with families reporting increased alertness, mobility and mood. The fourth patient, who saw no changes, was the oldest included in the study, at 90 years old. The others were all in their 80s.

Among those who improved, one man was able to speak to his granddaughter on the phone and remember her name, read aloud signs that were posted on the wall, and clap and sing along at a concert. Another patient was described in the study as having detailed conversations with her family about her past.

"She cried a few times,鈥 the study stated. 鈥淲hen asked whether she was in pain or upset, she replied, 鈥淣o, I鈥檓 very happy.鈥濃

鈥淚mprovement was in the interaction, in the recognition,鈥 Freedman explained. 鈥淥ne family member said that when a son came into the room [before this treatment], the patient wouldn't respond, wouldn鈥檛 acknowledge that the person was there.

And after the radiation, they did.鈥

or another dementia,a progressive brain disease with no cure.

Because there is no cure, treatments focus on restoring some functioning in order to improve the quality of life for patients suffering from Alzheimer鈥檚.

However, the

Freedman noted that the patients they looked at in the study, which was run in collaboration with Sunnybrook Health Sciences, were experiencing 鈥渧ery severe鈥 Alzheimer's.

鈥淭hey had advanced Alzheimer's disease, and any kind of improvement is significant, especially the kinds of improvements that translate into an awareness of family members, interaction, bringing back memories, bringing back behaviours that were there before 鈥 these things are very important,鈥 Freedman said. 鈥淎nd it really reflects on their quality of life. So I think that this is quite significant.鈥

Another person who found the results exciting is Tammy, whose 87-year old father Allan was part of the study.

Tammy, who asked us not to use her last name, recorded a video of her father before treatment, and another afterwards, showing the sudden and dramatic improvements.

鈥淚 got him to clap his hands,鈥 Tammy said. 鈥淗e was more responsive, with yeses and no's.鈥

A big moment for her was hearing her father address her with more recognition than he had in a very long time.

鈥淚 can't put it into words, it was really like a miracle,鈥 she said. 鈥淗e said 'you came to see me'. I haven't heard him speak in I can't tell you how long it was.鈥

Having that moment with her father was incredibly important to her.

鈥淚t was really just, aside from the day that my kids were born, just one of the most beautiful days I've ever had,鈥 Tammy said.

Despite animal research and case reports where patients with Alzheimer's improved after CT scan exposures, many remain sceptical, according to Jerry Cuttler, lead author of the Baycrest-Sunnybrook study and a nuclear engineer who has previously published several case reports following the progress of one patient with Alzheimer's who received radiation.

鈥淢ost doctors don't believe this,鈥 Cuttler told 麻豆影视. 鈥淭hey think it's snake oil. It鈥檚 not accepted, it's not mainstream medicine.鈥

The controversy stems from the fact that radiation is 鈥済enerally accepted鈥 as a cause of DNA mutations and something that increases the risk of cancer, according to the study itself.

The radiation dose in CT scans is low 鈥 not a risk to the patients 鈥 but researchers believe it triggers the body to somehow repair damage in the brain.

The mechanisms that may be involved are not fully understood, which is why more studies are needed, scientists say.

鈥淩adiation is the kind of thing that in a low dose may do a very different effect than in a high dose,鈥 Freedman said. 鈥淚n a low dose, that might actually be stimulating protective mechanisms in the brain 鈥 in a high dose, it may be causing harm.鈥

Cuttler has long advocated for more investigation into the use of radiation for Alzheimer's patients, and now medical professionals such as Freedman are seeing enough potential to merit further studies.

鈥淚f you had asked me five years ago, whether I thought it would help Alzheimer's disease, I probably would have said, I don't think so,鈥 Freedman said.

鈥淎nd here I am talking about the results of our pilot study, where it looks like it could be a potential treatment for Alzheimer's disease.鈥

, a woman in her 80s experienced such an improvement after receiving CT scans that she was able to be moved from hospice care to long-term care for around a year after her treatment starting in 2015.

The goal in this new pilot study was to see if those results could be replicated.

"Numerous neurological disorders, including Alzheimer's disease, are thought to be caused in part by oxidative stress that damages all cells, including those in the brain,鈥 Cuttler explained in a press release. 鈥淲e have natural protection systems to combat the damage, but they become less effective as we get older. Each dose of radiation stimulates our natural protection systems to work harder 鈥 to produce more antioxidants that prevent oxidative damage, to repair more DNA damage and to destroy more mutated cells.鈥

Because this study was so limited in scope and size, researchers believe more work needs to be done before we can know definitely if this strategy works.

鈥淚 think that we should do this study again with a larger number of people,鈥 Freedman said. 鈥淲e should have a [control] group, where there's the real radiation treatment group, where there isn't, and really see what the effectiveness of this treatment is. This would require funding. But that would be the next thing to do.鈥

鈥淭he nice thing about this is the treatment works quickly, it see results later that day or the next day,鈥 Cuttler said. 鈥淎nd so, if we can get organized, properly planning treatments, we should be able to get meaningful scientific results.鈥

If funding and support can be found, this could be the start of a new method to treat dementia and Alzheimer鈥檚 patients.