Studies in health risks from medical radiation diagnostic procedures, radiotherapy and environmental nuclear contamination as well as for Earth-orbit and space missions have shown that low-dose irradiation (10 cGy) causes down-regulation of neural pathways associated with cognitive dysfunctions that are also down-regulated in normal human aging and Alzheimer's disease.
Curiously Mice exposed to high-dose radiation (2 Gy)did not show these effects and associations. Intriguily, there are also reports indicating stimulatory or beneficial effects after exposure to cell phone radiofrequency radiation.
Increased brain glucose consumption after exposure to radiofrequency radiation, as confirmed by PET studies, may be a potential mechanism in this phenomenon. Some scientists think that this is related to the possible beneficial effects of infrared exposure that are sometimes asserted.
Moreover, Schuz et al. in 2009 reported that long-term cell phone users had a 30–40% decreased risk of hospitalization due to AD and vascular dementia!
Following similar observations, Beaumont Cancer Center in Michigan USA, began treated patients Alzheimer's disease with ionizing radiation at doses of 30 to 60 Gray (Gy) given in 2 Gy fractions.
In 2015 in Canada, a patient in hospice with Alzheimer's disease was treated with ionizing radiation to her brain using repeated CT scans. Improvement in cognition, speech, movement, and appetite was observed. These improvements were so momentous that she was discharged from the hospice to a long-term care home.
This was described in a report which was criticized for failing to acknowledge alternate hypotheses and confounding variables.
Two clinical trials were conducted in Canada with 5 patients in one case and 4 patients in the other, but no results were posted which presumably was due to an absence of positive results. Yet minor improvements on quantitative measures were noted. It should be noted that for having statistical significance a clinical trial should enroll several hundreds to thousands patients. Otherwise it's easy to make unsubstantiated claims.
A clinical trial with 5 patients was interrupted by COVID-19.
It seems history is repeated, a new publication describes another clinical trial with 5 patients, this time in USA at Barrow Neurological Institute.
Five patients were treated with LD-WBRT (a new acronym for radiotherapy) (2Gy x 5). Three subjects were female and two male. Four of the 5 patients experienced minimal improvement or stability in MMSE-2 scores comparing baseline before treatment and post-treatment scores at 12 months. The mini–mental state examination (MMSE) or Folstein test is a 30-point questionnaire that is used extensively in clinical and research settings to measure cognitive impairment. Three patients saw their scores improve, another remained stable, and the last experienced a considerable drop in the MMSE score. Curiously the publication does not provide any clinical trial registration number.