A study by IRCCS Santa Lucia con UCBM and the University of Turin
June 21, 2021 - Alzheimer's disease is the leading cause of dementia in the Italian population and over 600.000 people live with this condition. Currently, the few therapies approved to contrast its evolution seem to be effective only in the very early stages of the disease, which is why neuroscience research plays a central role in identifying the pathological mechanisms underlying the disease.
The study, published in the Journal of Alzheimer's Disease, of the Dr. Laura Serra, from the Neuroimaging Laboratory of the Santa Lucia IRCCS in Rome, from the prof. Marcellus D'Amelio, Head of the Molecular Neuroscience laboratory of the Santa Lucia IRCCS e Full Professor of Human Physiology at the Campus Bio-Medico University of Rome and prof. Marco Bozzali, Associate Professor of Neurology at the University of Turin. The same team, within the integrated research platform between IRCCS Santa Lucia and Università Campus Bio-Medico di Roma, coordinated by prof. D'Amelio, had identified in 2017 in theventral tegmental area (VTA)related to the production of dopamine, an early event in the course of disease development, using experimental models.
"The VTA" explains the prof. D'Amelio "it is represented by a very small area, which has about 600-700 thousand neurons, a small number compared to the over 80 billion neurons that make up the human brain. Our study focused on the connections that are established between the VTA and the rest of the brain and how these, due to damage in the VTA, change during the course of the disease.The result, the result of years of research, was the surprising ability that lesions of the VTA have in predicting the development of Alzheimer's disease and the The goal of this last work was to understand the time window that a VTA analysis can offer before disease symptoms develop".
"The experimental setting" continues Dr. Serra "involved the use of functional neuroimaging and neuropsychological tests, two painless and non-invasive techniques with which we analyzed the activity of the VTA in 35 patients with mild cognitive impairment, an important risk factor for the development of Alzheimer's disease and other forms of dementia.So we have monitored the evolution of the patients' condition for 24 months, finding that, within the first two years of observation, in 16 of the 35 patients mild cognitive impairment converted to Alzheimer's disease, and this conversion was anticipated by a significant reduction in VTA connectivity towards critical brain areas for symptoms of the disease. In patients who did not develop the disease, on the other hand, the VTA maintained its function unchanged". Analyzing the results, the researchers were able to confirm that the reduction of VTA connections anticipates damage to other areas of the brain and the appearance of the first clinical symptoms by about two years, a time window within which it is possible to use drugs aimed at counteracting the evolution of the disease.
"The person who notices that they are showing the first symptoms of a cognitive disorder"suggests the teacher. Carlo Caltagirone, neurologist, Scientific Director of the Santa Lucia IRCCS and co-author of the study, "Today he has many tools that he can use to take care of his health. In Alzheimer's disease, according to the scientific evidence available today, the poor efficacy of the drugs seems to be due to an excessively late use of therapies that fail to interrupt the degeneration in already compromised areas or to improve the clinical picture. For this reason, prevention and early diagnosis are important, in order to be able to face the disease with all the weapons that neuroscience research makes available".
Finally, this study confirmed the greater specificity of this method in accurately diagnosing Alzheimer's disease by distinguishing it from other forms of dementia. In fact, patients with atrophy of the hippocampus, an area of the brain responsible for memory, but without a reduction in VTA activity, did not develop Alzheimer's disease, confirming previous studies that found the synergistic presence of brain atrophy and VTA disconnection events related to the early presentation of clinical symptoms of the disease.
