Posterior cortical atrophy (PCA), a rare disease, causes strange and disturbing problems with vision and spatial perception; a new study highlights, in more detail than ever, its close link with Alzheimer’s disease.
• Read also: This now banned injection spread Alzheimer’s disease
• Read also: Controversial treatment for Alzheimer’s disease withdrawn from market
• Read also: A blood test could detect Alzheimer’s disease
PCA and Alzheimer’s disease have long been linked to each other because they share a large number of pathological changes in the brain. However, due to the rarity of PCA, researchers have had difficulty fully evaluating it in relation to Alzheimer’s disease.
To remedy this situation, an international team of researchers, who published the results of their research this week in the journal Lancet Neurology, analyzed data from 1,092 people with PCA and found that it was a very strong predictive factor for Alzheimer’s disease.
In 94% of cases, brain changes indicative of Alzheimer’s disease were indeed observed and most likely contributed to PCA.
Visual symptoms of PCA
According to the Alzheimer Society of Canada, PCA is a “rare progressive neurodegenerative disease that damages the posterior region of the brain,” which is “responsible for processing visual information.”
ACP can therefore “affect vision, reading and writing, orientation and the execution of basic gestures, such as grasping an object,” the company further indicates.
Here are the main vision-related symptoms caused by PCA:
– Blurred vision
– Difficulty reading and writing
– Difficulty filling out forms
– Difficulty seeing objects in front
– Problems with depth perception
“We need to raise awareness of PCA so that clinicians can detect it,” says neuropsychologist Marianne Chapleau of the University of California, San Francisco (UCSF).
“Most patients see their optometrist when they begin to experience visual symptoms and may be referred to an ophthalmologist who also may not recognize PCA. We need better tools in the clinical setting to identify these patients at an early stage and offer them treatment,” he adds.
One of the positive effects of this study could therefore be to encourage people with symptoms of PCA to be examined as early as possible. The average age of onset of the disease is 59 years, several years younger than for Alzheimer’s disease, and the average time between the onset of symptoms and the first diagnostic visit is 3.8 years. .
Shared diseases
The study noted many similarities between PCA and Alzheimer’s disease with respect to levels of amyloid and tau in the brain, with the accumulation of these proteins having long been associated with the onset of the disease. dementia.
However, the diseases also have differences, which could give researchers clues about the best treatments to follow.
“Patients with PCA present more significant tau pathology in the posterior parts of the brain, involved in the processing of visuospatial information, compared to those who present with other forms of Alzheimer’s,” explains neuropsychologist Renaud La Joie de UCSF.
“This could make them more amenable to receiving anti-tau therapies,” he adds.
The researchers behind this new study hope their work will lead to a better understanding of how Alzheimer’s disease can manifest and how Alzheimer’s disease and PCA begin to take over the brain.