Search Here

Recent research sheds light on a potential early indicator of Alzheimer's disease, linking it to a rare eye condition known as posterior cortical atrophy (PCA).

The study, conducted by researchers at the University of California - San Francisco, highlighted the importance of early detection in managing Alzheimer's and related neurodegenerative disorders.

Alzheimer's disease affects millions worldwide, with its impact extending beyond cognitive functions to include visual impairments associated with changes in the brain.

Published in The Lancet Neurology, the study found that PCA, characterized by progressive visual loss, may serve as an early sign of Alzheimer's pathology.

Dr. Gil Rabinovici, lead author of the study and neurologist at the University of California - San Francisco, noted the significance of recognizing PCA as a potential indicator of Alzheimer's disease. He emphasized the importance of proper diagnosis, enabling timely access to treatments that can slow disease progression and improve patient outcomes.

"From a clinical point of view, posterior cortical atrophy is probably the second most common clinical presentation of Alzheimer's disease after memory loss, yet it is under-recognized, and patients can go undiagnosed or misdiagnosed for years," Dr. Rabinovici told Medical News Today.

"There has been a major need in the field for a large, international multi-site study that comprehensively characterizes the syndrome and raises awareness amongst clinicians."

PCA manifests as a deterioration of brain cells responsible for visual processing, leading to symptoms such as difficulty recognizing objects, reading impairments, and spatial perception deficits.

Despite its rarity, PCA holds critical insights into the underlying pathology of Alzheimer's disease, with approximately 94% of individuals with PCA exhibiting Alzheimer's pathology.

The study, encompassing data from over 1,000 participants across 16 countries, underscored the need for heightened clinical awareness of PCA among healthcare professionals. Dr. Rabinovici advocates for comprehensive diagnostic assessments, including brain imaging and biomarker testing, to confirm Alzheimer's-related changes in individuals presenting with visual impairments.

"Early brain scans such as MRI can clarify that the problem is in the brain, not the eyes, since tissue loss in the visual areas of the brain can be profound," he noted. "Further tests like PET scans, spinal fluid, or blood tests for Alzheimer's disease proteins can seal the diagnosis of posterior cortical atrophy due to Alzheimer's disease.

"An early and accurate diagnosis can facilitate care planning for patients and their families. Furthermore, patients can avoid unnecessary and unhelpful procedures such as constantly trying new eyeglasses or even undergoing surgery for early cataracts that are not actually the cause of vision loss."

Dr. Alexander Solomon, a surgical neuro-ophthalmologist at Pacific Neuroscience Institute, also stressed the importance of proactive screening for PCA in patients experiencing visual processing difficulties. He suggests collaborative efforts between neurologists, neuropsychologists, and eye care professionals to facilitate early detection and intervention.

"It is good to see more attention being brought to the disease, which I think (is) more awareness from neurologists than your average eye care professional. I think it can serve as an impetus to start screening patients complaining about difficulty with visual processing early for evidence of underlying posterior cortical atrophy by referring them appropriately to a neurologist, neuropsychologist, or neuro-ophthalmologist more familiar with diagnosing the condition."

Moving forward, further research is needed into refining diagnostic criteria and screening tools for PCA to improve diagnostic accuracy and facilitate timely interventions. Dr. Solomon said there's a need for prospective studies to evaluate the efficacy of clinical tests in identifying PCA and guiding appropriate management strategies.