A team of international researchers, led by UC San Francisco, completed the first large-scale study of posterior cortical atrophy (PCA). PCA is a brain and nervous system syndrome that causes brain cells to die over time and causes problems with eyesight and processing visual information. The loss of brain cells is in the region responsible for visual processing and spatial reasoning. People with the syndrome may not be able to recognize objects and familiar faces. Other symptoms include trouble reading, judging distances and reaching for objects. The study found that 94 percent of the PCA patients had Alzheimer’s pathology, and the remaining 6 percent had conditions like Lewy body disease, the second most common type of dementia after Alzheimer’s disease and frontotemporal lobar degeneration. (University of California - San Francisco: “Could bizarre visual symptoms be a telltale sign of Alzheimer’s?”; ScienceDaily: sciencedaily.com/releases/2024/01/240123122251.htm, accessed March 6, 2024)

Patients may not associate early PCA symptoms with vision problems and may not report them during a routine eye exam. Most patients with PCA have normal cognition early on, but by the time of their first diagnostic visit, an average of nearly four years after symptom onset, mild or moderate dementia was apparent with deficits identified in memory, executive function, behavior, and speech and language, according to the researchers’ findings. What’s more, the average age of symptom onset of PCA is 59, several years younger than that of typical Alzheimer’s.

In the study of data from more than 1,000 patients in 16 countries, levels of amyloid and tau, proteins that accumulate in the brain in Alzheimer’s disease, matched those found in typical Alzheimer’s cases. Early identification of PCA may have important implications for Alzheimer’s treatment, according to co-first author Renaud La Joie, PhD, also of the UCSF Department of Neurology and the Memory and Aging Center. “Patients with PCA have more tau pathology in the posterior parts of the brain, involved in the processing of visuospatial information, compared to those with other presentations of Alzheimer’s. This might make them better suited to anti-tau therapies,” notes La Joie. As a result, patients with PCA may be candidates for anti-amyloid therapies, which are believed to be more effective in the earliest phases of the disease, according to La Joie.

In the study discussion, the researchers note, “People with posterior cortical atrophy often face a delay in diagnosis because of their young age and visual-predominant symptoms. Better awareness of the syndrome of posterior cortical atrophy among neurologists, primary care providers, optometrists and ophthalmologists is needed for early detection and treatment.”

• Linda Conlin
Pro to Pro Managing Editor
[email protected]