According to a US study published in The Lancet Neurology, a rare eye condition known as posterior cortical atrophy (PCA) could be the first symptom of Alzheimer’s disease in 10 per cent of patients. Patients with PCA have difficulty reading and writing, judging distances, differentiating between moving and stationary objects and picking up a dropped item.
To find out how predictive of dementia PCA might be, researchers reviewed data from 1,092 patients at 36 sites in 16 countries. The average age of symptom onset was 59 years and 60 per cent of the patients were women. About 94 per cent of patients with PCA went on to develop Alzheimer's disease and the remaining 6 per cent developed other types of dementia such as Lewy body disease or frontotemporal lobar degeneration.
According to researchers, PCA is far more predictive of dementia than memory loss—only 70 per cent of people with memory problems eventually get a diagnosis of dementia. Though most patients do not have cognitive issues early on, they show mild or moderate deficits in memory, executive function, behaviour and speech and language about 3.8 years after PCA symptoms onset.
“It is critical that doctors learn to recognise the syndrome so patients can receive the correct diagnosis, counselling and care,” said the study.
