A joint study by Gangnam Severance Hospital and the University of California San Francisco (UCSF) has discovered vital clues to enhance the precision of initial diagnosis for early-onset Alzheimer's.

Typically, Alzheimer's disease (AD) symptoms appear in people over 65. However, an estimated 10 percent of the population exhibited symptoms earlier, termed as early-onset Alzheimer's disease (EOAD).

Individuals with EOAD usually begin displaying symptoms in their 50s or 60s, when most are socially and professionally active. That means a substantial impact on their careers, families, and social circles. Consequently, the social and familial burden is higher than typical late-onset Alzheimer's.

Diagnosing EOAD has been particularly challenging due to its rarity and atypical symptoms, complicating large-scale clinical trials and research.

To overcome these limitations, Professor Cho Han-na of the Department of Neurology, in tandem with UCSF's Memory & Aging Center, embarked on the LEADS (Longitudinal Early-onset Alzheimer's Disease Study) project from 2018 to 2022.

The global collaborative project involved examining amyloid and tau protein distribution and concentration in the brains of 321 EOAD patients and 87 control subjects using positron emission tomography (PET) imaging.

Their findings revealed a notably higher distribution of tau protein across extensive brain regions in EOAD patients compared to typical Alzheimer's patients, indicating a greater functional decline in EOAD individuals.

A comparative observation showed that EOAD patients had a notably higher distribution of amyloid and tau proteins than the regular Alzheimer's dementia group and the control group.

"The results from this study confirm that amyloid and tau PET imaging can significantly aid in early diagnosis of EOAD," Professor Cho said. "We're optimistic that these findings will pave the way for more precise diagnosis and treatment strategies for the often-neglected EOAD patients."

The study was published in Alzheimer's & Dementia.