Similarities to Alzheimer’s Disease
LATE shares many clinical features with AD, including…

• Memory loss (progressive difficulty in recalling recent events or information).
• Cognitive decline (gradual worsening of thinking and reasoning abilities).

Because of these similarities, LATE is often misdiagnosed as AD. However, the the underlying brain changes are different, as LATE involves TDP-43 protein aggregation, rather than beta-amyloid and tau proteins as seen in AD.

Coexisting with Alzheimer’s Disease
It is common for LATE to coexist with AD, especially in older adults. Studies have found that among individuals over the age of 80, a significant proportion exhibit both LATE-NC and AD pathology in their brains.

• Autopsy studies have shown that approximately 40% of elderly individuals with LATE-NC also have AD pathology. This means that many older adults with dementia symptoms may have contributions from both conditions.
• When LATE and AD coexist, they can have an additive effect on cognitive decline, leading to more severe symptoms and a faster progression of dementia than either condition on its own.
• The overlapping symptoms and shared affected brain regions make it challenging to distinguish between LATE and AD clinically. This underscores the importance of considering LATE as a potential contributor to dementia in the elderly.

Pure LATE
Some older adults exhibit symptoms consistent with Alzheimer’s disease yet, upon neuropathological examination, do not show characteristic signs of AD such as beta-amyloid plaques and tau tangles. Instead, these individuals may have LATE, involving TDP-43 protein deposits in the brain. This is more common in individuals over the age of 80 and highlights the importance of considering LATE as a potential diagnosis in elderly patients with dementia symptoms.