Facts and Comparisons
Early-onset Alzheimer’s typically appears in the 40s, 50s and early 60s. However, it is not unheard of for an individual to be diagnosed in their 20s or 30s, especially in families who carry one of the three genetic mutations predicting early-onset Alzheimer’s disease.
Individuals with early-onset Alzheimer’s demonstrate more often atypical presentations than those with late-onset Alzheimer’s disease. Many of those with early-onset don’t have significant memory loss initially – the classic hallmark symptom of Alzheimer’s. Their disease progression does not begin with symptoms of forgetfulness. Some of these individuals present with visual symptoms – inability to see the full picture giving them in essence a “tunnel vision”, impaired depth perception or inability to recognize faces – or impaired speech/difficulty coming up with words in conversation.
These unusual symptoms present one of the biggest challenges in the diagnostic process. Since the presentation of early-onset is confusing, individuals with the beginning stages of the disease are often misdiagnosed and labeled as having a psychiatric disease, ultimately resulting in them not receiving the care and education they need. Early-onset Alzheimer’s disease also progresses much faster than late-onset.
Since very few single-site research studies have been conducted on early-onset Alzheimer’s disease, the data that is available only reflects the local demographic of the individual study location.
The life expectancy for an individual diagnosed with early-onset Alzheimer’s is unknown due to the rarity of this form of Alzheimer’s and the fact that very few research studies have been done to date. The average life expectancy for an individual diagnosed with late-onset Alzheimer’s is between 8-12 years. It is believed that early onset Alzheimer’s has a more aggressive disease course and progresses faster.
This is another unknown answer for now; however, researchers at IU School of Medicine would not expect any of the above factors to be the case for development. Since early-onset cases develop in younger individuals, these patients rarely have high blood pressure, cholesterol or other chronic diseases which may have an impact on the body and brain. It is more likely that genetic factors have a more significant role in someone developing the disease before 65.
- Amnestic variant: Memory predominant cases present themselves much like late-onset Alzheimer’s disease. Some have visual variances associated with the disease such as not being able to integrate everything within one visual field (i.e. tunnel vision). These individuals cannot fully appreciate the remaining stimuli in the entire environment.
- Logopenic aphasia variant: Language deficit individuals have difficulty finding the “right words” to express themselves, resulting in distressed speech. As the language deficit progresses, the individual becomes less able to communicate with others.
- Dysexecutive variant: Loss in judgement and problem solving/executive skills results in irrational actions, impulsive behaviors and what researchers and physicians observe in frontotemporal dementia.
- Visual Variant (posterior cortical atrophy): difficulties with visual tasks such as reading a line of text, inability to perceive more than one object at a time, impaired depth perception, judging distances or inability to recognize faces, etc.
The diagnosis of early-onset Alzheimer’s remains a clinical one. In the cases with known genetic mutations, pre-symptomatic identification of individuals at risk is possible. Children of individuals who carry the mutation are able to receive genetic testing when they reach 18 years of age.
Like any other brain disease, the healthier the brain is, the more damage it can withstand without any demonstrated symptoms. Leading a healthy lifestyle with mental and cognitive stimulation, physical exercise and a healthy diet such as the Mediterranean diet helps to protect the brain, therefore allowing the individual to live a healthier life.
Recruitment for studies is by far the greatest challenge for medical research as it relates to early-onset Alzheimer’s since it’s such a rare disease. Raising awareness among primary care physicians, neurologists, psychiatrists and other health care providers significantly increases the likelihood for detection of early-onset cases, allowing the provider to refer the patient to participate in a research study such as LEADS. In addition, finding individuals to serve as control cases for the study proves difficult as it is a large time commitment that is strictly voluntary.