Early-Onset Alzheimer’s Disease Prognosis: You May Get This Disease Even In Your 30s And 40s

Unlike late-onset dementia, early-onset dementia was more prevalent in men. Read on to know more about this condition.

Age is considered to be the most significant factor for Alzheimer's disease. The disease usually develops in people above the age of 65 years. However, there are many cases of people developing this disease at an age below 65 years, even in their 30s and 40s. Developing Alzheimer's disease before the age of 65 is known as early-onset Alzheimer's disease or young-onset Alzheimer's disease.

PREVALENCE OF EARLY-ONSET ALZHEIMER'S DISEASE

Alzheimer's disease is considered to be the most common cause of dementia. Approximately 60-80 per cent of people with dementia have Alzheimer's disease. The overall prevalence of Alzheimer's disease is 3.2 per cent. It was generally considered that early-onset Alzheimer's disease accounts for almost 1-2 per cent of the total number of Alzheimer's disease patients. However, some researchers believe that the share of early-onset Alzheimer's disease is increasing. More specifically, it was 5.9 per cent in developed countries and 4.4 per cent in developing countries. It indicates an increased prevalence of people developing Alzheimer's disease at an early age.

A study reported that the early-onset dementia prevalence doubles every five years. It rises from 42 to 54 per 100,000 for people between the age of 30 and 64 years to 78 98 years per 100,000 for those aged between 45 and 64 years. Unlike late-onset dementia, early-onset dementia was more prevalent in men.

TYPES OF EARLY-ONSET ALZHEIMER'S DISEASE

Early-onset Alzheimer's disease is associated with delays in diagnosis, an aggressive course, and age-related psychosocial needs such as unexpected loss of independence, and difficulty juggling active responsibilities at the job and with family.

The vast majority of individuals with early-onset Alzheimer's disease are non-familial. Approximately 11 per cent are familial and due to mutations in three known genes- APP, PSEN1, PSEN2. More than one-third of individuals with EOAD present with language, visuospatial, or other symptoms rather than the usual memory loss as seen in Late-onset Alzheimer's disease.

The delay in diagnosis is predominantly related to varied presentations in early-onset Alzheimer's disease.

Amnestic early onset Alzheimer's disease

Patients have an inability to remember where they left their spectacles, won't remember their appointments, would forget if they had their breakfast or lunch, and account for a small percentage of individuals diagnosed as EOAD

Non-Amnestic Early Onset Alzheimer's disease

In this form, patients present with progressive difficulty in speaking and understanding which also includes their ability to read and write. They may also have problems driving, getting dressed, navigating surroundings, or problems with calculations or as simple as planning a party.

PROGRESSION OF EARLY-ONSET ALZHEIMER'S DISEASE

The progression of early-onset Alzheimer's disease is relatively faster than late-onset Alzheimer's disease. There are several reasons for that. First, there is an inherent faster progression of this condition. Second, and believed to be more important, is the misdiagnosis or a delay in diagnosis in most cases. As opposed to typical late-onset Alzheimer's disease symptoms, there is usually no memory loss, and the patient does not have forgetfulness and has non-memory associated symptoms. These unusual symptoms cause challenges in diagnosis, and the clinicians most often consider it a psychiatric disease. It prevents such patients from receiving appropriate care, treatment, and overall management.

(This article is authores by Dr. Veena Vedartham - Consultant - Neurology, Manipal Hospital Old Airport Road, Bengaluru)