Alzheimer’s disease is said to be early onset when it occurs before the age of 60-65. This concerns few patients, exactly 3%, or between 20,000 and 30,000 people in France. “In extremely rare cases, we see people affected by the disease at 30 or 40 years old“, explains Dr. Olivier Rouaud, neurologist. “When this is the case, we must look for a genetic cause of the disease, which would then have a familial form.“. This represents less than 1% of cases of the disease, but “we can find ourselves with families who have several members affected by the disease before the age of 65“, says the specialist. The actress Camille Lou is currently playing in a TF1 series with Hugo Becker who plays the role of Emile, a young man suffering from Alzheimer’s. The series is broadcast from January 27, 2025 and adapted from the novel by Melissa Da CostaAll the blue in the sky.”
What is early-onset Alzheimer’s?
Alzheimer’s disease begins in the brain. The neurons are then affected by two types of lesions: “There is amyloid pathology and Tau protein pathology“, explains Dr. Rouaud. In the first, amyloid plaques are found between neurons, in the second, the Tau protein causes neurofibrillary degeneration within the neurons themselves. In general, Alzheimer’s disease appears after 65 years, then progresses slowly When it occurs before the age of 65, it is considered “early”.This doesn’t happen overnight. The disease takes time to start, and young patients do not necessarily see the signs.explains the neurologist. This is why patients under 65 spend an average of 5 years in diagnostic wandering.“.
What are the symptoms of early Alzheimer’s?
“Usually these are subtle symptoms.” the neurologist immediately tells us. Initially, the person may show changes in behavior, a lack of motivation and desire (apathy), a change in character or even depression. These first symptoms are not alarming. “Then cognitive symptoms generally appear; in young patients, we have aphasic-type elements, explains the doctor, patients lose words or use one word for another“. The person may also have difficulty writing with a change in graphics, gestural difficulties. “Patients have difficulty tying their shoes or putting an envelope in a mailbox” describes the specialist. It is these small elements which, put together, trigger the consultation process.
The process generally begins with a medical consultation with the attending physician, who will alert himself to neurological symptoms. He will look for associated symptoms, such as motor problems. “Then, there is a brain imaging examination which will give an orientation in favor of this hypothesis: we will look if there are thinner or more atrophied regions of the brain (for memory, this is the lobe internal temporal or hippocampus) which would testify to a degenerative process taking place“, explains Doctor Olivier Rouaud. We must also look for other causes which would give the same symptoms. If MRI does not indicate a degenerative process in young people, “it is possible to do metabolic imaging called the PET Scan which allows you to see brain activity to see if there are any synapses being lost “, explains the neurologist. All this gives clues to the cause of the disease.
To be certain that it is Alzheimer’s disease, there is a validated technique: cerebrospinal fluid biomarkers
But to be certain that it is Alzheimer’s disease, there is a validated technique: cerebrospinal fluid biomarkers. Via a lumbar puncture, we have access to biomarkers in the cerebrospinal fluid to measure Tau and amyloid proteins. “If they are in abnormal concentrations, this is a biological sign of the disease and we can therefore confirm that the symptoms are linked to this disease.explains the doctor. In the case of a person under 50 years old in whom we have biological confirmation of the disease, or in a person under 65 years old with several cases of early Alzheimer’s in the family, we will have to look for a genetic cause“. This is done by taking a blood test to look for an abnormal gene which could be at the origin of the production of the amyloid protein.
There is no cure for Alzheimer’s disease.”but there is research, we are trying to create a sort of vaccine to eliminate the famous amyloid protein at the origin of the disease“, explains the doctor. But all this is only at the experimental stage. Currently, there are four drugs available:
- Donepezil (Aricept),
- Rivastigmine (Exelon),
- Galantamine (Reminyl),
- Memantine (Exiba).
The first three are called acetylcholinesterase inhibitors. “These are exclusively symptomatic treatments, which do not prevent the disease from progressing, specifies our interlocutor. Their goal is to make up for the lack of certain neurotransmitters that are destroyed by the disease“Memantine protects these receptors against the excitotoxicity that occurs in Alzheimer’s disease.”There are also non-drug therapies (or medico-psychosocial): there is occupational therapy, which consists of organizing everyday gestures taking into account gestural difficulties, speech therapy to overcome language problems, physiotherapy when there are has motor problems…“There are also memory, music or physical activity workshops for people with Alzheimer’s. According to the neurologist, “all this helps to increase the quality of life of patients and to avoid psychotropic medications.”
What is the life expectancy with Alzheimer’s disease?
There are not many epidemiological studies on the early form of Alzheimer’s disease: as it only concerns 3% of patients and 1% for the very young, it is difficult to find those to participate. “In people of all ages, life expectancy is estimated to decrease by an average of 50% at the onset of the disease.“, explains the doctor. “This is due to the fact that Alzheimer’s promotes the appearance of other complications, or even other chronic diseases.“The life expectancy of patients with early-onset Alzheimer’s will therefore be shorter, since the disease arrived earlier.”We also know that it progresses negatively much more quickly in younger patients: they decline more quickly cognitively.“, concludes the neurologist.
Thanks to Olivier Rouaud, neurologist, deputy director of the Leenaards Memory Center.