The Alzheimer’s disease manifests itself by memory impairment, but not only. Doctors realized that other signs could herald the development of this slowly progressive neurodegenerative disease. “In the years preceding the obvious manifestations, we sometimes find unusual character disorders, such as the appearance of great anxiety, irritability, hyperactivity or, on the contrary, apathy”, explains Prof. Vincent. Camus, psychiatrist, CHRU Bretonneau (Tours), co-head of the Memory, Resource and Research Center (CMRR) of the Center region. Signs that are often more difficult for the family to bear than memory impairment, at least in the beginning.
Today, the diagnosis is made on observations
There is no test with a positive result for Alzheimer’s disease. The diagnosis is made by a specialist in memory disorders from several evaluations : a clinical examination (postural disorders, oculomotor disorders …), a neuropsychic assessment (from tests evaluating memory and language), and an ibrain imaging (CT scan, MRI, brain scintigraphy).
In some cases, this assessment is not sufficient to make the diagnosis and the specialist suggests a lumbar puncture to measure, in the cerebrospinal fluid, specific proteins (TAU proteins, beta-amyloid proteins). Their concentration is correlated with the presence of specific abnormalities in the brain.
Tomorrow, we will spot abnormalities in the brain
The CT scan and MRI can only spot one indirect sign of the disease: brain atrophy. Hence the interest in new molecular imaging techniques which make it possible to visualize the brain abnormalities typical of the disease (amyloid plaques and neurofibrillary degeneration).
New radiotracers (substances injected into a vein in the arm before the examination) electively attach themselves to them and then emit signals detected by a sophisticated device (positron emission tomography or PET). The radiologist can thus observe live in the brain of the sick person the anomalies described by Dr. Alois Alzheimer in 1903 under a microscope. It was at the time from brain sections of deceased patients. Used in the context of research, in particular to test the effectiveness of treatments under study, this type of examination could take a more important place in the future by making it possible to identify the disease at an earlier stage. that is, before the onset of signs of mental confusion.
Why it’s important to diagnose the disease early
“I understand that in the absence of specific treatments, which is the case today, we ask ourselves the question of the interest of an early diagnosis, explains Professor Caroline Hommet, head of the Resource and Memory Center. research (CMRR), Tours Bretonneau University Hospital. But this has several advantages: giving information on the disease, supporting the patient and his family, avoiding medication errors (benzodiazepines are not recommended), but using them others who will help to live better, delay entry into an institution by setting up appropriate care as the disease progresses. And let’s not forget that many therapeutic molecules are currently in development in laboratories.
Thanks to Pr Denis Guilloteau, head of the nuclear medicine department, CHRU Bretonneau.
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