Today, Alzheimer’s disease diagnosis is a combination of several clinical and paraclinical exams (medical imaging, lumbar puncture), making the patient's journey complex, long and expensive. For the patient, it involves numerous consultations and a waiting time sometimes up to 6 months for a diagnostic conclusion.
With Noratest®, we make it possible for each of our patients and for the physicians, all across the country, to benefit from a simple, clear and effective diagnostic tool. Noratest® enables the physicians to gain insight when they suspect the onset of Alzheimer's disease in a patient with characterized cognitive disorders.
Alzheimer's disease is frightening as it is often not well understood. Yet, it is a disease one can live with! Patients live with the disease for many years before becoming dependent. What we know today is that adapted and personalized care, from the onset of the very first symptoms, is the best way to slow down the progression of the disease.
We believe that "big data" technologies can serve the public interest and contribute to a positive societal impact. Noratest® is based on the dosage of blood neurotransmitters interpreted by a powerful algorithm. By putting data in the service of life and opening up the diagnosis to the greatest number of people, we are contributing at our level to advancing research on Alzheimer's disease.
Noratest® is an in vitro diagnostic medical device software that calculates a score for Alzheimer's disease based on the plasma concentrations of three catecholamines (adrenaline, noradrenaline, dopamine), as well as clinical and demographic parameters. The calculation is performed by an algorithm, based on a mathematical model developed by the company.
The Locus Coeruleus (LC) is an area of the brain that is believed to be impacted early during Alzheimer's disease.1–3 This region includes most of the noradrenergic neurons of the brain, which project their extensions towards several brain regions involved in particular in the phenomena of memory and spatial orientation.4 Starting at an early stage, the density of these neurons has been shown to decrease progressively during the disease.5 Today, the emerging hypothesis is that Alzheimer's disease is actually preceded by overactivation of the LC area even before the first symptoms of the disease are visible.6
Overactivation of noradrenaline receptors in the cortex is believed to stimulate the formation of amyloid plaques in this region.7 The loss of cortical neurons due to inflammatory phenomena would result in the reduction of neuronal cortical stimulation of the LC, meaning the degeneration of noradrenergic neurons.
This phenomenon would explain the noradrenaline concentration decrease observed post-mortem inside the cortex of patients suffering from Alzheimer's disease. A correlation between the MMSE score of Alzheimer's patients and the concentration of noradrenaline in a brain cortical region has already been observed.8–10 A deregulation of noradrenaline concentration has also been observed in the Cerebrospinal Fluid (CSF) of some patients.11,12
Noratest® is based on a mathematical scoring model built according to physiopathological phenomena observed during several clinical studies carried out with the Lariboisière, Saint-Louis, Fernand Widal and Saint-Eloi University hospitals. These studies highlighted correlations between plasma catecholamines concentrations, Alzheimer's patients cognitive MMSE scores and CSF biomarkers. The methods used to calculate the Noratest® score rely on these results.
In addition to the three plasma catecholamines concentrations and the MMSE score, the algorithm also takes into account the age and sex of the patients, which are known parameters involved in the prevalence of the disease.13,14 Thus, the mathematical model provides a rapid and simple means of identifying among patients with memory impairment those whose pathological cause is AD.