Scientists from the Center for Applied Medical Research (CIMA) and the University Hospital of Navarra have demonstrated, using Positron Emission Tomography (PET), the progress of dopamine deficit in Parkinson's disease from its initial stages. This work, undertaken with animal models, was awarded the Basic Research Prize during the Congress of the International Society for Movement Disorders. Some 3,000 specialists in this discipline met in Paris.

Parkinson's disease is mainly characterised by the death of the neurones that produce dopamine in the brain. Diagnosis of patients is currently carried out when at least 60% of this neuronal death has occurred. The study carried out by CIMA and the University Hospital of Navarra characterised the progress of the illness in the macaque animal experimental model in different states: healthy, asymptomatic, recovered from a Parkinsonian state, with slight Parkinson's and with serious Parkinson's.

This is the first progressive study with all these states of Parkinson's disease, undertaken in an animal model, explain researchers Carlos Juri and Javier Blesa, from Movement Disorders' Laboratory at CIMA and authors of the research.
Neuroprotector strategies

The researchers estimate, using a non-invasive diagnostic imaging technique, the quantity of dopamine at each stage with two different radiotracers. Moreover, they analysed the metabolic activity of the brain, measuring the consumption of glucose. In this way, they were able to verify the gradual changes produced in the brain in the course of the illness. As Dr. Juri pointed out, they showed that there is a progressive loss of dopaminergic neurones and that, apparently, each state has its own metabolic pattern. According to this study, adaptive or compensatory mechanisms are produced which vary according to the rate of death of the brain cells.

The CIMA specialists emphasised that the principal objective of this line of research is to get to know in detail what happens in Parkinson's disease before the symptoms manifest themselves and how progressive dopaminergic deficit is compensated for. In this way, new neuroprotector stragegies can be put forward that boost the most relevant factors at each stage. It has also acted to optimise the role of the PET technique which, at times, has shown findings that were not concordant.