Prognosis Value of the Neuronal Damage Detected by Positrons Emission Tomography (PET) With 11C-Flumazenil in Early Multiple Sclerosis.

It is now well admitted that multiple sclerosis (MS), which is an inflammatory demyelinating disease of the central nervous system (CNS) is not restricted to white matter, but also involves grey matter, either the cortex or the deep grey matter. The progression of grey matter atrophy measured by MRI during disease course represents an interesting prognosis marker for long term progression, but this marker lack sensitivity and is hard to interpret at the individual level.

In the EAE animal models, an early neuronal damage has been described, characterized both by a synaptic and dendritic loss and by a neuronal apoptosis.

These data strongly suggest that the occurrence of an early neuronal damage during MS course could represent a major prognosis marker. Therefore there is a crucial need for the development of imaging techniques, aimed at visualizing and quantifying neuronal damage in early MS. To date MRI techniques are not able to specifically assess neuronal pathology in vivo.

In this prospective project we will determine the chronology of appearance and the prognosis value of the neuronal damage measured by PET with 11C-Flumazenil, concerning further grey matter atrophy progression and disability progression among a cohort of MS patients with recent onset.

Four groups of subjects will be included: i) patients with a RRMS evolving since less than 5 years (revised Mc Donald criteria, n=20); ii) patients with a RRMS evolving since more than 5 years and less than 10 years (n=20); iii) patients with a primary progressive MS (PPMS) evolving since less than 10 years (n=20); iv) Healthy volunteers matched for age and sex (2/3 matched with RRMS patients; 1/3 matched with PPMS patients).