• Sciences cognitives/Neurosciences
  

Neurofilament light chain (NfL) has been demonstrated to correlate with multiple sclerosis disease severity as well as treatment response. Nevertheless, additional serum biomarkers are still needed to better differentiate disease activity from disease progression. The aim of our study was to assess serum glial fibrillary acid protein (s-GFAP) and neurofilament light chain (s-NfL) in a cohort of 129 multiple sclerosis (MS) patients. Eighteen primary progressive multiple sclerosis (PPMS) and 111 relapsing remitting MS (RRMS) were included. We showed that these 2 biomarkers were significantly correlated with each other (R = 0.72, p < 0.001). Moreover, both biomarkers were higher in PPMS than in RRMS even if multivariate analysis only confirmed this difference for s-GFAP (130.3 ± 72.8 pg/ml vs 83.4 ± 41.1 pg/ml, p = 0.008). Finally, s-GFAP was correlated with white matter lesion load and inversely correlated with WM and GM volume. Our results seem to confirm the added value of s-GFAP in the context of multiple sclerosis.

Chronic subjective tinnitus is a widespread disorder. This perceptual anomaly is assumed to result from a dysbalance of excitatory and inhibitory mechanisms on different levels of the auditory pathways. However, the brain areas involved are still under discussion. Using resting-state functional magnetic resonance imaging, we investigate differences in cerebral regional homogeneity (ReHo) between patients with unilateral chronic tinnitus and nontinnitus control subjects. To our knowledge, our study is the first to investigate the intraregional connectivity of patients with unilateral tinnitus in relation to hearing loss. Our analyses, based on strict recruitment and characterization of the participants, showed reduced ReHo in the primary auditory cortex contralateral to the side of the perceived tinnitus percept in patients. Reduced ReHo in this same region was also correlated with increased Tinnitus Handicap Inventory and Visual Analogue Scale for loudness scores, reflecting an alteration of synchronization in this region related to the perceived loudness of the tinnitus and the related distress. Furthermore, increased ReHo in the supramarginal and angular gyri ipsilateral to the tinnitus side was correlated with increased tinnitus duration and hearing threshold at the tinnitus pitch. The correlations observed in these brain areas, which are normally related to the nontinnitus ear, could highlight compensatory mechanisms in these secondary auditory regions.

Diffuse low-grade gliomas (DLGG) are brain tumors of young adults. They affect the quality of life of the inflicted patients and, if untreated, they evolve into higher grade tumors where the patient's life is at risk. Therapeutic management of DLGGs includes chemotherapy, and tumor diameter is particularly important for the follow-up of DLGG evolution. In fact, the main clinical basis for deciding whether to continue chemotherapy is tumor diameter growth rate. In order to reliably assist the doctors in selecting the most appropriate time to stop treatment, we propose a novel clinical decision support system. Based on two mathematical models, one linear and one exponential, we are able to predict the evolution of tumor diameter under Temozolomide chemotherapy as a first treatment and thus offer a prognosis on when to end it. We present the results of an implementation of these models on a database of 42 patients from Nancy and Montpellier University Hospitals. In this database, 38 patients followed the linear model and four patients followed the exponential model. From a training data set of a minimal size of five, we are able to predict the next tumor diameter with high accuracy. Thanks to the corresponding prediction interval, it is possible to check if the new observation corresponds to the predicted diameter. If the observed diameter is within the prediction interval, the clinician is notified that the trend is within a normal range. Otherwise, the practitioner is alerted of a significant change in tumor diameter.