Parietal dysfunctional connectivity in depression in multiple sclerosis

The evidence of parietal depletion and frontal hyper-excitability in multiple sclerosis (MS) fatigue guided the development of the personalized neuromodulation – symptom mitigation with electrical signals – called FaReMuS (Fatigue Relief in Multiple Sclerosis), whose efficacy against fatigue was observed in two independent randomized controlled trials. Performing a preliminary analysis on a group of 14 MS patients with eligibility criteria similar to those of Jeager et al. (MS patients with EDSS<2.5 at low BDI levels), who underwent FaReMuS in parallel 7 Real and 7 Sham, we observed that the BDI was reduced by Real (9 pre vs 5 post, two-tailed t-test for paired samples p=0.0005) in the absence of any Sham effect (7 pre vs 7 post, p = 0.8902). We believe that it could be relevant to consider enriching the protocols that typically aim to balance the excitability of the right versus left dorsolateral prefrontal regions, taking into account the possible parietal involvement.