Val66Met MS patients had a higher volume of hippocampal subfields than BDNF Val66Val MS patients, suggesting that BNDF Val66Met polymorphism may protect MS patients from cognitive impairment and hippocampal atrophy, and that the BDNF genotype may be a biomarker for predicting cognitive prognosis [143]. This evidence concerns the gene BDNF and hippocampal atrophy.