Another postulated mechanism associated with beneficial role of riluzole application is related to observed increase of serum concentrations of brain-derived neurotrophic factor (BDNF) (Katoh-Semba et al., 2002), which neurotrophic factor is known to be significantly diminished in the brains of HD patients, and its level seems to be correlated with diseases onset progression and severity (Gauthier et al., 2004). This evidence concerns the gene BDNF and Huntington disease.