The issue with eventivity in nominal lexical units was approached with great interest by the generative grammar in the seventies; however, the focus of those first investigations was centered on nouns derived from verbs. On the contrary, studies about non-deverbal eventive nouns (NDEN) or simple event nouns have been largely scarce. For this purpose, the objective of this work is to stablish an analysis of the polysemy of a NDEN group belonging to the medical field, based on the Lexicon-Grammar (LG) proposal (Gross, 1975) and a subsequent articulation with the Generative Lexicon Theory (TLG) (Pustejovsky, 1995). For this, the following methodological steps are considered: (i) development of LG tables of lexical selection preferences; (ii) elaboration of LG tables of transformational possibilities of the argument structures (AE) resulting from the distributional analysis of (i); (iii) analysis of the AEs that select NDENs as arguments, and (iv) organization of Semantic Structures (SE) for the lexical units analyzed, according to the TLG criteria. The results allow observing, on one hand, that the LG proposal allows to account for the eventual meanings of NDEN; nevertheless, it is necessary to expand the methodology proposed by the LG to the AE in order to cover other possibilities of meaning. Likewise, on the other hand, it is demonstrated that eventivity is a syntactic fenomenon that arises through a mechanism of co-composition of the infraspecified lexical units.