Spin dynamics in a weakly itinerant magnet from 29Si NMR in MnSi

29Si NMR spectra and nuclear spin-lattice relaxation rate measurements in MnSi paramagnetic phase are presented. The experimental results are analyzed in the framework of the self-consistent renormalization theory for spin fluctuations, and detailed estimates of microscopic parameters describing the q and frequency dependence of the dynamical spin susceptibility are obtained. It is shown, in the light of a comparison with neutron scattering results, that some early determined parameters need to be revised. Accordingly, also the derivation of Curie-Weiss law within this model should be critically reconsidered.