The loss of coherence between any pair of spin-inverted states is independent of adiabatic (secular), second-order perturbations associated with the electric quadrupole interaction. Thus, consideration of various dephasing mechanisms, commonly ignored for NMR studies of quadrupolar nuclei (1>1/2), may be important whenever extreme narrowing approximations fail. In this work, the consequences of various magnetic and higher-order electric effects, as well as mutual interferences, are considered in greater detail.