The method commonly used in elastic continuum mechanics to describe lo
w-amplitude waves in non-uniformly strained medium is generalized to a
n elastic isotropic medium containing Volterra disclinations for which
distortion is a non-unique function of the spatial coordinates. The M
urnagan law of slate is used to find the equation of elastic energy de
nsity and obtain dynamic equations describing small vibrations of the
medium strained with elastic disclination fields. The particular probl
em of normal vibrations of an extended cylinder with a wedge disclinat
ion whose line is along the cylinder axis is studied. The disclination
effect on the family of axis-symmetrical torsional oscillation modes
of the cylinder is studied thoroughly. A theory of small-parameter (di
mensionless disclination strength) perturbation has been developed and
used to find analytical expressions for the law of dispersion and osc
illatory states.