AIMTo investigate the mechanism of EA improving the obstruction of inner ear microcirculation and the effect on the vestibulo-ocular reflex (VOR) by comparing the effects of electroacupuncture (EA) with sibelium (flunarizine hydrochloride) on vertebrobasilar insufficiency(VBI).

METHODSInjected with sclerosant-775 injection into the solt tissue on the left side of cervical vertebral transverse processes of rabbits to set up the vertebral artery type of cervical spondylosis (VCS) models. Electronystagmography (ENG) induced by linear acceleration (LA) and horizontal rotation (HR), the transcranial Doppler (TCD), laser Doppler flowmetry (LDF) and hemorheology were used to measure changes of the frequencies of nystagmus, the hemodynamics in the basilar artery (BA), inner ear blood flow(IEBF) and blood viscosity in VBI rabbits.

RESULTSThe frequencies of ENG, the velocity of blood flow in BA and IEBF decreased obviously, and whole blood middle where viscosity, whole blood lower where viscosity and erythrocyte distortion index ( EDI) increased significantly in the model group. Sibelium could reduce whole blood viscosity and EDI, and increased the systolic phase velocity (Vs) of blood flow in BA, but had no effect on diastolic phase velocity (Vd) and mean velocity (Vm). EA could not reduce the viscosity of blood and EDI, but had more significant effects on improving IEBF and ENG induced by LA than those of sibelium,and had the tendency of increasing Vs, Vd and Vm. EA and sibelium had no effect on improving ENG induced by HR.

CONCLUSIONInner ear microcirculation obstruction caused by VBI can induce dysfunctions of vestibule cyst macula and horizontal semicircular canals. EA may depend upon the neurohumoral regulation to improve VBI, and ameliorate inner ear blood supply obstruction by enhancing mechanism of local adjusting for microcirculation in the inner ear to recover vestibular cyst macula irritability for LA chiefly. There exist complicated mechanism that EA adjusts blood flow distribution and vestibular signal transduction in vestibular organ in VBI model likely, and remain to be researched deeply.