[Disabling positional vertigo (DPV): syndrome of vestibulo-cochlear organ impairment during vascular compression of the vestibulo-cochlear nerve (VCS)].

In 1984 Jannetta et al. introduced a new term-disabling positional vertigo (DPV). DPV is a term used to describe syndrome of cochleo-vestibular organ impairment during vascular compression syndrome of eight cranial nerve. They introduced this term to distinct this syndrome from other established vertigo syndromes on the basis of recognized in angio - MRI exam compression of VIII nerve by vessel and clinical and electrophysiological criteria. Existence of DPV syndrome is still not universally accepted, because it is difficult to diagnose vertigo as vascular compression syndrome of the eight cranial nerve when there are no specific finding to detect this syndrome. Only Moller proposed specific ABR abnormalities as a criterion in DPV diagnosis (prolongation of I - III interval). The authors performed retrospective analysis of 28 patients (16 female, 12 men, average age 43) with recognized on basis angio - MRI vascular compression syndrome of eight cranial nerve. Contrasted magnetic resonance imaging identified a vascular loop near to cochleo - vestibular nerve in all 28 cases. All patients were performed pure tone audiometry, DPOAE, ABR and ENG exam. The most common symptoms were unilateral tinnitus (89% cases), unilateral hearing loss (86%) and dizziness (61%). The most frequent abnormalities in above mentioned exams were sensorineural hearing loss in pure tone audiometry (92%). ABR data were interpreted with respect to Mollerís criteria and asymmetry of the I - III, III - V and I - V interval and prolongation of V waves in the auditory brainstem response was found in 36% cases. Abnormal changes in electronystagmography were found: absence (10%) or weakness (36%) of caloric response. The differential diagnosis of DPV syndrome are discussed. We could not find any specific clinical findings valuable for DPV diagnosis. There is no significantly more weakness or absence of caloric response of vestibular organ in patients with DPV. Disabling positional vertigo is the syndrome which should be considered in differential diagnosis in every case of vertigo.