OBJECTIVES: The aim of this paper is to study the association between audiovestibular symptoms and the presence of vascular loops and to study the association between vestibular paroxysmia and vascular loops.
DESIGN: This is a retrospective analysis of clinical, audiological and MRI findings of patients with and without vascular loops and vestibular paroxysmia from 2000 to 2020.
RESULTS: A total of 470 MRI Internal Auditory Meatus scans were performed during the study period of which, 71 (15.1%) had vascular loops and 162 (34.5%) had normal MRI which were used as controls. From the 233 subjects recruited, there were 37 subjects with VP and 196 non VP subjects were used as controls. There was no association between the vascular loop and control groups in terms of co-morbidity and audiovestibular symptoms. The VP group had a significantly older mean age of 51.8 (SD ± 10.3) as compared to the non VP group with the mean age of 45.6 (SD ± 15.5). The VP group had higher number of patients presenting with hearing loss at 97.3% when compared with those without VP (80.1%) (P = .01). The odds of having a vascular loop giving rise to VP was not statistically significant at 0.82 (95% CI 0.3735-1.7989) P = .62.
CONCLUSION: The vascular loop is a normal variant which may or may not give rise to audiovestibular symptoms or vestibular paroxysmia. Clinical assessment is still most important tool in deriving a diagnosis of VP and MRI may be useful to rule out other central causes.
DATABASES REVIEWED: Science Direct, Pubmed, Embase via Ovid databases, and Cochrane library.
METHODS: This review following the guidelines of PRISMA, systematically and independently examined papers published up to March 2021 which fulfilled the predetermined criteria. PROSPERO Registration (CRD42020222334).
RESULTS: A total of 15 studies were included (MRI = 4, SPECT = 1, resting state fMRI = 4, task-based fMRI = 5, task-based fMRI + MRI = 1). Significant changes in the gray matter volume, cortical folding, blood flow, and connectivity were seen at different brain regions involved in vestibular, visual, emotion, and motor processing.
CONCLUSION: There is a multisensory dimension to the impairment resulting in chronic compensatory changes in PPPD that is evident by the significant alterations in multiple networks involved in maintaining balance. These changes observed offer some explanation for the symptoms that a PPPD patient may experience.Systematic Review Registration: This study is registered with PROSPERO (CRD42020222334).