Vestibular paroxysmia: Clinical features and imaging findings; a literature review

Clinical features and outcome of 10 dogs with suspected idiopathic vestibular epilepsy

BACKGROUND

In humans, vestibular epilepsy (VE) is described as focal seizures with transient signs of vestibular disease. In dogs, 2 cases of vestibular episodes, called vestibular paroxysmia, are reported.

HYPOTHESIS/OBJECTIVES

The objective of this study was to define the clinical features, phenotypical manifestation, and outcome of suspected VE in dogs.

ANIMALS

Ten dogs with recurrent vestibular episodes.

METHODS

Retrospective study. Medical records between 2009 and 2023 were reviewed, and dogs with a normal neurological examination, a history of transient signs of vestibular disease, absence of abnormalities detected on blood exams and brain magnetic resonance imaging (MRI) or computed tomography (CT), besides a minimum 10-month follow-up were included. Clinical improvement was defined as a ≥50% reduction in frequency or the cessation of clinical signs after the onset of antiseizure medications (ASMs).

RESULTS

Pugs were the most prevalent breed (5/10; 50%). In 2 cases, additional generalized tonic-clonic (GTC) seizures were reported. MRI exam was performed in most cases (9/10; 90%), whereas 1 dog underwent a CT scan (1/10; 10%). Electroencephalography (EEG) was carried out in 3 dogs that showed interictal spikes in the fronto-temporal and fronto-parietal areas. All cases received ASMs, with clinical improvement in 10/10 dogs (100%).

CONCLUSION AND CLINICAL IMPORTANCE

The presence of GTC seizures, EEG interictal spikes, and responsiveness to ASMs supported the hypothesis of an epileptic origin of vestibular episodes and thus the existence of VE in these dogs, with a presumed idiopathic cause and apparent favorable outcome.

The "Near"-Narrowed Internal Auditory Canal Syndrome in Adults: Clinical Aspects, Audio-Vestibular Findings, and Radiological Criteria for Diagnosis

INTRODUCTION

Vestibular Paroxysmia (VP) refers to short attacks of vertigo, spontaneous or triggered by head movements, and implies the presence of a compressive vascular loop in contact with the cochleovestibular nerve (CVN). Classically, a narrowed internal auditory canal (IAC) corresponds to a diameter of less than 2 mm on CT, usually associated with a hypoplastic CVN on MRI. The aim of this study was to discuss a distinct clinical entity mimicking VP in relation to a "near"-narrowed IAC (NNIAC) and to propose radiological criteria for its diagnosis.

METHODS

Radiological measurements of the IAC were compared between three groups: the study group (SG, subjects with a clinical presentation suggestive of VP, but whose MRI of the inner ear and pontocerebellar angle excluded a compressive vascular loop) and two control groups (adult and children) with normal vestibular evaluations and no history of vertigo.

RESULTS

59 subjects (18 M and 41 F) were included in the SG. The main symptoms of NNIAC were positional vertigo, exercise- or rapid head movements-induced vertigo, and dizziness. The statistical analysis in the study group showed that the threshold values for diagnosis were 3.3 mm (in tomodensitometry) and 2.9 mm (in MRI) in coronal sections of IAC. Although a significantly lower mean value for axial IAC diameter was found in SG compared with controls, the statistics did not reveal a threshold due to the large inter-individual variations in IAC measurements in normal subjects. There was no significant difference in IAC diameter between the adult and pediatric controls.

CONCLUSIONS

In the present study, we report a new anatomopathological condition that appears to be responsible for a clinical picture very similar-but not identical-to VP in association with the presence of an NNIAC. The diagnosis requires a careful analysis of the IAC's shape and diameters in both axial and coronal planes.

Vestibular paroxysmia associated with congenital vascular malformation: A case report

Vestibular paroxysmia (VP) is an uncommon paroxysmal disease, characterized by vertigo, tinnitus, and postural unsteadiness. The main reason of VP is neurovascular cross compression, while few cases of VP accompanied with congenital vascular malformation were reported. Here, we describe a 22-year-old patient with VP caused by congenital anterior inferior cerebellar artery (AICA) malformation who completely recovered after taking oral medicine. This report shows that VP caused by congenital vascular malformation can occur in adults and that oral medication is effective.

Long-term Prognosis of Vertigo Attacks and Health-related Quality of Life Limitations in Patients With Vestibular Paroxysmia

OBJECTIVE

To explore the long-term course of outcomes in vestibular paroxysmia (VP).

STUDY DESIGN

Cross-sectional observational study with a retrospective collection of baseline data.

SETTING

Tertiary referral center.

PATIENTS

Adult patients who visited the Apeldoorn Dizziness Center between 2010 and 2020 and were diagnosed with definite or probable VP according to the Bárány Society criteria were contacted by telephone to complete a study-specific questionnaire. Baseline data were retrospectively collected from patients electronic medical records to allow comparison between baseline and follow-up data.

MAIN OUTCOME MEASURES

Vertigo attack frequency, use of carbamazepine and health-related quality of life (HRQoL) limitations were the primary outcomes. Secondary outcomes were the number of attack-free years and perceived effect of medication for VP.

RESULTS

Seventy three patients were included, 61 (84%) of whom agreed to participate in the follow-up study. Mean age was 55.0 (SD 13.1) years, 49.2% were females. Mean follow-up was 3.4 years (range 0.4-11.3). At follow-up, 44 responders (72%) still experienced vertigo attacks. Average attack frequency in the past 6 months was 307 (SD 451) at baseline and 153 (SD 279) at follow-up (p = 0.050). At follow-up, 19.7% (n = 12) of the responders reported to use or have used carbamazepine, 58% of patients who (had) used this medication reported a positive perceived effect. Overall, 71% (n = 31) of the responders reported to have limitations in one or more HRQoL items due to their VP.

CONCLUSION

Our study shows a rather unfavorable prognosis in patients with VP in terms of vertigo attacks and HRQoL limitations. After the initial diagnosis follow-up is warranted to monitor clinical outcomes in these patients.