Clinical and electrographic findings in epileptic vertigo and dizziness

Objective: Seizures can cause vestibular symptoms, even without obvious epileptic features. We sought to characterize epileptic vertigo or dizziness (EVD) to improve differentiation from nonepileptic causes, particularly when vestibular symptoms are the sole manifestation. Methods: We conducted a systematic review with electronic (Medline) and manual search for English-language studies (1955-2014). Two independent reviewers selected studies. Study/patient characteristics were abstracted. We defined 3 study population types: (1) seizures, some experiencing vertigo/dizziness (disease cohort); (2) vertigo/dizziness, some due to seizures (symptom cohort); (3) vertigo/dizziness due to seizures in all patients (EVD-only cohort). Results: We identified 84 studies describing 11,354 patients (disease cohort 8,129; symptom cohort 2,965; EVD-only cohort 260). Among 1,055 EVD patients in whom a distinction could be made, non-isolated EVD was present in 8.5%, isolated EVD in 0.8%. Thorough diagnostic workups (ictal EEG, vestibular testing, and brain MRI to exclude other causes) were rare (<0.1%). Ictal EEG was reported in 487 (4.3%), formal neuro-otologic assessment in 1,107 (9.7%). Localized EEG abnormalities (n 350) were most frequently temporal (79.8%) and uncommonly parietal (11.8%). Duration of episodic vestibular symptoms varied, but was very brief (<30 seconds) in 69.6% of isolated EVD and 6.9% of non-isolated EVD. Conclusions: Non-isolated EVD is much more prevalent than isolated EVD, which appears to be rare. Diagnostic evaluations for EVD are often incomplete. EVD is primarily associated with temporal lobe seizures; whether this reflects greater epidemiologic prevalence of temporal lobe seizures or a tighter association with dizziness/vertigo presentations than with other brain regions remains unknown. Consistent with clinical wisdom, isolated EVD spells often last just seconds, although many patients experience longer spells.