Vertiginous epilepsy: documentation of clinical and electrophysiological findings of nine patients.

Epileptic vertigo is often a diagnostic problem. We aimed to present the clinical and electrophysiological features of patients with epileptic vertigo with a view to addressing the pathophysiology of this rare aura symptom. Nine epileptic vertigo patients were included in the study. All patients were subjected to neuro-otologic examination, interictal electroencephalogram (EEG), audiogram, cervical vestibular evoked myogenic potential testing (cVEMP), video head impulse testing (vHIT) and brain magnetic resonance imaging (MRI). Eight patients described their aura as epileptic vertigo and one as dizziness. In three patients, auditory hallucinations preceded epileptic vertigo. The semiology of epileptic vertigo was true vertigo in five patients, vertigo with nausea in two patients and vertigo with hearing loss in one patient. Two patients suffered from focal seizures, and in seven patients the seizures were evaluated as focal to bilateral tonic-clonic seizures. MRI was normal in all patients. EEG was abnormal in all cases and showed high-voltage spike or spike-slow-wave complexes, or both, located more frequently in the temporal region, more left than right. On vHIT examination, abnormal responses were recorded bilaterally or unilaterally in five patients. Similarly, cVEMP revealed no response bilaterally or unilaterally in five patients. In three patients, the side of no response to cVEMP corresponded to the side of epileptiform pathology based on EEG. Two patients with bilateral abnormalities on EEG showed bilateral abnormalities either on cVEMP or vHIT, or on both. Taken together, these findings support the involvement of the brainstem connections of the peripheral vestibular system in vertiginous epilepsy. The pathological results of vestibular tests in the majority of our patients, combined with the EEG abnormalities, support the hypothesis of system epilepsies which is based on the dysfunction of specific neural systems.