Localizing and lateralizing value of auditory phenomena in seizures

Background: Auditory seizures (AS) are a rare type of focal seizures. AS are classically thought to involve a seizure onset zone (SOZ) in the temporal lobe, but there remain uncertainties about their localizing and lateralizing value. We conducted a narrative literature review with the aim of providing an up-to-date description of the lateralizing and localizing value of AS.

Methods: The databases PubMed, Scopus, and Google Scholar were searched for literature on AS in December 2022. All cortical stimulation studies, case reports, and case series were analyzed to assess for auditory phenomena that were suggestive of AS and to evaluate if the lateralization and/or localization of the SOZ could be determined. We classified AS according to their semiology (e.g., simple hallucination versus complex hallucination) and the level of evidence with which the SOZ could be predicted.

Results: A total of 174 cases comprising 200 AS were analyzed from 70 articles. Across all studies, the SOZ of AS were more often in the left (62%) than in the right (38%) hemisphere. AS heard bilaterally followed this trend. Unilaterally heard AS were more often due to a SOZ in the contralateral hemisphere (74%), although they could also be ipsilateral (26%). The SOZ for AS was not limited to the auditory cortex, nor to the temporal lobe. The areas more frequently involved in the temporal lobe were the superior temporal gyrus (STG) and mesiotemporal structures. Extratemporal locations included parietal, frontal, insular, and rarely occipital structures.

Conclusion: Our review highlighted the complexity of AS and their importance in the identification of the SOZ. Due to the limited data and heterogeneous presentation of AS in the literature, the patterns associated with different AS semiologies warrant further research.