Olfactory Testing in Temporal Lobe Epilepsy: a Systematic Review

Abstract

Purpose of Review

Olfactory testing is a potentially safe, cost-effective, bedside evaluation tool for diagnosis, monitoring, and risk assessment for surgery in temporal lobe epilepsy (TLE) patients, but testing methods and relevant olfactory domains are not standardized. We conducted a systematic review to evaluate olfactory tests in TLE and summarize the results of the literature.

Recent Findings

Olfactory tests varied significantly in odorant administration tools and devices, target odorants, evaluation timing, and grading scales. The Smell Threshold Test and University of Pennsylvania Smell Identification Test were the most validated single-domain tests for odor detection and odor identification, respectively. For multi-domain tests, Odor Memory/Discrimination Test and the Sniffin’ Sticks test were the most validated. Results of olfactory tests in TLE are presented by domain.

Summary

Rigorous validation, standardization, and comparative analysis of existing olfactory tests by domain is urgently needed to establish the utility and efficacy of olfactory testing in TLE.

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Fig. 1
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Data Availability

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Code Availability

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Correspondence to Brian Y. Hwang.

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Brian Y. Hwang, David Mampre, Rachel Penn, and Joon Kang each declare no potential conflicts of interest. William S. Anderson has received personal fees from Globus Medical and is on the Advisory Board of NeuroLogic and Longeviti NeuroSolutions. Vidyulata Kamath reports grants from National Institute of Health.

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Hwang, B.Y., Mampre, D., Penn, R. et al. Olfactory Testing in Temporal Lobe Epilepsy: a Systematic Review. Curr Neurol Neurosci Rep 20, 65 (2020). https://doi.org/10.1007/s11910-020-01083-x

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Keywords

  • Mesial temporal lobe
  • Olfactory testing
  • Complex partial seizures
  • Temporal lobe epilepsy