The clinical use of electroencephalography in a general psychiatric setting

Abstract

Objective

Electroencephalography (EEG) is used in psychiatric services, however, clinical guidelines do not clearly state when EEG is indicated, and its diagnostic value in psychiatric settings is unclear. We aimed to characterize the clinical use and diagnostic consequences of EEG in a general psychiatric setting to evaluate and optimize its use.

Methods

We performed a quality development project at the psychiatric services of the Central Denmark Region. We identified patients referred for EEG examination from psychiatric services between 1 September 2017 and 1 September 2022. We extracted data from electronic health records on patient characteristics, indications, EEG results, and treatment consequences and analyzed risk factors for abnormal EEGs.

Results

Among 57,031 persons seen in the psychiatric services in the study period, 219 (0.4%) were referred for EEG examination. Psychosis (n = 70, 32%) was the most common symptom and suspicion of epilepsy (n = 129, 59%) was the most common clinical suspicion leading to referral. Of the 219 patients, 53 (24%) had an abnormal EEG result including 17 (7.8%) with epileptiform changes. Abnormal EEGs led to treatment alterations in six patients (3%). Age, prior epilepsy, use of antiseizure medication, use of clozapine, and convulsions were associated with epileptiform changes in the EEG.

Conclusion

EEG is rarely used in psychiatric settings and seldom has treatment consequences. However, in specific clinical settings, the EEG result leads to an alteration of clinical management and the findings, therefore, call for refinement of clinical guidelines to optimize the use of EEG.

Keywords:

• Electroencephalography
• psychiatry
• epileptiform
• guidelines

Acknowledgements

The authors thank Bettina Nørremark from Aarhus University Hospital – Psychiatry for assisting with the extraction of data.

Disclosure statement

S.H.: Speaker fees from H. Lundbeck A/s and Medice Nordic Denmark ApS, educational grant from Takeda A/s. JC reports speaker honoraria and scientific advisory board honoraria from Eisai AB and UCB Nordic. The remaining authors do not have any competing interests to declare.

Data availability statement

Data is not available due to legal restrictions.

Additional information

Funding

There was no specific funding for the present study. O.H.J. was funded by a grant from the Health Research Foundation of the Central Denmark Region (R64-A3090-B1898). J.C. reports funding from the Danish Epilepsy Association, the Central Denmark Region, and the Novo Nordisk Foundation (NNF16OC0019126 and NNF22OC0075033).

Notes on contributors

Oskar Hougaard Jefsen

Oskar Hougaard Jefsen, M.D., is a Ph.D. student at the Psychosis Research Unit at Aarhus University Hospital - Psychiatry and the Center of Functionally Integrative Neuroscience, Department of Clinical Medicine, Aarhus University.

Johannes Reinau Windelborg Nielsen

Johannes Reinau Windelborg Nielsen is a medical student at Aarhus University and research assistant at the Center of Functionally Integrative Neuroscience, Department of Clinical Medicine, Aarhus University.

Jakob Christensen

Jakob Christensen, M.D., Ph.D., is a Clinical Professor at the Department of Neurology, Aarhus University Hospital and Department of Clinical Medicine, Aarhus University.

Simon Hjerrild

Simon Hjerrild, M.D., Ph.D. is a Clinical Associate Professor at the Psychosis Research Unit, Aarhus University Hospital - Psychiatry and Department of Clinical Medicine, Aarhus University.