Epidemiology of Functional Seizures Among Adults Treated at a University Hospital.

TitleEpidemiology of Functional Seizures Among Adults Treated at a University Hospital.
Publication TypeJournal Article
Year of Publication2020
AuthorsGoleva, SB, Lake, AM, Torstenson, ES, Haas, KF, Davis, LK
JournalJAMA Netw Open
Date Published2020 12 01
KeywordsAdult, Anxiety, Case-Control Studies, Comorbidity, Delayed Diagnosis, Depression, Female, Hospitals, University, Humans, Male, Mental Disorders, Middle Aged, Odds Ratio, Risk Factors, Seizures, Stress Disorders, Post-Traumatic

Importance: Functional seizures (formerly psychogenic nonepileptic seizures), paroxysmal episodes that are often similar to epileptic seizures in their clinical presentation and display no aberrant brain electrical patterns, are understudied. Patients experience a long diagnostic delay, few treatment modalities, a high rate of comorbidities, and significant stigma due to the lack of knowledge about functional seizures.

Objective: To characterize the clinical epidemiology of a population of patients with functional seizures observed at Vanderbilt University Medical Center (VUMC).

Design, Setting, and Participants: This case-control study included patients with functional seizures identified in the VUMC electronic health record (VUMC-EHR) system from October 1989 to October 2018. Patients with epilepsy were excluded from the study and all remaining patients in the VUMC medical center system were used as controls. In total, the study included 1431 patients diagnosed with functional seizures, 2251 with epilepsy and functional seizures, 4715 with epilepsy without functional seizures, and 502 200 control patients who received treatment at VUMC for a minimum of a 3 years. Data were analyzed from November 2018 to March 2020.

Exposure: Diagnosis of functional seizures, as identified from the VUMC-EHR system by an automated phenotyping algorithm that incorporated International Classification of Diseases, Ninth Revision (ICD-9) codes, International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10) codes, Current Procedural Terminology codes, and natural language processing.

Main Outcomes and Measures: Associations of functional seizures with comorbidities and risk factors, measured in odds ratios (ORs).

Results: Of 2 346 808 total patients in the VUMC-EHR aged 18 years or older, 3341 patients with functional seizures were identified (period prevalence, 0.14%), 1062 (74.2%) of whom were women and for which the median (interquartile range) age was 49.3 (39.4-59.9) years. This assessment replicated previously reported associations with psychiatric disorders including posttraumatic stress disorder (PTSD) (OR, 1.22; 95% CI, 1.21-1.24; P 

Conclusions and Relevance: This case-control study found evidence to support previously reported associations, discovered new associations between functional seizures and PTSD, anxiety, and depression. An association between cerebrovascular disease and functional seizures was also found. Results suggested that sexual trauma may be a mediating factor in the association between female sex and functional seizures.

Alternate JournalJAMA Netw Open
PubMed ID33372972
PubMed Central IDPMC7772716
Grant ListR01 NS102371 / NS / NINDS NIH HHS / United States
UL1 RR024975 / RR / NCRR NIH HHS / United States
R01 MH118233 / MH / NIMH NIH HHS / United States
U54 MD010722 / MD / NIMHD NIH HHS / United States
R01 MH113362 / MH / NIMH NIH HHS / United States
U01 HG009086 / HG / NHGRI NIH HHS / United States
RM1 HG009034 / HG / NHGRI NIH HHS / United States
R21 HG010652 / HG / NHGRI NIH HHS / United States
R01 NS105746 / NS / NINDS NIH HHS / United States
R56 MH120736 / MH / NIMH NIH HHS / United States