Influence of cannabis use on length of stay in patients admitted to the epilepsy monitoring unit.

Purpose: Epilepsy affects approximately 50 million people worldwide, many of whom undergo evaluation in Epilepsy Monitoring Units (EMUs) for seizure classification, medication management, or presurgical assessment. With increasing numbers of states legalizing marijuana use, a growing number of EMU admissions involve individuals who use cannabis-based products. If cannabis users are unable to use cannabis products during their EMU admission, this may lead patients to be discharged before recording typical events. This study evaluates the impact of cannabis use on EMU outcomes, specifically length of stay (LOS) and likelihood of capturing a clinical event. Methods: A retrospective chart review was conducted using a REDCap database including demographics, epilepsy risk factors, anti-seizure medication use, social history, urine drug screen results, and final diagnoses. Patients were categorized as users (self-reported use, positive urine test, or both) or non-users (negative test and no self-report). Primary outcomes in the analysis were LOS and event capture rates. Results: Cannabis use was associated with a 0.9 day LOS reduction compared to non-users. Among patients admitted for spell classification, event capturability was 18.1 % higher in cannabis users. Additionally, cannabis users had increased prevalence of psychosocial comorbidities: 12.6 % reported physical abuse, 11.1 % sexual abuse, and 10.2 % mental abuse. Psychiatric diagnoses were also more prevalent; users were 18.9 % more likely to have Major Depressive Disorder and 22.1 % more likely to have Generalized Anxiety Disorder. Conclusions: Cannabis use significantly affects EMU evaluation outcomes and correlates with distinct psychosocial and psychiatric profiles. These findings support a holistic approach in epilepsy patient management.