Visualizing diagnostic delays in functional/dissociative seizures using the referral odyssey plot: A retrospective...

Functional/dissociative seizures (FDS) are often misdiagnosed as epilepsy, leading to delays in appropriate interventions. Although certain factors are associated with diagnostic delays, the overall referral trajectory remains unclear. This study aimed to illustrate the diagnostic journey with a novel visual approach, the "referral odyssey plot," and to depict patient pathways and identify factors associated with referral delays and diagnosis.

We retrospectively reviewed 50 patients diagnosed with documented FDS at Tohoku University Hospital (2014-2024). All patients underwent comprehensive inpatient evaluation, including long-term video-electroencephalogram monitoring, brain MRI, and psychosocial assessment. Four milestones were defined: seizure onset (T1), first non-epileptologist visit (T2), first epileptologist consultation (T3), and epilepsy monitoring unit admission (T4). Diagnostic pathways were visualized using a referral odyssey plot. Associations between variables and intervals were analyzed using Spearman's correlation, Friedman test, Mann-Whitney U test, and Kruskal-Wallis test.

The median total delay (T1-T4) was 51 months (interquartile range: IQR, 83.8). The longest delay occurred between T2 and T3 (median, 41 months; IQR, 74.8) and strongly correlated with total delay (ρ=0.95, p < 0.001). Younger age at onset and a family history of epilepsy were significantly associated with longer T2-T3 intervals. Seizure worry scores were negatively correlated with T1-T2 intervals.

Referral delay to an epileptologist was the main contributor to prolonged diagnosis of FDS. The referral odyssey plot visualized individual trajectories and bottlenecks, supporting earlier specialist referrals. These findings highlight the need for timely access to epileptologists experienced in the comprehensive evaluation of epilepsy and FDS.