Diagnostic reassessment in patients previously diagnosed with childhood-onset epilepsy during the transition to adult care: A retrospective cohort study in a tertiary epilepsy center.

OBJECTIVE: To investigate the frequency, predictors, and clinical implications of diagnostic reassessment in patients previously diagnosed with childhood-onset epilepsy during the transition period to adult care at a tertiary epilepsy center.

METHODS: We conducted a retrospective cohort study of 317 patients previously diagnosed with childhood-onset epilepsy who underwent diagnostic reassessment between April 2018 and December 2023 at age 16 years or older at a tertiary epilepsy center in Japan. Diagnostic revision was defined as a newly established or corrected epilepsy/epilepsy syndrome diagnosis, identification of structural or genetic/metabolic etiologies, or diagnosis of non-epileptic conditions. Univariate and multivariate logistic regression analyses were performed to identify independent predictors of diagnostic revision.

RESULTS: A new or revised diagnosis was established in 60 of the 317 patients (18.9%). Independent predictors of diagnostic revision included exclusively non-motor seizures (adjusted odds ratio [aOR] = 7.610; 95% confidence interval [CI]: 2.660-21.767; p < 0.001) and weekly or monthly seizure frequency (aOR = 3.370; 95% CI: 1.265-8.976; p = 0.015), whereas prior visits to other epilepsy centers were strongly protective (aOR = 0.047; 95% CI: 0.015-0.146; p < 0.001). Sensitivity analyses yielded consistent results. Newly identified etiologies include focal cortical dysplasia, hippocampal sclerosis, and pathogenic genetic variants such as CDKL5, PCDH19, and SYNGAP1. Diagnostic reassessment facilitated antiseizure medication withdrawal in patients with self-limited epilepsy and non-epileptic events.

SIGNIFICANCE: Nearly one in five patients previously diagnosed with childhood-onset epilepsy required diagnostic revision during the transition to adult care. Non-motor seizure semiology and moderate seizure frequency were the major predictors of diagnostic revision, highlighting the diagnostic uncertainty associated with subtle clinical presentations. These findings highlight that systematic reassessment, especially for individuals who have not previously undergone specialized epilepsy center evaluation, is essential for achieving an accurate diagnosis and optimizing management in adulthood.

PLAIN LANGUAGE SUMMARY: Many people diagnosed with epilepsy in childhood continue medical care into adulthood, but their diagnosis may need to be reviewed later in life. In this study, nearly one in five patients who had been diagnosed with childhood-onset epilepsy required a change or refinement of their diagnosis when reassessed after age 16. Patients with seizures without clear physical movements and those whose seizures occurred weekly or monthly were more likely to need diagnostic review. These findings highlight the importance of reviewing the diagnosis during adolescence, especially for patients who have not previously been evaluated at specialized epilepsy centers.