Cerebral Palsy Phenotypes In Genetic Epilepsies

INTRODUCTION While there are established connections between genetic epilepsies and neurodevelopmental disorders like intellectual disability, the presence of cerebral palsy (CP) in genetic epilepsies has been under-characterized. We performed a retrospective chart review evaluating the motor phenotype of patients with genetic epilepsies. METHOD Patients were ascertained through a research exome sequencing study to identify genetic causes of epilepsy. We analyzed data from the first 100 individuals with molecular diagnoses. We determined motor phenotype by reviewing medical records for muscle tone and motor function data. We characterized patients according to CP subtypes: spastic diplegic, spastic quadriplegic, spastic hemiplegic, dyskinetic, hypotonic-ataxic. RESULTS Of 100 individuals with genetic epilepsies, 14% had evidence of possible CP, including 5% characterized as hypotonic-ataxic CP, 5% spastic quadriplegic CP, 3% spastic diplegic CP, and 1% hemiplegic CP. Presence of CP did not correlate with seizure onset age (p=0.63) or seizure control (p=0.07). CP occurred in 11% (n=3/27) with focal epilepsy, 9% (n=5/54) with generalized epilepsy, and 32% (n=6/19) with combined focal/generalized epilepsy (p=0.06). CONCLUSIONS In this retrospective analysis of patients with genetic epilepsies, we identified a substantial portion with CP phenotypes, representing an under-recognized comorbidity. These findings underscore the many neurodevelopmental features associated with neurogenetic conditions, regardless of the feature for which they may have been ascertained for sequencing. Detailed motor phenotyping is needed to ascertain the prevalence of CP and its subtypes among genetic causes of epilepsy. These motor phenotypes require clinical management and represent important targeted outcomes in trials for patients with genetic epilepsies.