Seizure and movement disorder in CACNA1E developmental and epileptic encephalopathy: Two sides of the same coin or same side of two different coins?

Abstract

AbstractPathogenic variants in CACNA1E are associated with early‐onset epileptic and developmental encephalopathy (DEE). Severe to profound global developmental delay, early‐onset refractory seizures, severe hypotonia, and macrocephaly are the main clinical features. Patients harboring the recurrent CACNA1E variant p.(Gly352Arg) typically present with the combination of early‐onset DEE, dystonia/dyskinesia, and contractures. We describe a 2‐year‐and‐11‐month‐old girl carrying the p.(Gly352Arg) CACNA1E variant. She has a severe DEE with very frequent drug‐resistant seizures, profound hypotonia, and episodes of dystonia and dyskinesia. Long‐term video‐EEG‐monitoring documented subsequent tonic asymmetric seizures during wakefulness and mild paroxysmal dyskinesias of the trunk out of sleep which were thought to be a movement disorder and instead turned out to be focal hyperkinetic seizures. This is the first documented description of the EEG findings in this disorder. Our report highlights a possible overlap between cortical and subcortical phenomena in CACNA1E‐DEE. We also underline how a careful electro‐clinical evaluation might be necessary for a correct discernment between the two disorders, playing a fundamental role in the clinical assessment and proper management of children with CACNA1E‐DEE.