Dravet syndrome: Early electroclinical findings and long-term outcome in adolescents and adults

Domenica Immacolata Battaglia, Daniela Pia Rosaria Chieffo, Massimiliano Patrini, Elisa Fontana, Giorgia Olivieri, Ida Turrini, Francesca Darra, Mara Patrini, Francesca Offredi, Elena Piazza, Elena Fontana, Bernardo Dalla Bernardina, Tiziana Granata, Francesca Ragona

Research output: Contribution to journalArticlepeer-review

4 Citations (Scopus)


To describe the outcome of Dravet syndrome (DS) in adolescents and adults we conducted a longitudinal retrospective study of two independent cohorts of 34 adolescents (group 1) and 50 adults (group 2). In both cohorts, we collected information about genetic mutation, and semiology of seizures at onset and during disease course. At the last evaluation, we considered the following features: epilepsy (distinguishing myoclonic/complete and nonmyoclonic/incomplete phenotype), neurologic signs, intellectual disability (ID), and behavioral disorders. Moreover, in both cohorts, we performed a correlation analysis between early characteristics of the disease and the outcome of DS with regard to seizure persistence, ID, behavioral disorder, and neurologic impairment at last evaluation. Group 1 includes 22 adolescents with complete form of DS and 12 with incomplete form; group 2 includes 35 adults with complete form and 15 with incomplete form. The seizures persisted in 73.6% of adolescents and in 80% of adults, but epilepsy severity progressively decreased through age. Seizure persistence correlated with the complete phenotype and with the occurrence of reflex seizures. At last evaluation, ID was moderate or severe in 70.5% of adolescents and in 80% of adults. The most severe cognitive and motor impairment was observed in patients with persisting seizures. The severity of cognition, language, and neurologic impairment at last evaluation correlated statistically with the complete phenotype. The study confirms that the global outcome of DS is poor in most cases, albeit epilepsy severity decreases throughout adulthood. The improvement of epilepsy throughout ages is not associated with improvement in intellectual abilities and motor skills; this confirms that the unfavorable outcome is not a pure consequence of epilepsy.
Original languageEnglish
Pages (from-to)S49-S58
Publication statusPublished - 2019


  • Adolescent
  • Adult
  • Age Factors
  • Epilepsies, Myoclonic
  • Epilepsy
  • Female
  • Humans
  • Intellectual Disability
  • Male
  • NAV1.1 Voltage-Gated Sodium Channel
  • Phenotype
  • Seizures
  • Time
  • Young Adult
  • adolescents and adults
  • complete Dravet syndrome
  • developmental and epileptic encephalopathy
  • long-term outcome
  • myoclonic phenotype
  • reflex seizures

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