Pediatric-Onset Epilepsy and Developmental Epileptic Encephalopathies Followed by Early-Onset Parkinsonism

Area of Science:

• Neurology
• Genetics
• Epileptology

Background:

• Genetic early-onset Parkinsonism frequently co-occurs with hyperkinetic movement disorders and neurological or systemic findings, including epilepsy (10-15% of cases).
• Existing classifications for childhood Parkinsonism and epilepsies provide a framework for understanding these complex presentations.

Purpose of the Study:

• To review and identify distinct presentations of genetic early-onset Parkinsonism associated with epilepsy.
• To highlight the need for long-term follow-up in at-risk individuals.

Main Methods:

• Literature review of PubMed using classifications from Leuzzi et al. for Parkinsonism and the 2017 ILAE classification for epilepsies.
• Analysis of identified presentations linking childhood epilepsy/developmental and epileptic encephalopathies to later-onset Parkinsonism.

Main Results:

• Four discrete presentations were identified: Parkinsonism as a late manifestation of neurodevelopmental disorders (DE-EE), Parkinsonism in syndromic conditions, neurodegenerative conditions with brain iron accumulation, and monogenic juvenile Parkinsonism.
• Monogenic juvenile Parkinsonism involves intellectual disability/developmental delay (ID/DD) and hypokinetic movement disorders developing between ages 10-30, often preceded by childhood epilepsy.

Conclusions:

• Emerging genetic conditions link childhood epilepsy or DE-EE to juvenile Parkinsonism.
• Careful long-term follow-up is essential for individuals with ID/DD to detect early signs of Parkinsonism.