EEG Patterns in Patients with Prader-Willi Syndrome.

Maurizio Elia,Giuliana Trifirò,Silvana De Lucia,Irene Rutigliano,Malgorzata Wasniewska,Michele Sacco,Paolo Di Bella,Maurizio Delvecchio,Alessandra Li Pomi,Lorenzo Iughetti,Simona F Madeo,Luigi Vetri

doi:10.3390/brainsci11081045

Abstract

Prader–Willi syndrome (PWS) is a rare disease determined by the loss of the paternal copy of the 15q11-q13 region, and it is characterized by hypotonia, hyperphagia, obesity, short stature, hypogonadism, craniofacial dysmorphisms, and cognitive and behavioral disturbances. The aims of this retrospective study were to analyze interictal EEG findings in a group of PWS patients and to correlate them with genetic, clinical, and neuroimaging data. The demographic, clinical, genetic, EEG, and neuroimaging data of seventy-four patients were collected. Associations among the presence of paroxysmal EEG abnormalities, genotype, and clinical and neuroimaging features were investigated. Four patients (5.4%) presented drug-sensitive epilepsy. Interictal paroxysmal EEG abnormalities—focal or multifocal—were present in 25.7% of the cases, and the normalization of the EEG occurred in about 25% of the cases. In 63.2% of the cases, the paroxysmal abnormalities were bilaterally localized over the middle–posterior regions. Brain magnetic resonance imaging (MRI) was performed on 39 patients (abnormal in 59%). No relevant associations were found between paroxysmal EEG abnormalities and all of the other variables considered. Interictal paroxysmal EEG abnormalities—in particular, with a bilateral middle–posterior localization—could represent an important neurological feature of PWS that is not associated with genotype, cognitive or behavioral endophenotypes, MRI anomalies, or prognosis.

Highlights

Prader–Willi syndrome (PWS) is a rare genetic condition with an estimated prevalence of about 1:15,000 that is characterized by multisystemic features, such as severe early hypotonia, hyperphagia, childhood obesity, short stature, small hands and feet, hypogonadism, growth hormone or other endocrine deficiencies, craniofacial dysmorphisms, developmental delay, intellectual disability (ID), behavioral disturbances, and autism spectrum disorder [1].PWS is a genomic imprinting disorder, as it occurs due to the loss of a paternal copy of the 15q11-q13 region
Seizure onset ranged from 1 year and 3 months to 7 years, and in all cases, seizures were controlled with antiepileptic drugs in monotherapy or polytherapy
We showed that about 25% of PWS patients presented EEG abnormalities, irrespective of their genetic defects, gender, and intellectual disabilities, and that about 5% presented epilepsy

Summary

Introduction

PWS is a genomic imprinting disorder, as it occurs due to the loss of a paternal copy of the 15q11-q13 region. Imprinting center (IC) defects (micro-deletions, mutations) in the 15q11-q13 region or other chromosomal abnormalities are found in the remaining 5% of PWS patients [2]. No peculiar interictal electroencephalographic patterns have been identified in PWS, as they have in other chromosome abnormalities, and heterogeneous EEG pictures have been reported, such as focal, multifocal, or generalized epileptiform abnormalities [3,4,5,6,7,8,9]. Epilepsy does not represent a typical neurological feature, recently, a prevalence ranging from 4% to 26% was estimated in several retrospective PWS series worldwide.

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