Angelman’s Syndrome

Posted on
May 3, 2024
Let's learn all the facts about a brain pattern called

Angelman’s Syndrome

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Laura A.E.M. Laan, Alla A. Vein, Angelman syndrome: is there a characteristic EEG?, Brain and Development, Volume 27, Issue 2, 2005, Pages 80-87, ISSN 0387-7604,

Angelman syndrome (AS)also known as “Happy Puppet Syndrome” is a genetic disorder characterized by severe mental retardation, subtle dysmorphic facial features, epileptic seizures, and EEG abnormalities. AS can be caused by various genetic mechanisms involving the chromosome 15q11-13 region.

Seizures in AS have an age of onset beginning at approximately 1-3 years of age. 25% will have seizures before ethe age of 1. Seizures are usually most frequent and most intense in early childhood and tend to improve with puberty. These can return and persist into adulthood but are typically much less frequent and less intense.

Epilepsy in Angelman syndrome is a generalized epilepsy that may include the following or any combination of Generalized tonic-clonic, Atypical absence, Atonic, Myoclonic, Tonic (rare), and Spasms (exceedingly rare). In addition, Focal seizures can be present in ~30% of cases.

What are the 3 most seen patterns on the EEG of patients with Angelman’s Syndrome (AS)?
Sharp and slow-wave complexes with intervals of 1 to 5 seconds
Bi-frontal predominant slow spike and wave (appear “triphasic”)
Rhythmic 4-6 Hz centrotemporal activity
Posterior “notched” delta activity
Correct Answer: 

1. Prolonged runs of anterior dominant, rhythmic 2–3 Hz (200–500 mV) with or without admixed spike-wave discharges

2. Persistent rhythmic 4–6 Hz, > 200 mV activities during wakefulness

3. Posterior dominant 3–4 Hz >200 mV notched delta and theta activities (admixed with ill-defined spike wave) facilitated with eye closure. Predominantly children less than 12 yo.

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