Angelman syndrome: is a neuro-genetic disorder characterized by intellectual and developmental delay, sleep disturbance, seizures, jerky movements , frequent smiling, and usually a happy demeanor.Angelman syndrome is a classic example of genetic imprinting in that it is usually caused by deletion or inactivation of genes on the maternally inherited chromosome 15 while the paternal copy, which may be of normal sequence, is imprinted and therefore silenced. The sister syndrome, Prader-Willi syndrome, is caused by a similar loss of paternally-inherited genes and maternal imprinting. Three distinct interictal EEG patterns are seen in these patients. The most common pattern is a very large amplitude 2–3 Hz rhythm most prominent in prefrontal leads. Next most common is a symmetrical 4–6 Hz high voltage rhythm . The third pattern, 3–6 Hz activity punctuated by spikes and sharp waves in occipital leads, is associated with eye closure.
Posted on: Fri, 07 Nov 2014 19:04:53 +0000
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