Angelman Syndrome Pt 3: Neurophysiology
See previous posts on an intro to and symptoms of Angelman Syndrome.
One of the more notable features of Angelman Syndrome (AS) is the syndrome’s pathognomonic neurophysiological findings. The electroencephalogram (EEG) in AS is usually very abnormal, and more abnormal than clinically expected (Williams 2005). Three distinct interictal patterns are seen in these patients (Fig. 1; normal EEG in Fig. 2 for comparison) (Dan 2009). The most common pattern is a very large amplitude 2-3 Hz rhythm most prominent in prefrontal leads (Fig. 1 A). Next most common is a symmetrical 4-6 Hz high voltage rhythm (Fig. 1 B). The third pattern, 3-6 Hz activity punctuated by spikes and sharp waves in occipital leads, is associated with eye closure (Fig. 1 C). Paroxysms of laughter have no relation to the EEG, ruling out this feature as a gelastic phenomenon (Williams 2005).
Fig. 1 The three distinct EEG patterns seen in AS. Courtesy Dan 2009
Fig. 2 EEG from a normal subject. Courtesy MGH website
Epileptic seizures occur in 80% of patients with AS (Clay-Smith & Laan 2003). Many different types of seizures have been reported, including absence, myoclonic, atonic, and tonic-clonic seizures (Pelc et al 2008). Seizures commonly progress to nonconvulsive status epilepticus.
Pelc K, Boyd SG, Cheron G, Dan B. (2008b) “Epilepsy in Angelman syndrome.” Seizure 17:211–217.
Other citations: see previous posts
6 Comments »
RSS feed for comments on this post. TrackBack URL
[...] previous posts on history, symptoms, and neurophysiology of Angelman [...]
[...] previous posts on history, symptoms, and neurophysiology of Angelman [...]
[...] previous posts on history, symptoms, neurophysiology, and genetics of Angelman [...]
[...] previous posts on history, symptoms, neurophysiology, genetics, and molecular biology of Angelman [...]
[...] previous posts on history, symptoms, neurophysiology, genetics, molecular biology, and targets of UbE3A in Angelman [...]
[...] previous posts on history, symptoms, neurophysiology, genetics, molecular biology, targets of UbE3A , and systems pathophysiology of Angelman [...]