An Atypical Case Of Kmt2b-Related Dystonia Manifesting Asterixis And Effect Of Deep Brain Stimulation Of The Globus Pallidus

We present a boy with KMT2B-related dystonia (DYT-KMT2B), a recently identified early-onset generalized dystonia. He manifested prominent asterixis, which improved following bilateral globus pallidus interna deep brain stimulation (GPi-DBS). Although variable involuntary movements, including myoclonus and tremor, can be seen in patients with DYT-KMT2B, asterixis has not been reported. This is also the first report which shows the beneficial effect of bilateral GPi-DBS for asterixis, suggesting that dysfunction of the cortico-basal ganglia-thalamo-cortical circuit may be involved in its pathomechanism.