A case of progressive supranuclear palsy with cortical myoclonus

Progressive supranuclear palsy (PSP), a neurodegenerative disease with the parkinsonism, is characterized by supranuclear eye movement disorders and static reflex disorder appearing in the neck / trunk from early period of muscle rigidity and illness. Myoclonus is the lightning involuntary muscle shrinkage resulting from excessive neurologic excitement. This disease develops with various conditions of a patient including side effects of drugs, nervous diseases and systemic metabolic derangements. In the neurodegenerative disease group with parkinsonism, myoclonus develops with 15-50% frequency for Diffuse Lewy body disease, multiple system atrophy, and corticobasal degeneration; however, it is very rare in PSP [1]. We encountered one PSP patient with cortical myoclonus.