Complex sentence: Primary Parkinson's disease is referred to as idiopathic (having no known cause), although some atypical cases have a genetic origin, while secondary parkinsonism is due to known causes like toxins.
Split into simpler sentences: Primary Parkinson's disease is referred to as idiopathic (having no known cause), although some atypical cases have a genetic origin. While secondary parkinsonism is due to known causes like toxins.