neurologic disorders
Secondary and Atypical Parkinsonism
Introduction
Secondary parkinsonismrefers to a group of disorders that have features similar to those of Parkinson disease but have a different etiology.Atypical parkinsonismrefers to a group of neurodegenerative disorders other than Parkinson disease that have some features of Parkinson disease but have some different clinical features, different pathology, and a different response to treatment, and the prognosis is worse. Diagnosis is by clinical evaluation and response tolevodopa. Treatment is directed at the cause when possible. (See also Overview of Movement and Cerebellar Disorders .) Insecondary parkinsonism,the mechanism is blockade of or interference withdopamine’saction in the basal ganglia. Atypical parkinsonismencompasses neurodegenerative disorders such as Progressive Supranuclear Palsy (PSP) None Dementia with Lewy Bodies and Parkinson Disease Dementia None Corticobasal ganglionic degeneration Multiple System Atrophy (MSA) None Multiple System Atrophy (MSA) None Wilson Disease None Multiple System Atrophy (MSA) None Westphal variant of Huntington Disease None Certain Hereditary ataxias None 