神经病学课件：帕金森病和运动障碍疾病.pptVIP

The incidence of parkinson syndrome and Parkinson’s disease rises with age, and has been reported at between five and twenty-four cases per hundred thousand. The best available incidence studies--those from the Rochester, Minnesota, database--suggest the incidence of parkinson syndrome in the U.S.A. is 20.5 per 100,000 population. Because the population is slowly aging, and the recognition of parkinsonism is improving, it is expected that the incidence will slowly rise. Door-to-door prevalence surveys of the general population have revealed that 35-42% of the cases of parkinson syndrome in the general population remain undiagnosed. Most of those would be early cases, those with akinetic-rigid form of parkinsonism, or those who have been mistaken as having had a neurological disease such as essential tremor. The reported prevalence rates range from 57-371 per 100,000 population. In the U.S. and Canada it is estimated that the prevalence is 300 per 100,000 population. This should be regarded as a conservative estimate. A review of 934 patients found the onset of parkinson syndrome was at age 61.6, while the onset of Parkinson’s disease was at age 62.4 years. Parkinsonism is very rare before age 30 and only 4-10% of the cases have onset before the age of 40 years. The cause in idiopathic Parkinson’s disease is unknown, but it is not accelerated aging. Rarely is Parkinson’s disease inherited as a dominant disorder. Mutation of Alpha synuclein gene (chromosome 4q) has been identified in one large Italian family, the Contursi family, and in five Greek families. Mutation of the parkin gene has been identified as the cause of autosomal-recessive juvenile parkinsonism. In the overwhelming majority of familial cases of Parkinson’s disease, no genetic abnormality has been identified. In the majority of cases the disease is believed to be caused by environmental factors. The place of birth and residence seem to play a greater role than the race. Blacks living in the U.S. ha