[Methods for the early diagnosis of Parkinson's disease].

Patients with idiopathic Parkinson's disease display a 60% degeneration of the nigrostriatal neurons before motor symptoms have progressed enough to allow clinical diagnosis. It is clear that any neuroprotective therapy starting at such a late stage can have no substantial effect on the disease progression. Therefore, earlier diagnosis must be the goal of future research,when at most mild motor or non-motor symptoms are present or when only risk factors can be identified. Evidence of various gene mutations associated with idiopathic Parkinsonism raise the hope that these or other biological markers will allow earlier identification of patients at risk. A possibly significant vulnerability factor for developing Parkinson's disease can also be demonstrated by means of transcranial sonography. Since the individual tests are not sufficiently specific or sensitive, a gradual, precise, and inexpensive battery of tests needs to be developed for the successful identification of a risk group for this disease. The extent of damage to the dopaminergic system in these patients can be quantified using nuclear techniques.