TY - JOUR T1 - Timing the initiation of treatment in Parkinson’s disease JF - Journal of Neurology, Neurosurgery & Psychiatry JO - J Neurol Neurosurg Psychiatry SP - 615 LP - 615 DO - 10.1136/jnnp.2008.144741 VL - 79 IS - 6 AU - Donald G Grosset AU - Anthony H Schapira Y1 - 2008/06/01 UR - http://jnnp.bmj.com/content/79/6/615.1.abstract N2 - It is estimated that the dopaminergic neuronal loss that causes the characteristic motor features of Parkinson’s disease (PD) has reached 50–70% by diagnosis and it is progressive. Clinical, imaging and pathological studies suggest that the cell loss begins 7–10 years before the onset of clinical features sufficient to allow the diagnosis of PD. During this period of pre-diagnostic neurodegeneration, compensatory mechanisms are developed to maintain normal basal ganglia function.1 Eventually, these fail and symptoms emerge, enabling a diagnosis which is usually based on the combination of bradykinesia, rigidity and tremor. The delay from symptom onset to diagnosis is variable and … ER -