Low clinical diagnostic accuracy of early vs advanced Parkinson disease | Neurology

We read with interest the report by Adler et al. in which Parkinson disease (PD) patients were followed, comparing initial and final diagnosis with neuropathological findings. [1] Subjects with less than 5 years of disease only had a 26-53% accuracy in early PD diagnosis based on clinical criteria. With no levodopa trial, it was as low as 26%. Potential problems were mentioned: some studies have failed in neuroprotective therapy trials, or in searches for early biomarkers, where the focus is early diagnosis. However, we noticed levodopa challenge had not been discussed. We believe levodopa challenge as a diagnostic tool should be brought to light. Some older publications showed acute challenge as a possible marker of levodopa response. In 1990, Hughes [2] reported a 90% agreement between apomorphine or levodopa challenge and long-term levodopa response. Clarke and Davies [3] reviewed this and concluded it showed the same diagnostic accuracy in diagnosing PD as chronic levodopa. Its use

We read with interest the report by Adler et al. in which Parkinson disease (PD) patients were followed, comparing initial and final diagnosis with neuropathological findings. [1] Subjects with less than 5 years of disease only had a 26-53% accuracy in early PD diagnosis based on clinical criteria. With no levodopa trial, it was as low as 26%. Potential problems were mentioned: some studies have failed in neuroprotective therapy trials, or in searches for early biomarkers, where the focus is early diagnosis. However, we noticed levodopa challenge had not been discussed. We believe levodopa cha