Imaging for early differential diagnosis of parkinsonism

Abstract

Clinical diagnosis of Parkinson's disease relies on the presence of characteristic motor symptoms, such as bradykinesia, rigidity, and resting tremor, and non-motor features are increasingly being recognised as early symptoms. 1 Gelb DJ Oliver E Gilman S Diagnostic criteria for Parkinson disease. Arch Neurol. 1999; 56: 33-39 Crossref PubMed Scopus (2278) Google Scholar , 2 Tolosa E Wenning G Poewe W The diagnosis of Parkinson's disease. Lancet Neurol. 2006; 5: 75-86 Summary Full Text Full Text PDF PubMed Scopus (504) Google Scholar Nonetheless, early differential diagnosis can be difficult, especially because essential tremor, vascular parkinsonism, drug-induced parkinsonism, and atypical parkinsonian syndrome (ie, multiple system atrophy and progressive supranuclear palsy) might initially present with overlapping clinical features. 3 Hughes AJ Daniel SE Blankson S Lees AJ A clinicopathologic study of 100 cases of Parkinson disease. Arch Neurol. 1993; 50: 140-148 Crossref PubMed Scopus (820) Google Scholar Good response to dopaminergic drugs, particularly levodopa, is often used to support the clinical diagnosis of Parkinson's disease. However, some patients with pathologically confirmed Parkinson's disease have a poor response to levodopa; conversely, some patients with early multiple system atrophy or progressive supranuclear palsy have beneficial responses to drug treatment. 3 Hughes AJ Daniel SE Blankson S Lees AJ A clinicopathologic study of 100 cases of Parkinson disease. Arch Neurol. 1993; 50: 140-148 Crossref PubMed Scopus (820) Google Scholar , 4 Rajput AH Rozdilsky B Rajput A Accuracy of clinical diagnosis in parkinsonism: a prospective study. Can J Neurol Sci. 1991; 18: 275-278 Crossref PubMed Scopus (512) Google Scholar As the disease progresses the accuracy of clinical diagnosis increases, particularly if patients are assessed by movement disorder specialists, and can reach up to 90% accuracy compared with diagnosis at post-mortem examination. 5 Hughes AJ Daniel SE Kilford L Lees AJ The accuracy of the clinical diagnosis of Parkinson's disease: a clinicopathological study of 100 cases. J Neurol Neurosurg Psychiatry. 1992; 55: 181-184 Crossref PubMed Scopus (8190) Google Scholar Differential diagnosis of parkinsonism: a metabolic imaging study using pattern analysisAutomated image-based classification has high specificity in distinguishing between parkinsonian disorders and could help in selecting treatment for early-stage patients and identifying participants for clinical trials. Full-Text PDF