Early onset Parkinson's disease: Are juvenile‐ and young‐onset different?

Abstract

It is controversial if early onset Parkinson's disease (EOPD) (onset at < 41 years of age) is Parkinson's disease (PD) occurring at a younger age or a different disease. This controversy is due to some clinical and pathological differences between EOPD and PD. Within EOPD, there appear to be two groups namely: young onset Parkinson's disease (YOPD), with onset between 21 and 40 years, and juvenile parkinsonism (JP), with onset at < 20 years. The two major clinical differences between these groups are a higher familial occurrence of PD and dystonia in JP. In this study, we determine if the two groups have the classical features of PD, namely rest tremors, rigidity, bradykinesia, and postural instability, and have a meaningful response to levodopa. Furthermore, we compare their other clinical features, autonomic and cognitive functions, and levels of CSF monoamine metabolites to determine differences between these groups. We observe that all YOPD (100%) and JP (85%) patients had rest tremors. Most of these patients also had a meaningful response to levodopa (YOPD: 72%; JP: 100%). The prevalence of family history of PD was similar, whereas dystonia was more frequent in JP (43%) compared to YOPD (9%). Autonomic symptoms were twice as common in JP (42%) compared to YOPD (17%). However, bedside autonomic functions were abnormal in similar proportions and, like in PD, suggest involvement of parasympathetic nervous system. Cognitive dysfunction does occur but with no difference in severity between the two groups. The difference in number of patients between YOPD and JP groups makes statistical comparison of the occurrence of clinical features like dystonia and autonomic dysfunction difficult.(ABSTRACT TRUNCATED AT 250 WORDS)

[18F]‐Dopa positron emission tomography imaging in early‐stage, non‐parkin juvenile parkinsonism

“…Whereas the clinical features of JP have been well characterized,8, 9, 18–25 there are few reports of FD PET in JP8–11, 24 which show great variability in the degree of reduction in FD uptake, the severity of which (according to the literature) does not seem to correlate with disease duration. Snow and colleagues9 reported PET findings in three JP patients with mild parkinsonism in their third decade of life, after a disease duration of 5–19 years.…”

The Heterogeneity of Early Parkinson’s Disease: A Cluster Analysis on Newly Diagnosed Untreated Patients

“…Subtypes of PD have previously been profiled mainly according to the relevance of such demographic and clinical features as age at disease onset and motor phenotype [2]–[5]. Recently, two independent groups reviewed the results of the cluster analyses performed on PD patients, showing that the cluster profiles “old age-at-onset with rapid disease progression” and “young age-at-onset with slow disease progression” emerged from the majority of studies [6], [7].…”

A data-driven approach to the study of heterogeneity in idiopathic Parkinson's disease: identification of three distinct subtypes

“…However, IPD can occur in patients much younger providing the basis for an early-onset subclassification of IPD. [7][8][9][10][11] Cognitive performance is often impaired in patients with IPD and the prevalence of clinical dementia is approximately 10-15% greater than in an age-matched population. 12 Frontal lobe executive function deficits have been identified in tasks such as set-shifting, 13,14 sequencing, 15 and planning.…”