Variable expression of Parkinson's disease

TLDR

The DATATOP database, containing clinical data on 800 early untreated Parkinson’s disease patients, is ideal for studying PD heterogeneity. Early‑onset PD patients reached comparable disability to late‑onset PD but progressed more slowly and performed better cognitively, while rapid‑progressing (malignant) cases showed more bradykinesia and PIGD; tremor‑dominant versus PIGD subtypes differed in impairment, with PIGD patients reporting greater functional deficits, and older age at onset with bradykinesia or PIGD was associated with greater disability.

Abstract

The DATATOP database, which includes clinical information on 800 patients with early untreated Parkinson9s disease (PD), is well suited to explore clinical heterogeneity in PD. Patients with early-onset PD (≤40 years, N = 33) reached the same level of disability as the late-onset PD (≥70 years, N = 85) group at a significantly slower rate (2.9 vs. 1.7 years). Early-onset PD patients functioned cognitively better than late-onset PD patients. Bradykinesia, and postural instability and gait difficulty (PIGD), were more common at onset in patients with a rapid rate of disease progression (“malignant PD”; duration of symptoms <1 year and Hoehnflahr stage of 2.5, N = 11) as compared with those with a relatively slow rate of progression (“benign PD”; duration of symptoms >4 years, N = 65). Comparisons of tremor-dominant PD (mean tremor score/ mean PIGD score ≤1.5, N = 441) with the PIGD-dominant type (mean tremor score/mean PIGD score ≥1.0, N = 233) provided support for the existence of clinical subtypes. The PIGD group reported significantly greater subjective intellectual, motor, and occupational impairment than the tremor group. Stage II patients had higher depression scores than stage I patients. Among the patients participating in the DATATOP, older age at onset with bradykinesia, or with the PIGD form of PD, is associated with more functional disability than when the symptoms are dominated by tremor or begin at a younger age.