Onset of Postural Instability in Parkinson’s Disease Depends on Age rather than Disease Duration

Figure 2

Onset of postural instability occurs later in the disease course in patients with early manifestation of PD. (a) Patients with onset of PD < 50 years (n = 23 patients, left) have on average 18.6 (median; range: 6.7–28.3) PD years before the onset of postural instability. This time is significantly different compared to patients with PD onset at 50–70 years (middle, n = 66 patients, median: 14.2 years, range: 5.5–26.4) and >70 years (right bar, n = 17, median: 5.6 years, range: 2.7–10.8 years); (b) From the graph in (a), only the tremor-dominant patients were selected. Patients with onset of PD < 50 years (n = 5 patients, left) have median 19 (range: 18.8–28.33) PD years before onset of postural instability. This is not different compared with patients with first manifestation between 50 and 70 years (middle, n = 24 patients, median: 15.5 years, range: 8.67–26.42) but both groups are significant different to manifestation of PD > 70 years (right bar, n = 7, median: 7.8 years, range: 3.2–10.8 years); (c) From the graph in (a), only the patients treated with DBS were selected. Patients with manifestation of PD < 50 years (n = 20 patients, left) have median 18.2 (range: 6.3–22.1) PD years before onset of postural instability. This is significantly longer compared with patients with first manifestation between 50 and 70 years (right, n = 33 patients, median: 15.5 years, range: 6.33–22.1). In (a) and (b), we used Kruskal-Wallis test followed by Dunn’s multiple comparisons test, in (c) Mann-Whitney test; the plots show median with range and single values value <0.05, , .

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