Table 1 Patients' characteristics (n = 10, 9 men and 1 woman)

Age (years)

66 (59–69)

Height (m)

1.76 (1.66–1.90)

Weight (kg)

77 (60–95)

Duration of disease (years)

18 (10–22)

Duration of DBS treatment (months)

37 (15–70)

DBS parameter settings¹

   Right (amplitude: V, pulsewidth: μs, frequency; Hz)

3.3 (2.5–4.3), 60 (60–90), 145 (100–185)

   Left (amplitude: V, pulsewidth: μs, frequency; Hz)

3.4 (2.2–4.3), 60 (60–90), 130 (100–185)

Localization of the contacts with negative polarity

   Right

11.7 (10.4–13.1) mm lateral to the midsagittal plane through the intercommissural line (IC), 3.4 (3.0–4.0)mm posterior to the midpoint of IC and 2.1 (1.0–5.6)mm inferior to IC.

   Left

11.4 (9.6–13.0) mm lateral, 3.5 (3.3–5.2) mm posterior, and 2.6 (1.2–4.2) mm inferior to IC. The median length of IC was 24.8 (23.5–25.6) mm

L-dopa equivalents (mg/day)²

416 (242–989)

Physical Activity Scale for the Elderly (PASE)³

112 (75–187)

UPDRS part III⁴ total score

DBS OFF: 41.0 (35.0–83.5), DBS ON: 21.5 (11.0–30.5)

n

Occupation

10 retired (6 due to age, 4 due to disease)

Comorbidity

2 (1 patient had lumbar degenerative changes, 1 had hypertonia and a previous heart infarct)

Postural hypotension⁵

None

Prior surgery related to Parkinson's disease⁶

2 (1 pallidotomy, 1 thalamotomy + earlier DBS surgery)

Pain symptoms

6 (2 hip pain, 2 back pain, 2 shoulder pain)

Assistive device (walking indoors)

None

Assistive device (walking outdoors)

1 (cane)

Falls within the past 6 months⁷

7 patients reported falls (range 1–15 falls), whereof 5 patients reported at least 2 falls

3 patients reported no falls: 1 experienced near falls every week, and 2 every month (whereof one of the two had fractured twice due to falls, but the last incidence was a year before the study)