Table 1.
Patient's motor symptom severity before and after variable-frequency stimulation.*
| Clinical variable | Off | HFS | 2nd VFS (1-day follow-up) | 2nd VFS (1-month follow-up) | 3rd VFS (3-months follow-up) |
|---|---|---|---|---|---|
| Total | 90 | 50 | 45 | 39 | 35 |
| Tremor | 10 | 6 | 6 | 5 | 5 |
| Rigidity | 20 | 8 | 8 | 2 | 2 |
| Bradykinesia | 40 | 24 | 22 | 22 | 22 |
| Axial symptoms | 20 | 12 | 9 | 10 | 6 |
| Speech | 4 | 3 | 3 | 2 | 2 |
| Gait | 4 | 2 | 2 | 2 | 1 |
| Posture | 4 | 2 | 1 | 2 | 1 |
| Postural stability | 4 | 2 | 2 | 2 | 2 |
| Arise from chair | 4 | 3 | 1 | 2 | 0 |
| TUG (sec) | Unable to complete | 10 | 12 | 10 | 11 |
| Hoehn-Yahr Stage | 5 | 3 | 3 | 3 | 3 |
| GFQ | NA | 36 | 32 | 32 | 32 |
| Voice loudness | NA | Max duration = 2.2, max SPL = 89.0 |
Max duration = 3.3, max SPL = 98.1 |
Max duration = 2.3, max SPL = 93.2 |
Max duration = 3.4, max SPL = 97.6 |
*
Motor symptom severity was assessed by using the Unified Parkinson's Disease Rating Scale (UPDRS)-III, unless indicated otherwise. Off, no STN-DBS; HFS, 170 Hz; HFS, High Frequency Stimulation; LFS, Low Frequency Stimulation; TUG, Time Up and Go test; GFQ, Gait and Falls Questionnaire; SPL, Sound Pressure Level; NA, Not Available.