Table 1
Monopolar Threshold Programming Review at the Initial DBS Programming Session.
| CONTACT NUMBER | LEFT STN DBSTHRESHOLD (IN MA) | SIDE EFFECT | RIGHT STN DBSTHRESHOLD (IN MA) | SIDE EFFECT |
|---|---|---|---|---|
| 0 | 1.0 | Light-headedness, Paresthesias at 1.2 mA | 1.8 | Paresthesias of the hand |
| 1 | 0.9 | Dyskinesia | 2.3 | Dyskinesia |
| 2 | 0.5 | Dyskinesia | 2.5 | Arm tightness, dysarthria |
| 3 | 1.5 | Dyskinesia | 2.6 | Arm tightness, dysarthria |
[i] Note the low current densities necessary to elicit dyskinesia in the initial DBS programming session. Thresholds were obtained at a pulse width of 90 µS and a frequency of 135 Hz.
Figure 1
Lead locations within the STN. (1a) Top, lateral view of the right STN (orange) and left STN (blue) lead locations within the STN region (green). (1b) Bottom, anterior view of the right STN (orange) and left STN (blue) lead locations within the STN region (green). These locations are relatively ventral and anterior within the target region.
Table 2
Optimized DBS Settings.
| CONTACTS | AMPLITUDE (MA) | PULSE WIDTH (µS) | FREQUENCY (HZ) | |
|---|---|---|---|---|
| Left STN: Interleaving, Bipolar | 3– C+ | 1.3 | 70 | 150 |
| 3– 2+ | 0.6 | 20 | 60 | |
| Right STN Directional, Double Monopolar | 11- 9c– | 1.4 11– (1.2) 9c– (0.4) | 60 | 150 |
Video Segment 1
Stimulation induced dyskinesia and response to optimized programming. The patient manifested tremor that was severe when both medication and stimulation were “off”. There was a manifested reduction in tremor, but increased dyskinesia in the medication “on”, stimulation “off” state and in the medication “off”, stimulation “on” state. Following optimization of DBS programming, there was no tremor, but there was mild dyskinesia, in the medication and stimulation “on” state.
Figure 2
The See-Saw Dilemma in STN Related Stimulation Induced Dyskinesia. In cases of STN induced SID, the clinician is challenged to balance the see-saw. Small increases in stimulation result in improvement in one symptom (tremor) with worsening in another (dyskinesia). Alternatively, reduction in medication, may lead to worsening of tremor and improvement in dyskinesia. The clinician may apply programming and medication strategies to attempt to balance the see-saw.
Figure 3
Gamma Band Increase from STN DBS: Time-Frequency Spectrogram of Local Field Potential Data from the Left STN lead. The application of stimulation using 1.5 mA of current applied to the left STN DBS lead (bottom tracing, blue line) induced visualized dyskinesia on physical examination that correlated with the onset of a band of increased gamma frequency (30–100 Hz) activity (red box in the top tracing).