Table 1
Post-operative monopolar review. The thresholds for sensory and motor side effects are appropriate and suggest an adequate position within the STN.
| LEFT LEAD | RIGHT LEAD | |
|---|---|---|
| Contact 0 | 0.9 mA (hand dysesthesia, anxiety) | 1.4 mA (dysarthria) |
| Contact 1 | 1.4 mA (double vision and hand dysesthesia) | 1.4 mA (face and hand contraction) |
| Contact 2 | 2 mA (hemibody tingling) | 1.4 mA (face and hand contraction) |
| Contact 3 | 3 mA (hand and face contraction) | 1.5 mA (face and hand contraction) |
Video 1
Intra-operative recording while creating a lesion. We show impedance monitoring, neurological testing, and finalization of the lesion.
Figure 1
Directional DBS lead diagram (A). When the lead is “unraveled” it has a total of 8 contacts – two monopolar levels and 2 levels with 3 segments each (B). At the proximal end of the lead, where it would normally connect to the extension cable (C.) the 8 contacts are now split into 8 sequential contacts. This is where the alligator clips (represented by white trapezoids) of the radiofrequency ablation device connect for the lesioning procedure (D). Note that each alligator clip covered two contacts due to its width (e.g. 1A and 1B, or 2B and 2C).
Figure 2
A graphical representation of the radiofrequency ablation procedure is demonstrated through a segmented lead. Left panel: a test lesion was made stimulating from contact segments 1A and 1B, followed by 1B and 1C. Middle panel: since there were no neurological deficits after the test lesion, we began to shape the permanent lesion. We set the stimulation at a higher amplitude in different combinations of segment pairs to cover the tissue surrounding contacts 1 and 2. Right panel: The final lesion spans the area surrounding all segments comprising contacts 1 and 2.
Figure 3
Axial sections of a brain MRI FLAIR sequence showing the lesion one-month post-procedure. The lesion can be seen on the left hemisphere as a hyperintense signal in the subthalamic region (green arrow heads).