Figure 1
Omnidirectional and Directional DBS Electrodes. DBS electrodes generally have four contact points spaced out at variable distances. Omni directional leads are a complete band, and the entire band is either utilized or not utilized. Directional leads on the Abbott/St. Jude system are present on the 2 middle contacts and the band is divided into 3 sections, each of which can be stimulated independently of the others. A bi-polar configuration results in a narrower stimulation field whereas a directional configuration shifts the field laterally. Figure is modified from material provided by Abbott/St. Jude.
Figure 2
Patient Enrollment. Forty-two patients received VIM DBS over the time period we examined. Of those patients the 33 that had the Abbott/St. Jude system, received programming at our center, and were done for essential tremor without significant other neurological disease were included in our analysis.
Table 1
Population Demographics. D = Directional and O = omnidirectional.
| TOTAL | AGE (SD) | SEX % MALE (N) | DISEASE DURATION YEARS (SD) | DIRECTIONAL AT 30 DAYS % (N) | DIRECTIONAL AT 90 DAYS % (N) | DIRECTIONAL AT LAST FOLLOW UP % (N) | |
|---|---|---|---|---|---|---|---|
| All Patients | 33 | 68 (9.3) | 58% (19) | 27.2 (18.9) | 51% (17) | 84% (28) | 88% (29) |
| D at 90 days | 28 | 68 (9.7) | 54% (15) | 29.2 (19.0) | 57% (17) | 100 % (28) | 96% (27) |
| O at 90 days | 5 | 70.2 (4.5) | 60 % (3) | 16.6 (15.7) | 0% (0) | 0% (0) | 40% (2) |
| Statistics O vs. D 90-day groups | t(31) = –0.43, p = 0.66 | Fisher’s Exact χ2 = 1.0 | t(31) = 1.39, p = 0.17 | Fisher’s Exact χ2 = 0.018 | Fisher’s Exact χ2 = 0.007 |