Table 2.
Summary of key findings according to the mutated gene
| Gene | Studies (n) | Patients (n) | Target | Outcome |
|---|---|---|---|---|
| LRRK2 | 17 | 87a |
STN: n = 79 (90.8%) NA: n = 8 (9.2%) |
Mostly favourable motor outcome. Four studies with eight patients (9.2%) reported poor motor outcomes and one study reported moderate outcomes for two patients. Both patients with the LRRK2 p.T2031S (c.6091A > T) mutation (n = 2) developed neuropsychiatric problems 5–7 years after implantation. The outcome appears poor in patients with LRRK2 p.R1441G (c.4321C > G) mutations (n = 5), whereas it appears excellent in patients with LRRK2 p.G2019S (c.6055G > A) mutations |
| PRKN | 18 | 67b |
STN: n = 51 (76.1%) GPi: n = 5 (7.5%) Zona incerta: n = 1 (1.5%) NA: n = 10 (14.9%) |
Fifty-one patients (76.1%) had favourable long-term motor outcomes. Four patients (6.0%) were reported to have modest outcome in two different studies and one study with two patients (3.0%) reported poor benefit |
| GBA | 5 | 50c |
STN: n = 33 (66.0%) GPi: n = 4 (8.0%) VIM: n = 1 (2.0%) NA: n = 12 (24.0%) |
Eighteen patients were reported to have favourable, three patients moderate and 9 patients poor long-term motor outcomes. One study reported better outcomes with STN-DBS and VIM-DBS than with GPi-DBS. GBA mutation carriers developed cognitive impairment faster than patients without mutations |
| SNCA | 5 | 5 |
STN: n = 4 (80.0%) GPi: n = 1 (20.0%) |
Favourable motor outcome but three of five patients developed cognitive or neuropsychiatric problems a few years after implantation |
| VPS35 | 4 | 5 |
STN: n = 3 (60.0%) NA: n = 2 (40.0%) |
Favourable motor outcome in four cases and minor motor benefit complicated by dysarthria in one case |
| PINK1 | 5 | 5b |
STN: n = 4 (80.0%) GPi: n = 1 (20.0%) |
Favourable motor outcome in three cases and moderate in one case |
| 22q11.2.Del. Syndrome | 1 | 3 |
STN: n = 1 (33.3%) GPi: n = 2 (66.6%) |
Favourable motor outcome |
STN subthalamic nucleus, GPi globus pallidus interna, VIM ventral intermediate nucleus, NA not available
aOne patient had also PRKN mutation and one had GBA mutation
bOne patient had both PRKN and PINK1 mutations
cTwo studies reported partially same patients, but it was not possible to separate individual patients that were reported twice. One patient had also LRRK2 mutation and one had PRKN mutation