Case series of patients with essential tremor with a mean follow-up period of at least 5 years
| Author (year of publication) | Number of patients | Average follow-up period | Clinical (%) improvement DBS off vs on state* | Complications |
|---|---|---|---|---|
| Rehncrona et al (2003) | 13 total | 6.5±0.3 years | ETRS (total): (43%) p<0.025. Hand function: (56%) | NR |
| Sydow et al (2003) | 19 total 12 unilateral 7 bilateral | 6.53±0.6 years | Tremor items: 19.4 vs 10.4, (46.4%). Hand function items: 25.6 vs 16.4, (36%). ADL items: 17.4 vs 8.4, (51.7%). All subscores: p<0.001. Overall improvement: 43% | Total postoperative adverse events: 40. Dysarthria was more common with bilateral stimulation |
| Pahwa et al (2006) | 22 total 15 unilateral 7 bilateral | 5 years | Tremor scores: Unilateral: 21.7 vs 11.7, (46%) p<0.01. Bilateral: 21.3 vs 6.4, (70%) p=0.02 ADL items: (36–51%) | Dysarthria, balance difficulties, dysphagia, salivation were more common with bilateral thalamic stimulation |
| Blomstedt et al (2007) | 19 total (All unilateral) | 86±9 months | Tremor items: 19.3 vs 11.7, (39.3%). Hand function items: 25.6 vs 20.6, (19.5%). ADL, items: 20.1 vs 13.6, (32.3%). Total: 68.1 vs 47.4, (30.4%). All subscores: p≤0.01 | 6 patients had a broken wire |
| Zhang et al (2010) | 12 total | 90.7 months | Tremor: 3.33 vs 0.67, (79.8%) Handwriting: 2.80 vs 1.30, (53.5%) | Overall hardware complications: 23.5% |
| Present series | 13 total 7 bilateral 6 unilateral | 132.54±15.3 months | Tremor items (blinded): 28.2 vs 14.85 (47.5%), p=0.02. Hand function items (blinded)†: 27.8 vs 20.3, (27%), p=0.02. ADL items: (31.7%), p<0.001. Total: 80.6 vs 49.1 (39%), p<0.001 | Hardware complications: 23%. Dysarthria and ataxia were more common with bilateral stimulation |
*Fahn–Tolosa–Marin tremor rating scale, including tremor items 1–9, hand function items 10–14 and ADL items 15–21.
†Including handwriting (item 10).
ADL, activities of daily living; DBS, deep brain stimulation; ETRS, Essential Tremor Rating Scale.