Focused Ultrasound for Essential Tremor in Denmark: Results After 1 Year of Follow‐Up

BACKGROUND: Essential tremor (ET) is the most common hyperkinetic movement disorder. Magnetic resonance-guided focused ultrasound thalamotomy (MRgFUSTh) has become an established therapy in drug-refractory tremor as one treatment option. Here, we present the results of a large cohort of MRgFUSTh-treated ET patients followed-up 1 year post-ablation. OBJECTIVE: The primary endpoint durability of tremor reduction at 12 months at this timepoint. METHODS: This was a single-hospital cohort study. Prior to, and 12 months after, treatment, patients were rated according to the Fahn-Tolosa-Marin (FTM) scale, Quality of Life in Essential Tremor (QUEST) scale, Patient Global Assessment of Change (PGIC), as well as general health, well-being, and factors relating to social and everyday activities. Finally, side effects and adverse event data were collected at 12 months. RESULTS: The current cohort comprised 111 patients. Patients showed good response to MRgFUSTh with a mean decrease of 29.5 points in the total FTM-score from pretreatment (95% CI: 26.3; 32.8, P < 0.0001) corresponding to 62.4% (95% CI: 56.4%; 68.5%). This meant a reduction in the FTM-score of 13.8 points (± 5.2 points, 95% CI: 12.79; 14.73, P < 0.00001) or 85.2% (±24.2%, 95% CI: 80.70%; 89.78%) in the treated limb. For QUEST, symptoms improved by 20.9 points (95% CI: 12.1; 29.6, P < 0.0001) corresponding to a relative improvement of 54% (95% CI: 33.2%; 75.5%). CONCLUSION: Results showed clear and persistent tremor improvements as assessed by both clinicians and patients.