RESUMEN
Introduction: Magnetic resonance-guided focused ultrasound (MRgFUS) thalamotomy of the ventralis intermediate (Vim) nucleus is an "incisionless" treatment for medically refractory essential tremor (ET). We present data on 49 consecutive cases of MRgFUS Vim thalamotomy followed-up for 3 years and review the literature on studies with longer follow-up data. Methods: A retrospective chart review of patients who underwent MRgFUS thalamotomy (January 2018-December 2020) at our institution was performed. Clinical Rating Scale for Tremor (CRST) and Quality of Life in Essential Tremor (QUEST) scores were obtained pre-operatively and at each follow-up with an assessment of side effects. Patients had post-operative magnetic resonance imaging within 24 h and at 1 month to figure out lesion location, size, and extent. The results of studies with follow-up ≥3 years were summarized through a literature review. Results: The CRST total (baseline: 58.6 ± 17.1, 3-year: 40.8 ± 18.0) and subscale scores (A + B, baseline: 23.5 ± 6.3, 3-year: 12.8 ± 7.9; C, baseline: 12.7 ± 4.3, 3-year: 5.8 ± 3.9) and the QUEST score (baseline: 38.0 ± 14.8, 3-year: 18.7 ± 13.3) showed significant improvement that was stable during the 3-year follow-up. Three patients reported tremor recurrence and two were satisfactorily retreated. Side effects were reported by 44% of patients (severe: 4%, mild and transient: 40%). The improvement in tremor and quality of life in our cohort was consistent with the literature. Conclusion: We confirmed the effectiveness and safety of MRgFUS Vim thalamotomy in medically refractory ET up to 3 years.
RESUMEN
BACKGROUND: Functional motor disorders encompass a variety of manifestations characterized by abnormal movements that are clinically incongruent with those known to be caused by neurological diseases. CASES: We report 2 cases in which functional motor disorders developed after complete recovery of motor symptoms originating from underlying vascular brain lesions. The first case describes a young woman who developed a motor and sensory hemisyndrome after surgical removal of a postrolandic cavernoma. The second describes a 16-year-old girl who presented with a mixed component tremor after ventricular derivation and endovascular embolization for rupture of a brainstem arteriovenous malformation. CONCLUSION: Motor symptoms and signs attributed to an underlying lesion may trigger "pure" functional motor disorders. In such cases, the differential diagnosis may be even more challenging. However, diagnosis of a functional rather than a defined structural disorder can be achieved by a "positive diagnostic process," considering the findings of internal inconsistency and incongruity.