Safety of Bilateral Staged Magnetic Resonance‐Guided Focused Ultrasound Thalamotomy for Essential Tremor
Bibliographic record
Abstract
Staged, open-surgical lesioning of the thalamic ventral intermediate nucleus to abate medication-refractory essential tremor (mrET) has been historically associated with a high frequency of adverse events (AEs), including speech and balance impairments.1 More recently, the real-time imaging and thermometry guidance offered by magnetic resonance-guided focused ultrasound (MRgFUS) have allowed for minimally-invasive thalamotomies with increased focal accuracy to address upper limb tremor in ET patients.2 Qualitative and semi-quantitative trials evaluating the safety of staged, bilateral MRgFUS thalamotomy have reported AEs that were mostly transient with mild to moderate severity based on patients' and physicians' perceived deficits.[3][4][5] However, a comprehensive quantitative analysis of the potential post-thalamotomy changes in stance and gait balance (ie, equilibrium), and oro-motor function is lacking.Further, cognitive assessments have been mostly limited to screening instruments.We comprehensively evaluated the incidence and severity of AEs, including changes in equilibrium, speech, and cognition, following staged, bilateral MRgFUS thalamotomy for patients with mrET.This prospective, open-label trial (NCT04720469) screened 16 consecutive mrET patients who had undergone MRgFUS thalamotomy at least 1 year prior (MRgFUS 1 ).Three patients were excluded due to mild cognitive impairment.Two others were excluded given abnormal gait, measured using the Scale for Assessment and Rating of Ataxia (SARA).6 The SARA's speech item revealed no baseline impairment.Eleven patients underwent MRgFUS 2 (seven males; median age 71 years, range 52-80 years; eight right-sided thalamotomy; Table S1).Tremor severity of individual hands was measured pre-and 3-6 months post-MRgFUS (median 3.9 months post-MRgFUS 1 ; median 4.4 post-MRgFUS 2 ) using Part A (resting, postural, action/intention) and Part B (Archimedes spiral/line drawing, water pouring) of the Clinical Rating Scales for Tremor (CRST).AEs were systematically captured during MRgFUS 2 and up to 6 months post-MRgFUS 2 .Pre-and post-MRgFUS 2 speech measures from eight patients were assessed using the Frenchay Dysarthria Assessment-2 (FDA-2), 7 a 99-word passage, and diadochokinetic single syllable repetition (eg, /pa/, /ta/, /ka).Vocal tremor was extracted as Frequency (FTrP) and Amplitude (ATrP) Tremor Power from maximum phonation task recordings (ie, "say 'ah' for as long as you can") using the TREMOR.PRAAT algorithm.8 The neuropsychological battery consisted of the Montreal Cognitive Assessment and tests measuring processing speed, attention/working memory, executive function, language, verbal fluency, and visuospatial perception.Least-square mean (LS-mean) with 95% confidence intervals (95%CI) were reported using generalized estimating equations in SAS9.4.CRST scores for the targeted hand improved after each MRgFUS (P < 0.001), while the untargeted-hand tremor had no significant change (Fig. 1A).Twenty-one AEs were identified with 81% rated as mild per the Common Terminology Criteria for AEs v5.0, consistent with other trials.[3][4][5] No severe AEs were
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".