Long-Term Follow-up of Unilateral Pallidotomy in Advanced Parkinson's Disease
Bibliographic record
Abstract
BACKGROUND: Although the short-term benefits of posteroventral pallidotomy for patients with advanced Parkinson's disease have been well documented, little is known about the long-term outcome of the procedure. METHODS: We conducted a long-term follow-up study of a cohort of 40 patients who had undergone unilateral posteroventral medial pallidotomy between 1993 and 1996. Twenty patients were not evaluated because they had undergone a second surgical procedure (11 patients) or had died (2) or because they had dementia or another debilitating illness (4), lived too far away (1), or had been lost to follow-up (2). We conducted serial postoperative assessments of parkinsonism in the remaining 20 patients while they were taking medications ("on" period) and after overnight withdrawal of the drugs ("off" period). The mean follow-up time was 52 months (range, 41 to 64). RESULTS: The combined off-period score for activities of daily living and motor function on the Unified Parkinson's Disease Rating Scale was 18.0 percent better at the last evaluation than at base line (95 percent confidence interval, 4.9 to 31.0 percent; P=0.01). Significant improvements were also evident in the off-period scores for contralateral tremor (65.4 percent improvement, P=0.007), rigidity (43.2 percent, P=0.03), and bradykinesia (18.2 percent, P=0.04) and in the on-period score for contralateral dyskinesia (70.6 percent, P<0.001). Changes in medication did not contribute to the sustained improvement. The 20 patients who could not be included in the long-term analysis had similar base-line characteristics but a worse response to surgery at six months. CONCLUSIONS: In the group of patients with advanced Parkinson's disease who could be enrolled in our long-term follow-up study of unilateral posteroventral medial pallidotomy (20 patients from the original cohort of 40), significant early improvements in off-period contralateral signs of parkinsonism were sustained for up to five and a half years. There was a sustained significant improvement in on-period contralateral dyskinesia but not in other on-period signs of parkinsonism.
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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 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 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".