Chronic <scp>Neuroleptic‐Induced</scp> Parkinsonism Examined With Positron Emission Tomography
Bibliographic record
Abstract
BACKGROUND: Neuroleptic drug-induced parkinsonism (NIP) is a leading cause of parkinsonism, particularly in aging. Based on abnormal dopamine transporter scan results, individuals displaying chronic NIP are often diagnosed with Lewy-body Parkinson's disease (PD), but this assumption needs further substantiation. OBJECTIVE: To quantitate the profile of striatal dopaminergic nerve terminal density in NIP relative to PD. METHODS: C](+)-dihydrotetrabenazine targeting vesicular monoamine transporter type 2 (VMAT2) binding sites and collected various clinical parameters (motor ratings, olfaction, polysomnography to document rapid eye movement sleep muscle activity, quantitative sensory testing for pain thresholds) possibly predicting binding results in patients older than age 50 living with schizophrenia spectrum disorders under long-term stable antipsychotic drug treatment, with (N = 11) or without (N = 11) chart documention of chronic NIP, and compared them to healthy volunteers (N = 11) and others medicated for PD (N = 12). RESULTS: Striatal VMAT2 binding was dichotomous in the NIP group between those with spared (N = 5) or low (N = 6) PD-like values. Striatal binding reduction in the low VMAT2-NIP group was asymmetric without the gradient of maximal involvement in the posterior putamen typical of PD. Anosmia was the only nonmotor parameter measured matching the abnormal striatal VMAT2 binding status. CONCLUSION: These preliminary observations suggest that striatal VMAT2 binding is abnormal in a fraction of chronic NIP cases and differs in spatial distribution from PD. The possibility of a drug-induced axonopathy and resultant synaptopathy, as well as the evolution of the binding deficit, warrant further longitudinal studies in a large cohort. © 2020 International Parkinson and Movement Disorder Society.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".