P.011 Piano Player Hand Sign: description of a novel clinical sign elicited by cortical electrical stimulation in epileptic patients
Bibliographic record
Abstract
Background: Cortical electrical stimulation (CES) may produce different motor responses according to the brain area stimulated. In this study, we describe a new motor response characterized by finger movements such as a person playing piano, which we named the Piano Player Hand (PPH) sign. Methods: We retrospectively reviewed the CES results of 252 patients with drug-resistant epilepsy who underwent SEEG between January 2005 and December 2019 at the Grenoble-Alpes University Hospital. The patients’ characteristics, SEEG findings and CES parameters were extracted to find common clinical and anatomical features. Results: The PPH sign was identified 20 times from 12 patients, with stimulation of either the supplementary motor area (SMA), anterior cingulate gyrus (ACG), pre-SMA, middle frontal gyrus and anterior insula. It was obtained with high frequency stimulation, with intensity ranging from 0,7 to 3mA and mostly contralateral to the stimulation side (19/20). It was part of the ictal semiology of five patients. An afterdischarge was observed in five of the relevant CES. Conclusions: The PPH sign is a novel clinical sign, obtained mainly, but not exclusively, with CES of a small vicinity encompassing the SMA, pre-SMA and ACG. The PPH sign, when occurring ictally, may point to the premotor mesial frontal surface of the brain.
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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 | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| 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".