Abstract 73: Neurophysiology Of Ipsilateral Corticomotor Projections After Perinatal Stroke
Bibliographic record
Abstract
Objectives: Perinatal stroke (PS) causes most hemiparetic cerebral palsy. Persistence of ipsilateral corticomotor connections from unlesioned hemisphere to affected hand are established. Their neurophysiology is not understood and developmental plasticity models suggest they are a therapeutic target. We hypothesized that ipsi projections have distinct neurophysiology that correlates with motor disability. Methods: Children 6-18 years with PS (arterial or PVI) and hemiparesis were recruited (Alberta Perinatal Stroke Project). Transcranial magnetic stimulation (TMS) protocols were applied to the non-lesioned M1. Outcomes included rest motor thresholds and bilateral stimulus response curves (SRC). Paired pulse TMS at 2 and 10 ms (90% active motor threshold conditioning) explored short-latency intracortical inhibition (SICI) and intracortical facilitation (ICF). Ipsi motor evoked potentials (MEPs) were quantified (≥0.05mV at 120% RMT in ≥5/20 trials). Motor outcomes were Assisting Hand (AHA) and Melbourne (MA) assessments. Ipsi physiology was compared to contra and motor outcome (t-test, (rm)ANOVA). Safety and tolerability was assessed. Results: Of 35 children (20 male; 55% arterial, 45% PVI), 14 (40%) met ipsi criteria. Presence of ipsi projections correlated with motor disability (AHA, p=0.03, MA p=0.10) but not stroke type. Ipsi intensity correlated with AHA (r=-0.58; p=0.004) and MA (r=-0.45; p=0.013). Ipsi SRC slope was lower than contra (p=0.01). SICI (contra -38.5%, ipsi -30.7%; p<0.05) and ICF (contra +15.4%, ipsi +23.1%; p<0.05) were present and differed between sides (p= 0.004). Procedures were well tolerated. Conclusions: Cortical physiology of ipsilateral projections can be measured in children with PS. Differences between ipsi and contralateral physiology may be relevant central therapeutic targets.
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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 | 0.000 | 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) | 0.003 | 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".