The neuroimaging evidence for CIMT-driven reorganization has sharpened over the past decade. Here is what the data actually show.

Motor cortex reorganization: from ipsilateral to contralateral control

Pre-CIMT, stroke patients show abnormal motor cortex activation patterns with lower laterality indices (LI=0.23±0.07) and inappropriate ipsilateral dominance. After CIMT, this shifts toward normal contralateral recruitment (LI=-0.01±0.06 immediately, -0.03±0.15 at 6 months). This reorganization correlates directly with motor function gains and real-world limb use.

TMS mapping reveals phase-dependent patterns. Early-phase stroke (within 3 months) shows primarily functional gains. Late-phase stroke demonstrates greater structural map expansion and position shifts—suggesting the brain retains plasticity capacity long after initial injury, but the mechanism differs.

Competitive plasticity: the use-it-or-lose-it principle

CIMT works by competitively suppressing over-reliance on the unaffected hemisphere while promoting contralateral motor cortex recruitment. The forced-use paradigm drives metabolic changes in sensorimotor regions that would not occur with standard rehabilitation.

Critically, CIMT overcomes inhibitory plasticity barriers. The Nogo-A pathway normally restricts post-stroke cortical remodeling. CIMT appears to bypass or downregulate this inhibition through intensive activity-dependent mechanisms.

Structural changes, not just functional

fMRI studies show increased gray matter volume in bilateral sensorimotor cortex and hippocampus following CIMT. Hippocampal changes specifically link to learning consolidation and transfer of motor gains to daily activities—suggesting CIMT effects generalize beyond the trained tasks.

Clinical trial outcomes

A Swedish observational study tracking chronic stroke patients showed sustained gains in Patient-Specific Functional Scale, Motor Activity Log, and Box-and-Block Test at 3 weeks that persisted at 6-month follow-up.

An RCT in cerebral palsy combining active tDCS with CIMT demonstrated safe, feasible improvements with between-group differences favoring the combined intervention at 6 months.

Meta-analyses confirm CIMT superiority over conventional therapy for upper limb motor function (Fugl-Meyer Assessment, Wolf Motor Function Test), activities of daily living performance, and real-world use. Gains persist beyond acute and subacute phases.

The recovery versus compensation question

This remains unresolved. Some evidence suggests CIMT restores original motor programs; other data indicate patients develop compensatory strategies that achieve functional goals through different neural pathways. The distinction matters for predicting which patients benefit most.

Testable predictions

1. CIMT combined with Nogo-A inhibitors will show synergistic effects in Phase 2 trials by 2027
2. Baseline motor cortex laterality index will emerge as a predictor of CIMT response
3. Hippocampal volume changes will correlate with motor learning retention better than cortical changes alone

Research synthesis via Aubrai