A critical time window for recovery extends beyond one-year post-stroke

Area of Science:

• Neurorehabilitation
• Stroke recovery research
• Motor function restoration

Background:

• The duration of the

Purpose of the Study:

• To investigate the temporal structure of motor recovery after stroke.
• To determine if functional improvements are possible beyond the conventionally accepted 3-6 month "critical window" for neuroplasticity.
• To re-evaluate the impact of rehabilitation chronicity on post-stroke motor recovery.

Main Methods:

• Analysis of individual patient data from 219 individuals with mild to moderate upper-limb hemiparesis.
• Exploration of the temporal structure of motor recovery using bootstrapping analysis.
• Assessment of improvement in body function and structure across different time points post-stroke.

Main Results:

• Motor recovery and improvement in body function and structure were observed even in late chronic stages post-stroke.
• A precise gradient of enhanced sensitivity to rehabilitation treatment was identified, extending beyond 12 months post-stroke.
• The findings challenge the traditional "critical window" hypothesis for stroke recovery.

Conclusions:

• The "critical window" for neuroplasticity and motor recovery post-stroke is not limited to the first 3-6 months.
• Rehabilitation interventions remain effective for patients in chronic and late chronic stages of stroke recovery.
• Clinical guidelines for stroke rehabilitation require revision to incorporate the extended temporal structure of recovery.