Does Severe Early Motor Deficit Define Recovery Ceiling After Basal Ganglia or Thalamic Hemorrhage?

BACKGROUND: Whether severe early motor deficit after deep intracerebral hemorrhage represents a fixed recovery ceiling or a recoverable mixture of structural and reversible mechanisms is unclear. We synthesized time-dependent motor outcomes and corticospinal tract-related predictors after basal ganglia or thalamic hemorrhage. METHODS: Following PRISMA 2020 and Synthesis Without Meta-analysis guidance, with the protocol prospectively registered on OSF (DOI 10.17605/OSF.IO/JH86X), we searched PubMed/MEDLINE, Embase, Web of Science, Scopus, and the Cochrane Library from inception to April 2026. Adults with spontaneous deep supratentorial intracerebral hemorrhage and any motor outcome measure were eligible. Studies were classified into severe-deficit, broader, and predictor cohorts. The primary synthesis was structured, with a limited aggregate proportion for rehabilitation-discharge walking independence. Risk of bias was assessed with the Quality in Prognosis Studies tool. RESULTS: Of 1,463 records identified, 25 studies were included. Six severe-baseline cohorts demonstrated meaningful six-month motor recovery; gains in severe putaminal hemorrhage appeared concentrated within the first four months. In two broader rehabilitation cohorts, approximately 53% achieved Functional Ambulation Category ≥4 at discharge - a contextual estimate, not a severe-baseline recovery rate. Across fourteen imaging-predictor studies, corticospinal tract integrity, fractional anisotropy, CT-based corticospinal tract lesion load, and posterior-limb internal-capsule involvement were directionally consistent predictors of motor outcome, with supportive multicenter CT-based evidence from a multinational study. CONCLUSION: Severe early motor deficit does not define an immediate recovery ceiling after basal ganglia or thalamic hemorrhage, but recovery is anatomically constrained by corticospinal tract and posterior-limb internal-capsule involvement. Prognostic counseling should integrate acute imaging-based assessment with the four-month recovery window suggested in severe putaminal hemorrhage.