Deep Brain Stimulation for Disorders of Consciousness: An Individual Patient Data Meta-Analysis

Abstract

Background: Deep brain stimulation (DBS) has been proposed as a promising therapeutic intervention for patients with disorders of consciousness (DoC). DBS is hypothesized to modulate brain activity in local and widespread functional networks by delivering electrical impulses to deep brain nuclei, thereby promoting arousal.

Objectives: This individual patient data meta-analysis aimed to evaluate the therapeutic impact of DBS on improving conscious awareness in patients with DoC and to identify potential predictors of treatment responsiveness.

Materials and methods: Nine studies comprising 81 patients with DoC who underwent DBS were included. The primary outcome measure across all studies was the Coma Recovery Scale-Revised (CRS-R). Subgroup analyses were performed based on age, duration of DoC, etiology, and DBS target. Study-level data were pooled using random-effects meta-analytic models.

Results: The pooled mean CRS-R improvement post-DBS was 2.15 (95% CI: 1.06-3.23), indicating a modest treatment effect. Only 39.5% of patients achieved the minimum clinically important difference of ≥three CRS-R points, and 30.9% transitioned to a higher DoC category. Younger patients with shorter DoC durations tended to show greater improvements. Etiology was largely nonpredictive, although patients with hypoxic-ischemic encephalopathy exhibited marginally better responses. Considerable heterogeneity was observed across studies (I² = 76.5%). Adverse effects, including infections and seizures, were reported.

Conclusions: DBS may confer modest improvements in conscious awareness for selected patients with DoC, but therapeutic benefits remain limited and risks substantial. Rigorous patient selection frameworks and standardized protocols are essential to guide clinical decision-making and future trials.

Keywords: Arousal; centro-median parafascicular complex; deep brain stimulation (DBS); disorders of consciousness (DoC); neuromodulation.