Providing an accurate prognosis for prolonged disorder of consciousness (pDOC) patients remains a clinical challenge. Large cross-sectional studies have demonstrated the diagnostic and prognostic value of functional brain networks measured using high-density electroencephalography (hdEEG). Nonetheless, the prognostic value of these neural measures has yet to be assessed by longitudinal follow-up. We address this gap by assessing the utility of hdEEG to prognosticate long-term behavioural outcome, employing longitudinal data collected from a cohort of patients assessed systematically with resting hdEEG and the Coma Recovery Scale-Revised (CRS-R) at the bedside over a period of two years. We used canonical correlation analysis to relate clinical (including CRS-R scores combined with demographic variables) and hdEEG variables to each other. This analysis revealed that the patient’s age, and the hdEEG theta band power and alpha band connectivity, contributed most significantly to the relationship between hdEEG and clinical variables. Further, we found that hdEEG measures recorded at the time of assessment augmented clinical measures in predicting CRS-R scores at the next assessment. Moreover, the rate of hdEEG change not only predicted later changes in CRS-R scores, but also outperformed clinical measures in terms of prognostic power. Together, these findings suggest that improvements in functional brain networks precede changes in behavioural awareness in pDOC. We demonstrate here that bedside hdEEG assessments conducted at specialist nursing homes are feasible, have clinical utility, and can complement clinical knowledge and systematic behavioural assessments to inform prognosis and care.

为长期意识障碍（pDOC）患者提供准确的预后仍然是临床挑战。大量的横截面研究表明，使用高密度脑电图（hdEEG）测量的功能性大脑网络的诊断和预后价值。尽管如此，这些神经测量的预后价值尚未通过纵向随访来评估。我们通过评估hdEEG预测长期行为结局的效用来解决这一差距，方法是使用一段时间内静息hdEEG和昏迷恢复量表修订版（CRS-R）对患者进行系统评估的纵向数据两年。我们使用规范相关分析将临床（包括结合人口统计学变量的CRS-R评分）和hdEEG变量相互关联。该分析表明，患者的年龄以及hdEEG theta谱带功率和alpha谱带连通性对hdEEG与临床变量之间的关系影响最大。此外，我们发现在评估时记录的hdEEG度量值在预测下一次评估时的CRS-R分数方面增加了临床度量值。此外，hdEEG的变化率不仅可以预测CRS-R评分的后续变化，而且在预后方面也优于临床指标。总之，这些发现表明，功能性大脑网络的改善先于pDOC行为意识的改变。我们在这里证明，在专业疗养院进行的床边hdEEG评估是可行的，具有临床实用性，