| Coma & Chronic Disorders of Consciousness  

Long-term clinical evolution of patients with prolonged disorders of consciousness due to severe anoxic brain injury: A meta-analytic study

Systematic review and meta-analysis addressing long-term clinical evolution of patients with prolonged Disorders of Consciousness due to severe anoxic brain injury.

The prognosis of prolonged (28 days to 3 months post-onset) Disorders of Consciousness (pDoC) due to anoxic brain injury is uncertain. The present study aimed to evaluate long-term outcome of post-anoxic pDoC and identify the possible predictive value of demographic and clinical information.

A systematic review and meta-analysis was performed. The rates of mortality, any improvement in clinical diagnosis, and recovery of full consciousness at least 6 months after severe anoxic brain injury were evaluated. A cross-sectional approach searched for differences in baseline demographic and clinical characteristics between survivors and non-survivors, patients improved vs. not-improved, and patients who recovered full consciousness vs. not-recovered.

Twenty-seven studies were identified. The pooled rates of mortality, any clinical improvement, and recovery of full consciousness were 26%, 26%, and 17%, respectively. Younger age, baseline diagnosis of minimally conscious state vs. vegetative state/unresponsive wakefulness syndrome, higher Coma Recovery Scale-Revised total score, and earlier admission to intensive rehabilitation units were associated with a significantly higher likelihood of survival and clinical improvement. These same variables, except time of admission to rehabilitation, were also associated with recovery of full consciousness.

This study demonstrated that patients with anoxic pDoC might improve over time up to full recovery of consciousness and some clinical characteristics can help predict clinical improvement. These new insights could support clinicians and caregivers in the decision-making on patient management.

Key Points:

  • There is a lack of studies on long-term outcomes of patients with prolonged Disorders of Consciousness due to anoxic etiology.
  • Data from 357 individual patients with pDoC due to anoxic brain injury, enrolled between 28 days and 3 months from injury and with a follow-up diagnosis at least 6 months after injury, could be analysed.
  • The estimated pooled mortality rate was 26%, rate of any clinical improvement was also 26%, and rate of recovery of full consciousness was found to be 17%.
  • Clinical status at admission could help clinicians to identify patients with a high probability of recovery.

References:

Magliacano, A., De Bellis, F., Panico, F., Sagliano, L., Trojano, L., Sandroni, C., & Estraneo, A. (2023). Long-term clinical evolution of patients with prolonged disorders of consciousness due to severe anoxic brain injury: A meta-analytic study. European journal of neurology, 10.1111/ene.15899. Advance online publication. doi.org/10.1111/ene.15899

Co-author(s):
Alfonso Magliacano, IRCCS Fondazione Don Carlo Gnocchi ONLUS
Luigi Trojano, Department of Psychology, University of Campania Luigi Vanvitelli, Caserta, Italy
Claudio Sandroni, Department of Intensive Care, Emergency Medicine and Anaesthesiology, Fondazione Policlinico Universitario ‘Agostino Gemelli’ IRCCS, Università Cattolica del Sacro Cuore, Rome, Italy

Publish on behalf of the Scientific Panel on Coma and chronic disorders of consciousness