Rehabilitation outcome of anoxic-ischaemic encephalopathy survivors with prolonged disorders of consciousness

Abstract

Objectives: To examine the natural clinical course of patients admitted to inpatient neurorehabilitation in a coma, vegetative state (VS), or minimally conscious state (MCS) after anoxic-ischaemic encephalopathy (AIE).

Methods: This is a retrospective cohort study of 113 consecutive patients admitted to a German inpatient neurorehabilitation centre with severe disorders of consciousness (DOC) following AIE due to cardiac arrest over a 6-year period. Functional independence was measured with the Glasgow Outcome Scale (GOS) and recovery of consciousness with the Coma Remission Scale (CRS). Separate binary logistic regression models were used to identify independent predictors for functional and behavioural outcomes.

Results: Seven patients (6.2%) achieved a good functional outcome (GOS 4-5). Five of these showed significant functional improvement within the first 8 weeks. 22 patients (19.5%) recovered consciousness; the last patient began to make significant improvement between weeks 10 and 12. Logistic regression showed that both increasing age and lower admission CRS predicted unfavourable functional outcome and persistent DOC. A longer stay in the ICU also predicted persistent DOC at the end of neurorehabilitation. However, neither malignant somatosensory evoked potential (SEP) test results nor hypothermia treatment on the ICU were outcome predictors in either outcome category.

Conclusion: Even among severely affected AIE patients arriving at a neurological rehabilitation centre in a DOC, there remains potential for functional and behavioural improvement. However, significant improvements may not begin for up to 3 months post-injury. This study suggests that recovery of consciousness and even a good neurological outcome are possible despite malignant SEP test results.

Keywords: AIE; Anoxic-ischaemic encephalopathy; CRS; Cardiac arrest; Coma; Coma Remission Scale; DOC; Evoked potentials; LST; MCS; NSE; Prognostication; Resuscitation; SEP; VS; anoxic-ischaemic encephalopathy; disorder of consciousness; life-sustaining therapy; minimally conscious state; neuron specific enolase; somatosensory evoked potentials; vegetative state.