Somatosensory and auditory deviance detection for outcome prediction during postanoxic coma

Area of Science:

• Neuroscience
• Clinical Neurology
• Electrophysiology

Background:

• Auditory deviance detection is a known marker for consciousness recovery.
• The value of somatosensory deviance detection for outcome prediction in comatose patients remains unclear.

Purpose of the Study:

• To investigate if somatosensory deviance detection offers added value for predicting outcomes in postanoxic comatose patients.
• To compare the predictive power of auditory and somatosensory deviance detection for coma recovery.

Main Methods:

• Electroencephalography (EEG) was used to record responses to frequent and rare stimuli in 66 comatose patients.
• Sensory discrimination was assessed on the first and second day after coma onset.
• Multivariate decoding analysis was applied to EEG data.

Main Results:

• Auditory discrimination was detected above chance in 25 patients on day 1 and 31 on day 2.
• Tactile discrimination was significant in 16 patients on day 1 and 23 on day 2.
• Improvement in auditory discrimination from day 1 to day 2 predicted good outcome (PPV=0.73), but tactile or combined sensory improvement did not.

Conclusions:

• Deviance detection is preserved in both auditory and tactile modalities in the acute phase of coma.
• Improvement in auditory deviance detection is a significant predictor of good outcome.
• Somatosensory deviance detection does not provide added value for coma-outcome prediction beyond auditory measures.