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Intensive care medicine · Jan 1996
Event-related potentials--neurophysiological tools for predicting emergence and early outcome from traumatic coma.
- N M Kane, S H Curry, C A Rowlands, A R Manara, T Lewis, T Moss, B H Cummins, and S R Butler.
- Burden Neurological Institute, Bristol, UK.
- Intensive Care Med. 1996 Jan 1;22(1):39-46.
ObjectiveTo determine the prognostic value of multimodal evoked potentials (EPs) and event-related (ERPs) potentials in coma (Glasgow Coma Score <8), after severe traumatic brain injury (TBI).DesignProspective, longitudinal study of neurophysiological responses recorded during traumatic coma.SettingIntensive Care Unit, Frenchay Hospital, Bristol, UK.ParticipantsFifty-four comatose TBI patients (age range 1-80 years, mean 36.4).MethodsNeurophysiological responses were recorded from 11 scalp electrodes with earlobe reference. Conduction times were measured for brainstem auditory, flash visual and somatosensory, short-latency EPs. Peak latencies and amplitudes were determined for long-latency components of visual and auditory ERPs, generated by passive "oddball" paradigms. These neurophysiological and various clinical parameters were correlated with patient outcome using Pearson's coefficient.Main Outcome MeasureThree month Glasgow Outcome Scale (GOS).Results And ConclusionHighly significant (P <0.001) correlations exist between long-latency ERP components and 3-month outcome. Short-latency EPs, brainstem (wave I-V) and somatosensory conduction times also correlate significantly with the GOS (P <0.01). Of the clinical measurements, pupillary response patterns, APACHE II and Glasgow Coma Scores (GCS) correlate significantly with outcome, as do the retrospective measures of duration of coma and post-traumatic amnesia (PTA) in survivors. Unfortunately, due to variance of long-latency responses, even in controls, absolute values cannot be relied upon as prognosticators. The presence of "mismatch negativity" predicted the return of consciousness (89.7% sensitivity and 100% specificity) and preceded changes in GCS. Its latency was the single best indicator of 90-day outcome from coma (r = -0.641).
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