Elsevier

Resuscitation

Volume 187, June 2023, 109801
Resuscitation

Clinical paper
Discrepancies in the late auditory potentials of post-anoxic patients: Watch out for focal brain lesions, a pilot retrospective study

https://doi.org/10.1016/j.resuscitation.2023.109801Get rights and content
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Abstract

Aims

Late auditory evoked potentials, and notably mismatch negativity (MMN) and P3 responses, can be used as part of the multimodal prognostic evaluation in post-anoxic disorders of consciousness (DOC). MMN response preferentially stems from the temporal cortex and the arcuate fasciculus. Situations with discrepant evaluations, for example MMN absent but P3 present, are frequent and difficult to interpret. We hypothesize that discrepant MMN-/P3+ results could reflect a higher prevalence of lesions in MMN generating regions. This study presents correlations between neurophysiological and neuroradiological results.

Methods

This retrospective study was conducted on 38 post-anoxic DOC patients. Brain lesions were analyzed on 3T MRI both anatomically and through computation of the local arcuate fasciculus fractional anisotropy values on Diffusion Tensor Imaging sequences. Neurophysiological data and outcome were also analyzed.

Results

Our cohort included 8 MMN-/P3+, 7 MMN+/P3+, 21 MMN-/P3− and 2 MMN-/P3+ patients, assessed at a median delay of 20.5 days since cardiac arrest. Our results show that MMN-/P3+ patients tended to have fewer temporal and basal ganglia lesions than MMN-/P3− patients, and more than MMN+/P3+ patients (p-values for trend: p = 0.02 for temporal and p = 0.02 for basal ganglia lesions). There was a statistical difference across groups for mean fractional anisotropy values in the arcuate fasciculus (p = 0.008). The percentage of patients regaining consciousness at three months in MMN-/P3+ patients was higher than in MMN-/P3− patients and lower than in MMN+/P3+ patients.

Conclusion

This study suggests that discrepancies in late auditory evoked potentials may be linked to focal post-anoxic brain lesions, visible on brain MRI.

Keywords

Auditory evoked potentials
Heart arrest
Hypoxia-ischemia
Brain
Disorders of consciousness
Neurophysiology
Prognosis

Abbreviations

ACNS
American Clinical Neurophysiological Society
AEP
Auditory Evoked Potentials
CNIL
Commission Nationale Ethique et Liberté
CPC
Cerebral Performance Category
CRSr
Coma Recovery Scale revised
DOC
Disorders of Consciousness
DTI
Diffusion Tension Imagery
EEG
Electroencephalogram
EP
Evoked Potentials
FA
Fractional Anisotropy
FLAIR
Fluid Attenuated Inversion Recovery
GCS
Glasgow Coma Scale
GOSE
Glasgow Outcome Scale Extended
ICU
Intensive Care Unit
IQR
Interquartile Range
MCS
Minimal Conscious State
MMN
Mismatch Negativity
MMN-/P3+
absent MMN, present P3
MMN+/P3-
present MMN, absent P3
MMN+/P3+
present MMN, present P3
MMN-/P3-
absent MMN, absent P3
MRI
Magnetic Resonance Imaging
NSE
Neuron Specific Enolase
ROI
Region of Interest
SON
Subject’s Own Name
SSEP
Somatosensory Evoked Potentials
UWS-VS
Unresponsive Wakefulness State – Vegetative State
WLST
Withdrawal of Life-Sustaining Therapies

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