Cerebral hypoxia, missing cortical somatosensory evoked potentials and recovery of consciousness.
BACKGROUND
Bilaterally absent N20 components of the sensory evoked potentials (SEP) from the median nerve are regarded as accurately predicting poor outcome after cardiac arrest.


METHODS
We are reporting on a patient, who regained consciousness despite this ominous finding. Early after cardiac arrest, MRI showed signal alterations in diffusion weighted imaging (DWI) bilaterally in the primary visual and sensorimotor cortex and in the basal ganglia. SEP were repeatedly absent. The patient survived shut out form sensory and visual experience and locked in for voluntary movements, but kept her verbal competence in several languages.


CONCLUSIONS
SEP inform about integrity only of a narrow cortical strip. It is unguarded, but common practice, to conclude from absent SEP, that a patient has suffered diffuse cortical damage after cardiac arrest. Cerebral MRI with DWI helps to avoid this prognostic error and furthers understanding of the sometimes very peculiar state of mind after cardiac arrest.
Abteilung weiterführende Neurorehabilitation, Fachklinik Bad Liebenstein, Kurpromenade 2, 36448 Bad Liebenstein, Germany. gustav.pfeiffer@fachklinik-bad-liebenstein.de.
Gustav
G
Pfeiffer
Rüdiger
R
Pfeifer
Stefan
S
Isenmann
D003243:Consciousness; D038524:Diffusion Magnetic Resonance Imaging; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D006323:Heart Arrest / Q000150:complications; D006801:Humans; D002534:Hypoxia, Brain / Q000150:complications* / Q000473:pathology* / Q000503:physiopathology*; D020127:Recovery of Function; D055815:Young Adult