Cortical somatosensory evoked high-frequency (600Hz) oscillations predict absence of severe hypoxic encephalopathy after resuscitation.
Following cardiac arrest (CA), hypoxic encephalopathy (HE) frequently occurs and hence reliable neuroprognostication is crucial to decide on the extent of intensive care. Several investigations predict severe HE leading to persistent unresponsive wakefulness or death, with high specificity. Only few studies attempted to predict absence of severe HE. Cortical somatosensory evoked high-frequency (600Hz) oscillation (HFO) bursts indicate the presence of highly synchronized spiking activity in the primary somatosensory cortex. Since global neuronal damage characterizes severe HE preserved cortical HFOs may early exclude severe HE.



We determined amplitudes of early and late HFO bursts in 302 comatose CA patients after median nerve somatosensory evoked potential (SSEPs) and clinical outcome upon intensive care unit discharge using the cerebral performance category (CPC) scale.



We detected significant early HFO bursts in 146 patients and late HFO bursts in 95 patients. Only one of 27 unresponsive wakefulness patients had a late HFO burst amplitude above 70nV and all seventeen patients who died despite higher amplitudes died from non-neurological causes.



High-frequency SSEP components can reliably be studied in comatose CA patients using standard equipment.



Late HFO burst amplitudes above 70nV largely exclude severe HE incompatible with regaining consciousness.
Department of Neurology, AG Emergency and Critical Care Neurology, Campus Virchow Klinikum, Charité Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany. Electronic address: christian.endisch@charite.de.
Christian
C
Endisch
Department of Neurology, Neurophysics Group, Campus Benjamin Franklin, Charité Universitätsmedizin Berlin, Hindenburgdamm 30, 12203 Berlin, Germany.
Gunnar
G
Waterstraat
Department of Nephrology and Intensive Care Medicine, Cardiac Arrest Center of Excellence Berlin, Campus Virchow Klinikum, Charité Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany.
Christian
C
Storm
Department of Neurology, AG Emergency and Critical Care Neurology, Campus Virchow Klinikum, Charité Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany.
Christoph J
CJ
Ploner
Department of Neurology, Neurophysics Group, Campus Benjamin Franklin, Charité Universitätsmedizin Berlin, Hindenburgdamm 30, 12203 Berlin, Germany.
Gabriel
G
Curio
Department of Neurology, AG Emergency and Critical Care Neurology, Campus Virchow Klinikum, Charité Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany.
Christoph
C
Leithner
D000368:Aged; D002540:Cerebral Cortex / Q000502:physiology* / Q000503:physiopathology; D005073:Evoked Potentials, Somatosensory; D005260:Female; D006801:Humans; D002534:Hypoxia, Brain / Q000175:diagnosis* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D012151:Resuscitation / Q000009:adverse effects*
Cardiac arrest; High-frequency oscillations; Posthypoxic coma; Prognostication; Somatosensory evoked potentials