Myoclonus After Cardiac Arrest Did Not Correlate with Cortical Response on Somatosensory Evoked Potentials
Abstract number :
3.119
Submission category :
3. Neurophysiology / 3B. ICU EEG
Year :
2023
Submission ID :
145
Source :
www.aesnet.org
Presentation date :
12/4/2023 12:00:00 AM
Published date :
Authors :
Presenting Author: Adriana Koek, MD – University of California San Francisco
Kyle Darpel, MD – St. Elizabeth Physicians; Temenuzhka Mihaylova, MD, PhD – University of Michigan; Wesley Kerr, MD, PhD – University of Michigan
Rationale: Neurologic prognostication after anoxic brain injury is critical in guiding resource utilization and caregiver support. Myoclonus after anoxia is a marker of significant cerebral injury. It is also well-known that absent cortical signal (N20) on somatosensory evoked potentials (SSEPs) after cardiac arrest consistently predicts poor neurologic recovery. We hypothesized that post-anoxic myoclonus and SSEPs are fundamentally related, with cortical myoclonus representing a brain-generated motor potential which could be considered a motor correlate of an externally evoked sensory potential. We speculated that in the case of a global cerebral event, the distinction between motor and sensory cortices is irrelevant to prognostication and that presence of cortical myoclonus may predict intact SSEPs and obviate need for formal testing.
Methods: This was a retrospective chart review of all adult patients at the University of Michigan from 2005 to 2021 with post-cardiac arrest myoclonus who underwent both electroencephalographic monitoring and SSEPs for neuroprognostication. Myoclonus was categorized as clinical myoclonus only, subcortical myoclonus, cortical myoclonus, and status myoclonus. SSEP results were categorized as all absent, all present, N18 and N20 absent bilaterally, and N20 only absent bilaterally. Cox proportional hazards with censoring was used to evaluate the association of myoclonus category, SSEP results, and confounding factors with survival.
Results: In 57 patients, the median time from arrest to either confirmed death or last follow up was nine days. The category of myoclonus was not associated with SSEP result or length of survival. Absence of N20s or N18s was associated with shorter survival (N20 hazard ratio [HR] 3.5, p=0.0002; N18 HR 5.1, p< 0.000006).
Neurophysiology