Enhanced Interplay of Neuronal Coherence and Coupling in the Dying Human Brain.
Raul Vicente, Michael Rizzuto, Can Sarica, Kazuaki Yamamoto, Mohammed Sadr, Tarun Khajuria, Mostafa Fatehi, Farzad Moien-Afshari, Charles S Haw, Rodolfo R Llinas, Andres M Lozano, Joseph S Neimat, Ajmal Zemmar
Frontiers in Aging Neuroscience January 1, 2022 DOI: 10.3389/fnagi.2022.813531 (opens in new tab) via PubMed
Summary
AI-generated from the abstractAn 87-year-old patient dying from cardiac arrest after a traumatic brain injury showed a surge in high-frequency gamma brain waves on EEG, even after blood flow to the brain stopped. Gamma power increased before cardiac arrest, and after arrest, relative gamma power remained higher than during the patient's baseline. Cross-frequency coupling showed gamma activity modulated by alpha and theta rhythms, strongest after left-sided brain suppression and after cardiac arrest. These findings suggest the dying human brain can generate coordinated neural activity during the near-death period, offering the first human evidence from a real-life clinical setting.
Study at a glance
| Characteristics | Case study Case report Peer reviewed |
|---|---|
| Sample size | 1 |
| Population | 87-year-old patient with traumatic subdural hematoma undergoing cardiac arrest |
| Keywords | Coherence Coupling End-of-life Life recall Near-death |
| Key finding | The dying human brain shows increased relative gamma power and cross-frequency coupling after cardiac arrest, suggesting capacity for coordinated activity during the near-death period. |
Abstract
The neurophysiological footprint of brain activity after cardiac arrest and during near-death experience (NDE) is not well understood. Although a hypoactive state of brain activity has been assumed, experimental animal studies have shown increased activity after cardiac arrest, particularly in the gamma-band, resulting from hypercapnia prior to and cessation of cerebral blood flow after cardiac arrest. No study has yet investigated this matter in humans. Here, we present continuous electroencephalography (EEG) recording from a dying human brain, obtained from an 87-year-old patient undergoing cardiac arrest after traumatic subdural hematoma. An increase of absolute power in gamma activity in the narrow and broad bands and a decrease in theta power is seen after suppression of bilateral hemispheric responses. After cardiac arrest, delta, beta, alpha and gamma power were decreased but a higher percentage of relative gamma power was observed when compared to the interictal interval. Cross-frequency coupling revealed modulation of left-hemispheric gamma activity by alpha and theta rhythms across all windows, even after cessation of cerebral blood flow. The strongest coupling is observed for narrow- and broad-band gamma activity by the alpha waves during left-sided suppression and after cardiac arrest. Albeit the influence of neuronal injury and swelling, our data provide the first evidence from the dying human brain in a non-experimental, real-life acute care clinical setting and advocate that the human brain may possess the capability to generate coordinated activity during the near-death period.