Case studies in neuroscience: reversible signatures of edema following electric and piezoelectric craniotomy drilling in macaques

Rober Boshra, Manoj Eradath, Kacie Dougherty, Bichan Wu, Britney M. Morea, Michael Harris, Mark A. Pinsk, Sabine Kastner

Research output: Contribution to journalArticlepeer-review


In vivo electrophysiology requires direct access to brain tissue, necessitating the development and refinement of surgical procedures and techniques that promote the health and well-being of animal subjects. Here, we report a series of findings noted on structural magnetic resonance imaging (MRI) scans in monkeys with MRI-compatible implants following small craniotomies that provide access for intracranial electrophysiology. We found distinct brain regions exhibiting hyperintensities in T2-weighted scans that were prominent underneath the sites at which craniotomies had been performed. We interpreted these hyperintensities as edema of the neural tissue and found that they were predominantly present following electric and piezoelectric drilling, but not when manual, hand-operated drills were used. Furthermore, the anomalies subsided within 2-3 wk following surgery. Our report highlights the utility of MRI-compatible implants that promote clinical examination of the animal's brain, sometimes revealing findings that may go unnoticed when incompatible implants are used. We show replicable differences in outcome when using electric versus mechanical devices, both ubiquitous in the field. If electric drills are used, our report cautions against electrophysiological recordings from tissue directly underneath the craniotomy for the first 2-3 wk following the procedure due to putative edema.NEW & NOTEWORTHY Close examination of structural MRI in eight nonhuman primates following craniotomy surgeries for intracranial electrophysiology highlights a prevalence of hyperintensities on T2-weighted scans following surgeries conducted using electric and piezoelectric drills, but not when using mechanical, hand-operated drills. We interpret these anomalies as edema of neural tissue that resolved 2-3 wk postsurgery. This finding is especially of interest as electrophysiological recordings from compromised tissue may directly influence the integrity of collected data immediately following surgery.

Original languageEnglish (US)
Pages (from-to)919-926
Number of pages8
JournalJournal of neurophysiology
Issue number4
StatePublished - Oct 1 2022

All Science Journal Classification (ASJC) codes

  • Neuroscience(all)
  • Physiology


  • craniotomy
  • MRI
  • MRI-compatible implants
  • nonhuman primate
  • piezoelectric drill


Dive into the research topics of 'Case studies in neuroscience: reversible signatures of edema following electric and piezoelectric craniotomy drilling in macaques'. Together they form a unique fingerprint.

Cite this