Efficacy of intraoperative monitoring of transcranial electrical stimulation-induced motor evoked potentials and spontaneous electromyography activity to identify acute-versus delayed-onset C-5 nerve root palsy during cervical spine surgery: clinical article.

Object: Deltoid muscle weakness due to C-5 nerve root injury following cervical spine surgery is an uncommon but potentially debilitating complication. Symptoms can manifest upon emergence from anesthesia or days to weeks following surgery. There is conflicting evidence regarding the efficacy of spontaneous electromyography (spEMG) monitoring in detecting evolving C-5 nerve root compromise.

Transcranial electric motor evoked potential detection of compressional peroneal nerve injury in the lateral decubitus position.

The peroneal nerve is susceptible to injury due to compression at the fibular head for patients placed in the lithotomy, hemilithotomy or lateral decubitus positions during surgery. Upper extremity somatosensory and transcranial electric motor evoked potential monitoring has proven efficacious for identifying impending positional brachial plexopathy or upper extremity peripheral neuropathy in adult and pediatric patients undergoing spine surgery. We report on two cases to illustrate the usefulness of monitoring transcranial electric motor evoked potentials recorded from tibialis anterior muscle to identify emerging peroneal nerve compression secondary to lateral decubitus positioning.

Mixed blocked/event-related designs separate transient and sustained activity in fMRI.

Recent functional magnetic resonance imaging (fMRI) studies using mixed blocked/event-related designs have shown activity consistent with separable sustained task-related processes and transient trial-related processes. In the mixed design, control blocks are intermixed with task blocks, during which trials are presented at varying intervals. Two studies were conducted to assess the ability of this design to detect and dissociate sustained task-related from transient trial-related activity.