Intraoperative Neurophysiological Monitoring (IONM) Unit

Led by Dr. Khalil Husari, the Johns Hopkins Intraoperative Neurophysiological Monitoring unit is a multi-disciplinary specialty program that provides intraoperative monitoring procedures to our surgeons.

What is intraoperative neurophysiological monitoring?

Intraoperative neurophysiological monitoring (IONM) describes a group of procedures used during surgery to monitor neural pathways during high-risk neurosurgical, orthopedic, peripheral nerve, and vascular surgeries. These procedures assist surgeons in preventing damage and preserving functionality of the nervous system.

There are two types of IONM: techniques used to identify impending damage to the nervous system, and techniques used to map the structures of the nervous system.

Types of Intraoperative Monitoring

To preserve the function of the nervous system (brain, spinal cord, nerves) and to map the structures of the nervous system, we use advanced intraoperative neurophysiological testing, such as:

  • Somatosensory evoked potentials (SSEP)
  • Motor evoked potentials (MEP)
  • Brainstem auditory evoked potentials (BAEP)
  • Visual evoked potentials (VEP)
  • Electrocochleography ( ECochG)
  • Electromyography (EMG) and nerve conduction monitoring
  • Electroencephalography (EEG) and electrocorticography (ECoG)
  • Cortical and subcortical motor mapping