INTRAOPERATIVE NEUROPHYSIOLOGICAL MONITORING (IOM)
Intraoperative Neurophysiological Monitoring, or Spinal Cord Monitoring,
is a field of electroneurodiagnostics devoted to the recording and study
of the electric activity of the brain and nervous system during surgery.
Technologists use a variety of techniques and instruments to record electric
activity arising from the brain, spinal cord and peripheral nerves. These
recordings are reported to the surgeon and supervising electrodiagnostic
Spinal-cord monitoring involves putting sensors on the patient to monitor
changes in electric signals. It can spot changes in brain, spinal-cord
and peripheral-nerve function before there is any irreversible damage.
Monitoring of nerves can guide the surgeon through dissection and alert
him or her of a stimulated nerve. It can show nerve stress or damage and
pinpoint the location of the irritation. Your physician will provide information
to you regarding intraoperative spinal cord monitoring prior to your surgery.
Spinal cord monitoring is often conducted during the following procedures:
Electroencephalogram (EEG) - EEG testing records brain activity and allows physicians to diagnose
brain disorders. During surgery, surgeons can also use an EEG to make
sure the patient is receiving enough oxygen.
Electromyography - Electromyography studies assess the electric potentials of both spinal
nerve roots and peripheral nerves. Electrodes are placed on a patient's
arms and legs to monitor muscle activity during surgery. Testing these
nerves allows surgeons to make sure they have not caused damage during surgery.
Evoked potential (EP) - Evoked potential studies use external stimuli to record the electric
activity in a patient's brain, spine and peripheral nerves. My monitoring
the waveforms produced by these studies, surgeons can better avoid causing
any nerve damage.
Nerve-conduction studies - Nerve-conduction studies involve stimulating nerves with an electric
current and measure how long the resulting nerve impulse takes to the
reach the muscle.
Pedicle-screw testing – These studies allow surgeons deliver a low electric current to
the pedicle screw during spine fusion procedures. By monitoring the current,
surgeons can verify that no breach or crack in the bone occurred during