Table 1.

Summary of Strengths and Weaknesses of IONM Modalities.

Type of Monitoring	Strengths	Weaknesses
SSEP	Allows continuous monitoring throughout the surgery Does not preclude the use of neuromuscular blockade	Its interpretation requires temporal summation, which can delay the detection of a signal change by up to 16 minutes Unable to detect motor changes Individual nerve root function is not effectively monitored by SSEPs
tcMEP	Allows monitoring of the entire motor pathway (cortex, corticospinal tract, nerve root, peripheral nerve) Sensitive in the detection of postoperative motor deficits Sensitive for detecting spinal cord ischemia	Does not allow for continuous monitoring Precludes use of neuromuscular blockade Highly sensitive to inhalational anesthetics, demanding rigid anesthetic protocols
Spontaneous EMG	Sensitive for nerve root injury Provides real-time information about nerve root function throughout surgery May be combined with SSEPs to improve specificity	Sensitive to temperature changes High rate of false positive alarms Precludes use of neuromuscular blockade
Triggered EMG	High sensitivity for medial pedicle wall breach Useful in minimally invasive surgery where anatomical landmarks may be challenging to visualize Relatively easy technique	Accepted set thresholds not firmly established Less sensitive for thoracic pedicle screws than for lumbar pedicle screws High rate of false positive alarms

Abbreviations: IONM, intraoperative neurophysiological monitoring; SSEP, somatosensory sensory evoked potential; tcMEP, transcranial motor-evoked potential; EMG, electromyography.