MION IONM

The purpose of IONM is to reduce the risk to the patient of iatrogenic damage to the nervous system, and/or to provide functional guidance to the surgeon and anesthesiologist.

TYPES of SURGERIES and examples of correspondent IONM modalities

Reference: Heidi Yu Wing-hay & Eric Chung Chun-kwong, General Anaesthesia Tutorial 397

A) Intracranial or vascular surgeries involving cortical/subcortical pathways or their blood supplies

1. Resection of intracranial tumour/arterial venous malformation

2. Vascular surgeries involving carotid systems (eg, carotid endarterectomy, reconstructive head and neck surgery, aortic arch aneurysm surgery)

IONM MODALITIES Examples

Somatosensory evoked potentials (SSEPs) Motor evoked potentials (MEPs)

B) Surgery at the posterior fossa, cerebellopontine angle, or brainstem Brainstem auditory evoked potentials (BAEPs)

C) Surgery with risk of direct injury to spinal cord/roots or risk of compromising their blood supply

1. Removal of intramedullary/extramedullary/intradural spinal tumour

2. Spine deformity surgery

3. Trauma of the spine

4. Other decompressive surgeries of the spine

5. Embolization of vascular tumours/arteriovenous malformation of spinal cord

6. Thoracoabdominal aneurysm repair

IONM MODALITIES Examples

Somatosensory evoked potentials (SSEPs) Motor evoked potentials (MEPs) Electromyography (triggered/free-running EMG)

D) Surgery close to cranial nerves or peripheral nerves

1. Parotid surgery (close to facial nerve)

2. Thyroid surgery (close to recurrent laryngeal nerve)

3. Surgical resection of vestibular schwannoma (close to facial nerve and lower cranial nerves)

IONM MODALITIES Examples

Electromyography (triggered/free-running EMG)