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ENT
Neurophysiologic Monitoring in Otologic and Neurotologic Surgery
Built from Haynes-Glasscock-Shambaugh Surgery of the Ear, Seventh Edition
What’s inside
7 sections · 69 slides
Principles of intraoperative monitoring
- Definition and role of intraoperative monitoring
- Neural structures at risk in cerebellopontine angle surgery
- Modalities of neurotologic monitoring
Facial nerve monitoring
- Rationale for facial nerve monitoring
- Electromyography compared with motor evoked potentials
- Acquisition formats in facial nerve electromyography
- Free-run electromyography
- Triggered and stimulated electromyography
- Free-run and triggered electromyographic traces
- Electrode configurations for facial electromyography
- Referential recording
- Electromyographic response types
- Romstock classification of electromyographic trains
- Three morphologies of electromyographic train activity
- Prognostic value of A-train activity
- Setup for direct nerve stimulation
- Triggered electromyographic response to a 0.5 milliampere stimulus
- Stimulus parameters for facial nerve stimulation
- Search mode during early tumour resection
- End-of-resection stimulation thresholds
- Amplitude threshold criteria after vestibular schwannoma resection
- Facial nerve monitoring in otologic surgery
- Principle of facial nerve motor evoked potentials
- Technique of transcranial facial motor evoked potentials
- Excluding current spread across the scalp
- Facial nerve motor evoked response from orbicularis oris
- Interpretation and safety in motor evoked potential monitoring
Anaesthetic requirements
- Neuromuscular blockade and electromyographic monitoring
- Volatile agents and facial nerve motor evoked potentials
Hemifacial spasm and ephaptic responses
- Pathophysiology of hemifacial spasm
- Ephaptic response monitoring during microvascular decompression
Personnel, indications and controversy
- Personnel for neurophysiologic monitoring
- Diffuse electromyographic activity as an anaesthetic warning
- Indications for facial nerve monitoring in otologic disease
- Controversy over routine monitoring in otologic surgery
Auditory monitoring
- Goals of auditory monitoring
- Auditory brainstem response compared with direct eighth nerve monitoring
- Hearing preservation outcomes in small vestibular schwannoma
- Waves of the auditory brainstem response and their generators
- Normal latency values in the intraoperative auditory brainstem response
- Baseline recording as the reference for change
- Serial auditory brainstem response traces in tumour and non-tumour ears
- Intraoperative recording montage for auditory brainstem response
- Sound delivery and canal preparation
- Stimulus and averaging parameters
- Effect of sensorineural hearing loss on wave I
- Compound nerve action potential and direct eighth nerve monitoring
- Practical advantages and limitations of direct monitoring
- Compound nerve action potential when the brainstem response is absent
- Alarm criteria for auditory monitoring
- Distinguishing artefact from true auditory change
Other cranial nerves
- Motor cranial nerves monitored by electromyography
- Electrode placement for other cranial nerves
- Vagus nerve monitoring
- Summary of intraoperative neurophysiologic monitoring
- Communication in the monitored operation
- References
- References
- References
- References
- Haynes-Glasscock-Shambaugh Surgery of the Ear, Seventh Edition
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