Neurophysiology in Neurosurgery: A Modern Approach

Cover
Neurophysiology in Neurosurgery
Copyright
Dedication
	Reference
Contents
List of contributors
Preface
Intraoperative neurophysiological monitoring—why we need it and a personal perspective of its development
	1 Introduction
	2 Theoretical background
	3 Detection of developing neural damage and avoidance of permanent deficits
	4 Intraoperative neurophysiological monitoring as a teaching tool
	5 Detection of adverse systemic or nonsurgical influences
	6 Reassurance to surgeon about lack of damaging effect of specific risky maneuvers
	7 Value of intraoperative neurophysiological monitoring in today’s world
	8 Conclusion on why we need intraoperative neurophysiological monitoring
	9 A personal perspective on the development of intraoperative neurophysiological monitoring
		9.1 An early period of evoked potential applications
		9.2 From diagnostics to intraoperative neurophysiological monitoring
		9.3 Further clinical development
		9.4 The problem of motor-evoked potentials monitoring
	10 Conclusion
	References
Part I: Introduction to intraoperative neurophysiology
1 Animal and human motor system neurophysiology related to intraoperative monitoring
	1.1 Introduction
	1.2 Corticospinal responses
		1.2.1 Configuration of corticospinal tract waves
			1.2.1.1 Conducted impulses
			1.2.1.2 Blocked impulses
		1.2.2 Eliciting D waves
		1.2.3 Eliciting I waves
			1.2.3.1 Extrinsic inputs
			1.2.3.2 Intrinsic inputs
	1.3 Muscle responses
	References
2 Intraoperative neurophysiology and methodologies used to monitor the functional integrity of the motor system
	2.1 Intraoperative monitoring of the motor system: a brief history
		2.1.1 Penfield’s time
		2.1.2 Spinal cord to spinal cord
		2.1.3 Spinal cord to peripheral nerve (muscle)
	2.2 New methodologies
		2.2.1 Single-pulse stimulation technique
		2.2.2 Multipulse stimulation technique
	2.3 Methodological aspects of transcranial electrical stimulation during general anesthesia
		2.3.1 Electrode montage over the scalp for eliciting motor-evoked potentials (for single and multipulse stimulation techniques)
	2.4 Recording of MEPs over the spinal cord (epidural and subdural spaces) using single-pulse stimulation technique
		2.4.1 D-wave recording technique through an epidurally or subdurally inserted electrode
			2.4.1.1 Choice of electrode
		2.4.2 Proper placement of epidural electrodes
			2.4.2.1 Percutaneous placement of catheter electrode
			2.4.2.2 Placement of electrode after laminectomy/laminotomy or flavectomy/flavotomy
		2.4.3 Factors influencing D- and I-wave recordings
		2.4.4 Neurophysiological mechanisms leading to the desynchronization of the D-wave
	2.5 Recording of motor-evoked potentials in limb muscles elicited by a multipulse stimulating technique
		2.5.1 Selection of optimal muscles in upper and lower extremities for motor-evoked potential recordings
		2.5.2 Neurophysiological mechanisms for eliciting muscle motor-evoked potentials using a multipulse stimulation technique
			2.5.2.1 Recovery of amplitude and latency of the D-wave
			2.5.2.2 Facilitation of I-wave
			2.5.2.3 Total number of D- and I-waves
			2.5.2.4 Generation of muscle MEPs depends on two systems: the CST and the supportive system of the spinal cord
		2.5.3 Surgically induced transient paraplegia
			2.5.3.1 Neurophysiological basis for surgically induced transient paraplegia
	2.6 Conclusion
	References
3 Monitoring somatosensory evoked potentials
	3.1 Introduction
	3.2 History
	3.3 Methodology
		3.3.1 Basic techniques
			3.3.1.1 Electrodes
			3.3.1.2 Stimulation
			3.3.1.3 Recording
			3.3.1.4 Potentials and sites
				3.3.1.4.1 Peripheral controls
				3.3.1.4.2 Cortical monitors
				3.3.1.4.3 Other potentials
			3.3.1.5 Averaging
		3.3.2 Traditional methods
		3.3.3 Optimal methods
			3.3.3.1 Lower limbs
			3.3.3.2 Upper limbs
			3.3.3.3 Optional derivations
			3.3.3.4 Fallback derivations
			3.3.3.5 Benefits
	3.4 Warning criteria
		3.4.1 Traditional criteria pitfalls
		3.4.2 Recommended adaptive criterion
	3.5 Cortical somatosensory evoked potential mapping
		3.5.1 Median nerve
		3.5.2 Tibial and trigeminal nerves
	3.6 Future directions
	3.7 Conclusion
	References
4 Neurophysiology of the visual system: basics and intraoperative neurophysiology techniques
	4.1 Introduction
	4.2 Historical review
	4.3 Neurophysiology of the visual pathway
	4.4 Recording of intraoperative flash visual evoked potentials
		4.4.1 Indication for intraoperative visual evoked potential monitoring
		4.4.2 Anesthesia
		4.4.3 Stimulation
		4.4.4 Recording
		4.4.5 Waveform acquisition
		4.4.6 Intraoperative assessment of visual evoked potentials and warning criteria
	4.5 Results
		4.5.1 Case examples
	4.6 Optic nerve action potentials and evoked potentials
	4.7 Monitoring and mapping the posterior visual pathway
	4.8 Conclusion
	References
5 Neurophysiology of the auditory system: basics and ION techniques
	5.1 The auditory nerve
	5.2 History of recordings of the auditory brainstem response
	5.3 Generation of far-field-evoked potentials
	5.4 Intraoperative neurophysiological monitoring of the auditory brainstem response
		5.4.1 Techniques for recording the auditory brainstem response
		5.4.2 Getting interpretable responses in the shortest possible time
		5.4.3 Optimal stimulus rate and intensity
		5.4.4 Reduction of electrical and magnetic interference
		5.4.5 Optimal placement of the recording electrodes for auditory brainstem response for intraoperative monitoring
		5.4.6 Filtering of the auditory brainstem response
		5.4.7 Practical ways of recording auditory brainstem responses intraoperatively
	5.5 Detection of signs of hearing loss from manipulations of the auditory nerve
	5.6 Recording directly from the exposed auditory nerve
	5.7 Recording of the response from the cochlear nucleus
	5.8 What to report to the surgeon?
	5.9 The neural generators of the auditory brainstem response
		5.9.1 Generators of peak I and II of the auditory brainstem response
		5.9.2 Contribution to the auditory brainstem response from nuclei
			5.9.2.1 The cochlear nucleus
			5.9.2.2 Superior olivary complex
			5.9.2.3 Lateral lemniscus
			5.9.2.4 Inferior colliculus
		5.9.3 Lateralization of auditory-evoked potentials
		5.9.4 The absence of contributions from some ascending auditory pathways
		5.9.5 Summary of the neural generators of the auditory brainstem response
	5.10 Use of auditory brainstem response in monitoring to detect changes in the function of the brainstem
	References
6 Intraoperative neurophysiological monitoring of the sacral nervous system
	6.1 Introduction
	6.2 Functional anatomy
		6.2.1 Neural control of the lower urinary tract
		6.2.2 Anorectum
		6.2.3 Sexual organs
	6.3 Clinical neurophysiological tests in diagnostics
	6.4 Intraoperative clinical neurophysiology
		6.4.1 Basic technical aspects of stimulation for intraoperative sacral monitoring
		6.4.2 Basic technical aspects of recording for intraoperative sacral monitoring
		6.4.3 Specific sacral neuromuscular system monitoring procedures
			6.4.3.1 Pudendal dorsal root action potentials
			6.4.3.2 Pudendal spinal somatosensory evoked responses
			6.4.3.3 Pudendal cerebral somatosensory evoked potentials
			6.4.3.4 Anal sphincter motor response monitoring
			6.4.3.5 Bulbocavernosus reflex monitoring
	6.5 Discussion and Conclusion
	References
	Further reading
7 Neurophysiology of language and cognitive mapping
	7.1 Introduction
	7.2 Language mapping
		7.2.1 Current model of language organization
		7.2.2 Language mapping workup
			7.2.2.1 Preoperative workup
			7.2.2.2 Neuropsychological evaluation
			7.2.2.3 Language examination
			7.2.2.4 Training to the awake phase
			7.2.2.5 Intraoperative workup
			7.2.2.6 Postoperative workup
		7.2.3 Neurophysiological approach
		7.2.4 Defining eloquent sites in language mapping
		7.2.5 How to perform the mapping?
		7.2.6 Besides standard language mapping
			7.2.6.1 Reading and writing
			7.2.6.2 Language mapping in multilingual patients
	7.3 Advanced mapping: cognitive mapping
		7.3.1 Brain mapping of visual system and visuospatial cognition
		7.3.2 Cognitive control
	7.4 Conclusion
	References
8 Effects of subthreshold stimuli on the excitability of axonal membrane
	8.1 Introduction
	8.2 Methodology
		8.2.1 Test subjects
		8.2.2 Stimulation
			8.2.2.1 Median nerve
			8.2.2.2 Facial nerve
		8.2.3 Recording
			8.2.3.1 Median nerve
			8.2.3.2 Facial nerve
		8.2.4 Testing protocol
	8.3 Results
	8.4 Discussion
	8.5 Conclusion
	References
Part II: Intraoperative neurophysiology: neurophysiologic perspective
9 Cortical and subcortical brain mapping
	9.1 Introduction
	9.2 Brain mapping and anesthesia
	9.3 Recording and documentation
	9.4 Physical background
	9.5 Choice of stimulation paradigm
	9.6 Choice of stimulation probe
	9.7 Subcortical mapping and distance to the corticospinal tract
	9.8 Continuous subcortical mapping
	9.9 Possible pitfalls
	9.10 Case illustrations
		9.10.1 Case no 1, video 9.1 – Intraoperative DCS MEP monitoring, cortical mapping and continuous subcortical mapping in a c...
		9.10.2 Case no 2, video 9.2 – Continuous subcortical mapping and intraoperative DCS MEP and SEP monitoring in a right insul...
	9.11 Summary and conclusion
	Acknowledgment
	References
10 Corticobulbar motor evoked potentials in skull base surgery
	10.1 Introduction
	10.2 Methodology
		10.2.1 Stimulation
		10.2.2 Recording parameters
	10.3 Anesthesia regime
	10.4 Facial corticobulbar motor evoked potentials
		10.4.1 Methodological improvement
			10.4.1.1 Increase the number of monitored muscles
			10.4.1.2 Localization of the best position for recording electrodes
			10.4.1.3 Optimization of stimulation parameters through the surgical procedure
			10.4.1.4 Double-stimulation technique
			10.4.1.5 Hook wire electrodes for recording
			10.4.1.6 Filtering
		10.4.2 Facial corticobulbar motor evoked potentials interpretation and correlation with clinical outcome
		10.4.3 Pitfalls in facial corticobulbar motor evoked potentials methodology
			10.4.3.1 Blink versus facial corticobulbar motor evoked potentials
			10.4.3.2 Confounding peripheral activation of the facial nerve during corticobulbar tract monitoring
	10.5 Vagal corticobulbar motor evoked potentials
		10.5.1 The origin of laryngeal response after transcranial electrical stimulus
		10.5.2 Vagal corticobulbar motor evoked potentials recorded from vocalis muscles
		10.5.3 Vagal corticobulbar motor evoked potentials recorded from cricothyroid muscle
	10.6 Limitations of corticobulbar motor evoked potentials
	10.7 Conclusion
	References
11 Brain stem mapping
	11.1 Introduction
		11.1.1 What is brain stem mapping?
		11.1.2 Anatomical background for brain stem mapping
		11.1.3 Corticobulbar tracts
	11.2 Methodology of brain stem mapping
		11.2.1 Anesthesia regimen
	11.3 Results of brain stem mapping
	11.4 Surgical implications of brain stem mapping
	11.5 Clinical limitations of brain stem mapping
	11.6 Representative case of brain stem mapping
	11.7 Clinical application of brain stem mapping
	11.8 Conclusion
	References
12 Neurophysiological identification of long sensory and motor tracts within the spinal cord
	12.1 Introduction
	12.2 Dorsal column mapping
		12.2.1 Neurophysiological generators of somatosensory evoked potentials in the spinal cord
		12.2.2 Measuring the amplitude gradient of spinal SEP via miniature multielectrode grid electrodes
		12.2.3 Phase-reversal somatosensory evoked potentials over the scalp
		12.2.4 Antidromic responses over peripheral nerves
	12.3 Corticospinal tract mapping
		12.3.1 D-wave collision technique
		12.3.2 Direct stimulation of the spinal cord
			12.3.2.1 What are we really stimulating?
		12.3.3 Mapping the DC and CST with a double-train stimulation paradigm
	12.4 Conclusion
	References
13 Electromyographic monitoring for pedicle screw placements
	13.1 Introduction
	13.2 Monitoring pedicle screw placements
		13.2.1 Electromyographic techniques
			13.2.1.1 Spontaneous or free-running electromyography
			13.2.1.2 Triggered electromyography
		13.2.2 Nerve root excitation
		13.2.3 False-positive findings
		13.2.4 False-negative findings
			13.2.4.1 Degree of muscle relaxation
			13.2.4.2 Current shunting
			13.2.4.3 Physiologic factors
			13.2.4.4 Technical factors
		13.2.5 Efficacy of electromyographic monitoring
		13.2.6 Minimally invasive applications
	13.3 Conclusion
	References
14 Clinical and neurophysiologic features of the pure motor deficit syndrome caused by selective upper motor neuron lesion:...
	14.1 Introduction
	14.2 Underlying pathology of pure motor deficit
	14.3 Diagnosis
		14.3.1 Clinical and neurological examination
		14.3.2 Use of neuroimaging techniques
		14.3.3 Neurophysiological markers obtained peri- and intraoperatively
		14.3.4 Postmortem pathology
	14.4 Methodologies
	14.5 Topography of the corticospinal tract and corticobulbar tract lesions producing pure motor deficit
		14.5.1 Typical lesion within brain, brainstem, and spinal cord producing pure motor deficit
		14.5.2 Cortical, subcortical, and capsular lesion producing pure motor deficit
		14.5.3 Brainstem lesion producing pure motor deficit
		14.5.4 Spinal cord lesion producing pure motor deficit
	14.6 Prognosis
	14.7 Conclusion
	References
	Further reading
Part III: Neurophysiology of brainstem and spinal cord reflexes
15 Intraoperative monitoring of the vagus and laryngeal nerves with the laryngeal adductor reflex
	15.1 Introduction
	15.2 History
	15.3 Methodology
		15.3.1 Far-field muscle contamination
		15.3.2 Impact on surgical strategy
	15.4 Examples
		15.4.1 Example 1
		15.4.2 Example 2
	15.5 Conclusion
	References
16 Bringing the masseter reflex into the operating room
	16.1 Introduction
	16.2 History
	16.3 Methodology
	16.4 Examples
	16.5 Conclusion
	References
17 Blink reflex
	17.1 Introduction
	17.2 Methodology
		17.2.1 Stimulation parameters
		17.2.2 Recording parameters
	17.3 Anesthetic considerations
	17.4 Clinical assessment/results
	17.5 Practical applications
		17.5.1 Feasibility and practicality of monitoring
		17.5.2 Interpretation of blink reflex
		17.5.3 Combined interpretation of blink reflex and corticobulbar motor evoked potentials
		17.5.4 Pitfall of interpretation of facial corticobulbar motor evoked potentials in relation to blink reflex: “upper facial...
	17.6 Summary
	References
18 The posterior root-muscle reflex
	18.1 Introduction
	18.2 History
	18.3 Anatomy of the posterior roots
	18.4 Methodologies for evoking posterior root-muscle reflexes
		18.4.1 Epidural spinal cord stimulation
		18.4.2 Transcutaneous spinal cord stimulation
	18.5 Physiology and electromyographic characteristics of posterior root-muscle reflexes
		18.5.1 Characteristics of posterior root-muscle reflexes evoked by stimulation over the lumbar and upper sacral spinal cord
		18.5.2 Posterior root-muscle reflexes and the H-reflex
		18.5.3 Characteristics of evoked responses to stimulation over the cauda equina
		18.5.4 Body-position dependence of the evoked responses
	18.6 Examples of intraoperative monitoring applications
		18.6.1 Intraoperative neurophysiological monitoring of epidural lead placement
		18.6.2 Intraoperative monitoring of peripheral nerve function during complex hip surgeries
	18.7 Conclusion
	References
Part IV: Intraoperative Neurophysiology: Surgical Perspective
19 Functional approach to brain tumor surgery: awake setting
	19.1 Introduction
	19.2 Rationale of surgical treatment
	19.3 The concept of functional neuro-oncology: resection according to functional boundaries
	19.4 Preoperative workup
		19.4.1 Patient interview
		19.4.2 Neuropsychological evaluation and psycho-oncological interview
		19.4.3 Imaging workup
			19.4.3.1 Basic methods: magnetic resonance imaging standard evaluation
			19.4.3.2 Advanced magnetic resonance imaging evaluation
	19.5 Decision for surgery
	19.6 Intraoperative setup
		19.6.1 Intraoperative anesthesia
		19.6.2 Intraoperative neurophysiology
			19.6.2.1 Mapping techniques
			19.6.2.2 Monitoring techniques
	19.7 Surgical time
		19.7.1 Cortical time
		19.7.2 Subcortical time
	19.8 How to manage intraoperative complications
	19.9 Functional results of surgery
	19.10 Conclusion
	References
	Further reading
20 Surgery of brain tumors asleep
	20.1 Introduction
	20.2 Cortical mapping
	20.3 Monitoring
	20.4 Subcortical mapping
	20.5 Conclusion
	References
21 Surgery and intraoperative neurophysiological monitoring for aneurysm clipping
	21.1 Introduction
	21.2 Somatosensory-evoked potentials
	21.3 Motor-evoked potentials
	21.4 Early auditory-evoked potentials
	21.5 Visual-evoked potentials
	21.6 General remarks for safety considerations and anesthesia
		21.6.1 Auditory-evoked potential and somatosensory-evoked potential
		21.6.2 Motor-evoked potential
		21.6.3 Visual-evoked potential
		21.6.4 Anesthesia
	21.7 Intraoperative Neuromonitoring (ION) and surgical workflow
	21.8 Surgical aspects in cerebrovascular surgery
	21.9 Vascular territories and recommended recordings
		21.9.1 Anterior circulation aneurysms
		21.9.2 Posterior circulation aneurysms and arteriovenous malformations
		21.9.3 Perforating arteries
	21.10 Temporary vessel occlusion
	21.11 Permanent vessel occlusion
	21.12 Special remarks on arteriovenous malformation surgery
	21.13 Surgical reaction on ION alteration and duration of monitoring
	21.14 Conclusion
	References
22 Surgery of brainstem lesions
	22.1 Introduction
	22.2 Patient selection and rationale for surgery
	22.3 General principle of the surgical strategy
		22.3.1 Midbrain
		22.3.2 Pons
		22.3.3 Medulla and cervicomedullary junction
	22.4 Postoperative care
	22.5 Neurophysiological monitoring
	22.6 Conclusion
	References
23 Continuous dynamic mapping during surgery of large vestibular schwannoma
	Abbreviations
	23.1 Introduction
	23.2 Neurophysiological setup
		23.2.1 Continuous dynamic mapping suction probe
		23.2.2 Software adaptations
		23.2.3 Surgical technique using continuous monopolar mapping
	23.3 Anatomy in the cerebellopontine angle
	23.4 What current neurophysiological methods provide?
	23.5 Continuous dynamic mapping as an adjunct
	23.6 What might be the best strategy to protect the facial nerve?
		23.6.1 Illustrative case example
	23.7 Limitations
	23.8 Further applications in skull base surgery
	23.9 Summary
	References
24 Surgery of the face
	24.1 Introduction
	24.2 Anatomy, physiology, and surgery of the facial nerve
	24.3 Methodology
		24.3.1 Instruments and electrodes
		24.3.2 Preoperative mapping
	24.4 Continuous compound muscle action potential monitoring
	24.5 Intraoperative mapping
	24.6 Warning criteria and correlation with outcome
	24.7 Our experience on facial nerve monitoring and comparison with other studies
	24.8 Conclusion
	References
25 Carotid endarterectomy
	25.1 Introduction
		25.1.1 Carotid endarterectomy and shunt application
		25.1.2 Cerebral blood supply and clamping-related ischemia
		25.1.3 Monitoring neuronal function to detect critical cerebral perfusion
	25.2 Intraoperative neurophysiologic monitoring for carotid endarterectomy
		25.2.1 Electroencephalogram
		25.2.2 Somatosensory evoked potentials
		25.2.3 Transcranial electrical motor evoked potentials
	25.3 Conclusion
	References
26 Surgery for intramedullary spinal cord tumors and syringomyelia
	26.1 Introduction
	26.2 Neurophysiology
	26.3 Anesthesia
	26.4 Clinical assessment and correlation
	26.5 Feasibility and practicality of monitoring
		26.5.1 Interpretation of D-wave
		26.5.2 Interpretation of muscle motor-evoked potential
		26.5.3 Combined muscle motor-evoked potential and D-wave monitoring
		26.5.4 Influence of D-wave and MEP monitoring on extent of resection and neurologic outcome
	26.6 Observations on the behavior of MEPs during spinal cord tumor surgery and their practical consequences
		26.6.1 Muscle motor-evoked potential build-up effect
		26.6.2 Behavior of motor-evoked potential disappearance and how to react to them
	26.7 Mapping of individual pathways in the spinal cord
	26.8 Illustrative cases
		26.8.1 Case 1
		26.8.2 Case 2
		26.8.3 Case 3
		26.8.4 Case 4
		26.8.5 Case 5
		26.8.6 Case 6
	26.9 Conclusion
	References
27 Intraoperative neurophysiological monitoring in tethered cord surgery
	27.1 Introduction
	27.2 Tethered cord etiopathogenesis
	27.3 Anesthesia
	27.4 Intraoperative neurophysiology techniques during tethered cord surgery
	27.5 Monitoring techniques
		27.5.1 Somatosensory evoked potentials
		27.5.2 Motor-evoked potentials
		27.5.3 Free-running (spontaneous) electromyography
		27.5.4 Bulbocavernosus reflex
	27.6 Mapping techniques
		27.6.1 Triggered EMG: direct nerve stimulation
	27.7 Surgical use of intraoperative neurophysiology in lipomas exertion
	27.8 Conclusion
	References
28 Intraoperative neuromonitoring and complex spine surgery
	28.1 Introduction
	28.2 Complex spine instrumentation and deformity surgery
	28.3 Spinal instability
	28.4 Monitoring loss protocol
		28.4.1 Case example 1
		28.4.2 Case example 2
	28.5 Conclusion
	References
29 Neurophysiological monitoring during endovascular procedures on the spine and the spinal cord*
	29.1 Spinal cord vascularization and ischemia
		29.1.1 Vascular anatomy of the human spinal cord
		29.1.2 Primers on pathophysiology of spinal cord ischemia secondary to spinal cord vascular malformations
	29.2 Neurophysiological monitoring
		29.2.1 Evoked potentials in spinal cord ischemia: experimental and clinical studies
		29.2.2 Clinical application of neurophysiological monitoring for endovascular treatment of spine and spinal cord vascular l...
			29.2.2.1 Patient setup and anesthesiological management
			29.2.2.2 Endovascular procedure and provocative tests
	29.3 Endovascular treatment of vascular malformations and tumors of the spine and the spinal cord
		29.3.1 Indications
		29.3.2 Angiographic vascular anatomy of the spine and spinal cord
		29.3.3 Spinal angiography
		29.3.4 Angiographic evaluation, endovascular treatment, and clinical aspect of neurophysiological monitoring
			29.3.4.1 Tumors
			29.3.4.2 Vascular malformations
				29.3.4.2.1 Dural/extradural lesions
				29.3.4.2.2 Intradural vascular malformations
	29.4 Conclusion
	References
30 Intraoperative neurophysiology of the peripheral nervous system
	30.1 Background
	30.2 Nerve regeneration
	30.3 Equipment for intraoperative recordings
	30.4 Electrodes for intraoperative recording and stimulation
	30.5 Anesthetic considerations
	30.6 Recording compound nerve action potentials intraoperatively
	30.7 Criteria for appraising a compound nerve action potentials
	30.8 Operative results
	30.9 Troubleshooting
	30.10 Conclusion
	References
31 An intraoperative neurophysiological monitoring method for testing functional integrity of the low extremity peripheral ...
	31.1 Introduction
	31.2 Material and methods
		31.2.1 Subjects
		31.2.2 Anesthesia
		31.2.3 Multimodal neuromonitoring methodologies
			31.2.3.1 Somatosensory-evoked potential
			31.2.3.2 Motor-evoked potential
			31.2.3.3 Free-running electromyography
			31.2.3.4 Anterior root muscle response and posterior root muscle reflex
			31.2.3.5 Electroencephalography
		31.2.4 Recordings
		31.2.5 Specific attention for placement of nerve-stimulating and muscle recording electrodes
	31.3 Results
	31.4 Discussion
	31.5 Conclusion
	References
	Further reading
Part V: Functional neurosurgery
32 Surgery for epilepsy
	32.1 Introduction
	32.2 Preoperative evaluation
	32.3 Surgical options
		32.3.1 Temporal lobectomy (with or without removal of amygdala, hippocampus, and parahippocampal tissue)
		32.3.2 Other extratemporal resection
		32.3.3 Callosotomy
		32.3.4 Multiple subpial transections
	32.4 Electrocorticography
		32.4.1 History of cortical recordings
		32.4.2 Current status of classical electrocorticography during epilepsy surgery
		32.4.3 Newer intraoperative neurophysiologic techniques during epilepsy surgery
		32.4.4 Clinical interpretation of electrocorticography
	32.5 Anesthetic considerations
	32.6 Electrodes
	References
33 Intraoperative neurophysiological monitoring during microvascular decompression of cranial nerves
	33.1 History
	33.2 Pathologies
		33.2.1 Trigeminal neuralgia
		33.2.2 Hemifacial spasm
		33.2.3 Glossopharyngeal neuralgia
		33.2.4 Others syndromes related to neurovascular compression (NVC)
	33.3 Radiologic considerations
	33.4 Pathogenic mechanisms underlying vascular compression
	33.5 Surgical treatment
		33.5.1 Microvascular decompression surgical procedure
			33.5.1.1 Patient positioning and preparation
			33.5.1.2 Surgical technique
	33.6 Monitoring modalities for microvascular decompression
		33.6.1 Achieving the therapeutic goal
			33.6.1.1 Abnormal muscle response: (lateral spread)
			33.6.1.2 Other abnormal responses
		33.6.2 Avoiding complications
			33.6.2.1 Brainstem auditory response
			33.6.2.2 Auditory nerve compound action potentials
			33.6.2.3 Free-running and triggered electromyography
			33.6.2.4 Somatosensory-evoked potentials and transcranial motor-evoked potentials
	33.7 Microvascular decompression and intraoperative neurophysiology: practical implementation and pearls
	33.8 Conclusion
	References
	Further reading
34 Neurophysiological monitoring during neurosurgery for movement disorders
	34.1 Introduction
	34.2 History and theory
		34.2.1 Historical notes
			34.2.1.1 Surgery for movement disorders
		34.2.2 Neurophysiology and movement disorder surgery
		34.2.3 Theoretical basis for surgery in the basal ganglia
		34.2.4 Modern movement disorder surgery: general overview
			34.2.4.1 Anatomical targeting techniques
			34.2.4.2 Physiological targeting: recording techniques
				34.2.4.2.1 Impedance techniques
				34.2.4.2.2 Macroelectrode recording
				34.2.4.2.3 Semimicroelectrode technique
				34.2.4.2.4 Microelectrode techniques
				34.2.4.2.5 Local field potentials
	34.3 Operating room environment and basic equipment
		34.3.1 Operating room
			34.3.1.1 Electrical noise (recording only)
			34.3.1.2 Electrical noise (internal system influences)
		34.3.2 Recording electrodes
		34.3.3 Amplification
		34.3.4 Stimulation
	34.4 Technique for movement disorder surgery
		34.4.1 General stereotactic technique
			34.4.1.1 GPi procedures
			34.4.1.2 Ventral intermediate procedures
			34.4.1.3 Subthalamic nucleus procedures
	34.5 Conclusion
	References
35 Neurosurgical lesioning-procedures for spasticity and focal dystonia
	35.1 Introduction
	35.2 Lesioning procedures
		35.2.1 Peripheral neurotomies
		35.2.2 Dorsal rhizotomies
		35.2.3 Surgery in the dorsal root entry zone
			35.2.3.1 Microsurgical DREZotomy at the cervical level
			35.2.3.2 Microsurgical DREZotomy at the lumbosacral level
		35.2.4 Longitudinal myelotomies
	35.3 Intraoperative neurophysiology as an aid to surgery
	35.4 Indications for surgery
		35.4.1 Decision-making in adults
		35.4.2 Decision-making in children
	35.5 Conclusion
	References
36 Deep brain stimulation for treatment patients in vegetative state and minimally conscious state
	36.1 Introduction
	36.2 A short history of deep brain stimulation for vegetative state and minimally conscious state
	36.3 Patients and methods
	36.4 Neurological evaluation
	36.5 Selection criteria for deep brain stimulation unit implantation
	36.6 Surgical targeting and procedure
	36.7 Results
	36.8 Discussion
	36.9 Conclusion
	References
37 Neuromonitoring for spinal cord stimulation placement under general anesthesia
	37.1 Introduction
	37.2 Methods
		37.2.1 Compound muscle action potential system–based technique
			37.2.1.1 Recording
			37.2.1.2 Stimulation
		37.2.2 Collision-based technique
			37.2.2.1 Stimulation
			37.2.2.2 Recording
			37.2.2.3 Testing
		37.2.3 Stimulation intraoperative neurophysiology placement techniques
	37.3 Reliability of the techniques
	37.4 Conclusion
	References
38 Neurosurgical lesioning procedures in spinal cord and dorsal root entry zone for pain
	38.1 Introduction
	38.2 The surgical lesioning procedures directed to the spinal cord
	38.3 The procedures for dorsal root entry zone–lesioning
		38.3.1 The microsurgical DREZotomy
			38.3.1.1 Operative procedure at the cervical level and for brachial plexus avulsion
			38.3.1.2 Operative procedure at the lumbosacral level and for conus medullaris injury
			38.3.1.3 Microsurgical DREZotomy for pain resulting from peripheral nerve pathologies or as herpes zoster sequela
			38.3.1.4 Microsurgical DREZotomy pain in malignancies
		38.3.2 The dorsal root entry zone procedures with other lesion makers
			38.3.2.1 Radiofrequency thermocoagulation
			38.3.2.2 Dorsal root entry zone–lesioning with the laser beam
			38.3.2.3 Ultrasonic dorsal root entry zone–lesioning
	38.4 Intraoperative neurophysiology
		38.4.1 Neurophysiology as an aid to surgery
		38.4.2 Research methods
			38.4.2.1 Microelectrophysiology
			38.4.2.2 Microdialysis
	38.5 Conclusion
	References
39 Selective dorsal rhizotomy
	39.1 History
	39.2 Patient selection
	39.3 Surgery
	39.4 Physiotherapy
	39.5 Follow-up
	39.6 Results
	39.7 Complications
	39.8 Conclusion
	References
	Further reading
Part VI: Other Important Aspects of Intraoperative Neurophysiology
40 Principles of anesthesia
	40.1 Anesthesia: safety, comfort, and facilitation of the procedure
	40.2 Medical and physiological management
	40.3 Patient positioning
	40.4 Pharmacologic management
		40.4.1 Initial choice of anesthetic agents
		40.4.2 Choice of agents: behavioral goals
			40.4.2.1 Amnesia
			40.4.2.2 Unconsciousness
			40.4.2.3 Antinociception
			40.4.2.4 Immobility
	40.5 Conclusion: summary of anesthesia choice and management
	References
41 Safety
	41.1 Introduction
	41.2 Electrical safety
		41.2.1 Electric shock
			41.2.1.1 Risk of cardiac failure
			41.2.1.2 Leakage currents
			41.2.1.3 Means of protection against electric shock
				41.2.1.3.1 Single fault safe
				41.2.1.3.2 Leakage current limits
				41.2.1.3.3 Periodic inspection
				41.2.1.3.4 Power cords and lead connectors
		41.2.2 Hazardous output
			41.2.2.1 Parameters of electrical stimulation
			41.2.2.2 Strength–duration properties
			41.2.2.3 Protection against thermal injury
			41.2.2.4 Protection against excitotoxicity
			41.2.2.5 Protection against electrochemical toxicity
		41.2.3 Electrode burns
			41.2.3.1 Protection against stray electrosurgery current burns
			41.2.3.2 Protection against intraoperative magnetic resonance imaging burns
			41.2.3.3 Protection against direct current burns
		41.2.4 Fire
	41.3 Procedure-specific safety
		41.3.1 Invasive techniques
		41.3.2 Direct cortical stimulation
			41.3.2.1 Traditional 50–60Hz cortical stimulation
			41.3.2.2 Direct cortical stimulation for eliciting motor evoked potentials
		41.3.3 Direct subcortical stimulation
		41.3.4 Direct brainstem stimulation
		41.3.5 Direct spinal cord stimulation
		41.3.6 Transcranial electric stimulation for eliciting motor-evoked potentials
			41.3.6.1 Bite injuries
			41.3.6.2 Seizures
			41.3.6.3 Movement
			41.3.6.4 Other adverse effects
			41.3.6.5 Relative contraindications
		41.3.7 Somatosensory evoked potentials
		41.3.8 Brainstem auditory and visual evoked potentials
		41.3.9 Electromyography
	41.4 Infection control
		41.4.1 Standard precautions
		41.4.2 Needlestick
		41.4.3 Additional precautions
	41.5 Essential performance
		41.5.1 Monitoring device essential performance
		41.5.2 Monitoring practice essential performance
			41.5.2.1 Excessively slow feedback
			41.5.2.2 Incorrect interpretation
			41.5.2.3 Means of protection
	41.6 Conclusion
	References
42 Costs and benefits of intraoperative neurophysiological monitoring in spinal surgeries
	42.1 Introduction
	42.2 General considerations for cost-effectiveness analysis
	42.3 Cost-effectiveness analysis in spine ION
	42.4 Cost and outcomes research using “big data”
	42.5 Future directions in cost and outcomes research in ION for spine surgeries
	References
43 Evidence-based medicine and intraoperative neurophysiology
	43.1 Introduction
	43.2 Principles of evidence-based medicine
		43.2.1 All evidence is not created equal
		43.2.2 The totality of evidence is considered
		43.2.3 Patient values and quality of evidence determine the value of a treatment or practice
	43.3 Intraoperative neurophysiological monitoring and outcomes: back to basics for causal links
		43.3.1 Intraoperative neurophysiological monitoring has an indirect effect on outcomes
		43.3.2 Surgeons use intraoperative neurophysiological monitoring as surrogate endpoints
		43.3.3 Estimates of intraoperative neurophysiological monitoring treatment effects from comparative observational studies m...
	43.4 Evidence for improved outcomes with intraoperative neurophysiological monitoring
	43.5 How accurate are my SEPs and MEPs?
		43.5.1 The alert criterion and contingency results
		43.5.2 Positive prediction and likelihood
		43.5.3 Reversible signal change: approaches toward proper categorization
		43.5.4 Illustrative case series
		43.5.5 Diagnostic test accuracy and evidence-based medicine
		43.5.6 Diagnostic test accuracy and clinical efficacy
	43.6 Moving forward with the evidence base of intraoperative neurophysiological monitoring
	43.7 Glossary of contingency terms for intraoperative neurophysiological monitoring tests
	References
44 The intraoperative neurophysiological monitoring team
	44.1 Introduction: airliners and operating rooms
	44.2 ION teamwork and models of care
	44.3 Injury prediction versus injury prevention
	44.4 Systematic review of intraoperative teamwork
	44.5 Medical error avoidance
		44.5.1 Bias among peers
		44.5.2 Bias mitigation
		44.5.3 The ION interventional cascade and team-based communication cycle
	44.6 Optimizing current models of ION care
		44.6.1 Ideal model
		44.6.2 Challenged models
		44.6.3 Other (possibly acceptable) options
			44.6.3.1 Remote telepresence
			44.6.3.2 Advanced technologist training/credentials
			44.6.3.3 Surgeon supervised ION
			44.6.3.4 Semiautomated ION devices
	44.7 Conclusion
	References
Conclusion
Index
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