Neuromonitoring Cortical Mapping During Craniotomy Surgery MSET - - PowerPoint PPT Presentation
Intraoperative Neuromonitoring Cortical Mapping During Craniotomy Surgery MSET Annual Fall Meeting, 2017 Ryan Mandziara MS, CNIM Neuromonitoring Overview What? Application of neurophysiologic modalities to monitor the functional integrity of
MSET Annual Fall Meeting, 2017 Ryan Mandziara MS, CNIM
Application of neurophysiologic modalities to monitor the functional integrity of neural structures during surgery
Prevention of Iatrogenic injury and functional guidance
Neuro-, Orthopedic-, Vascular and ENT Surgery
SSEP, TCeMEP, EEG, EMG, BAEP, NAP, Mapping
Methods
Sensory Monitoring
Cortex
Motor and Muscle Monitoring
Combined approach to Cortical Mapping Anesthesia Protocol Case Study
Dorsal Column Pathway Medulla Cord Pons
Watt, J. (2016). SSEP Pathway, Waveforms and Generators. Retrieved from http://neurodiagnosticsolutions.com/course/view.php?id=2
MN Stimulation Results in Depolarization
Cortex PTN Stimulation Results in Depolarization
Cortex
Watt, J. (2016). SSEP Pathway, Waveforms and Generators. Retrieved from http://neurodiagnosticsolutions.com/course/view.php?id=2
Cortical SSEP Responses are Recorded from Subdermal needle electrodes placed according to 10-20 System v A sufficient number of repetitions must be averaged to produce an interpretable and reproducible SSEP. Generally 250 – 1000 repetitions are needed; the number of repetitions depends on the amount of noise present and the amplitude of the SSEP signal itself (signal to noise ratio).
ACNS Guideline 11B https://www.researchgate.net/figure/267306345_fig2_Figure-4-International-10-20-system-electrode-position
v
The first number/letter combination represents the actively recording lead and the second represents the reference recording lead
Fpz Cpz CP4 CP3 CS3 R EP L EP
Each peak and trough is designated by a letter/number combination. The letter P for positive, N for negative describes the polarity of the response (A Negative signal results in upward deflection, and a Positive signal results in downward deflection) So is there a net movement of electrons toward or away from the recording electrodes The number indicates the latency in milliseconds after stimulus presentation.
Methods
Sensory Monitoring
Cortex
Motor and Muscle Monitoring
Combined approach to Cortical Mapping Anesthesia Protocol Case Study
Corticospinal Tract
Figure 1.2. Adapted from Neuroanatomy, An Illustrated Colour Text, 4th Ed (Page 37), A. R.Crossman, D.Neary. Elsevier Publishing, 2010.
v
C3 and C4 Positions used to Evoke MEPs using Anodal Electrical Stimulation
C3 v C4 Anode = Right Side Motor Responses Anode = Left Side Motor Responses v C3 v C4
Motor Evoked Potentials
Generated over Motor Cortex and Recorded in all extremities
Methods
Sensory Monitoring
Cortex
Motor and Muscle Monitoring
Combined approach to Cortical Mapping Anesthesia Protocol Case Study
https://upload.wikimedia.org/wikipedia/commons/thumb/f/fe/Medulla_spinalis_-_tracts_-_English.svg/2000px-Medulla_spinalis_-_tracts_-_English.svg.png
Primary Motor Cortex (Post. Frontal Lobe) Primary Sensory Cortex (Ant. Parietal Lobe) Central Sulcus
Axial MRI +DTI Coronal MRI With DTI Sagittal MRI with Tumor Reconstruction 3D rendering with DTI Tumor Reconstruction
Watt, J. (2016). SSEP Pathway, Waveforms and Generators. Retrieved from http://neurodiagnosticsolutions.com/course/view.php?id=2
https://assets.ysjournal.com/wp-content/uploads/2016/04/brain-990x622.png
http://pediatricsnationwide.org/2016/10/18/in-sight-two-stage-surgery-for-epilepsy/
Post. Ant.
Phase Reversal Theory Dipole Characteristic of Brodmann’s Area 1, 3a, 3b.
Advanced IONM, Brain Mapping Presentation, Gertsch (2017) ASET Annual Conference
https://assets.ysjournal.com/wp-content/uploads/2016/04/brain-990x622.png
ECoG Electrical Stimulation
Resection of Frontal Lobe Tumor Areas Involved in upper and lower extremity motor function are discovered using the mapping technique described. Tumor resection (anterior to “Hand” and Lleg” markings) may be conducted with new motor deficit being unlikely.
Subcortical Stimulation
http://www.en.inomed.com/fileadmin/_processed_/csm_Anwendung_Mappin gsauger_2_web_e203b88c15.jpg
Patients whom subcortical MEPs were recorded, the mean stimulus intensity was 10.4 ± 5.2 mA and the mean distance from the probe tip to the corticospinal tract (CST) was 7.4 ±4.5 mm. There was a trend toward worsening neurological deficits if the distance to the CST was short (<5mm), and a small minimum stimulation threshold was recorded. (1mA : ~1 to 1.5mm)
Subcortical Stimulation
Sample Anesthesia Technique
Induction 0.5 μg/kg sufentanil, 2 mg/kg propofol, 2 mg midazolam, 20 mg pepcid, and 0.6 mg/kg rocuronium (a very short-acting muscle relaxant) are initially used. Scalp Block approximately 30 ml of 0.5% ropivacaine with epinephrine in a 1:200,000 ratio to the greater/lesser occipital, auricular-temporal, zygomatic-temporal, V1, and supratrochlear nerves, respectively. Maintenance 50 μg/kg/min propofol, 0.05 μg/kg/min remifentanil, approximately 0.5%–0.6% isoflurane, and 50% oxygen/50% air. No additional muscle Relaxants used during surgery.