Ignite Creation Date:
2024-07-17 @ 11:00 AM
Last Modification Date:
2024-10-26 @ 3:33 PM
Study NCT ID:
NCT06480370
Status:
NOT_YET_RECRUITING
Last Update Posted:
2024-06-28
First Post:
2024-06-24
Brief Title:
Optimization of Transcranial Motor Evoked Potentials in Supratentorial Surgeries
Sponsor:
Insel Gruppe AG University Hospital Bern
Organization:
Insel Gruppe AG University Hospital Bern
Study Overview
Official Title:
Optimization of Transcranial Motor Evoked Potentials in Supratentorial Surgeries
Status:
NOT_YET_RECRUITING
Status Verified Date:
2024-06
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
MEPO
Brief Summary:
This project aims to optimize the methodology to elicite transcranial motor evoked potentials in intraoperative neurophysiological monitoring of brain surgery It includes accelerometer measurements and microscope video image to determine movement of the surgical field making possible minimization of movement during brain stimulation
Detailed Description:
Background During supratentorial brain surgery there is a risk of iatrogenic injury resulting in post-operative motor deficits Intraoperative neurophysiological monitoring IONM can help surgeons avoid this outcome while also expanding evidence of its prognostic and preventive benefit 1 2 However there are still pending issues such as standardization of optimal methodologies for data acquisition and interpretation as well as technical improvement
There are two main IONM strategies mapping to localize nervous structures and monitoring to provide real-time assessment of functional integrity 3 With respect to monitoring muscle motor evoked potentials MEPs enable motor system assessment They can be elicited by pulse train transcranial electric stimulation TES through scalp electrodes placed at standard 10-20 system sites C1 C2 C3 C4 Cz-1cm Cz6cm or at neuronavigation-guided scalp sites The stimulation circuit consists of the user-selected anode and cathode sites chosen from the scalp electrodes 4 The stimulation parameters are user-selected pulse duration interstimulus interval ISI number of pulses and single train stimulation vs double-train or multi-train facilitation MEP threshold is the stimulation intensity required to elicit a certain number of MEPs with a predefined amplitude The recording montage consists of user-selected recording electrode orientation and target muscles Practitioner preferences for these technical aspects vary widely 5 and can influence monitoring efficacy
During surgery significant MEP deterioration from an earlier baseline indicates a warning based on various criteria such as amplitude reduction or threshold elevation 2 Warnings trigger rescue manoeuvres to recover MEPs With reversible MEP deterioration recovery to values above the warning level a post-operative motor deficit might be prevented Continuous real-time monitoring facilitates this favourable result by providing early warnings and is therefore important With irreversible MEP deterioration there is an increased risk of a motor deficit 1 and discontinuous intermittent monitoring may fail to help prevent this adverse outcome
A major concern regarding TES MEPs is that the stimuli often produce movement of the surgical field which entails the risk of the patient being harmed by surgical manoeuvres if they are not paused during the measurements 4 This can delay the surgical procedure andor preclude real-time monitoring Thus there is a need to establish optimal TES MEP methodology that minimizes objectively assessed movement
Objective The hypothesis of this project is that MEP stimulation and recording paradigms can be optimized to minimize movement of the surgical field during supratentorial brain surgery Consequently the overall aim is to identify the most effective stimulation and recording techniques to maximize TES MEP performance by minimizing movement The specific objectives are to determine
1 The best stimulation circuit to elicit MEPs with the lowest possible movement
2 The best stimulation parameters to elicit MEPs with the lowest possible movement
3 The best recording montages to obtain MEPs with the lowest possible stimulation threshold
Methods General methods Adult patients undergoing routine brain surgery with IONM and giving informed consent will be eligible Muscle MEP recordings will be performed from limbs ipsilateral to the operation side Patients with preoperative ipsilateral motor impairment will be excluded Movement and MEP threshold will be the primary endpoints Movement will be assessed through one accelerometer on the forehead with quantification through kinetic energy For comparison secondary endpoint another accelerometer on the ipsilateral shoulder to the recording site will be used as well as the subjective evaluation by the surgeon on an ordinal scale through visualization of the surgical field Additionally we propose to quantify the magnitude of motion using post-processing of digital images from the surgical microscope
Comparative analyses of movement and MEP thresholds will be performed by successively varying one of the variables and keeping the others at Inselspital standard Videos of the surgical field will be recorded with the microscope for all the proposed experimental setups to recover the images for the quantification of the movement
The study will be divided into four different parts each of them with different steps outlined below Consequently each patient participates in a specific part and stepThis subdivision is necessary due to time constraints in the operating room as it would not be feasible to perform all the different combinations on every patient
Patients who have already been included in the study and require a redo surgery will also be eligible for inclusion in a different part or step of the study
Threshold current will be defined as the minimum current to elicit MEP responses with an amplitude higher than 20 µV in at least 5 consecutive trials The procedure will be to increase current until MEPs appear then reduce current until they disappear and then finely adjust current to the minimum for a consistent response
Part 1 determination of the best stimulation circuit Step 1 - comparison of 10-20 system stimulation circuits Evaluation of 12 patients Circuits of C1C2 C3C4 and C3 or C4Cz-1cm for upper limb MEPs and C1C2 C3C4 and Cz-1cmCz6cm for lower limb MEPs Acquisition of 12 MEPs per limb with each circuit
Step 2 - comparison of the best Step 1 circuit to the neuronavigation-guided stimulation circuit Evaluation of 16 patients Acquisition of 22 upper limb MEPs with each circuit
Part 2 determination of the best stimulation parameters Step 1 - comparison of different pulse durations Evaluation of 21 patients Pulse duration of 100 200 350 500 650 800 and 1000 µs Acquisition of 21 upper limb MEPs with each pulse duration
Step 2 - comparison of different ISIs Evaluation of 30 patients 15 per limb ISI of 1 2 3 4 and 5 ms Acquisition of 20 upper and lower limb MEPs with each ISI
Step 3 - comparison of different numbers of pulses Evaluation of 15 patients Number of pulses of 3 4 5 7 and 9 Acquisition of 20 upper limb MEPs with each number of pulses
Step 4 - comparison of single train to double-train facilitation at different inter train intervals ITIs Evaluation of 21 patients Single train double train 27 and 44 pulses ITI of 20 85 and 150 ms Acquisition of 21 upper limb MEPs with each paradigm
Step 5 - comparison of single train to multi-train facilitation at different rates Evaluation of 21 patients Single train at rate of 05 Hz Multi-train facilitation at rates of 1 2 3 4 5 and 6 Hz Acquisition of 21 upper limb MEPs with each paradigm
Part 3 determination of the best recording montages Step 1 - comparison of recording electrode orientations Evaluation of 12 patients Recordings from extensor digitorum communis EDC and tibialis anterior TA Three recording orientations 1 bipolar perpendicular to muscle fibres 2 bipolar parallel to muscle fibres and 3 referential to the distal muscle tendon Determination of threshold per orientation within each muscle
Step 2 - determination of muscles of choice in distal upper limbs Evaluation of 21 patients Recordings from abductor pollicis brevis APB abductor digiti minimi ADM first dorsal interosseous EDC flexor carpi radialis FCR APBADM and EDCFCR Determination of threshold for all muscles
Step 3 - determination of muscles of choice in distal lower limbs Evaluation of 18 patients Recordings from abductor hallucis AH extensor digitorum brevis EDB TA soleus AHEDB and TAsoleus Determination of threshold for all muscles
Part 4 Evaluation of 16 patients Comparison of best stimulation and recording methodology from the results of Parts 1 to 3 with the current standard in our department Acquisition of 22 MEPs per limb by paradigm
There are two main IONM strategies mapping to localize nervous structures and monitoring to provide real-time assessment of functional integrity 3 With respect to monitoring muscle motor evoked potentials MEPs enable motor system assessment They can be elicited by pulse train transcranial electric stimulation TES through scalp electrodes placed at standard 10-20 system sites C1 C2 C3 C4 Cz-1cm Cz6cm or at neuronavigation-guided scalp sites The stimulation circuit consists of the user-selected anode and cathode sites chosen from the scalp electrodes 4 The stimulation parameters are user-selected pulse duration interstimulus interval ISI number of pulses and single train stimulation vs double-train or multi-train facilitation MEP threshold is the stimulation intensity required to elicit a certain number of MEPs with a predefined amplitude The recording montage consists of user-selected recording electrode orientation and target muscles Practitioner preferences for these technical aspects vary widely 5 and can influence monitoring efficacy
During surgery significant MEP deterioration from an earlier baseline indicates a warning based on various criteria such as amplitude reduction or threshold elevation 2 Warnings trigger rescue manoeuvres to recover MEPs With reversible MEP deterioration recovery to values above the warning level a post-operative motor deficit might be prevented Continuous real-time monitoring facilitates this favourable result by providing early warnings and is therefore important With irreversible MEP deterioration there is an increased risk of a motor deficit 1 and discontinuous intermittent monitoring may fail to help prevent this adverse outcome
A major concern regarding TES MEPs is that the stimuli often produce movement of the surgical field which entails the risk of the patient being harmed by surgical manoeuvres if they are not paused during the measurements 4 This can delay the surgical procedure andor preclude real-time monitoring Thus there is a need to establish optimal TES MEP methodology that minimizes objectively assessed movement
Objective The hypothesis of this project is that MEP stimulation and recording paradigms can be optimized to minimize movement of the surgical field during supratentorial brain surgery Consequently the overall aim is to identify the most effective stimulation and recording techniques to maximize TES MEP performance by minimizing movement The specific objectives are to determine
1 The best stimulation circuit to elicit MEPs with the lowest possible movement
2 The best stimulation parameters to elicit MEPs with the lowest possible movement
3 The best recording montages to obtain MEPs with the lowest possible stimulation threshold
Methods General methods Adult patients undergoing routine brain surgery with IONM and giving informed consent will be eligible Muscle MEP recordings will be performed from limbs ipsilateral to the operation side Patients with preoperative ipsilateral motor impairment will be excluded Movement and MEP threshold will be the primary endpoints Movement will be assessed through one accelerometer on the forehead with quantification through kinetic energy For comparison secondary endpoint another accelerometer on the ipsilateral shoulder to the recording site will be used as well as the subjective evaluation by the surgeon on an ordinal scale through visualization of the surgical field Additionally we propose to quantify the magnitude of motion using post-processing of digital images from the surgical microscope
Comparative analyses of movement and MEP thresholds will be performed by successively varying one of the variables and keeping the others at Inselspital standard Videos of the surgical field will be recorded with the microscope for all the proposed experimental setups to recover the images for the quantification of the movement
The study will be divided into four different parts each of them with different steps outlined below Consequently each patient participates in a specific part and stepThis subdivision is necessary due to time constraints in the operating room as it would not be feasible to perform all the different combinations on every patient
Patients who have already been included in the study and require a redo surgery will also be eligible for inclusion in a different part or step of the study
Threshold current will be defined as the minimum current to elicit MEP responses with an amplitude higher than 20 µV in at least 5 consecutive trials The procedure will be to increase current until MEPs appear then reduce current until they disappear and then finely adjust current to the minimum for a consistent response
Part 1 determination of the best stimulation circuit Step 1 - comparison of 10-20 system stimulation circuits Evaluation of 12 patients Circuits of C1C2 C3C4 and C3 or C4Cz-1cm for upper limb MEPs and C1C2 C3C4 and Cz-1cmCz6cm for lower limb MEPs Acquisition of 12 MEPs per limb with each circuit
Step 2 - comparison of the best Step 1 circuit to the neuronavigation-guided stimulation circuit Evaluation of 16 patients Acquisition of 22 upper limb MEPs with each circuit
Part 2 determination of the best stimulation parameters Step 1 - comparison of different pulse durations Evaluation of 21 patients Pulse duration of 100 200 350 500 650 800 and 1000 µs Acquisition of 21 upper limb MEPs with each pulse duration
Step 2 - comparison of different ISIs Evaluation of 30 patients 15 per limb ISI of 1 2 3 4 and 5 ms Acquisition of 20 upper and lower limb MEPs with each ISI
Step 3 - comparison of different numbers of pulses Evaluation of 15 patients Number of pulses of 3 4 5 7 and 9 Acquisition of 20 upper limb MEPs with each number of pulses
Step 4 - comparison of single train to double-train facilitation at different inter train intervals ITIs Evaluation of 21 patients Single train double train 27 and 44 pulses ITI of 20 85 and 150 ms Acquisition of 21 upper limb MEPs with each paradigm
Step 5 - comparison of single train to multi-train facilitation at different rates Evaluation of 21 patients Single train at rate of 05 Hz Multi-train facilitation at rates of 1 2 3 4 5 and 6 Hz Acquisition of 21 upper limb MEPs with each paradigm
Part 3 determination of the best recording montages Step 1 - comparison of recording electrode orientations Evaluation of 12 patients Recordings from extensor digitorum communis EDC and tibialis anterior TA Three recording orientations 1 bipolar perpendicular to muscle fibres 2 bipolar parallel to muscle fibres and 3 referential to the distal muscle tendon Determination of threshold per orientation within each muscle
Step 2 - determination of muscles of choice in distal upper limbs Evaluation of 21 patients Recordings from abductor pollicis brevis APB abductor digiti minimi ADM first dorsal interosseous EDC flexor carpi radialis FCR APBADM and EDCFCR Determination of threshold for all muscles
Step 3 - determination of muscles of choice in distal lower limbs Evaluation of 18 patients Recordings from abductor hallucis AH extensor digitorum brevis EDB TA soleus AHEDB and TAsoleus Determination of threshold for all muscles
Part 4 Evaluation of 16 patients Comparison of best stimulation and recording methodology from the results of Parts 1 to 3 with the current standard in our department Acquisition of 22 MEPs per limb by paradigm
Study Oversight
Has Oversight DMC:
None
Is a FDA Regulated Drug?:
False
Is a FDA Regulated Device?:
False
Is an Unapproved Device?:
None
Is a PPSD?:
None
Is a US Export?:
None
Is an FDA AA801 Violation?:
None