EP-4739213-A1 - INTRA-OPERATIVE LOWER SPINE MOTOR INTEGRITY MONITORING THROUGH TRANS-SPINAL STIMULATION

Abstract

Certain aspects of the present disclosure provide techniques for monitoring reflexive motor responses in a patient during a surgery on the patient. A method includes stimulating at least one cathodal electrode over a thoracic spinal region of the back of the patient with at least one anodal electrode over at least one anterior superior iliac crest area of the patient. The method includes detecting, with at least one recording electrode on at least one leg of the patient, one or more resulting muscle response electrical waveforms from one or more muscles of one or more lower extremities of the patient.

Inventors

• O'BRIEN, Richard Arthur
• SNOW, ROBERT GERARD

Assignees

• Alphatec Spine, Inc.

Dates

Publication Date

20260513

Application Date

20240628

Claims (1)

1. ATEC Ref. No.: 0222WO WHAT IS CLAIMED IS: 1. A method of monitoring reflexive motor responses in a patient during a surgery on the patient, the method comprising: stimulating with one or more pulses a thoracic spinal region of a back of the patient using at least one cathodal electrode positioned thereon and at least one anodal electrode positioned over at least one anterior superior iliac crest area of the patient, where the one or more pulses has a duration of at least 500 µs; and detecting, with at least one recording electrode on at least one leg of the patient, one or more resulting muscle response electrical waveforms from one or more muscles of one or more lower extremities of the patient. 2. The method of claim 1, wherein stimulating the at least one cathodal electrode comprises stimulating the at least one cathodal electrode cutaneously. 3. The method of any combination of claims 1-2, wherein stimulating the at least one cathodal electrode comprises stimulating the at least one cathodal electrode subcutaneously. 4. The method of any combination of claims 1-3, wherein the at least one cathodal electrode is located at or between the tenth, eleventh, or twelfth thoracic vertebrae of the patient. 5. The method of any combination of claims 1-4, further comprising a pair of cathodal electrodes located at the high thoracic or low cervical spinal region of the patient. 6. The method of any combination of claims 1-5, wherein the at least one cathodal electrode comprises a first pair of cathodal electrodes located on opposite sides of the thoracic spinal region of the back of the patient. 7. The method of claim 6, wherein the at least one cathodal electrode further comprises a second pair of cathodal electrodes located on opposite sides of the thoracic spinal region of the back of the patient above or below the first pair of cathodal electrodes. Dentons Ref. No.: 54530-3028WOU1 28 SL_6523603.1 ATEC Ref. No.: 0222WO 8. The method of claim 7, wherein the stimulating the at least one cathodal electrode comprises alternating between stimulating the first pair of cathodal electrodes and the second pair of cathodal electrodes. 9. The method of any combination of claims 1-8, further comprising: determining, by a computing device in communication with the at least one recording electrode, the at least one cathodal electrode to stimulate, from a plurality of cathodal electrodes over the thoracic spinal region of the back of the patient. 10. The method of claim 9, wherein determining the at least one cathodal electrode to stimulate comprises determining the at least one cathodal electrode to stimulate based on the one or more muscles to be monitored. 11. The method of any combination of claims 1-10, further comprising a pair of anodal electrodes positioned over the cranium of the patient. 12. The method of any combination of claims 1-11, wherein the pair of anodal electrodes are positioned over both temporal bones of the cranium of the patient. 13. The method of any combination of claims 1-12, wherein the at least one anodal electrode comprises a pair of anodal electrodes positioned over both anterior superior iliac crest areas of the patient. 14. The method of any combination of claims 1-13, wherein stimulating at least one cathodal electrode with the at least one anodal electrode comprises alternating stimulating with a first anodal electrode of a pair of anodal electrodes and a second anodal electrode of the pair of anodal electrodes. 15. The method of any combination of claims 1-14, wherein the at least one recording electrode is coupled to at least one muscle of the one or more lower extremities of the patient. Dentons Ref. No.: 54530-3028WOU1 29 SL_6523603.1 ATEC Ref. No.: 0222WO 16. The method of any combination of claims 1-15, further comprising: prior to the stimulating the at least one cathodal electrode with the at least one anodal electrode, stimulating one or more lower extremities of the patient using one or more peripheral electrodes located on the one or more lower extremities. 17. The method of claim 16, further comprising selecting the one or more peripheral electrodes to stimulate to enhance the one or more resulting muscle response electrical waveforms from the one or more muscles of the one or more lower extremities of the patient. 18. The method of any combination of claims 16-17, wherein the stimulating using the at least one cathodal electrode is performed after an inter-stimulus interval (ISI) after the stimulating using the one or more peripheral electrodes. 19. The method of any combination of claims 1-18, further comprising: determining, by a computing device in communication with the at least one recording electrode, an inadequacy of one or more resulting muscle response electrical waveforms from the one or more muscles of the one or more lower extremities of the patient; and stimulating the one or more lower extremities of the patient using one or more peripheral electrodes in response to the determination. 20. The method of any combination of claims 16-19, further comprising determining, by the computing device, one or more of: a number of priming pulses, a duration of the priming pulses, a frequency of the priming pulses, and an intensity of the priming pulses used to stimulate the one or more peripheral electrodes. 21. The method of any combination of claims 1-20, further comprising determining, by a computing device in communication with the at least one recording electrode, one or more of: a number of pulses, a duration of the pulses, a frequency of the pulses, and an intensity of the pulses used to stimulate using the at least one cathodal electrode with the at least one anodal electrode. Dentons Ref. No.: 54530-3028WOU1 30 SL_6523603.1 ATEC Ref. No.: 0222WO 22. The method of claim 21, wherein the determining is based on a target latency and amplitude of one or more components of the resulting muscle response electrical waveforms in response to the stimulating. 23. The method of claim 22, wherein the determining comprises: using a first intensity of the pulses used to stimulate using the at least one cathodal electrode with the at least one anodal electrode; when a first latency and amplitude of a first one or more resulting muscle response electrical waveforms does not satisfy the target latency and amplitude, using a second intensity of the pulses used to stimulate the at least one cathodal electrode with the at least one anodal electrode, wherein the second intensity is higher than the first intensity; and when the first latency and amplitude of the first one or more resulting components of the muscle response electrical waveforms satisfies the target latency and amplitude, using the first intensity of the pulses used to stimulate the at least one cathodal electrode with the at least one anodal electrode. 24. The method of any combination of claims 1-23, further comprising: determining pre-operatively, by a computing device in communication with the at least one recording electrode, a first stimulation pattern to be used during the surgery; and determining, during the surgery, a second stimulation pattern to be used during the surgery. 25. The method of any combination of claims 1-24, further comprising receiving input from a user to perform the stimulating the at least one cathodal electrode with the at least one anodal electrode, wherein the stimulating is in response to the user input. 26. The method of any combination of claims 1-25, further comprising detecting, by a computing device in communication with the at least one recording electrode, a change in the resulting muscle response electrical waveforms and their components over time or compared to a baseline established pre-operatively, wherein the Dentons Ref. No.: 54530-3028WOU1 31 SL_6523603.1 ATEC Ref. No.: 0222WO change comprises one or more of: a changed latency, amplitude, and morphology of the resulting muscle response electrical waveforms and their components. 27. The method of claim 26, further comprising identifying, by the computing device, an injury or potential injury along a motor pathway associated with the one or more muscles. 28. The method of claim 27, further comprising forwarding, by the computing device to a display, an alert associated with an identified injury or potential injury. 29. The method of any combination of claims 27-28, further comprising generating a recommended action to ameliorate the identified injury or potential injury. 30. The method of any combination of claims 26-29, further comprising forwarding, by the computing device to a display, one or more of: the resulting muscle response electrical waveforms and an anatomical diagram depicting a location of the detected change in the resulting muscle response electrical waveforms. 31. The method of any combination of claims 26-30, further comprising: obtaining information from one or more of: an anesthesia machine, a neuromuscular junction testing machine, an oximetry machine, and a blood pressure machine; and determining, based on the information, whether the changes in the resulting muscle response electrical waveforms are due to one or more of: anesthesia, a paralytic effect, blood pressure, and perfusion changes. 32. The method of any combination of claims 26-31, further comprising averaging multiple resulting muscle response electrical waveforms obtained in response to performing multiple stimulations of the at least one cathodal electrode with the at least one anodal electrode to reduce noise. Dentons Ref. No.: 54530-3028WOU1 32 SL_6523603.1 ATEC Ref. No.: 0222WO 33. The method of any combination of claims 1-32, further comprising receiving a user input indicating an accuracy of the resulting muscle response electrical waveforms. 34. The method of any combination of claims 1-33, wherein the patient is in a prone, supine, or lateral position. 35. The method of any combination of claims 1-34, wherein the surgery comprises a lumbar surgery or a cervical surgery. 36. An apparatus for monitoring reflexive motor responses in a patient during a surgery on the patient, the apparatus comprising: a memory comprising computer-executable instructions; and at least one processor configured to execute the computer-executable instructions and cause the apparatus to: stimulate a thoracic spinal region of the back of the patient with one or more pulses provided by at least one cathodal electrode positioned near the thoracic spinal region and at least one anodal electrode positioned over at least one anterior superior iliac crest area of the patient, the one or more pulses having a duration of at least 500 µs; and obtain, from at least one recording electrode on at least one leg of the patient, one or more resulting muscle response electrical waveforms from one or more muscles of one or more lower extremities of the patient. 37. A system for monitoring reflexive motor responses in a patient during a surgery on the patient, the system comprising: one or more cathodal electrodes positioned over a thoracic spinal region of the back of the patient; one or more anodal electrodes positioned over at least one anterior superior iliac crest area of the patient; one or more recording electrodes positioned on at least one leg of the patient; and a computing device configured to: Dentons Ref. No.: 54530-3028WOU1 33 SL_6523603.1 ATEC Ref. No.: 0222WO stimulate the thoracic spinal region with one or more pulses using at least one of the one or more cathodal electrodes with at least one of the one or more anodal electrodes, wherein the one or more pulses have a duration of at least 500 µs; and obtain, from at least one of the one or more recording electrodes, one or more resulting muscle response electrical waveforms from one or more muscles of one or more lower extremities of the patient. 38. A method of monitoring reflexive motor responses in a patient during a surgery on the patient, the method comprising: stimulating with one or more pulses a high thoracic or low cervical spinal region of the back of the patient using at least one cathodal electrode positioned thereon and at least one anodal electrode positioned over at least one temporal bone of the patient, where the one or more pulses has a duration of at least 500 µs; and detecting, with at least one recording electrode on one or more upper extremities of the patient, one or more resulting muscle response electrical waveforms from one or more muscles. 39. The method of claim 38, wherein stimulating the at least one cathodal electrode comprises stimulating the at least one cathodal electrode cutaneously. 40. The method of any combination of claims 38-39, wherein stimulating the at least one cathodal electrode comprises stimulating the at least one cathodal electrode subcutaneously. 41. The method of any combination of claims 38-40, wherein the at least one cathodal electrode comprises a pair of cathodal electrodes located at the high thoracic or low cervical spinal region of the patient. 42. The method of any combination of claims 38-41, further comprising at least one cathodal electrode located at or between the tenth, eleventh, or twelfth thoracic vertebrae of the patient. Dentons Ref. No.: 54530-3028WOU1 34 SL_6523603.1 ATEC Ref. No.: 0222WO 43. The method of any combination of claims 38-42, wherein the at least one cathodal electrode comprises a first pair of cathodal electrodes located on opposite sides of the thoracic spinal region of the back of the patient. 44. The method of claim 43, wherein the at least one cathodal electrode further comprises a second pair of cathodal electrodes located on opposite sides of the thoracic spinal region of the back of the patient above or below the first pair of cathodal electrodes. 45. The method of claim 44, wherein the stimulating the at least one cathodal electrode comprises alternating between stimulating the first pair of cathodal electrodes and the second pair of cathodal electrodes. 46. The method of any combination of claims 38-45, further comprising: determining, by a computing device in communication with the at least one recording electrode, the at least one cathodal electrode to stimulate, from a plurality of cathodal electrodes. 47. The method of claim 46, wherein determining the at least one cathodal electrode to stimulate comprises determining the at least one cathodal electrode to stimulate based on the one or more muscles to be monitored. 48. The method of any combination of claims 38-47, wherein the at least one anodal electrode comprises a pair of anodal electrodes positioned over each temporal bone of the patient. 49. The method of any combination of claims 38-48, further comprising a pair of anodal electrodes positioned over both anterior superior iliac crest areas of the patient. 50. The method of any combination of claims 38-49, wherein stimulating at least one cathodal electrode with the at least one anodal electrode comprises alternating stimulating with a first anodal electrode of a pair of anodal electrodes and a second anodal electrode of the pair of anodal electrodes. Dentons Ref. No.: 54530-3028WOU1 35 SL_6523603.1 ATEC Ref. No.: 0222WO 51. The method of any combination of claims 38-50, wherein the at least one recording electrode is coupled to at least one muscle of the arm of the patient. 52. The method of any combination of claims 38-50, wherein the at least one recording electrode is coupled near an ulnar nerve of the patient. 53. The method of any combination of claims 38-52, further comprising: prior to the stimulating the at least one cathodal electrode with the at least one anodal electrode, stimulating one or more extremities of the patient using one or more peripheral electrodes located on the one or more extremities. 54. The method of claim 53, further comprising selecting the one or more peripheral electrodes to stimulate to enhance the one or more resulting muscle response electrical waveforms from the one or more muscles of the one or more extremities of the patient. 55. The method of any combination of claims 53-54, wherein the stimulating using the at least one cathodal electrode is performed after an inter-stimulus interval (ISI) after the stimulating using the one or more peripheral electrodes. 56. The method of any combination of claims 38-55, further comprising: determining, by a computing device in communication with the at least one recording electrode, the inadequacy of one or more resulting muscle response electrical waveforms from the one or more muscles of the one or more extremities of the patient; and stimulating the one or more lower of the patient using one or more peripheral electrodes in response to the determination. 57. The method of any combination of claims 53-56, further comprising determining, by the computing device, one or more of: a number of priming pulses, a duration of the priming pulses, a frequency of the priming pulses, and an intensity of the priming pulses used to stimulate the one or more peripheral electrodes. Dentons Ref. No.: 54530-3028WOU1 36 SL_6523603.1 ATEC Ref. No.: 0222WO 58. The method of any combination of claims 38-57, further comprising determining, by a computing device in communication with the at least one recording electrode, one or more of: a number of pulses, a duration of the pulses, a frequency of the pulses, and an intensity of the pulses used to stimulate using the at least one cathodal electrode with the at least one anodal electrode. 59. The method of claim 58, wherein the determining is based on a target latency and amplitude of the one or more components of the resulting muscle response electrical waveforms in response to the stimulating. 60. The method of claim 59, wherein the determining comprises: using a first intensity of the pulses used to stimulate using the at least one cathodal electrode with the at least one anodal electrode; when a first latency and amplitude of a first one or more resulting muscle response electrical waveforms does not satisfy the target latency and amplitude, using a second intensity of the pulses used to stimulate the at least one cathodal electrode with the at least one anodal electrode, wherein the second intensity is higher than the first intensity; and when the first latency and amplitude of the first one or more resulting components of the muscle response electrical waveforms satisfies the target latency and amplitude, using the first intensity of the pulses used to stimulate the at least one cathodal electrode with the at least one anodal electrode. 61. The method of any combination of claims 38-60, further comprising: determining pre-operatively, by a computing device in communication with the at least one recording electrode, a first stimulation pattern to be used during the surgery; and determining, during the surgery, a second stimulation pattern to be used during the surgery. 62. The method of any combination of claims 38-61, further comprising receiving input from a user to perform the stimulating the at least one cathodal electrode with the at least one anodal electrode, wherein the stimulating is in response to the user input. Dentons Ref. No.: 54530-3028WOU1 37 SL_6523603.1 ATEC Ref. No.: 0222WO 63. The method of any combination of claims 38-62, further comprising detecting, by a computing device in communication with the at least one recording electrode, a change in the resulting muscle response electrical waveforms and their components over time or compared to a baseline established pre-operatively, wherein the change comprises one or more of: a changed latency, amplitude, and morphology of the resulting muscle response electrical waveforms and their components. 64. The method of claim 63, further comprising identifying, by the computing device, an injury or potential injury along a motor pathway associated with the one or more muscles. 65. The method of claim 64, further comprising forwarding, by the computing device to a display, an alert associated with the identified injury or potential injury. 66. The method of any combination of claims 64-65, further comprising generating a recommended action to ameliorate the identified injury or potential injury. 67. The method of any combination of claims 63-66, further comprising forwarding, by the computing device to a display, one or more of: the resulting muscle response electrical waveforms and an anatomical diagram depicting a location of the detected change in the resulting muscle response electrical waveforms. 68. The method of any combination of claims 63-67, further comprising: obtaining information from one or more of: an anesthesia machine, a neuromuscular junction testing machine, an oximetry machine, and a blood pressure machine; and determining, based on the information, whether the changes in the resulting muscle response electrical waveforms are due to one or more of: anesthesia, a paralytic effect, blood pressure, and perfusion changes. 69. The method of any combination of claims 63-68, further comprising averaging multiple resulting muscle response electrical waveforms obtained in response to Dentons Ref. No.: 54530-3028WOU1 38 SL_6523603.1 ATEC Ref. No.: 0222WO performing multiple stimulations of the at least one cathodal electrode with the at least one anodal electrode to reduce noise. 70. The method of any combination of claims 38-69, further comprising receiving a user input indicating an accuracy of the resulting muscle response electrical waveforms. 71. The method of any combination of claims 38-70, wherein the patient is in a prone, supine, or lateral position. 72. The method of any combination of claims 38-71, wherein the surgery comprises a lumbar surgery. 73. The method of any combination of claims 38-72, wherein the high thoracic or low cervical spinal region of the back of the patient comprises a region at or between the C5-T3 vertebrae of the patient. 74. The method of any combination of claims 38-73, wherein the one or more upper extremities of the patient comprises at least one of the arms, wrists, or region near the ulnar nerve of the patient. 75. The method of any combination of claims 38-74, wherein the at least one anodal electrode is positioned over a mastoid process of the temporal bone of the patient. 76. An apparatus for monitoring reflexive motor responses in a patient during a surgery on the patient, the apparatus comprising: a memory comprising computer-executable instructions; and at least one processor configured to execute the computer-executable instructions and cause the apparatus to: stimulate a high thoracic or low cervical spinal region of the back of the patient with one or more pulses provided by at least one cathodal electrode positioned near the cervical spinal region and at least one anodal electrode positioned over at least temporal bone of the patient, the one or more pulses having a duration of at least 500 µs; and Dentons Ref. No.: 54530-3028WOU1 39 SL_6523603.1 ATEC Ref. No.: 0222WO obtain, from at least one recording electrode on one or more upper extremities of the patient, one or more resulting muscle response electrical waveforms from one or more muscles of one or more extremities of the patient. 77. A system for monitoring reflexive motor responses in a patient during a surgery on the patient, the system comprising: one or more cathodal electrodes positioned over a high thoracic or low cervical spinal region of the back of the patient; one or more anodal electrodes positioned over at least temporal bone of the patient; one or more recording electrodes positioned on one or more upper extremities of the patient; and a computing device configured to: stimulate the cervical spinal region with one or more pulses using at least one of the one or more cathodal electrodes with at least one of the one or more anodal electrodes, wherein the one or more pulses have a duration of at least 500 µs; and obtain, from at least one of the one or more recording electrodes, one or more resulting muscle response electrical waveforms from one or more muscles of one or more extremities of the patient. Dentons Ref. No.: 54530-3028WOU1 40 SL_6523603.1

Description

ATEC Ref. No.: 0222WO INTRA-OPERATIVE LOWER SPINE MOTOR INTEGRITY MONITORING THROUGH TRANS-SPINAL STIMULATION CROSS REFERENCE TO RELATED MATTER This application claims the benefit of U.S. Provisional Application No. 63/511,971, filed on July 5, 2023, titled INTRA-OPERATIVE LOWER SPINE MOTOR INTEGRITY MONITORING THROUGH TRANS-SPINAL STIMULATION, and is hereby incorporated by reference herein in its entirety. BACKGROUND Field of the Disclosure Aspects of the present disclosure relate to neurophysiological monitoring, and more particularly, to techniques for intra-operative monitoring of the nervous system during surgeries where the nervous system may be at risk. Description of Related Art Certain surgeries, such as lumbar surgery or cervical surgery, risk damage to the patient’s nervous system. Lumbar surgery, also known as lumbar spine surgery or lower back surgery, refers to surgical procedures performed on the lumbar region of the spine. The lumbar region is the lower part of the spine, consisting of the five vertebrae (L1 to L5) between the thoracic spine (upper back) and the sacrum (pelvic region). Lumbar surgery is typically considered when conservative treatments such as medication, physical therapy, and lifestyle changes have failed to alleviate severe or chronic back pain, instability, or other symptoms associated with conditions affecting the lumbar spine. Examples of lumbar surgical procedures include disectomy, spinal fusion such as lateral lumbar interbody fusion (LLIF) and transforaminal lumbar interbody fusion (TLIF), laminectomy, foraminotomy, posterior transposas procedures (PTP), and artificial disk replacement surgeries. In order to mitgate the risks of damage during such surgeries, it is helpful to perform neurophysiological monitoring of the motor pathways during such surgeries to detect early changes in neurological dysfunction that if left un-mitigated might lead to transient or permanent injury or dysfunction post operatively. Such neurophysiological monitoring may include a wide range of techniques including for example short latency Somatosensory Evoked Potentials (SSEP), Trans- Dentons Ref. No.: 54530-3028WOU1 1 SL_6523603.1 ATEC Ref. No.: 0222WO Cranial Electrical Motor Evoked Potentials (TceMEP), Electroencephalography (EEG), Hoffman waves (H waves), near nerve stimulation and recording from nerve and/or muscle (triggered EMG), and neuromuscular junction testing for paralytic effect (e.g., Train of Four (TOF) nerve stimulation and muscle recording). Current neurophysiological monitoring approaches, however, have drawbacks including patient movement (e.g., abdominal and axial muscular movement) that can disrupt surgical procedures, being subject to anesthetic effect which can lead to false negative or false positives in detection of changes in neurological dysfunction, use of invasive stimulator electrodes, and limited to intermittent use. TceMEP is a technique used to assess the integrity of the motor pathways in the brain and spinal cord through the application of electrical stimulation to the motor cortex of the brain, such as through scalp electrodes, while monitoring the electrical responses in the muscles of the body. During a TceMEP procedure, electrical pulses are delivered to the motor cortex through the cranium, which activate the motor neurons responsible for controlling specific muscles. The electrical signals generated by these neurons travel down the spinal cord and peripheral nerves, causing muscle contractions. These muscle contractions produce electrical activity, which can be recorded using electrodes placed near, on or in the muscles. By analyzing the recorded electrical responses, neurophysiologists can evaluate the time it takes for the electrical signals to travel from the motor cortex to the muscles, as well as the amplitude and waveform characteristics of the evoked potentials. Any abnormalities or delays in the response can provide insights into the functional status of the motor pathways and help diagnose conditions such as spinal cord injury. TceMEP helps surgeons avoid damaging critical motor pathways and provides real-time feedback on the functional integrity of these pathways. TceMEP is often of particular interest to clinical users as it directly measures the integrity of the motor tracts, which is a primary concern. Typically, motor tract recordings are collected on one side and then the other so that individual side testing can be performed as appropriate. Unfortunately, TceMEP has several limitations in both use and interpretation. One drawback to TceMEP is that it may cause excessive axial movement, which may cause surgical disruption and/or render results difficult to obtain. Another drawback to TceMEP is its sensitivity to inhaled anesthetic agents requiring use of total intravenous Dentons Ref. No.: 54530-3028WOU1 2 SL_6523603.1 ATEC Ref. No.: 0222WO anethesia (TIVA). In addition, TceMEP requires careful stimulator electrode placement. Othe