Electrocautery and Spinal Cord damage- loss of motor activities..!

Nerve damages or spinal cord damage during brain and spine surgical procedures depends upon various myraids of factors, one of them is mechanical. However, how many of you even thought of an electrocautery can produce spinal cord damage resulting EMGs and motor activity loss?. This report published in an porcine model discusses a case. I have not read a human case yet, but it is a real possibility, it can happen during surgery.  If anyone knows a human case or clinical scenario's, please post a comment below.

Spinal cord injury from electrocautery: observations in a porcine model using electromyography and motor evoked potentials. Stanley A. Skinner, et al  Journal of Clinical Monitoring and Computing November 2012

Abstract

We have previously investigated electromyographic (EMG) and transcranial motor evoked potential (MEP) abnormalities after mechanical spinal cord injury. We now report thermally generated porcine spinal cord injury, characterized by spinal cord generated hindlimb EMG injury activity and spinal cord motor conduction block (MEP loss). Electrocautery (EC) was delivered to thoracic level dural root sleeves within 6–8 mm of the spinal cord (n = 6). Temperature recordings were made near the spinal cord. EMG and MEP were recorded by multiple gluteobiceps intramuscular electrodes before, during, and after EC. Duration of EC was titrated to an end-point of spinal motor conduction block (MEP loss). In 5/6 roots, ipsilateral EMG injury activity was induced by EC. In 4/5 roots, EMG injury activity was identified before MEP loss. In all roots, a minimum of 20 s EC and a temperature maximum of at least 57 °C at the dural root sleeve were required to induce MEP loss. Unexpectedly, conduction block was preceded by an enhanced MEP in 4/6 trials. EMG injury activity, preceding MEP loss, can be seen during near spinal cord EC. Depolarization and facilitation of lumbar motor neurons by thermally excited descending spinal tracts likely explains both hindlimb EMG and an enhanced MEP signal (seen before conduction block) respectively. A thermal mechanism may play a role in some unexplained MEP losses during intraoperative monitoring. EMG recordings might help to detect abnormal discharges and forewarn the monitorist during both mechanical and thermal injury to the spinal cord.

Full PDF: click on the top right corner of the journal for pdf article. Link:

Median Nerve SSEP:- Is there a relationship between Median Nerve SSEP & Level of Spinal Cord Injury?

This case study was conducted by the American Spinal Cord Injury Association (ASIA) on patients with Quadriplegia. The question asked was is there a relationship between median nerve SSEP changes and level of spinal cord injury?.

The answer is yes, neuromonitoring of median nerve SSEPs conducted on 14 quadriplegic patients and 8 normal individuals. Amplitude and latency analysis of waveforms N9, N13 and N20 was conducted. N9 responses were present in all the patients and normal subjects, both amplitude and latency were similar in both groups.

On the other hand, N13 was absent in Quadriplegia patients?
N20 was absent in C5 patients with Quadriplegia? but it was present in C6-7 patients, though the amplitudes were decreased with normal latency. Did you notice these waveform changes in your recording?.

Read further:

Original Article

Spinal Cord (2009) 47, 372–378; doi:10.1038/sc.2008.147; published online 20 January 2009

Relationship between median nerve somatosensory evoked potentials and spinal cord injury levels in patients with quadriplegia

M I F de Arruda Serra Gaspar¹, A Cliquet Jr^2,3, V M Fernandes Lima⁴ and D C C de Abreu¹

Methods:

Fourteen individuals with quadriplegia and 8 healthy individuals were evaluated. Electrophysiological assessment of the median nerve was performed by evoked potential equipment. The injury level was obtained by ASIA. N₉, N₁₃ and N₂₀ were analyzed based on the presence or absence of responses. The parameters used for analyzing these responses were the latency and the amplitude. Data were analyzed using mixed-effect models.

First Spinal Cord Endoscope Surgery Conducted in Iran

Can you imagine in this 21st century with so much of medical knowledge and medical care a first spinal endoscope surgical procedure is done on Oct 14, 2008?. A first spinal surgery in Iran, wow....finaly a surgical procedure to help patients with back or spinal problems is introduced in Iran by an American spine surgeon?.

Iran News Page One > Iran News First Spinal Cord Endoscope Surgery Conducted in Iran Oct 15, 2008 Iranian.ws The first spinal cord endoscope surgery was conducted in Iran, yesterday morning, by Professor John Chio, head of California Vertebrarium Research Center. Shedding light on details of such a surgery, Chio said: “During this surgery the tissues are not cut and the muscles are placed aside with highly delicate tools in order to reach the spinal cord and to lower disc pressure. Meanwhile, in order to stitch the wound, laser is used.” He added that in this surgery the patient does not bleed and therefore blood transfusion does not take place. The surgeon further underlined that the patient can leave three hours after surgery, resuming his social life within six days and commencing his athletic activities within three weeks. “The operation is also economically justified,” he added. He further said that one of his main goals is to train Iranian physicians, stressing that Iranian physicians are intelligent and can easily learn this operation.

Degenerative Disc Disease- in a Illustrative way?

Image from: Findhealcarethinfo.com

This picture illustrates the various conditions of the spine.

*****Another beautiful illustration about disc disease is presented in an interactive video at the Spine-Health.com. What is degenerative disc disease, how to make it simple to understand using illustration: here it is!

Spinal Cord Injury & the debilitating condition!

Why neuroregeneration research, stem cells and its research are important to this world?.
Just watch this video, put your few min aside to see this spinal cord injury and its impact on Mike's life...!?

American Society of Anesthesiologissts: Upcoming Conference & Abstracts on Neuromonitoring

Tha annual meeting of American Association of Anesthesiologist will be held during

October 13-17, 2007 San Francisco, CA. There are several interesting research and clinical studies on using neuromonitoring, how different anesthesia affects the intraoperative recording. You can click this highligted assn "Amer Assoc Anesthesiologist Meeting" and read all the important abstracts.

Here is a sample abstrat:

A1 October 13, 2007 9:00 AM - 10:30 PM

Room 301
Somatosensory and Motor Evoked Potentials during Sevoflurane and Propofol Anesthesia

Michael S. Kincaid, M.D., Michael J. Souter, M.D., Patrick D. Bryan, Mark Klein, Arthur M. Lam, M.D.Anesthesiology, University of Washington, Seattle, Washington

Background and Purpose: Transcranial electrical motor evoked potentials (MEP) have joined somatosensory evoked potentials (SSEP) as an important aspect of neurophysiologic monitoring during both intracranial and spine surgery. General anesthesia is known to diminish the quality of signals with SSEP, decreasing amplitude and increasing latency, with volatile anesthesia having a greater effect than intravenous anesthesia. There is little quantitative information on the comparative effect of volatile and intravenous anesthetics on MEP signal quality, however. The purpose of this study is to describe the effects of propofol and sevoflurane on SSEP and MEP in patients undergoing both spine and neurosurgical procedures.

Research & Case Studies using Neuromonitoring!

Years: 2005-2007
Neuromonitoring in Infants:
Motor Evoked Potentials After Transcranial Magnetic Stimulation Support Hypothesis of Coexisting Central Mechanism in Obstetric Brachial Palsy.
Abstract:
Six infants with obstetric brachial palsy, ranging from 4 to 7 months of age, were investigated. One was suspected of having extensive brachial plexus lesions and five were suspected of having a unilateral lesion of both roots C5 and C6. All were referred to our center to investigate the possibility for reconstructive surgery. In all infants, even at this age, transcranial magnetic stimulation resulted in motor evoked potentials (MEP) in the biceps (in one, in the brachioradial) muscles. Averaging could not be done because of the intraindividual variation in latency. The MEP was easier to recognize if evoked when the infant had the arm bent. In all five infants suspected of upper brachial plexus lesion with avulsion of both roots C5 and C6 and/or complete rupture of the upper trunk, proven in four, an MEP on the lesioned side could be evoked. Combined with earlier investigations showing (almost) normal EMG and somatosensory evoked potentials in infants with upper plexus lesion, this leads us to the conclusion that the paralysis of these infants cannot only be attributed to the peripheral axonal damage alone but that central plasticity must also play an important role. As this is a slow process, some infants might not yet be able to use the paralytic muscles. Some theoretic issues are discussed.

Neuromonitoring in Young Child:
Improvement of Motor-Evoked Potentials by Ketamine and Spatial Facilitation During Spinal Surgery in a Young Child.
Anesth Analg 2005;100:1634-1636© 2005
International Anesthesia Research Society
Monitoring motor evoked potentials is desirable during spine surgery but may be difficult to obtain in small children. In addition, the recording of reliable signals is often hampered by the presence of various anesthetics. We report the case of a young child whose motor evoked potentials were successfully monitored using a ketamine-based anesthesia and a newly introduced stimulation technique consisting of combined spatial and temporal facilitation.






Journal of Clinical Neurophysiology.
24(1):48-51,
February 2007. Colon, A J. *; Vredeveld, J W. *+; Blaauw, G ++

Is MEP monitoring is superior to SSEP in detecting nerve damages?

Our data again confirm that MEP monitoring is superior to SSEP monitoring in detecting impending impairment of the functional integrity of cerebral and spinal cord motor pathways
during surgery. Detection of MEP changes and adjustment of the surgical strategy might allow to prevent irreversible pyramidal tract damage. Stable SSEP/MEP recordings reassure the surgeon that motor function is still intact and surgery can be continued safely. The combined SSEP/ MEP monitoring becomes advantageous, if one modality is not recordable.

Neurosurgical Review
Springer Berlin, Volume 30, Number 2 / April, 2007
M. R. Weinzierl, Email: Martin.Weinzierl@ukaachen.de

Posterior thoracic segmental pedicle screw instrumentation: Evolving methods of safe and effective placement
Intraoperative neuromonitoringIntraoperative neuromonitoring (IONM) has become an integral part of complex spine surgery. The primary objective of IONM is to provide the surgeon with early warning of a potential neurological event. IONM, in the form of somatosensory-evoked potentials (SSEP's), initially gained popularity with deformity surgeons who routinely relied on the Stagnara wake up test to monitor neurologic integrity. Monitoring techniques have become much more sophisticated since their inception affording a higher level of protection to the patient. At present, many centers employ SSEP's, motor-evoked potentials (MEP's), and spontaneous and triggered EMG responses during complex thoracic pedicle screw instrumentation procedures.

Neurology India
Year : 2005 Volume : 53 Issue : 4 Page : 458-465
Philadelphia, 19107 USA
zeiller@comcast.net

Years 2000-2005

Intraoperative Neuromonitoring.
Article Neurologist. 8(4):209-226, July 2002.
Minahan, Robert E. MD
Abstract:
BACKGROUND-: Intraoperative neuromonitoring (IONM) has been a valuable part of surgical procedures for over 25 years. Insight into the nervous system during surgery provides critical information to the surgeon allowing reversal or avoidance of neural insults.

REVIEW SUMMARY-: Electrophysiological tests including electroencephalography, electromyography, and multiple types of evoked potentials (somatosensory, auditory, and motor) are monitored during surgeries that involve risk to the nervous system. Deterioration of signals suggests a surgical insult and is associated with an increased risk of postoperative deficit. Intraoperative identification of this risk allows corrective action. In addition, IONM teams make use of their armamentarium of tests to evaluate anatomy or function of the nervous system in response to specific questions posed by the surgical team.

CONCLUSIONS-: Intraoperative recordings are now a routine part of many surgical procedures. Their correct application leads to improved surgical outcome.
(C) 2002 Lippincott Williams & Wilkins, Inc.



Years 1990- 2000


Years 1980-1990


Years 1970-1980



The Inception of Neuromonitoring: 1960
[1960-1970]