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:

Learning EMG control of a robotic hand: towards active prostheses

for those who are interested in "EMG's" and developments in the field of usage of EMGs...!

ABSTRACT

We introduce a method based on support vector machines which can detect opening and closing actions of the human thumb, index finger, and other fingers recorded via surface EMG only. The method is shown to be robust across sessions and can be used independently of the position of the arm. With these stability criteria, the method is ideally suited for the control of active prosthesis with a high number of active degrees of freedom. The method is successfully demonstrated on a robotic four-finger hand, and can be used to grasp objects

Intraoperative Neurophysiological Monitoring, by Leon K Liem

eMedicine
Liem's article on "Intraoperative Neurophysiological
monitoring", a good place for starters to know the basics of
neuromonitoring.  Author: Leon K Liem, MD, Assistant Clinical Professor, Division of Neurological Surgery, University of Hawaii, John Burns School of Medicine

Contributor Information and Disclosures

Updated: Feb 11, 2010

Introduction

This article provides an overview of the various neurophysiological monitoring techniques used intraoperatively.
Intraoperative neurophysiological monitoring has been utilized in attempts to minimize neurological morbidity from operative manipulations. The goal of such monitoring is to identify changes in brain, spinal cord, and peripheral nerve function prior to irreversible damage. Intraoperative monitoring also has been effective in localizing anatomical structures, including peripheral nerves and sensorimotor cortex, which helps guide the surgeon during dissection.
Evoked potential monitoring includes somatosensory evoked potentials (SSEP), brainstem auditory evoked potentials (BAEP), motor evoked potentials (MEP), and visual evoked potentials (VEP). Electromyography (EMG) also is used extensively during operative cases. Scalp electroencephalography (EEG) provides data for analysis in SSEP, BAEP, and VEP. Scalp EEG also can be used to monitor cerebral function during carotid or other vascular surgery. In addition, EEG recorded directly from the pial surface, or electrocorticography (ECoG), is used to help determine resection margins for epilepsy surgery, and to monitor for seizures during electrical stimulation of the brain carried out while mapping cortical function. http://emedicine.medscape.com/article/1137763-overview

IONM the Gold Standard of Patient Safety? By David J.Anschel, M.D

David J. Anschel, M.D.
Contributing Editor of MedCompare,

David J. Anschel writes about the developments in "Itraoperative Neurophysiological Monitoring and its medical usage:

IONM has become the gold standard for ensuring patient safety while undergoing operations which place the central or peripheral nervous system at risk. Technological advancements within the last few years have allowed monitoring techniques to evolve. The above robust systems are representative of the best that modern medicine has to offer. Allowing neurologists and surgeons to work together to provide better patient outcomes during more complicated procedures in close proximity to vital neurological tissues.

Some Stats about CNIM Exam

CNIM Written Exam 2003-2006
One of the following must be met and verified for candidates

to be eligible to take the CNIM Exam:

Health care credential plus documentation of 100 cases monitored
Bachelor’s degree plus documentation of 100 cases monitored
68% passed on their first attempt. The pass rate for repeaters was 46%.
39% had another health care credential. Their pass rate was 50%.
61% of candidates had a bachelor’s degree or higher and a 61% pass rate.
Some of the candidates with bachelor’s or advanced degrees, also documented they had another health care credential.
Procedures Performed in the OR Totals
Totals Percentage
Spinal Nerve EMG 911 83%
Motor Pathway 783 71%
Intraop Scalp EEG 719 65%
BAEP 661 60%
Cranial Nerve EMG 619 56%
Cortical mapping 337 31%
ECOG 197 18%
VEP 139 13%

41% of candidates stated CNIM was a Job Requirement. This was the most common reason stated for taking the exam. The second most common response was Professional Advancement (34%) and the third reason selected was Personal Goal (18%).