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Tuesday, June 19, 2012

The Essence of Neuromonitoring: 23 Year Retrospective Study of 3436 Spinal Deformity Surgeries, Staggering 99.6% Accuracy/Detection of Permanent damage!

 Emerson RG's article published in the latest issue of Journal of Clinical Neurophysiology must be an eye opener for Naysayer neurologists and to those skeptic spine specialists out there who is impetuously discredit the predictability values and reliability of intraoperative neurophysiological monitoring. My own personal IONM experience provided to more than 1500 surgical procedures reveal even more than 99.6% accuracy of detection, wherein about 4-5 spine patients lives been saved (four lumbar and cervical fusion spine cases, and one scoliosis procedure) because of the timely warning from the IONM results during the surgical procedures, the timely warning enabled surgeon to take immediate intervention measures to reverse the risk of permanent damage thereby saved the patient from paralysis.
               The number of years accounted in this study, and the number of patients who underwent surgical procedures used for this analysis of Dr.Emerson's study is compelling and producing an authoritative findings. It is a must have clinical paper for all those who work in IONM field and a great reference source to be given to those naysayers.
J Clin Neurophysiol. 2012 Apr;29(2):149-50.

NIOM for spinal deformity surgery: there's more than one way to skin a cat.

Emerson RG. Abstract

STUDY DESIGN: This was a 23-year retrospective study of 3436 consecutive pediatric orthopedic spinal surgery patients between 1995 and 2008.

OBJECTIVE: To demonstrate the effectiveness of multimodality electrophysiologic monitoring in reducing the incidence of iatrogenic neurologic deficit in a pediatric spinal surgery population.

SUMMARY OF BACKGROUND DATA: The elective nature of many pediatric spinal surgery procedures continues to drive the need for minimizing risk to each individual patient. Electrophysiologic monitoring has been proposed as an effective means of decreasing permanent neurologic injury in this population.

METHODS: A total of 3436 consecutive monitored pediatric spinal procedures at a single institution between January 1985 and September 2008 were reviewed. Monitoring included somatosensory evoked potentials, descending neurogenic evoked potentials, transcranial electric motor evoked potentials, and various nerve root monitoring techniques. Patients were divided into 10 diagnostic categories. True-positive and false-negative monitoring outcomes were analyzed for each category. Neurologic deficits were classified as transient or permanent.

RESULTS: Seven of 10 diagnostic groups demonstrated true-positive findings resulting in surgical intervention. Seventy-four (2.2%) potential neurologic deficits were identified in 3436 pediatric surgical cases. Seven patients (0.2%) had false-negative monitoring outcomes. These patients awoke with neurologic deficits undetected by neuromonitoring. Intervention reduced permanent neurologic deficits to 6 (0.17%) patients. Monitoring data were able to detect permanent neurologic status in 99.6% of this population. The ratio of intraoperative events to total monitored cases was 1 event every 42 surgical cases and 1 permanent neurologic deficit every 573 cases.

CONCLUSIONS: The combined use of somatosensory evoked potentials, transcranial electric motor evoked potentials, descending neurogenic evoked potentials, and electromyography monitoring allowed accurate detection of permanent neurologic status in 99.6% of 3436 patients and reduced the total number of permanent neurologic injuries to 6.

Review of Neuromonitoring field 32 Years Ago?.

The utilization and importance of Neuromonitoring in hospital or intensive care set up was reviewed elaborately 32 years ago during 1985. Did anything change or how much change has took place in this field is quite interesting, while basic principles and intraoperative modalities discussed remain pretty much same today as 32 years ago, IONM field did make lots of progress ever since, better tests, analysis and interpretation of results got savvy and reliable upto 96-99% accuracy than it was during1985. Advancements in terms of application in various surgical procedure and combinatorial tests to yield better results, some newer techniques, and the entire hardware/machine technology certainly been upgraded to fit the Operating Room environment.

W.Hacks, the author of this review from the then FRG (West Germany, no longer the case after 90s unified Germany) made a remarkable attempt to provide insights 32 years ago. The review has been published in "Journal of Neurology (interestingly, the very first issue of this journal was published way back in the year 1891 that continued till today with the same name Journal of Neurology Volume 1 / 1891 - Volume 259 / 2012), quite an respectable journal in the field of neurology, it is still exist with the same name with a significant impact factor score of 3.85, ranked 33 among 185 clinical neurology journals [The top five Neurology journals are rated as follows:  (Neurology, Brain, Annals of Neurology, Journal of Neurotrauma, and Stroke, for an interesting review of these top journals, click here LINK).
Here is the link to the partial or one page review available at the bottom of this abstract, it is a pay per view article, only one page is viewable for non subscribers.


Neuromonitoring—the continuous or intermittent observation of nervous system functions—has become a field of interdisciplinary interest. Basically there are two major applications of neuromonitoring: in the operating theatre and the neurological or neurosurgical intensive care unit. Evoked potential recording, intracranial pressure measurement, serial EEG recording, cerebral blood flow measurement and ultrasound techniques have all been used as monitoring methods. The application of these techniques for operations, intensive care and the evaluation of brain death will be described.
Key words  Neuromonitoring - Intraoperative monitoring - Evoked potential monitoring - Spinal cord monitoring - Brain death