NeuroMonitoring in Epilepsy Related Diseases & Surgeries!?.

Journal of Neurosurgical Focus
In the latest issue of the journal JNS, Scellig S. D. Stone, M.D., and James T. Rutka from The Hospital for Sick Children, and The University of Toronto, Ontario, Canada discuss issues relate to the topic "challenges in Epilepsy related diseases and neurosurgeries in epilepsy patients". 

These challenges can provide great opportunities for neuromonitoring, infact, in this very review you will find that the existing brain mapping and EcoG has been a gold standard to conduct successeful neurosurgeries, it has become an important tool for surgeons to identify and map the areas in epilepsy patients who undergo surgeries to get rid of the epileptic loci in the brain.

The authors described two combined approach that can be used to delineate a possible trajectory for the epilepsy surgeons, such methods may help to relieve the patients from epileptic activities. 

The neuronavigation system and the neuromonitoring approach, I will try to condense the information regarding neuromonitoring here, but one must read the whole article to get a better insight into this field. Three of the exisiting neuromonitoring protocols are discussed,

1.Electrocorticography recording method, using this method one can reliably map the brain areas of interest for surgical removal by directly placing grid electrodes on the surface of brain (invasive), using the method poineered by the Penfield and Jasper [34.Jasper H, Electrocorticography. Penfield W, Jasper H: Epilepsy and the Functional Anatomy of the Human Brain Boston, Little Brown, 1954. 692–738].

2.Depth Electrode Recordings, this method can be combined with the direct mapping of the brain using depth electrode, deep isertion of electrodes into subcortical areas will provide additional information about ictical and interactive epileptic regions, in reality, the DER can be performed outside the OR perioperatively as well as inside the OR intraoperatively, enabling the surgeon to develop a streamlined strategy into the brain area of interest to be lesioned, lesioning brain areas is the surgical procedures carried out to eliminate epileptic activities.

3.Intraoperative EcoG is  yet another recording used widely to operate on interactive epileptic patients, the most important use of EcoG seems to be to during extralesional resections or lesionectomy combined with spike-positive tissue resection procedures. EcoG monitoring seems to have helped reduce the rate of second surgical procedure and reduced epileptic activities significantly in those patients. One of the surgical procedure where EcoG was very useful in the removal of the hippocampal area or mesial temporal or gliosis surgical procedures.

4.Direct Cortical Stimulation method, mostly used in surgeries that involve sensory motor or language areas, a direct application of focal cortical pulses of low voltage current using a hand held bipolar electrode.

So, applying these

techniques in combination as a "multi-model" neuromonitoring procedure

can go long way in safegurding better surgical procedures in epilepsy patients. This is a great review any neurophysiologist or neurosurgeon or neurologist or neuromonitoring personnel must read for better understanding of surgical procedures and neuromonitoring in epilepsy patients.

Ulnar Neuropathy? If the surgery site is lower Lumosacral level, why should you monitor upper limp SSEPs?

This article in the latest Spine Journal (an electronic publication) demonstrates that upper limp SSEP monitoring is quite handy in detecting ulnar nerve neuropathy during lower back surgeries??.

PubMed-NCBI Spine J. 2008 Aug 4. [Epub ahead of print] Upper-limb somatosensory evoked potential monitoring in lumbosacral spine surgery: a prognostic marker for position-related ulnar nerve injury.

BACKGROUND CONTEXT: Somatosensory evoked potential (SSEP) is used to monitor integrity of the brain, spinal cord, and nerve roots during spinal surgery. It records the electrical potentials from the scalp after electrical stimulation of the peripheral nerves of the upper or lower limbs. The standard monitoring modality in lumbosacral spine surgery includes lower-limb SSEP and electromyography (EMG). Upper-limb SSEP monitoring has also been used to detect and prevent brachial plexopathy and peripheral nerve injury in thoracic and lumbosacral spine surgeries. We routinely monitor lower-limb SSEP and EMG in lumbosacral spine procedures at our institution. However, a few patients experienced postoperative numbness and/or pain in their ulnar distribution with uneventful lower-limb SSEP and EMG.