Intra-operatory Neurophysiological Monitoring Changes as a Predictive Clinical Outcome Measure in Lumbar Radiculopathy.

Intra-operatory Neurophysiological Monitoring Changes as a Predictive Clinical Outcome Measure in Radiculopathy Associated to Lumbar Disk Disease. Two Years Follow-up

The purpose of this study is to determine the relation among: (1) changes in voltage and amplitude of trans-operatory records obtained through the use of Intra-operative Neurophysiological Monitoring (IONM), and (2) clinical outcomes; of patients who underwent 1 or 2 levels surgical decompression at lumbar spine.

IONM is the use of real time neurophysiological techniques during spinal surgeries. The modalities included in this study are:

• Somatosensory evoked potentials (SSEPs).
• Trans-cranial electric motor evoked potentials (tceMEPs).
• Spontaneous electromyography (EMG).

Clinical outcome of the patients will be assessed through a careful evaluation of clinical data, as well as the application of three outcome scales:

• Oswestry Disability Index 2.1a
• Visual Analogue Scale for Pain
• Patient's Overall Impression of Change

Radiculopathy associated to lumbar disk disease is one of the most common reasons for a spine surgeon to be consulted. The pathophysiology of degenerative spine disease is acknowledged as complex, involving a wide array of risk factors ranging from genetic polymorphisms, to behavioural characteristics. While conflicting opinions exist with regard the direction of treatment for lumbar disk disease, de-compressive surgery is currently the gold standard for patients in which protocols of physiotherapy and analgesics have failed to comply.

Intraoperative neurophysiological monitoring (IONM) is widely used in the practice of spine surgery as a mean of preventing and reducing severe complications inherent to surgical techniques like paraparesis, paraplegia and quadriplegia. Indeed, a great deal of funding and work have been devoted to research projects seeking to determine the impact of IONM in reducing these risks. The results of such projects have been notoriously interesting, and frequently opposing to each other. This has lead to an open debate on weather the use of IONM may or not be justified by better outcomes in patients who undergo such procedure. To our knowledge there is no study in the literature that has addressed the potential role of the IOM to predict the long-term outcome of the patient in therms of radicular symptoms improvement.

Inclusion Criteria:

• Diagnosis of Lumbar Disk Disease
• Clinical Signs of Radiculopathy
• Undergoing neurological surgery of the spine

Exclusion Criteria:

• Previous neurological surgery of the lumbar spine
• More than 2 levels intervened at the surgery
• Serious post-operatory complications