Mapping and Monitoring During Surgery For Congenital Spinal Malformation

Objective: Surgery of complex congenital spinal malformations has a risk to damage functional neural structures. Intraoperative neurophysiological monitoring for congenital spinal pathologies is suggested to reduce this risk for neural tissues and thus improve the surgical results. Our aim is to evaluate which patients are liable to reveal critical neurophysiological changes during surgery by presenting our intraoperative neurophysiological approach and the early clinical outcome of patients with congenital spinal malformations. Methods: Nineteen patients (8 males and 11 females) were included in the study. Demographic data, symptoms and signs, radiological investigations, and other diagnostic tests for accompanying pathologies were evaluated together with neurophysiological findings. Results: The mean age of patients was 13.6 years (range: 16 months-62 years). Neurophysiological changes were seen in 7 patients (36.8%) during surgery. Most of them had mass lesion including dermoid and epidermoid tumor or intradural abscess. Motor evoked potential (MEP) changes were seen in 3 patients without any new postoperative motor deficit. Bulbocavernosus reflex (BCR) changed in 4 patients; stimulation threshold (15-25 mA) increased in 3 of them while the other one had additional morphological changes in BCR response and worsening of preexistent urological dysfunction. Conclusion: Mapping is the most critical part of surgery in terms of neurophysiology before cutting any structure in the operating area for preventing neurological deficit postoperatively. Among the spinal congenital malformations, MEP and BCR changes seem to occur during surgery for concomitant space occupying lesions or diastometamyelia and dermal sinus tract rather than isolated filum lipoma or tethered cord.