Summary:
The report has presented the experience with combined monitoring of
somatosensory (SEPs) and motor evoked potentials (MEPs) in the course
of 116 surgeries for scoliosis in the University Hospital Brno (89 females,
24 males, mean age 14.6 ± 3.27 years, range 10–35, investigated in January
2003 – April 2005). Scalp SEPs following stimulation to the tibial or
peroneal nerves were used for intraoperative monitoring. MEPs were elicited
by transcranial electrical stimulation and motor responses were
recorded from distal muscles at the lower extremities. MEPs were
successfully registered in 99.1% of operations while SEPs responses were
recorded in 86.2 % of all surgeries during the initial phase of operation. Significant changes of evoked potentials during the operation were registered in 13 % of SEP and in 3.6 % of MEP
monitorings, respectively. Most changes were due to the technical or systemic problems, only 3 SEP changes and 2
MEP changes were analysed as clinically relevant. The postoperative development of paraplegia with subsequent
regression into a mild degree without a previous intraoperative significant change of evoked potentials (false negative
monitoring) was recorded in 1 female-patient. The spinal affection probably occurred after the monitoring and
before awaking from anaesthesia by means of positioning and the following HALO traction. A postoperative deficit
with subsequent regression into a mild degree followed by positive change of both MEPs and SEPs lead to the
modification of a surgical method and was recorded in 1 female-patient (0.86 % operations). Based on these results,
the authors have recommended a combined monitoring of MEPs and SEPs as a safe and reliable standard in operations
for congenital and idiopathic scoliosis that may substitute a wake-up test.
Key words:
intraoperative monitoring, somatosensory evoked potentials, motor evoked potentials scoliosis
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