Intraoperative neurophysiologic monitoring in thoracoabdominal aortic aneurysm repair: A single-center prospective study

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Abstracts / Clinical Neurophysiology 130 (2018) e1–e19

consciousness. Patients underwent the first neurophysiological evaluations on day 2.8 ± 2.2. Considering non-reactive EEG pattern and pathological SEP, both measures together classified 70% of the patients into the unfavorable outcome group, after the first neurophysiological evaluation. We propose the combined neurophysiological monitoring of EEG with SEPs as an objective and reliable tool for evaluating brain function of sTBI coma patients.

MEPs deterioration and without alteration of peripheral potentials or arm MEPs developed paraplegia. Persistent bilateral MEPs changes, especially without concurrent peripheral alterations, are at high risk of SCI and justify prompt interventions for maximize spinal perfusion. The improvement of the accuracy in the identification of peripheral ischemia could help to clarify which MEPs alterations correlate with neurologic deficits.

doi:10.1016/j.clinph.2018.09.049

doi:10.1016/j.clinph.2018.09.051

Favorable outcome in post-anoxic coma despite bilateral absence of cortical N20: A case report F. Basaldella, G.M. Squintani, L. Alessandrini, C. Arcaro, V. Tramontano, S. Romito, T. Zanoni, M. Ferlisi, G. Avancini, B. Milan, M. Casartelli, P. Zanatta

Intraoperative neurophysiology multimodality techniques during skull-base surgery V. Tramontano, B. Masotto, G. Squintani, F. Sala

Verona, Italy Evaluation of the predictive value of SSEPs in post-anoxic brain injury. A 63-year-old man patient was admitted in Neuro ICU for post anoxic coma after cardiac arrest (CA). He was not treated with Hypothermia. Brain CT scan, SSEPs and EEG were respectively performed at admission and after 12 h from the CA. EEG and SSEPs were repeated between 7th and 9th day. MRI study was also performed after 24 days. First neurophysiological evaluation showed the absence of cortical N20 bilaterally and a continuous EEG activity. CT scan did not show any major brain abnormality. On day 3rd the sedation was stopped and the patient recovered consciousness. No sensory-motor or major cognitive deficits were observed. The second neurophysiological battery detected non-specific slow-frequencies EEG abnormalities and severely reduced amplitudes of bilateral cortical N20 potentials (lower than 0.3 lV). Diffuse cortical-subcortical atrophy and bilateral cortical necrosis in pre-/post-sulcus area were also visible at the MRI. Bilateral absence of cortical N20 still represent one of the strongest neurophysiological predictor of poor outcome in post-anoxic coma, with almost 100% specificity. Nevertheless our case stresses the need to apply a multimodality (EEG and SSEPs) neurophysiological strategy in order to reduce false positive SSEPs results caused by regional brain ischemia.

Verona, Italy Intraoperative Neurophysiological mapping and monitoring techniques, respectively, recognize and preserve both motor and corticobulbar pathway during skull-base surgery. A 25-year old male was admitted to our department for a brainstem cavernoma of the left pons. The patient presented with right hemiparesis and facial nerve palsy. During surgery we applied: (1) upper and lower extremity muscle motor evoked potentials (mMEPs) and last cranial nerves corticobulbar MEPs (CBT-MEPs) by Transcranial Electrical Stimulation (TES) with a short train of stimuli technique (duration 0.5 ms, ISI 2–4 ms, 1 Hz rate and intensity up to 200 mA); (2) direct brainstem mapping technique (hand-held concentric bipolar probe, 1 Hz rate, duration 0.5 ms, stimulation intensity 0.1–5 mA). Although neither mMEPs nor CBT-MEPs were recordable due to the neurological pre-operative deficits, direct brainstem mapping allowed to identify a safe entry zone to the pons. The cavernoma was totally removed and no new or worsen neurological deficits occurred. Vice versa, the pre-existing hemiparesis improved over time. Whenever pre-existing neurological deficits may compromise the success of monitoring techniques, direct mapping could be extremely valuable to avoid injuring the brainstem. To prepare for a multimodality, monitoring and mapping, strategy offers more chances for a valuable neuromonitoring. doi:10.1016/j.clinph.2018.09.052

doi:10.1016/j.clinph.2018.09.050

Intraoperative neurophysiologic monitoring in thoracoabdominal aortic aneurysm repair: A single-center prospective study F. Bianchi, M. Cursi, H. Caravati, I. Urban, S. Amadio, R. Guerriero, C. Butera, S. Tronci, G. Comi, R. Chiesa, G. Melissano, Y. Tshomba, D. Baccellieri, U. Del Carro Milano, Italy Intraoperative neuromonitoring (IOM) allow the assessment of spinal integrity during thoracoabdominal aneurysm (TAAA) surgery, giving the opportunity to predict or help to prevent spinal ischemia (SCI). The reliability of IOM depends on excluding confounding factors and on warning criteria. Our aims were to investigate the sensitivity and specificity of IOM for SCI and to verify if the study of compound motor action potential (CMAP) is reliable in the identification of limb ischemia and improve IOM sensitivity for SCI. Onehundred consecutive patients (mean 64.3 yrs) undergoing TAAAs surgery between February 2016 and March 2018 were studied prospectively. IOM included motor evoked potentials (MEPs), somatosensory evoked potentials (SEPs), popliteal potentials and CMAPs. MEPs and SEPs were recordable in 99% of cases. MEPs showed transient changes in 49.5% and persistent decrease in 16.2% (3% unilateral). All of 4 patients with persistent bilateral

Intraoperative neurophysiological monitoring during spinal surgery S. Lollini, C. Martinelli, D. Fabris, S. Caserta, P. Viganò, G. de Scisciolo Firenze, Italy Arezzo, Italy Intraoperative neurophysiological monitoring (IOM) is a technique that may contribute to avoiding permanent neurological injury during spine surgery procedure, especially in patients undergoing scoliosis correction. In the last 12 months 26 patients underwent spinal procedures for scoliosis and kyphosis, spinal (cervical or lumbar) stenosis, degenerative disc disease; a patient with posttraumatic L1 fracture and a patient with intradural extramedullary neurinoma were monitored too. TIVA-TCI anesthesia was used in all patients while muscle relaxants were limited only during some patient’s intubation. SEPs (median and tibial nerve) and MEPs (ADM and TA-AH muscles and in cervical surgery also deltoid and ECD muscles) were attempted in all patients. Spontaneous EMG activity was also recorded from multiple muscles. Only in two cases we had significant prolonged alterations of IOM: during a D3 neurinoma surgery we observed the loss of MEPs from a leg with return at normality after a stop and change of neurosurgery procedures; in a decompression/stabilization D10-S1 cortical SEPs and MEPs of right leg slowly reduced progressively until the end of surgery (with a