36. Monitoring motor evoked potentials of vagus nerve with endotracheal tube electrodes in brainstem surgery

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areas. No statistically significant difference emerged from the two conditions. Task-related coherence decreased in alpha2 band between left central - right frontal and left central – left parietal areas; beta band coherence decreased between C3–C4 electrodes, and increased between C3–Cz. These data contribute to the understanding of oscillatory activity during lower limb robot-assisted motor performance, and point to the advantages of this analysis to evaluate cortical oscillations changes. doi:10.1016/j.clinph.2016.10.044

33. Effects of global proprioceptive resonance on resting state EEG in healthy subjects—M. Fichera, A. Maffei, G. Comi, L. Leocani (Milano, Italy)

In the last few years Multifocal Vibration (MFV) has been evaluated as a tool to modify posture and to speed recovery after physical exercise. The aim of this study is to assess whether MFV can also modify resting state EEG. Eleven healthy subjects were included in this study. All subjects underwent a resting state EEG recording of six minutes (three with eyes closed and three minutes with eyes open) for evaluation of resting cortical rhythms, before and after one session of MFV with KEOPE-GPR. Data obtained were collapsed in four region of interest (ROIs): frontal, central, temporal and occipital. Frequency bands of interest were d(0.5–3.5 Hz), h(4–7.5 Hz), a1 (8–10.5 Hz), a2 (11– 12.5 Hz), b1 (13–19.5 Hz), and b2 (20–30 Hz). The ratio between slow (delta + theta) and faster (alpha1 + alpha2) rhythms was evaluated using paired t-test. Subsequent statistical analysis was carried on using repeated measures ANOVA (RM-ANOVA) using time (2levels), side (2-levels) and rhythm (6-levels) as within-subjects factors for each ROI. No statistically significant variations were observed on qEEG with eyes closed. The analysis of ratios between slow and faster frequencies after MFV identified significant variations following MFV (p < .001 for all ROIs). RM-ANOVA identified a significant rhythm effect and time * rhythm interaction in frontal (p.046), central (p.003) and temporal (p.004) ROIs; only a trend was observed for occipital ROI (p.055). Post-hoc analysis showed increase in alpha1 band relative power and decrease in delta band in frontal, central and temporal ROIs. MFV can modulate oscillatory activity as observed by qEEG. The increase in alpha band observed in central regions could be related to an enhancement in mu rhythm.

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12 and 24 h after cardiac arrest and classified as having identical bursts and/or highly epileptiform bursts. Outcome was evaluated at 6 months with GOS and dichotomized as good (GOS = 3–5) or poor (GOS = 1–2). Ten patients with BS were identified at 12 h: two had highly epileptiform bursts and identical bursts, one had highly epileptiform bursts, one had identical bursts, and six had ‘conventional’ BS. At 24 h 11 patients with BS were observed: one had highly epileptiform bursts and identical bursts, three had identical bursts and seven had ‘conventional’ BS. As a whole all patients with BS had poor outcome, except for one with ‘conventional’ BS at 12 h. Identical bursts and highly epileptiform bursts can both coincide or appear independently, either way they were invariably associated to poor outcome. Significance-BS with identical bursts and BS with highly epileptiform bursts appear two distinct subtypes of BS which is in itself highly prognostic for poor outcome. doi:10.1016/j.clinph.2016.10.046

35. Changes in standard EEG findings parallel improvements in the level of consciousness in patients in a vegetative state— C. Boccagni, S. Bagnato, A. Sant’Angelo, C. Prestandrea, G. Galardi (Cefalú, Italy)

Recent findings suggest that EEG amplitude, frequency, and reactivity are related to clinical outcomes in patients with severe disorders of consciousness. Moreover, their prognostic value increases if they are combined with a new Amplitude–Frequency–Reactivity (AFR) score (Bagnato et al., Clin Neurophysiol, 2015). This study evaluated if changes in standard EEG descriptors parallel changes in the level of consciousness in patients in a vegetative state (VS). EEGs were scored in 25 patients in a VS at admission to a rehabilitation department and six months later. Amplitude was scored as 1 if reduced or 2 if normal. Dominant frequency was scored as 1, 2, or 3 for delta, theta, or alpha, respectively. Reactivity to stimuli was scored as 1 if absent or 2 if present. Therefore, the AFR score ranged from 3 to 7. Changes in these scores after six months were compared between patients who improved (n = 14) or not (n = 11) their level of consciousness. Patients who improved their level of consciousness showed significant changes in EEG frequency (p = 0.02) and reactivity (p = 0.001). Moreover, 85.7% of them showed an increase of the AFR score (p < 0.001). In conclusion, EEG findings parallel the improvement of the level of consciousness in patients emerging from a VS. doi:10.1016/j.clinph.2016.10.047

doi:10.1016/j.clinph.2016.10.045

34. Burst-suppression with highly epileptiform bursts and with identical bursts: two subtypes within burst-suppression pattern— M. Spalletti, R. Carraia, M. Scarpino, C. Cossu, A. Ammannati, A. Peris, S. Valente, A. Grippo, A. Amantini (Firenze, Italy)

Objective is to identify and compare EEGs showing burstsuppression (BS) with identical bursts and BS with highly epileptiform bursts and their prognostic value in a cohort of postanoxic patients. In a retrospective cohort of postanoxic patients who underwent EEG, we selected all patients with BS (ACNS terminology, 2013) at

36. Monitoring motor evoked potentials of vagus nerve with endotracheal tube electrodes in brainstem surgery—P. Prandi, G. Tondo, G. Panzarasa, R. Cantello (Novara, Italy)

In surgery around brainstem for preservation of swallowing function, monitoring of the corticobulbar tract of the X cranial nerve – and not only vagal rootlets – is needed. A few researchers have studied intraoperative monitoring of the vagus nerve corticobulbar pathway. In the past, X nerve has been monitored using needle or hookwire electrodes, endoscopically or laryngoscopically placed in the vocal fold. Because of their complexity and invasiveness, these techniques have not been widely used. New studies with vagal MEPs have been recently published, although they required needle

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insertion into the vocal cord. Reports with non-invasive methods are still lacking. In this work we report our series of vagal nerve motor evoked potentials using endotracheal adhesive electrode in surgery around brainstem. In 26 patients who have undergone surgery around brainstem vocal cord MEPs were recordable in about 70% of cases. Correct electrode placement is the main issue to obtain signals. Latencies varied from 14 to 20 msec and amplitude from 40 to 200 uv. In 3 cases there was MEP loss and the patients suffered of post operative dysphagia. MEP recorded with endotracheal tube adhesive electrodes is a safe, effective and reliable method to monitor corticobulbar vagal tract. doi:10.1016/j.clinph.2016.10.048

37. Neurophysiological multimodal monitoring in newborns: normative SEP-continuous—S. Gabbanini, M. Bastianelli, G. Bertini, I. Corsini, C. Dani, S. Lori (Firenze, Italy)

Our aim was to record simultaneously V-EEG, aEEG, SEPContinuous (SEP-C) from median nerve bilaterally with a standardized Neurophysiological-Multimodal-Monitoring, lasting 1h (1hNMM) in neonatal period to collect normative SEP-C data in relation to behavior states. We studied 20 healthy term-newborns (37–42 weeks, mean 39.6-SD1.3) within two days from the birth by means of 1h-NMM, focusing to the methodology of SEP-C recording (filter band-pass, number and frequency of stimuli). 1h-NMM was easily obtained with identification cervical (Cv7N13) and cortical (N1, P1) SEP-C responses in all infants. SEP-C minimum and maximum N1 latencies/N1-P1 amplitudes were identified, bilaterally, during spontaneous sleep active-quietactive (AS-QS-AS) and quiet-Wakefull (qW). The minimum latencies and amplitudes occurred in 60% of AS/qW while the maximum in 70% of QS. The SEP-C components values (mean-SD) were: latencies of N13, 13.6–1.4 ms, N1, 33.6–3.9/34.2–4.8 ms in left and right hemisphere respectively; Central-Transmission-Time (N13–N1), 20.0–4.3/20.6–4.8 ms; N1–P1 amplitude 4.6–2.7/3.8–2.2 lV. 1h-NMM is able to record simultaneously VEEG-aEEG-SEPs-C already within a few days of birth; it shows the modulation of SEPs’ cortical responses according to behaviour states in all our newborns studied using an appropriate method. We emphasize the importance of knowing the normative data of neonatal SEP-C to better identify the pathological findings in neonatal brain injury. doi:10.1016/j.clinph.2016.10.049

38. Influence of age on laser-evoked potentials in normal subjects—E. Vecchio, A. Montemurno, K. Ricci, M. de Tommaso (Bari, Italy)

Laser stimuli selectively activate Ad and C thermo-nociceptors in the skin. Recording the brain’s response to these short laser pulses (laser evoked potentials, LEPs) is considered a useful tool for evaluating transmission along small-diameter sensory fibers and investigating the function of spino-thalamic pathways. Aging has been reported to reduce the amplitude of N2P2 or even to suppress LEPs in some healthy elderly subjects. Our aim was to explore how age may affect LEPs and to improve their reliability as a diagnostic tool for all ages. We conducted a study of 200 healthy subjects with ages spanning 6 decades. Nociceptive stimuli were delivered to the hand

and foot using a CO2 laser stimulator. Detection and pain perception thresholds did not correlate with age. The amplitude of N2–P2 resulted increased in the first decade, it remain almost stable until the seventh decade when it dramatically reduced for both areas. The effects of aging on amplitude may reflect a maturational process of nociceptive system. Additional changes in peripheral and central processes may explain the diffuse decrease of N2–P2 amplitudes observed in elderly subjects. doi:10.1016/j.clinph.2016.10.050

39. Central sensitization as the mechanism underlying pain in joint hypermobility syndrome/Ehlers–Danlos syndrome, hypermobility type—A. Pepe, C. Leone, G. Di Stefano, C. Celletti, R. Baron, M. Castori, M. Di Franco, S. La Cesa, G. Cruccu, A. Truini, F. Camerota (Roma, Italy, Kiel, Germany)

Patients with joint hypermobility syndrome/Ehlers–Danlos syndrome, hypermobility type (JHS/EDS-HT) commonly suffer from pain. How this hereditary connective tissue disorder causes pain remains unclear although previous studies suggested it shares similar mechanisms with neuropathic pain and fibromyalgia. In this prospective study seeking information on the mechanisms underlying pain in patients with JHS/EDS-HT, we enrolled 27 consecutive patients with this connective tissue disorder. Patients underwent a detailed clinical examination, including the neuropathic pain questionnaire DN4 and the fibromyalgia rapid screening tool. As quantitative sensory testing methods, we included thermal-pain perceptive thresholds and the wind-up ratio and recorded a standard nerve conduction study to assess non-nociceptive fibres and laserevoked potentials, assessing nociceptive fibres. Clinical examination and diagnostic tests disclosed no somatosensory nervous system damage. Conversely, most patients suffered from widespread pain, the fibromyalgia rapid screening tool elicited positive findings, and quantitative sensory testing showed lowered cold and heat pain thresholds and an increased wind-up ratio. While the lack of somatosensory nervous system damage is incompatible with neuropathic pain as the mechanism underlying pain in JHS/EDS-HT, the lowered cold and heat pain thresholds and increased wind-up ratio imply that pain in JHS/EDS-HT might arise through central sensitization. Hence, this connective tissue disorder and fibromyalgia share similar pain mechanisms. WHAT DOES THIS STUDY ADD?: In patients with JHS/EDS-HT, the persistent nociceptive input due to joint abnormalities probably triggers central sensitization in the dorsal horn neurons and causes widespread pain. doi:10.1016/j.clinph.2016.10.051

40. The Neurophysiology in Florence Spinal Unit : A 25 years long history—G. de Scisciolo, R. Caramelli, V. Schiavone, A. Cassardo (Firenze, Italy)

In 1991, in Florence began a tight collaboration between Spinal Unit and Neurophysiological Service. From the beginning it became evident that neurophysiological examinations (NE) was a valid asset to clinical examination, because it helps to better define the real damage in patients with spinal cord lesion, traumatic but also vascular, neoplastic, iatrogenic, etc.. Although at the beginning NE was mainly used for diagnostic purposes, its prognostic value became