LAUSR

Introduction Median somatosensory evoked potentials (SEP) are considered to be reliable marker of cortical ischemia in rolandic area. Intraoperative SEPs monitoring during carotid endarterectomy (CEA) is well established. Emergent neurosurgical internal carotid artery (ICA) desobliteration after ischaemic stroke is not yet recommended treatment because of uncertain efficacy. There is subgroup of patients that recover after early ICA recanalization despite severe paresis in admission. Preoperative SEPs might be helpful in selection in such subgroup. Prognostic value of preoperative median SEPs on 3 month clinical outcome and its comparison to admission upper extremity paresis. Methods During the period 05/2013–7/2017, were prospectively enrolled 33 patients after acute ischaemic stroke (AIS) that underwent emergent neurosurgical ICA recanalization. Intravenous thrombolysis preceded the surgery in 14 cases (42.4%). Patient file included 29 men (87.9%) and 4 women (12.1%) aged from 52 to 88 years (average 71). ICA occlusion and pseudoocclusion was: 21 (63.6%), 90–95% stenosis: 7 (21.2%), 70–95% stenosis 5 (15.2%). Median SEPs were performed before and monitored during the surgery in all cases. Preoperative N20/P25 amplitude decrease on symptomatic side was measured as “asymptomatic/symptomatic side ratio”. SEP ratio > 0.8 was evaluated as normal; 0.5–0.8: mild decrease; Results Clinical finding in admission: Average MRC was 2.4 and 3.1 on upper (UE) and lower extremity (LE) respectively, speech disorder was present in 20 (60.1%). 3 months after CEA: Average MRC was 3.9 and 4.2 on UE and LE respectively, speech disorder was present in 9 (27.2%). Functional outcome: mRS 0–2: 27 (81.2%); mRS 3–5: 5 (15.1%); died: 2 (6.1%). Outcome predictors: 3 month clinical outcome (mRS) was reanalysed according to admission UE muscle strength (UE-MRC) and preoperative SEP ratio. UE-MRC 0–1: in 12 (36.4%): mRS 0–2: 6 (50%), mRS 3–5: 4 (33.3%), died: 2 (16.7%). UE-MRC 2–3: in 8 (24.2%): mRS 0–2: 7 (87.5%), mRS 4: 1 (12.5%). UE-MRC 4–5: in 13 (39.4%): mRS 0–2: 13 (100%). SEP ratio   0.8: in 19 (57.6%): mRS 0–2: 18 (94.7%), mRS 5: 1 (5.3%). Conclusion Significant SEP amplitude decrease (ratio