Prognosis of outcomes of intracranial arterial aneurysm clipping using intraoperative neurophysiological monitoring data

The study objective is researching of neurological deficit (ND) increasing risk factors in early postoperative period after intracranial arterial aneurysms clipping, in the cases of a transient loss of responses (TLR) during transcranial motor evoked potentials (TcMEP) and somatosensory evoked potentials (SSEP) registration. Materials and methods. One hundred and eighty-four (184) patients, operated in the neurosurgical department of IRCH by intracranial arterial aneurysms from 2014 to 2019 using intraoperative neurophysiological monitoring were included. In the acute period, 67 (36.4 %) patients were operated, in the subacute period — 40 (21.7 %), in the cold period — 77 (41.8 %), of which 7 patients have a history of aneurysm rupture, 70 patients have no break. Eighty-one (44.0 %) patients registered SSEP, 75 (40.8 %) — TcMEP, 28 (15.2 %) — successively SSEP and TcMEP. Results . MEP TLR was noted in 27 (14.7 %) cases, of which in 15 (55.6 %) cases — without an increase in ND, and in 12 (44.4 %) cases — with an increase in ND by 5.17 ± 4.63points according to NIHSS (National Institutes of Health Stroke Scale), SSEP TLR was noted in 20 (10.9 %) cases, of which in 13 (65 %) cases — without an increase in ND, and in 7 (35 %) cases — with an increase in ND by 5.14 ± 4.91 points according to NIHSS. MEP TLR with the subsequent ND increase significantly more often developed during operations performed in cold period (66.7 %) vs in acute period (25.0 %), and in subacute period (8.3 %). MEP TLR without ND increase was more often observed in acute period (46.7 %) and subacute period (33.3 %) vs in cold period (20.0 %) (p = 0.044). Transient MEP TLR during approach to an aneurysm were significantly more often (36.4 %) associated with ND increase, and MEP TLR which developed within 10 min after the final clipping, with timely correction taken were significantly more often (66.7 %) associated with a favorable outcome. Conclusion . Transient MEP TLR is more significant in predicting of postoperative ND, in the case of clip intracranial arterial aneurysms in cold period. MEP TLR during approach to an aneurysm more often associated with ND increasing.