To explore the significance of bedside electromyography in diagnosis and prognosis of patients with neurocritical illness.

Fifty-eight patients with critical neurological diseases were included in this research for bedside electromyography study, who were hospitalized more than 3 d in neurological intensive care unit (NCU), Nangfang Hospital, Southern Medical University from November 2016 to April 2017. Abnormal conduction of 3 or more motor and/or sensory nerves in more than two limbs was identified as multiple nerve conduction abnormality. Groups were divided according to results of the electromyography, and then aetiology, electrophysiological and clinical characteristics were compared.

Of the 58 cases, 28 subjects (48.3%) were identified as multiple nerve conduction abnormality, the remaining 30 patients were in the control group. As comparing with the control group, the patients with multiple nerve conduction abnormality were more likely to have higher acute physiology and chronic health evaluation (APACHE)Ⅱscore [(12 ± 5) vs. (16 ± 6)], sepsis-related organ failure assessment (SOFA) score [4 (3, 6) vs. 7 (4, 11)], the incidences of sepsis [11/30 vs. 21/28] and multiple organ dysfunction syndrome (MODS) [2/30 vs. 10/28], as well as longer time of mechanical ventilation [0 (0, 4) d vs. 6 (0, 16) d] and ICU length of stay [8 (5, 13) d vs. 14 (7, 20) d], higher modified Rankin scale (mRS) scores in 30 d [4 (3, 4) vs. 5 (5, 6)] and 90 d [3.0 (2.0, 4.0) vs. 6.0 (4.2, 6.0)] after discharge, and higher mortalities in 30 d (2/30 vs. 12/28) and 90 d (4/30 vs. 15/28) after discharge (all P < 0.05). Multivariate Logistic regression analysis showed that the presence of multiple nerve conduction abnormality was an independent risk factor for the mortalities of 30 d and 90 d after discharge (all P < 0.05). The electrophysiological characteristics of patients with multiple nerve conduction abnormality showed that the proportion of motor nerve conduction not leading to compound muscle action potential (CMAP) waveform was higher (6/90 vs. 15/87) and the rates of abnormal sensory nerve conduction (58/83 vs. 28/81, 29/37 vs. 14/37, 29/44 vs. 14/44) were lower in the critical illness polyneuromyopathy (CIPNM) group (n=14) compared with the other etiological group (n=14).

The patients with neurocritical illness often have peripheral neuromuscular lesions, and have complicated causes. Bedside electromyography is of great significance for the diagnosis and prognosis of patients with critical neurological diseases.