The value of electroencephalography in differential diagnosis of altered mental status in emergency departments

Objective: To evaluate the value of electroencephalography in patients with altered mental status in emergency departments. Methods: Demographical characteristics, types and aetiologies of seizures, and clinical outcomes of the patients were recorded. Patients were divided into 4 groups according to the complaints of admission: findings and symptoms of seizure; stroke and symptoms of stroke-related seizures; syncope; and metabolic abnormalities and other causes of altered mental status. The electroencephalography findings were classified into 3 groups: epileptiform discharges; paroxysmal electroencephalography abnormalities; and background slowing. Electroencephalography abnormalities in each subgroup were evaluated. SPSS 21 was used for statistical analysis. Results: Of the total 190 patients in the study, 117(61.6%) had pathological electroencephalography findings. The main reason for electroencephalography in the emergency department was the presence of seizure findings and symptoms in 98(51.6%) patients. The ratio of electroencephalography abnormality was higher in patients who were admitted with complaints of metabolic abnormality-related consciousness disturbances (p 0.001). A total of 124(65.3%) patients had neuroimagings. Electroencephalography abnormalities were found to be significantly higher in patients with neuroimagings compared to those without neuroimagings (p 0.003). Conclusion: Despite advanced neuroimaging techniques, electroencephalography is still an important tool in the differential diagnosis of altered mental status such as epileptic seizures, metabolic abnormalities, pseudo-seizures and syncope.