Determining the Relationship Between EEG Findings and Prognosis of Patients with Decreased Consciousness Following Head Injury

Abstract

Background: Head injury is a silent epidemic in developed countries and is one of the leading causes of death and disability. Determining the precise and early prognosis of head injury, especially in severe cases, is essential and will help define treatment actions and rehabilitation plans and counsel other family members. The purpose of this study was to determine the relationship between electroencephalographic findings and prognosis in patients with decreased levels of consciousness due to head injury. Methods: This is a retrospective descriptive-analytical study on patients with reduced levels of consciousness due to head injury, referred to Tir Hospital (Tehran) in the first half of 2018. Overall, 52 patients were studied and divided according to their GCS into two groups: favorable prognosis (30 patients, 57.7%) and poor prognosis (22 patients, 42.3%). We tried to find the relation between EEG findings such as voltage, electrographic seizures, periodic and rhythmic patterns, and the prognosis. Results: Normal voltage was associated with a favorable prognosis, with a high specificity (95%) and a less robust sensitivity (63%). The isoelectric voltage (electrocerebral shutdown) was associated with a poor prognosis. Normal and isoelectric voltages were good predictors with 95% and 100% Positive Predictive Values (PPV), respectively. There was a statistically significant relationship between EEG frequency range and prognosis. Conclusion: This study showed that EEG parameters might provide valuable data regarding the prognosis of decreased consciousness of patients with a head injury, also for the guidance of physicians and informing the patients’ family.