Neuron-specific Enolase Level after the Onset of Delayed Neurological Sequelae with Acute Carbon Monoxide Intoxication

Background: Delayed neurological sequelae (DNS) is a major problem in carbon monoxide (CO) intoxication. Many other studies have showed whether serum NSE of acute phase can predict DNS in CO poisoning. However, no study has examined NSE levels after development of DNS. Therefore, we report serum NSE levels after the onset of DNS. Case presentation: We described the NSE levels in two cases of DNS. The first was a 33-year-old woman who presented with concentration problems 39 days after CO exposure. The second was a 51-year-old woman who presented with gait disturbance and urinary incontinence 23 days after CO exposure. Brain magnetic resonance imaging (MRI) and NSE levels were obtained in both patients. Brain MRI confirmed brain injury and the diagnosis of DNS was made. The NSE levels of the two patients were 12.51 and 16.18 ng/mL, respectively. Conclusion: Although the initial NSE elevated level may be useful in the prediction of carbon monoxide induced DNS, it may be decreased to normal reference range after the onset of DNS.