Use of neuron-specific enolase for assessing the severity and outcome of neurological disorders in patients

Abstract

Neuron-specific enolase (NSE) is a glycolytic enzyme present almost exclusively in neurons and neuroendocrine cells. NSE levels in cerebrospinal fluid (CSF) are assumed to be useful to estimate neuronal injury and clinical outcome of patients with serious clinical manifestations such as those observed in stroke, head injury, anoxic encephalopathy, encephalitis, brain metastasis, and status epilepticus. We compared levels of NSE in serum (sNSE) and in CSF (cNSE) among four groups: patients with meningitis (N = 11), patients with encephalic injuries associated with impairment of consciousness (ENC, N = 7), patients with neurocysticercosis (N = 25), and normal subjects (N = 8). Albumin was determined in serum and CSF samples, and the albumin quotient was used to estimate blood-brain barrier permeability. The Glasgow Coma Scale score was calculated at the time of lumbar puncture and the Glasgow Outcome Scale (GOS) score was calculated at the time of patient discharge or death. The ENC group had significantly higher cNSE (P = 0.01) and albumin quotient (P = 0.005), but not sNSE (P = 0.14), levels than the other groups (KruskalWallis test). Patients with lower GOS scores had higher cNSE levels (P = 0.035) than patients with favorable outcomes. Our findings indicate that sNSE is not sensitive enough to detect neuronal damage, but cNSE seems to be reliable for assessing patients with considerable neurological insult and cases with adverse outcome. However, one should be cautious about estimating the severity of neurological status as well as outcome based exclusively on cNSE in a single patient.

Biomarkers of Brain Injury in Cerebral Infections

“…The technique with which samples are collected has implications for their suitability; for example, hemolyzed blood samples may be contaminated by biomarkers released from erythrocytes (26 ). The collection tube may influence biomarker concentrations, and tubes appropriate to the biomarker of interest should be used (27 ).…”

“…Reference intervals for serum concentrations range from 5 to 15 ng/mL. When neuronal membranes are injured, NSE easily diffuses into the extracellular space and CSF (26 ). Consequently, increased concentrations of NSE in the CSF and serum have been identified in several cerebral pathologies, including encephalitis, cerebral infarction, Parkinson disease, amyotrophic lateral sclerosis, spinocerebellar degeneration, cervical spondylosis, polyradiculoneuritis, and TBI (23,57,58 ).…”

“…Lima et al (26 ) examined whether NSE concentrations correlate with severity of neurological impairment. They sampled serum and CSF in 51 adults: 11 with meningitis, 7 with encephalic injuries, 25 with neurocysticercosis, and 8 controls.…”

Serum and cerebrospinal fluid S100B concentrations in patients with neurocysticercosis

“…Among them, those most extensively studied are neuron-specific enolase (NSE), creatine kinase isoenzyme BB, 14-3-3 protein, myelin basic protein, tau protein, polyamines, glial fibrillary acidic protein, and S100B protein (1)(2)(3)(4)(5).…”

Cellular and Molecular Mechanisms Underlying Epilepsy: An Overview with Our Findings

“…insult in patients (Lima et al, 2004). Although multiple reports have documented elevation in NSE levels following neuronal injury in various neurological disorders, little is known about the localization of NSE in different brain regions after chemically induced acute and chronic seizures.…”