Background and aims
Neuron-specific enolase (NSE) is a dimeric, intracellular, glycolytic enzyme, which is released after stroke, cardiac arrest, traumatic brain injury. Serial assessment of its level may help in identification of patients at risk of poor outcomes, in decision making on intensive care, rehabilitation or palliative treatments.
Methods
An 80 years-old male patient came to our observation for confusion. At past case history, chronic coronary syndrome in aortic-coronary by-pass, mild-moderate mitral failure, paroxysmal atrial fibrillation, pulmonary emphysema, type II diabetes mellitus, recent SARS CoV2 were reported.
Results
Level of NSE was high (30.8 ng/ml). Episodes of O2 saturation below 90%, decreased lymphocyte absolute counts and g globulins were still present. IgM and IgG titers and nasopharyngeal swab were negative. Electroencephalogram showed dysrhythmia, with diffuse slow waves. Chronic cerebrovascular disease was evident at neuroimaging.
Conclusions
Our observations confirm our previous finding on worst outcomes after CoV2 infection in immunodepressed patients with comorbidities. We highlight that NSE may be a useful marker to assess the clinical course in anoxic encephalopathy. However, it is dependent on the ratio between neuronal and glial cells. Low levels do not rule out ongoing damage. In elderly patients, S100, a calcium-binding, astroglial protein may be more consistent. On the other hand, the brief half-life of the latter (25 min) compared to the longer half-life of former marker (30 hrs) may limit detection. Both may implement clinical and radiological findings, especially in ventilated and sedated patients. Lastly, they may add further information for ethical, social and legal issues.