Serial S-100 levels before, during and after cerebral herniation: a case report

S-100B is a small dimeric calcium-binding protein that is abundant in astroglial cells within the central nervous system (CNS). It has been shown to increase in cerebrospinal fluid (CSF) and serum after various neurological diseases, including minor head injury, severe head injury, subarachnoid haemorrhage and cerebral infarcts as well as after cardiopulmonary bypass surgery.

We report on a patient with severe head injury after a traffic accident who was followed with routine neuromonitoring techniques (intracranial pressure [ICP], microdialysis, clinical examination and neuroimaging) with the addition of serial serum S-100B measurements (a total of 41 S-100B measurements during admission of almost 3 days). Results of S-100B analysis were available within 2 hours of sampling allowing us to increase the sampling rate at physician discretion. Cerebral herniation, confirmed by cerebral angiography, occurred 1 day after admission. After brain death was established we continued to monitor S-100B levels in conjunction with an organ harvesting procedure for transplantation.

We found that S-100B levels seemed to peak immediately prior to cerebral herniation and then decreased shortly thereafter. In conjunction with the organ harvesting procedure S-100B levels increased, indicating a clear extracerebral source of the protein.