In Patients with minor head injury measurement of protein S100 will be introduced to the emergency departement as another tool to rule out intracerebral bleeding.

Severe intracerebral bleeding is still a complication even in obvious minor head injury (MHI) that makes the use of CT scanning necessary in patients with only few signs of intracerebral injury. To reduce the number of cerebral CT scans without pathologic findings measurement of protein S100 level in serum will be used in the emergency departement (ED) at our hospital.

Our hypothesis: with measurement of S100 levels cCT scans and inpatient treatment can be reduced, radiation and costs can be reduced.

From January 1st 2010 for 3-6 months all patients with head injury (all GCS) will be tested for their initial S100 level. Cut off level is set at 0,105ng/ml. During this period test results will be blinded. Decisions for further diagnostics (x-ray, cCT) and inpatient vs. outpatient treatment are made on clinical impressions as they are made now. The test results will be monitored and compared with clinical cases. Sensitivity, specificity, positive and negative predictive values will be measured.

The aim is to identify patients without risk for intracerebral bleeding (ie S100 level lower than 0,105ng/ml). Those can be managed in an outpatient way. All other patients will be diagnosed and treated as it is now.

If the test will not miss one intracranial bleeding and will save cCT scans and inpatient treatment, measurement of protein S100 will become a routine diagnostic in our ED for patients with MHI.

Inclusion Criteria:

• history of MHI during last 6 hours
• older than 3 years

Exclusion Criteria:

• more than 6 hours after MHI
• younger than 4 years
• informed consent not given

All patients older than 3 years entering the ED of the Kantonsspital Münsterlingen with the history of a MHI during the last 6 hours and after getting informed consent