Head injuries are one of the most common reasons for seeking emergency care. For a long time, computed tomography imaging of the head has been the only means of identifying intracranial injuries, such as brain bleeds, in head injury patients. Emergency department physicians have had to rely on their judgment to decide which patients require imaging and who can be discharged without further examinations. Over the years, various general guidelines for imaging head injury patients have been created to facilitate this decision-making. Still, up to 80% of head imaging scans reveal no intracranial abnormalities.
“Missing, for instance, a brain bleed can be incredibly risky for the patient which is why doctors have been more inclined to send patients for head imaging as a precaution rather than refraining from it. As a downside, this cautious approach leads to unnecessary imaging, which in turn means the patient spends more time in the emergency department and is exposed to unnecessary ionising radiation. In addition, this ties up imaging resources that other patients might need at the same time,” Mira Keski-Pukkila explains.
To address this problem, researchers have explored using blood-based biomarkers. An increase in the concentration of such biomarkers in the blood after a head injury may signal a need for imaging. In 2013, the S100B protein, released by astrocytes in the brain, was added to the Scandinavian guidelines for initial management of minimal, mild and moderate head injuries in adults. According to the guidelines, a specific group of patients can be discharged without imaging if the level of S100B in their blood is below a certain threshold.
In addition, a test containing two biomarkers released from brain tissue was approved in the United States in 2018. This test reliably identifies patients with head injuries that have resulted in intracranial injuries in imaging.
However, questions regarding the safe use of these biomarkers in different patient groups, such as the elderly, remain. More research is needed on possible non-injury-related factors that affect the biomarker levels in the patients’ blood.
In her dissertation, Keski-Pukkila examines the use of the Scandinavian guidelines and measuring S100B in the Finnish population. She also investigates the ability of several different biomarkers to identify intracranial injuries in elderly patients.
“The use of S100B, as recommended by the Scandinavian guidelines, is safe in the Finnish population and can reduce the unnecessary imaging of head injury patients. In the same population, intracranial injuries were also successfully identified using another biomarker, the glial fibrillary acidic protein (GFAP), which was also the only biomarker that reliably identified injury-related intracranial findings in elderly patients in one of the sub-studies in the dissertation,” Keski-Pukkila says.
Adding these biomarkers to the management practices of Finnish head injury patients could potentially reduce the time the patients spend in the emergency department and decrease medical costs associated with their treatment. The biomarkers are also hoped to contribute to reducing the long waiting times currently plaguing emergency departments.
Public Defence on Friday 1 December
The doctoral dissertation of MD Mira Keski-Pukkila, Acute Management of Head Injuries – A Clinical Study Focused on Blood-Based Biomarkers, in the field of neurosurgery, will be publicly examined at the Faculty of Medicine and Health Technology of Tampere University on Friday 1 December 2023 at 12 o’clock on the Kauppi campus. The venue is lecture hall F114 in the Arvo building (address: Arvo Ylpön katu 34, Tampere). The opponent will be Docent Johan Undén from Lund University, Sweden, and Professor Juhana Frösén from the Tampere University will act as the custos.
The doctoral dissertation is available online.
The public defence can be followed via a remote connection.
Photo: Saija Turkkinen