How is traumatic brain injury identified?

Patient history

As far as is possible, details of prior illnesses, medications taken (particularly any medications that inhibit blood clotting) and what happened during the accident should be obtained from the patient.

Examination

The examination initially focuses on determining the patient's state of consciousness (GCS) and taking the patient's vital signs (respiration, blood pressure and pulse). Concomitant injuries must then be identified. In case of a grade II or III traumatic brain injury, involvement of the cervical spine must be assumed until proven otherwise. Appropriate stabilisation measures must therefore be taken before the patient is mobilised. The neurological examination checks for the presence of signs of neurological deficits by examining the function of the cranial nerves, strength, sensitivity, tendon reflexes and coordination.

Laboratory

Laboratory testing routinely includes assessment of blood clotting, a blood count, blood gases, liver and kidney function parameters, blood sugar, blood alcohol level (if applicable) and blood typing.

Diagnostic testing for suspected traumatic brain injury

X-rays

Fractures can be detected with the aid of an x-ray of the skull and cervical spine. Even patients with minor traumatic brain injury are found to have a fractured skull in approximately 10 percent of cases.

Computed tomography (CT)

Computed tomography of the brain provides x-ray images of the brain and bone structures in the form of slices. They are used to detect and differentiate haemorrhages. They can help to evaluate the space-occupying effect (i.e. the pressure on the brain from haemorrhages and thus to determine quickly whether neurosurgical intervention is necessary. They can also identify cerebral oedema, any enlargement of the spaces containing cerebrospinal fluid, complications associated with strokes and skull fractures. The detection of air inside the skull is indicative of an open-head traumatic brain injury. Whether computed tomography has to be performed even in the case of minor traumatic brain injury must be decided on a case-by-case basis and will be dependent on risk factors such as being aged over 65 years, the patient taking medications that inhibit blood clotting or accidents with an unclear mechanism. In cases of more severe traumatic brain injury, it may in certain circumstances be necessary to perform several follow-up CT scans, depending on the initial findings and clinical course.

Magnetic resonance imaging (MRI)

Magnetic resonance imaging is an imaging procedure that uses powerful magnetic fields to generate images in the form of slices. Unlike computed tomography, this procedure can also be used to detect diffuse axonal injury. Furthermore, the method permits more precise assessment of the brainstem. Special test procedures such as diffusion MRI techniques can be used to identify abnormal blood flows early on. Imaging blood vessels by means of a procedure known as MRA (magnetic resonance angiography) can be used to identify tears in the walls of blood vessels (dissection). However, because the procedure takes a long time and requires patients to remain still, MRI plays a secondary role in acute diagnostics.

Neurosonography

Ultrasound procedures to detect the dissection of blood vessels and vasospasm.

Electroencephalography (EEG)

Procedures used to measure the electrical activity of the brain. These detect epileptic patterns of activity - an epileptic seizure resulting from traumatic brain injury may be the cause of impaired consciousness. EEG is also valuable to a certain degree for prognosis in cases of severe traumatic brain injury.

Evoked potentials

Evoked potentials are a test method used to check whether the optic, acoustic and sensory nerve tracts are intact from the peripheral areas to their central representative areas in the brain. This method is also of value for prognostic purposes in cases of severe traumatic brain injury.