Multimodal brain monitoring in traumatic brain injury: A prospective observational cohort study

Traumatic brain injury (TBI) is an important cause of death and disability
especially in young adults. Treatment of this heterogeneous patient group is
however challenging because of difficulties in monitoring real-time dynamics in
brain dysfunction which may lead to secondary brain damage. Achieving an
adequate cerebral bloodflow is of major importance in preventing such secondary
cerebral damage which is the cornerstone of treatment in TBI. Cerebral
perfusion computed tomography (CT perfusion) is a technique which makes it
possible to rapidly and easily evaluate cerebral perfusion in different brain
regions and therefore can identify brain areas which are prone to ischemia or
hypoperfusion. Rapid fluctuations in cerebral hemodynamics are however not
detected by imaging techniques such as computed tomography (CT) scans and
magnetic resonance imaging (MRI). Therefore bedside tools for the assessment of
cerebral perfusion are mandatory for on demand therapeutic interventions.
Transcranial doppler (TCD) measures direct cerebral blood flow velocity, is
non-invasive in nature, and can be performed semi-continuously.
Electroencephalographic (EEG) monitoring also detects rapid changes in the
function of regional cortical neurons and seems therefore promising in locating
cortical regions vulnerable for secondary brain damage. Intracranial pressure
(ICP) transducers give information about progressive intracerebral space
occupying lesions leading to intracranial hypertension subsequently
compromising cerebral blood flow.
Integrating the above mentioned tools and assessing their relations in terms of
cerebral perfusion may lead to a specific model which gives a more detailed
insight in the development and pathophysiological processes of secondary brain
damage following the initial TBI.

The primary objective is to study the relationship between these monitoring
tools (TCD, EEG, ICP and CT perfusion) and the neurological outcome and to
create a multimodal model for outcome prediction. The secondary objective is to
study the functional relationships between the monitoring tools (TCD,
continuous EEG, ICP measurement and CT perfusion).
Ultimately, we aim to develop an integrated model that leads to better
recognition of pathophysiological changes after TBI and that can be used for
the detection of secondary brain damage in an early stage.

This is a prospective, observational, single centre, cohort study.

There is no associated risk for participating patients. Continuous EEG and TCD
are both non-invasive monitoring tools. The placement of an ICP transducer and
serial native CT-imaging are part of normal clinical practice, so applying the
study protocol does not introduce further risk to patients concerning these
interventions. The introduction in the study protocol of a non-ionized
iodinated contrast agent in cerebral perfusion computed tomography imaging of
the brain introduces a very small risk for anaphylactic reactions, 1 to 2 per
10.000 interventions. In patients with normal renal function there is no
associated risk for the development of contrast nephropathy. Patients with
known renal dysfunction, who have a higher risk for contrast enhanced
nephropathy, are excluded from the study protocol. Furthermore, the use of
contrast agents in imaging in trauma patients is part of normal clinical
practice. Follow-up will be performed by telephone at 6 and 12 months.