The Relationship Between Traumatic Brain Injury and Dopamine (a Chemical in the Brain)
Status:
Completed
Trial end date:
1969-12-31
Target enrollment:
Participant gender:
Summary
Traumatic brain injury (TBI) is the most common cause of death and disability in young
adults. Patients can experience significant problems with concentration, attention, and
memory (so called 'cognitive impairments') following TBI. These cognitive impairments can
drastically impact on a patient's well-being, and can lead to significant economic and social
consequences. Roughly a quarter of TBI patients improve but an equal number deteriorate over
time. The investigators know little about why patients vary so much in how they recover.
Crucially, the investigators have no treatments to improve brain functioning or recovery
after TBI.
Trials investigating ways of protecting the brain just after injury have been disappointing.
An alternative strategy, however, is to improve the function of brain regions that remain
intact, but that function inefficiently after TBI. The investigators know that dopamine (a
chemical in the brain) is known to influence many brain functions and the investigators know
that pathways in the brain that use dopamine are affected by TBI.
In humans, drugs that increase dopamine in the brain, such as methylphenidate, are sometimes
used to enhance cognitive function after TBI, but the response to treatment can be highly
variable between patients. Therefore, what is needed in the clinic is a way to target the use
of these drugs to patients who are likely to respond.
In a single centre study, the investigators will use SPECT (Single Photon Emission
Tomography) imaging to measure dopamine levels in the brain. MRI (Magnetic Resonance Imaging)
scans will assess brain structure and function. The investigators will test whether treatment
with methylphenidate improves cognitive functions in TBI patients who have ongoing cognitive
problems, whether the mechanism involves a normalisation of brain functioning and whether
brain dopamine levels can predict the magnitude of any improvement in symptoms.