Mild traumatic brain injuries, better known as concussions, can result from a variety of incidents such as falls, sports injuries, cycling accidents and car crashes. Although labelled as mild, they can cause persistent symptoms and incomplete recovery, including depression, cognitive impairment, headaches, and fatigue. While some studies have suggested that nine out of 10 individuals who experience concussion will have a full recovery after six months, evidence is beginning to contradict this. Some studies now show that only half of concussion patients achieve a full recovery, meaning that a significant number may not receive the necessary post-injury care they require.
Predicting which concussion patients will recover quickly and which will take longer is challenging, and even if a patient undergoes a brain scan, such as a CT or MRI scan, which looks for structural problems like inflammation or bruising, this may not show whether a patient’s symptoms will persist. Consequently, scientists are looking for new ways to diagnose and treat concussion with more accuracy. In a recent study, researchers from the University of Cambridge studied fMRI brain scans to investigate which patients would have a fast recovery and those who would require longer recovery times.
The study examined 108 concussion patients and 76 healthy volunteers. The patients had all been recruited to Center-TBI, a European research project that aims to improve the care for patients with traumatic brain injuries, which is co-chaired by Professor David Menon, head of the Division of Anaesthesia, and funded by the European Union. The study found just under half (45%) of the concussion patients still had symptoms associated with their brain injury, with the most common being fatigue, poor concentration, and headaches.
The researchers found that concussed participants had abnormalities in the thalamus, a region of the brain that integrates all sensory information and relays it around the brain. Despite no structural damage, these patients had increased connectivity between the thalamus and the rest of the brain, and the more this connection increased, the poorer the prognosis for the patient. In other words, the thalamus was compensating for the anticipated damage causing some of the long-lasting symptoms experienced by patients.
Using data from Positron Emission Tomography (PET) scans, the researchers were also able to make associations with key neurotransmitters depending on which long-term symptoms a patient displayed. For example, patients experiencing cognitive problems demonstrated increased connectivity between the thalamus and areas of the brain rich in the neurotransmitter noradrenaline, while patients experiencing emotional symptoms, such as depression or irritability, presented greater connectivity with areas of the brain rich in serotonin.
Dr Emmanuel Stamatakis from the Department of Clinical Neurosciences, Division of Anaesthesia, and Stephen Erskine Fellow at Queens’ College, Cambridge, said, “We know that there are already drugs that target these brain chemicals, so our findings offer hope that, in the future, we might be able to predict a patient’s prognosis and offer a treatment targeting their specific symptoms.”
This study offers insight into the complex nature of concussion and the need for more accurate diagnostic and treatment methods that focus on relieving specific symptoms. With the growing number of concussion cases worldwide, this research is crucial in ensuring that patients receive the care and attention they require.
