MOVERS & SHAKERS
Haemorrhage, Haematoma, stroke (Brain Bleeds)
A brain haemorrhage is essentially bleeding in the brain. There are a series of layers between the brain and the skull in order to keep the brain protected. Depending on where the bleeding occurs, there are various different labels for the different types of brain haemorrhage that can occur.
Description and Anatomy
A Subdural Haematoma is a collection of blood that is similar to a clot. It is a serious injury that is rare in the general population. In sports however, it is one of the most common head traumas that athletes can experience. The brain is separated from the bone of the skull by a sheet of thin durable tissue called the dura. The dura is connected to the brain's service by a thick network of veins, which are called "bridging veins". When the head is hit or shakes violently, it causes the veins to tear and bleed. The bleeding forms clots - this is a subdural haematoma.
An Epidural Haematoma is also a collection of blood or a clot that occurs in the brain after a trauma. This type of injury occurs between the skull and the dura.
An Intracerebral Haematoma is also labelled an intracranial haematoma, intracranial haemorrhage or intracerebral haemorrhage and is a bleed within the brain.
Not all head trauma in sport results in symptoms, such an sub-concussive injuries, however these may still result in injury to the specialist cells (neurons) that make up the brain. Research has shown that the longer an athlete participates in contact sport, regardless of whether they have a history of a concussion or not, that there is an association with abnormalities on brain imaging scans (Singh et al., 2014) and with the stage of CTE development (Stein, Alvarez & McKee, 2015).
Perry et al (2016) reviewed a wide range of studies to show collective evidence of higher odds of Alzheimer’s disease, Parkinson’s disease, mild cognitive impairment, depression, mixed affective disorders, and bipolar disorder in individuals with previous TBI compared to those without TBI.
In addition, co-morbid pathologies are common in CTE (Mez et al., 2017)
Chronic traumatic encephalopathy is diagnosed neuropathologically by the accumulation of hyperphosphorylated and aggregated tau in neurons, astrocytes, and cell processes around small vessels and in the depths of the cerebral sulci (McKee et al., 2016).
American football players, the number of years of contact sports play significantly predicts the severity of tau pathology in the dorsolateral frontal cortex and the CTE stage (McKee et al., 2013)
RHI may accelerate and alter the deposition and pathological progression of other neurodegenerative proteins. For example, individuals with a history of RHI and neuropathological diagnosis of CTE accumulate β-amyloid (Aβ) at a younger age and at an accelerated rate compared to a general autopsy cohort (Stein et al., 2015)
There has been some evidence of an increased risk of developing Motor Neuron Disease in NFL (Guerriero et al., 2012; Lehman et al, 2012).
Parkinson's disease and Parkinsonism
Evidence has shown an increased associated with contact sports and the development of Parkinson's disease and symptoms associated with this presentation (Crane et al., 2016).
Evidence from the general population have shown that of patients attending A&E with traumatic head injury, that there was a 44% increase in the development of Parkinson's disease over 5-7 years,
Among military veterans, mTBI is associated with 56% increased risk of PD, even after adjusting for demographics and medical/psychiatric comorbidities (Gardner et al., 2019)
What is left unknown?
Whether there is a specific severity of number of TBI's needed in order to alter risk for neurodegenerative diseases in athletes.