Chronic traumatic encephalopathy
The exact incidence and prevalence are unknown. It is most commonly seen in amateur and professional sports players where head contact is common (e.g. boxing, American football, rugby, ice hockey), as well as in military personnel exposed to explosive blasts .
Symptoms have an insidious onset, most often years after the initial injuries, with loss of normal attention, concentration and memory. This can progress, in some cases in 2-3 years, to include motor symptoms such as impaired gait, impaired, executive function, lack of insight and poor judgment .
There is generalized cerebral atrophy with more pronounced atrophy of the frontal and temporal lobes (including mesial temporal lobe) as well as the thalamus, hypothalamus and mammillary bodies. A cavum septum pellucidum may be present .
Chronic traumatic encephalopathy is characterized by the presence of neurofibrillary tangles and TDP-43 binding protein in subcortical and perivascular regions, often with reactive astrocytes and microglia .
Although the details remain to be elucidated, there is mounting evidence that reactive gliosis and redistribution of aquaporin 4 molecules, leading to disruption of transparenchymal CSF clearance of interstitial beta-amyloid via the glymphatic system may be a key component .
Imaging features of CTE are nonspecific, but the following may be seen
- generalized cortical atrophy
- hippocampal atrophy
- vermian atrophy
- cavum septum pellucidum
- features of diffuse axonal injury (e.g. microhemorrhages)
History and etymology
This syndrome was first recognized in boxers in 1928, and has been known as "punch drunk" and "dementia pugilistica".
There is clinical and imaging overlap of chronic traumatic encephalopathy with other neurodegenerative diseases, and traumatic brain injury is a risk factor for their development (i.e. not just chronic traumatic encephalopathy) and should be considered in the differential diagnosis :