Repeated Head Impacts may cause Chronic Traumatic Encephalopathy

Repetitive head impacts (RHI), defined as the cumulative exposure to recurrent concussive and subconcussive events, have long been associated with the neurodegenerative disease chronic traumatic encephalopathy (CTE). However, in recent years, the diagnosis of CTE in American and Australian football, soccer, rugby, ice hockey, and other contact sports has led to a renewed debate on whether the relationship between RHI and CTE is causal.

A recent study evaluated the strength of evidence underlying the possible causal relationship between RHI and CTE through the Bradford Hill criteria for causation. Evaluation by the nine viewpoints of the criteria – strength, consistency, specificity, temporality, biological gradient, plausibility, coherence, experiment, and analogy – resulted in convincing evidence of a causal relationship between RHI and CTE, as well as an absence of evidence-based alternative explanations. This finding calls for immediate action by the medical, scientific and public health communities to prevent CTE by minimizing and eliminating RHI and to develop therapeutics to slow or stop disease progression.

Improved diagnostics of concussion can be a way to reduce the occurrence of CTE. Medicortex Finland Plc (www.medicortex.fi) is developing a diagnostic kit for detection of even mild forms of traumatic brain injury, or concussion.