Diagnosis

There is currently no way to diagnose CTE. It can only be suspected in people who are at high risk due to repeated head trauma over the course of years during their sports or military experiences. A diagnosis requires evidence of degeneration of brain tissue and deposits of tau and other proteins in the brain that can be seen only upon inspection after death (autopsy).

Some researchers are actively trying to find a test for CTE that can be used while people are alive. Others continue to study the brains of deceased individuals who may have had CTE, such as football players.

The hope is to eventually use a range of neuropsychological tests, brain imaging such as specialized MRI tests and biomarkers to diagnose CTE. In particular, imaging of amyloid and tau proteins will aid in diagnosis.

PET scans

A positron emission tomography (PET) scan uses a low-level radioactive tracer that is injected into a vein. Then, a scanner tracks the tracer's flow through the brain. Researchers are actively working to develop PET markers to detect tau abnormalities associated with neurodegenerative disease in people who are living.

Researchers are also working to develop tracers that target and bind to tau buildup and other proteins on PET scans. Studies are underway using these types of scans and tracers to look for tau buildup in the brains of retired athletes who experienced head injuries. These PET scans are in the research phase and not available for clinical testing.

Other tests

There's been little research on plasma or cerebral spinal fluid to diagnose the long-term disease processes of CTE. Some biomarkers that are used in Alzheimer's disease research may be useful for CTE because the conditions are similar. These biomarkers would need to identify brain degeneration from CTE separately from the original brain trauma.