Dementia pugilistica, identified in boxers in the 1920s, and chronic traumatic encephalopathy, a more recent term, are thought to be the same disorder. Chronic traumatic encephalopathy has been widely studied. It occurs in some retired professional or college football players and other athletes who have had repetitive head trauma and in some soldiers with brain damage secondary to closed head injuries due to blast trauma.
Why only certain people who have repetitive head trauma develop chronic traumatic encephalopathy and what the risks of developing it are after various amounts of head trauma (eg, how many, how much force) are currently unknown. About 3% of athletes who have had multiple (even apparently minor) concussions develop chronic traumatic encephalopathy.
Pathologically, chronic traumatic encephalopathy is characterized by the deposition of hyperphosphorylated tau protein as neurofibrillary tangles, most prominently in the perivascular spaces, cortical sulcal depths, and subpial and periventricular areas.
Initial symptoms of chronic traumatic encephalopathy typically include ≥ 1 of the following:
There are two distinct clinical courses:
Mood disturbances and behavioral abnormalities develop during young adulthood (eg, during the patient's 30s), and cognitive impairment develops later.
Cognitive impairment develops later in life (eg, during the patient's 60s), and mood disturbances and behavioral abnormalities may develop after cognitive impairment.
Criteria for clinical diagnosis of chronic traumatic encephalopathy include the following:
These criteria are also used in research.
Results of routine neuroimaging such as CT or MRI are usually normal. Currently, there are no objective, validated in vivo biomarkers of chronic traumatic encephalopathy.
A definitive diagnosis of chronic traumatic encephalopathy is based on neuropathologic examination during autopsy.
There is no specific treatment for chronic traumatic encephalopathy.
If dementia develops, supportive measures, as for other dementias, may help. For example, the environment should be bright, cheerful, and familiar, and it should be designed to reinforce orientation (eg, placement of large clocks and calendars in the room). Measures to ensure patient safety (eg, signal monitoring systems for patients who wander) should be implemented.
Because insight and judgment deteriorate in patients with dementia, appointment of a family member, guardian, or lawyer to oversee finances may be necessary. Early in dementia, before the patient is incapacitated, the patient’s wishes about care should be clarified, and financial and legal arrangements (eg, durable power of attorney, durable power of attorney for health care) should be made. When these documents are signed, the patient’s capacity should be evaluated, and evaluation results recorded. Decisions about artificial feeding and treatment of acute disorders are best made before the need develops.
In advanced dementia, palliative measures may be more appropriate than highly aggressive interventions or hospital care.
Preventive measures are the most important intervention. Because chronic traumatic encephalopathy typically results from repeated head injury, people who have had a concussion are advised to rest and to gradually return to sports activity. Those who have had several concussions should be advised of the risks of continued play.