At least 5.3 million persons in the U.S., or 2% of the population, are currently living with a Traumatic Brain Injury (TBI)-related disability.¹ TBI is defined as a “blow or jolt to the head or a penetrating injury that disrupts the function of the brain” with a continuum of severity from mild to moderate to severe.¹ Mild TBI (M-TBI) the most commonly diagnosed TBI accounts for approximately 75% of all TBI cases, or roughly 1.1 million new cases in the U.S. per year. ^2-3

TBI severity must be carefully assessed and appreciated as it has certain implications for short- and long-term clinical outcomes. The most commonly used scale used during the initial phases (e.g., scene of the trauma, in the ER or ICU) is the Glasgow Coma Scale (GCS) which measures speaking, eye opening and motor abilities on a 15-point scale.⁵ The higher the score on the GCS, the less severe the injury; with scores categorized into 3 basic levels of functioning.

The Rancho Los Amigos Scale (RLAS, aka “Rancho” 3) has some overlap with the GCS, but emphasizes progress throughout the recovery processand takes on a more chronic injury perspective. In addition to measuring progress, the RLAS is also used to communicate clinical status between healthcare professionals.

Why Focus on TBI and Aging?

The number of persons with TBI-related disabilities in the U.S. is steadily growing. Consider that 28% of TBIs result from falls among those ages 65 or older.¹ As this age demographic increases, likely so will the incidence of new TBI cases. Further, as neuro-trauma care in the U.S. advances, the ‘net’ increase of persons living with TBI-related disabilities will rise annually.

The “normal” aging process itself can be viewed as a slow, steady decline of various neurological and physical functions regardless of trauma or disease. When a TBI is super-imposed upon the “normal” aging process, what occurs in many circumstances is a situation where 1 (normal aging) + 1 (TBI) = 3. TBI, especially severe TBI, leaves the injured person with increased “risk factors” for an accelerated aging process.^6-8 There is no absolute age that puts TBI patients into a higher risk pool for accelerated aging, rather ranges of ages (e.g.,  70 and above) that seem to be associated with a poorer prognosis with respect to TBI recovery.^9-11 Moreover, TBI can hasten or exacerbate age-related symptoms/illnesses such as insomnia, cardiovascular disease, cognitive decline, certain cancers, Type 2 diabetes, and depression.^12-14

One of the disease states that is getting particular attention within the brain injury research is Dementia of the Alzheimer’s Type (DAT).⁸ By definition, DAT is a progressive neurological disorder that currently has no known cure. To date, the relationship between TBI and DAT is ambiguous. While some persons with severe TBI share similar levels of functioning when compared to persons suspected of having DAT (e.g. impaired attention and memory, decreased ability to perform activities of daily living, preservative and confabulatory tendencies) the underlying neuron-anatomical and neuron-physiological mechanisms are different in many ways.¹⁵ The evidence to date suggests that there may be a causal link (e.g., genetic marker, presence of plaques, neuronal “tangles”) between TBI and DAT with severity of TBI and age at onset as possible mediators.^{6; 14-16} However, there is conflicting evidence regarding the potential link between TBI and vascular dementia, thus, further research is warranted.^6-7

Interestingly, seizures, if they do occur, are more likely to occur in the acute phase after TBI than in the chronic phase.⁵ As such, prophylactic use of anti-convulsant medications is deemed as a “best practice” in the days and weeks following injury, but in the event that no seizures occur, and the risk factors are low, then strong consideration should be given to gradually discontinuing anti-convulsant medication usage as it is well known that many anti-convulsant medications carry serious negative side effects including blunting of cognition and potential liver and kidney dysfunction. Because young children and elder adults are the two largest groups at risk for TBI, the issue of aging with TBI and the potential risk for late onset seizure (several years post-injury) remains for as long as 20 years, but then declines significantly as the person ages.¹⁹

Unfortunately, late onset (also often referred to as “breakthrough”) seizures are usually more difficult to manage than acute onset seizures. Fortunately, there is considerable research in process that involves diagnostic and treatment approaches to all forms of epilepsy. A valuable resource to review this ongoing research is www.ninds.nih.gov/disorders/epilepsy/epilepsy.htm.

In addition to exploring the relationship between TBI and DAT and TBI and seizure disorders, several studies have explored the influence of TBI on other health conditions such as, arthritis,  sleep disorder, higher risk for another TBI, hypertension and obesity, major depression, neuro-muscular disorders, and anxiety disorders.^{2; 21-24} Taken together, results suggest a higher incidence of each of these conditions among TBI patients as compared to their non-injured counterparts.