Understanding Traumatic Brain Injury

It is often the least outwardly visible but sometimes deadliest of injuries: traumatic brain injury (TBI). Tracy Morgan was one high-profile celebrity who suffered a “severe brain injury” per his lawyer in a highway crash with a Walmart truck driver. Accordingly, public awareness has been raised on a complex condition, one that can span a wide range of outcomes.

Motor vehicle accidents like Morgan’s are one of the most common causes of TBIs, and can be severe due to the high velocity impacts involved. TBIs can range anywhere from a mild concussion to catastrophic, fatal damage. It is in the large and gray middle zone where prognoses can highly vary and are difficult to predict, given the complexity of the brain and the still mysterious mechanisms of neuronal repair.

Even milder TBIs (aka concussions) can lead to major consequences when repeatedly administered, leading to recent concerns in football, boxing, and other sports. This has also been a concern with military service personnel who are exposed to repeated bomb blasts in war zones, particularly in Iraq and Afghanistan where improvised explosive devices (IEDs) have been the enemy’s weapon of choice. Each time a brain is hit, despite some protection by a thick skull and cushioning fluid layer, and even with additional external protection like helmets, the softer tissue inside runs into its walls at or near the speed of impact.

That internal collision leads to damage, both at the macro level, where structures break and vessels might bleed, and on the micro level, where the neurons that make up brain tissue become like frayed electrical wires, no longer able to signal along their networks. In response to the damage, the tissues also go into inflammation mode, attempting to start the healing process but also causing dangerous swelling and other mechanisms that can instead worsen the damage. That cycle of microvascular damage is what becomes cumulative over time with repeated mild concussions, leading to scarring and cellular death.

With severe TBIs that require immediate surgical intervention to reduce the impact of brain swelling and bleeding, the prognosis can be very guarded. These TBIs might also involve direct intrusive trauma from internal brain hemorrhaging/bleeding or gunshots or shrapnel or other foreign bodies. Upon emergency assessment, along with brain imaging like MRIs and CT scans, the Glasgow Coma Scale (from 1 to 15, with 1 being the worst) is used to assess a person’s level of consciousness, which correlates with the amount of potential brain damage. For example, lack of response to painful stimuli indicates deeper unconsciousness and more severe injury. In general, comas are a negative prognostic factor and indicate severe damage. (It is not some benign magical sleep as shown on TV, where people wake up a year later and are instantly back to normal.) Emergency surgery might occur to relieve acute pressure on the brain from bleeding, objects, swelling, and inflammation and prevent death or further damage. “Medically-induced comas” are periods where a patient is sedated and medications to reduce brain swelling are given to help with this high-risk period of recovery.

Depending on what parts of the brain are impacted, the person can develop forms of dementia and personality changes. The frontal lobes which govern attention, problem-solving, and impulse control are commonly injured in TBIs (particularly sports-related injuries), since they are the largest part of the brain. Frontal lobe damage can lead increased irritability and limited self-control and disinhibition, combined with inattention, poor concentration, and memory problems. The most famous case of frontal lobe personality changes was Phineas Gage, the railroad worker who tragically had a spike shot into his brain. A May 2014 Slate article by Sam Kean details the tragic changes he suffered “from a virtuous foreman to a sociopathic drifter.” Higher rates of aggression and suicidal behavior have also been associated with frontal lobe damage, as seen in recent tragedies like NFL players Junior Seau, Ray Easterling, Jovan Belcher, and several other NFL suicides. A July 2013 JAMA Psychiatry study found an increased risk of suicide in military personnel with more lifetime TBIs.

As with people who have strokes, people with TBIs may also have difficulty with speech or with comprehension, or with areas of motor function in parts of their body or vision and hearing, depending on which brain structures governing these functions were affected. Intensive rehabilitation can help, as seen with the brave former Representative Gabrielle Giffords, who despite a devastating gunshot head wound has recovered some speech and the ability to walk. ABC News journalist Bob Woodruff also made remarkable gains despite a horrific TBI where he lost a large segment of his skull and brain and was comatose for 36 days.

Recovery from TBIs can highly vary, and per Tracy Morgan’s lawyer’s statement, despite an intensive rehabilitation regimen, the star was struggling and might have some permanent damage from his injuries. (In more recent media appearances, Morgan has shown reassuring and admirable improvement.) The brain is a malleable and mysterious organ, and recovers function in unusual ways, sometimes newly recruiting from remaining sections to restore abilities, as also seen with people who have had parts of their brains removed due to cancer or other medical conditions. Intensive external training and input during rehabilitation can enhance the amount of recovery possible, given the mind’s potential for plasticity in learning.

The mental health consequences of TBIs cannot be underestimated either, both as a direct effect of the injury, and as a reaction to its effects. Emotional support, particularly by family members and loved ones, is crucial during recovery, as it may help stimulate memories and provide a framework for one’s prior identity upon which to rebuild. This support helps both psychologically with a patient’s motivation and may also help neurologically as it preserves and restores memory and social reasoning.

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Giffords’ devoted spouse Mark Kelly has no doubt helped with her level of recovery. Morgan likely has a beloved support network, and of course a large fan base to cheer him on. TBIs will sometimes magnify or exacerbate any prior mental health conditions or personality traits that a person had, which will also affect recovery. It may be more difficult for someone who already had issues with impulsivity or depression to have those conditions aggravated. Professional mental health support is crucial in these situations and needs to be customized to each person and should not be ignored, alongside the physical and neurological issues. A comprehensive rehabilitation approach takes into account all these factors.

Expectations need to be realistic; recovery from TBIs is never an easy road, and permanent, life-changing adjustments happen. But this recovery is a journey where willpower and love in combination with medical science do seem to make at least some difference. TBIs can be tragic and difficult to overcome, but with human perseverance in combination with devoted care, one can fight and make the most of the struggle ahead.

(A version of this article was originally published in The Daily Beast on November 20, 2014.)