A Neuropsychiatric Overview of Traumatic Brain Injury (Part 1)

Posted by Nathan Cope, MD on April 20, 2011 under Traumatic Brain Injury | Read the First Comment

We have an esteemed guest joining us at Outlook on Outcomes for the next few weeks.  Dr. Nathan Cope is Paradigm’s Founder and Senior Medical Officer and he’ll be sharing his expertise in the field of traumatic brain injury.  Specifically for this series, we’ll discuss TBI and neuropsychiatry.  – Dr. Holt

It is unfortunate that the psychiatric community has only recently developed a neuropsychiatric interest in brain injury.  For much of modern medical history the injured brain was felt to be irreparable and no real attempts at treatment were developed beyond palliative approaches.  More recently, over the past 20 or 30 years, as the plastic capabilities (ability to change or recover from damage) of the brain have become appreciated, more work in how to treat brain injury from the psychiatric perspective have emerged.  Yet it is still important to realize that medical science in this area is in its infancy and most recommendations are not based upon gold standard, randomized, blinded investigations which characterize many other areas of medicine.

In a similar vein, the discussion that follows around specific neuroactive or psychoactive medication use is derived from limited evidence.  No large scale, prospective studies comparing one medication with another or with placebo are available in TBI.  There are scattered small studies and a larger number of case series that suggest efficacy, but they are far from the desired level of proof desired.  Complicating this situation is the common observation that TBI patients tend to have individualistic responses to psychoactive drug intervention.  Two TBI survivors with essentially similar clinical pictures can have vastly different responses—one can be dramatic improvement; the next a detrimental response.  Clinically, all psychoactive pharmacologic treatment should follow a “single-case design” process whereby a baseline is firmly determined before a drug is started and the response carefully tracked.  Then, even if an apparent positive response is seen, a period of drug withdrawal is usually indicated to demonstrate continued need for the drug.

Many of the treatments felt useful for TBI are derived from treatment of other psychiatric problems whose symptoms and signs bear some similarity to TBI.  While this has to a large extent proven useful, it should also suggest caution in being dogmatic about what does and doesn’t work for TBI.  Judicious trial and error in treatment is not an inappropriate attitude to take here.

It is also important to consider just how complicated the brain is.  The brain is easily the most complex organ of animals.  There are billions of individual neurons in the human brain; each with hundreds or thousands of separate connections to other nerve cells via many diffuse fiber tracts almost literally connecting all areas of the brain with all others.  The main outputs of clinical psychiatric or psychologic interest—namely cognition, behavior, and emotion—are all enormously complicated activities which can vary, first due to individual variation, and second from a variety of injury specifics: from essentially “normal” through stages of mild, moderate and severe impairment.  Each dimension can change independently although they tend to interact with each other.  For example, a survivor of brain injury who has difficulty with their cognition may have secondary depression develop which may eventually evolve to aggressive behaviors due to frustration.

I will only summarize here the most important or common issues, and published sources should be accessed for detail.  Entire textbooks have been written about the neuropsychiatry of TBI, most recently and authoritatively by Silver, McAllister and Yudofsky in their work, Textbook of Traumatic Brain Injury (2^nd Edition, 2011).

Widespread Effects

Although the image of traumatic brain injury is commonly a picture of an individual with major physical, sensory and speech deficits (e.g. paralyzed and aphasic), which are seen in the moderate and severe injuries, perhaps the most common and important deficits following trauma to the brain are in the neuropsychiatric area and thus “invisible” to the casual observer.  Recent study of concussion has proven beyond doubt that even these so-called minor injuries create significant and often permanent deficits in brain function.  Permanent disability is higher with repetitive concussions (the “punch-drunk” syndrome).  The CDC estimates the incidence of all TBI in the U.S. to be more than 1,600,000 a year.

One final general point should be appreciated.  TBI affects not only the injured individual, but also their family, social and work environments.  It is always important to consider the other individuals involved and provide appropriate education, counseling and support as needed.  Much of the complications following TBI can be minimized by preparing the injured person’s support structure to have realistic expectations and appropriate reactions to the cognitive and behavioral alterations of TBI.

Loss of Consciousness, Delirium and Confusion

The hallmark of TBI is an immediate disorder or loss of consciousness (LOC).  Without this the diagnosis of TBI must be questioned (although rarely TBI can occur without it.)  A hallmark of the severity of the injury is the depth and length of the loss (or impairment) of consciousness.  A period of a few seconds to minutes of unresponsiveness is typical of a mild injury.  Several hours of LOC are characteristic of moderate TBI.  When the LOC stretches into days it will typically result in a severe TBI with more pronounced deficits.  After the resumption of awareness and responsiveness, there is typically a period of confusion or delirium.  The only treatment usually required for this is protection of the individual from hurting himself or herself accidently.  Similar to LOC, the duration of confusion or delirium is correlated very highly with the severity of the TBI; confusion may be a permanent result for very severe injuries.

Mild TBI

The vast majority (more that 85%) of TBIs are mild injuries.  Many of these mild injuries have significant (if often transient) symptoms.  These commonly include headache, irritability, sleep disturbance and cognitive impairment (difficulty concentrating, distractibility, slowed speed of processing).  Often, counseling about these expected complications and reassurance that they are (usually) transient is all that is needed.  A brief period of excusal from day to day work or responsibility and gradual resumption with frequent periods of rest is also often helpful.  Analgesics, anti-anxiety and sedative/hypnotic medications (for sleep aid) are also useful on occasion.  If problems with cognition persist, it is often useful to give a trial of stimulant medication such as Ritalin or amphetamine.  This helps with fatigue, concentration and speed of cognition, although at the risk of more irritability and error.  Antidepressants are also useful at this time.

A later complication of mild injury is the development of post-traumatic stress disorder or PTSD.  There is still little clarity about distinguishing PTSD from symptoms of mild injury itself which are often similar.  PTSD can occur without TBI and vice versa.  It is felt that early and aggressive treatment of TBI symptoms when evidence of persistence occurs is the best prevention of longer term development of PTSD.  Interestingly, it is rare for PTSD to be associated with more severe TBI, which may be due to the severe memory and cognitive deficits of the latter which “cushion” the emotional trauma of the event.

Other complications may include chronic pain and depression.  Similarly to PTSD, chronic pain may develop following mild TBI, often in the form of chronic headache or cervalgia (neck pain).  Finally, depression is a later complication.  It is also probably more common in mild than in the more severe forms of TBI, although it is quite common with all levels of severity.  Early and aggressive treatment, counselling and pharmacotherapy with analgesics and antidepressants are believed to be the most effective in preventing longer term problems.

Moderate and Severe TBI

When the TBI moves beyond the mild into the moderate/severe categories, more pronounced psychiatric issues become prominent.  I’ll discuss these in more detail in next week’s post.