SPECT Imaging Offers More Accurate Diagnosis of Traumatic Brain Injury
Advanced neuroimaging can more accurately diagnose traumatic brain injury and post-traumatic stress disorder than CT or MRI.
Traumatic brain injury (TBI) has been all over the news — and consequently on the minds of Americans. Yet, TBI is neither a new problem nor a rare malady. TBI ranges from mild TBI (concussion), moderate TBI (usually associated with a loss of consciousness at the time of injury), and severe TBI.
The Centers for Disease Control and Prevention estimated that 1.5 million Americans sustained TBI annually in 2000.1 As of 2006, the estimates had risen to 1.7 million brain injuries per year.2 These prevalence proportions will increase as military personnel return home and the problem of repeated mild TBI (mTBI) becomes more recognized in sports. Current estimates of TBI among veterans range from 9.6% to 20%,3 with an estimated total of more than 300,000 cases among military personnel since 2000.4 The current estimates of combined sports-related concussions and brain injuries in the United States are 1.6-3.8 million each year.5
TBI results in a wide spectrum of neurological, psychiatric, cognitive, and emotional consequences. In part, the variation is related to the severity of the injury, which is stratified based on Glascow Coma score, periods of unconsciousness, and degrees of amnesia. Furthermore, the diversity of sequalae can be related to the areas of the brain that are injured, the severity of the injury (highly variable within the classification of “mild” and “moderate”), and the evolution of the injury over time due to neuro-inflammatory processes.
It is not easy to diagnose TBI. Perhaps the key complication is that the symptoms of persistent mild-to-moderate TBI have tremendous overlap with those of posttraumatic stress disorder (PTSD),6 a mental disorder that can develop after a person is exposed to 1 or more traumatic events. These overlapping symptoms include headaches, fatigue, irritability, cognitive difficulties, anxiety, sleep disturbance, memory impairment, difficulty concentrating, and emotional dysregulation. Clinically, these populations may overlap by 33% to 42%.7,8 The Congressional Research Service9 reported 103,792 servicemen and women diagnosed with PTSD from 2000-2012. For patients with both TBI and PTSD, the US Department of Veterans Affairs (VA) acknowledges that the patient is often diagnosed with one or the other. Note that several of the question items within the Clinician-Administered PTSD scale10 can be symptoms of TBI, such as poor concentration, memory difficulties, anhedonia, social isolation, sleep difficulties, and irritability. The VA recently concluded there was a lack of diagnostic accuracy for the dually affected veteran.11
The economic costs to society for treatment of PTSD and TBI are significant, with the Rand Corporation estimating an annual cost for TBI between $591 million and $910 million. Within the first 2 years after returning from deployment, the estimated costs associated with the treatment of PTSD and major depression for 1.6 million service members ranged between $4 billion to $6.2 billion.12