Table 2 outlines common neuro-psychiatric disorders seen following TBI. This author has delineated a medical model with evidence-based meth-odology for the assessment of TBI with comorbid medical, psychiatric, and neuropsychiatric conditions.7
The history taken at the time of the psychiatric examination of a patient presenting to a psychiatrist with PTSD is the most telling. It is important to take not only a strong psychological history of traumatic events but also a careful history of physical injury that occurred at the time of the trauma that precipitated the PTSD.
For the child psychiatrist, a history of inflicted harm should arouse immediate suspicion of an underlying TBI. Clearly, a child injured in a motor vehicle accident or other accident by blunt force trauma should be historically evaluated to determine whether there was loss of consciousness or whether posttraumatic cognitive changes are present.
In adults, the most common scenarios for comorbid TBI and PTSD include assault and battery, blunt force trauma in motor vehicle or industrial accidents, suicide attempts associated with severe blunt force trauma (such as jumping from a building), and blunt force trauma or blast-overpressure trauma sustained from ordinance explosions during combat. In particular, psychiatrists should be suspicious when examining any returning combat veteran with PTSD symptoms that have resulted from an explosion (blast-overpressure trauma). Blast-overpressure brain injury is frequently underdiagnosed in soldiers returning from Iraq and Afghanistan who have sustained mild TBI or explosion-induced concussions. Among veterans who have been evaluated since April 2007, 15% have screened positive for mild TBI.10 Since the psychiatrist tends to see posttrauma victims well after the initial injury, it is important not to defer the diagnosis of comorbid PTSD and TBI to physicians who examined the victim at the time of injury. Often the physical trauma obviates the ability of physicians in the acute care setting to determine whether comorbid TBI and PTSD exist.
The assessment of potential TBI within the context of PTSD is no different from the assessment of potential TBI comorbid with any other medical or psychiatric condition. The procedures are fairly standard and comprehensive. The psychiatrist will have to determine whether he or she has the clinical experience and skills to perform the TBI assessment outlined in Table 3. If not, it may be wise to refer the patient to a colleague who practices neuropsychiatry or behavioral neurology. A comprehensive neuropsychiatric assessment is the most important single tool with which to determine whether a patient with PTSD has comorbid TBI.
Table 3 outlines the specific information that must be gathered to differentiate TBI from PTSD. If the neuropsychiatric history gathering is the most important variable in a quality TBI assessment, the second most important variable is a return to the scene of the accident. The psychiatrist should secure the original injury records—including the ambulance run sheet, police report, and emergency department records. These will help determine whether there was head trauma and its relationship to the onset of PTSD. For instance, if the emergency medical services (EMS) run sheet indicates a Glasgow Coma Scale below 15, the likelihood that the patient has sustained at least a mild TBI is increased. If the patient remained impaired based on the Glasgow Coma Scale (score below 15) after the emergency medical personnel released him to an emergency department, the likelihood of TBI is further increased, because it is obvious that the patient’s mental state did not improve during transit. Lastly, if the medical history from the emergency department and/or EMS observers and police indicates confusion, disorientation, inability to provide a history, or inability to be interviewed because of mental status changes, TBI is probable.