SANTA FE, N.M. – The suggestions for diagnosing postconcussional disorder that appear in the text revision of the DSM-IV are inadequate for the assessment of mild traumatic brain injury, Dr. Stephen D. Anderson said at the annual meeting of the American College of Forensic Psychiatry.
Numerous studies have shown that people do not have to be unconscious after a head trauma or experience more than 1 hour of posttraumatic amnesia to suffer from postconcussional disorder, said Dr. Anderson of the University of British Columbia, Vancouver.
Yet the DSM-IV-TR would require that they fulfill two of the following three criteria to meet a threshold for closed head injuries: more than 5 minutes of unconsciousness, more than 12 hours of posttraumatic amnesia, or seizures. As seizures rarely follow a mild traumatic brain injury (TBI), most people would have to meet the first two overly rigorous criteria to satisfy the definition proposed in an appendix to the manual, he said.
Dr. Anderson also listed a multitude of symptoms as missing from the DSM-IV-TR discussion of postconcussional disorder.
He cited the omission of nausea; decreased balance and coordination; tinnitus; and sensitivity to light and noise as physical symptoms, and noted that cognitive defects in initiation and planning; judgment and perception; information-processing speed; and communication ability are not discussed. Likewise, increased sensitivity to lack of sleep, fatigue, stress, drugs, or alcohol is not mentioned, and loss of libido and decreased appetite are not included under psychological symptoms.
“It is easier to make a diagnosis of dementia [resulting from head trauma] than postconcussional disorder,” Dr. Anderson said.
The definition of postconcussional disorder “does not cut it,” he summarized in an interview after his talk. “It is in an appendix, so it is not fully accepted, but the fact that it is included in DSM IV lends it some legitimacy.”
Mild TBI is a real but underdiagnosed condition, according to Dr. Anderson, who offered as examples impairments in football, soccer, and hockey players. The same problems have been observed in patients with severe traumatic brain injuries, but the effects are more subtle with mild TBI.
Despite concerns about people using mild TBI to excuse malingering, researchers have shown that unemployment and underemployment can occur, and that some people struggle on neurocognitive tests. Patients with mild TBI have performed comparably with control groups in several studies, but imaging showed that their brains worked harder to achieve the same results. This may help explain why fatigue is a common complaint, Dr. Anderson said.
He also cited a study of brains taken from five people who died of causes not related to their mild TBI. The researchers found multifocal axonal injury and axonal damage to fornices in all five patients.
Unless structural damage is clearly seen, neither MRI nor CT is a good measure of mild TBI. Without images taken before the trauma, imaging cannot compare brain function before and after the injury, Dr. Anderson said.
An hour or more of posttraumatic amnesia is one of the best predictors of mild TBI, Dr. Anderson said. He recommended the Glasgow Coma Scale-Extended (GCS-E) amnesia scale but volunteered that results are rarely available. “It is great, but no one uses it,” he said. “You never see it in an ambulance report.”
Another option is to use the American Congress of Rehabilitation Medicine criteria instead of the DSM-IV-TR recommendations. “You don't have to have loss of consciousness,” he said. “You just have to be dazed at the scene.” He has also posted a list of symptoms in a paper on postconcussional disorder that can be accessed under the heading “Medical Articles” on the Web site www.braininjurylaw.ca
People do not have to be unconscious or experience more than 1 hour of posttraumatic amnesia. DR. ANDERSON