Cognitive dysfunction and mild closed head injury in traumatic spinal cord injury

Previous investigators have reported that 25%-50% of traumatic spinal cord injury (SCI) patients sustain loss of consciousness (LOC), posttraumatic amnesia (PTA), or both concurrently with their SCI. A LOC of 20 minutes or less, or a PTA of 24 hours has been associated with prolonged time off work, and deficits in attention, concentration, memory, and judgment. Consequently, many traumatic SCI patients may also be the victims of a concomitant closed head injury (CHI) with cognitive sequelae. To test this hypothesis, a prospective study was conducted of 30 consecutive trauma-related SCI patients admitted to the Rehabilitation Institute of Chicago to determine the incidence of CHI and cognitive dysfunction (CD). The Halstead Category Test (HCT) was administered to each patient between 8 and 12 weeks after injury, and was considered abnormal if the patient committed 51 or more errors. Fifty-seven percent (n = 11) of all patients had abnormal HCT scores suggestive of higher level cognitive dysfunction. Patients with a new CHI had a mean HCT score of 65.2, as compared to 63.5 for patients with a premorbid CHI, and 46.3 for patients without a history of CHI. Although there was a trend toward higher HCT scores in patients who had any history of CHI, these differences did not reach statistical significance. The results of this study suggest that many trauma-related SCI patients are at risk for CD eight weeks after injury. Such cognitive abnormalities would be expected to impede rehabilitation and retard the requisite learning of new skills.