Date of Award


Publication Type

Doctoral Thesis

Degree Name





Casey, Joe




The current study investigated the extent to which neuropsychological and functional outcome after complicated mild traumatic brain injury (MTBI) parallels that of moderate traumatic brain injury (TBI) recovery. A longitudinal design was employed to compare the neuropsychological and functional status of individuals with complicated MTBI and moderate TBI at discharge from inpatient rehabilitation and at 1-year postinjury. The complicated MTBI group was comprised of 102 participants, each with an intracranial brain lesion documented via neuroimaging and a highest Glasgow Coma Scale (GCS) score in the Emergency Department between 13 and 15. The moderate TBI group was comprised of 127 participants, each with a highest GCS score in the Emergency Department between 9 and 12. The outcome measures of interest included the Functional Independence Measure, Disability Rating Scale, Community Integration Questionnaire, Logical Memory Test I and II, Rey Auditory Verbal Learning Test, Trail Making Test (A and B), Controlled Oral Word Association Test, Oral Symbol Digit Modalities Test, Wisconsin Card Sorting Test, and the Block Design Test. Statistical analysis revealed few differences in neuropsychological performance between the TBI groups. Qualitative examination of levels of cognitive impairment revealed less severely impaired information processing speed and verbal learning in the complicated MTBI group at rehabilitation discharge and at 1-year post-injury. Despite overall improvement across cognitive domains within the complicated MTBI group, some degree of impairment remained at 1-year post-injury on those measures identified as impaired soon after injury. No differences on measures of functional ability were found between the TBI groups at either time period post-injury, with both groups exhibiting incomplete recovery of functional status at the 1-year follow-up. Overall, sufficient parallels in outcome after complicated MTBI and moderate TBI were found to indicate that when classifying severity of TBI based on GCS scores, consideration of a moderate injury designation should be given to persons with an intracranial bleed and a GCS score between 13 and 15.