Heterogeneity in Trail Making Test Performance in OEF/OIF/OND Veterans with Mild Traumatic Brain Injury

AbstractThisstudyusedclusteranalysistoexaminevariabilityinTrailMakingTest(TMT)performanceinasampleofOperationEnduringFreedom/OperationIraqiFreedom/OperationNewDawn(OEF/OIF/OND)veteransreferredformildtraumaticbraininjury(mTBI).Threeclusterswereextracted, two of which were characterized by level of performance and the third with a unique performance pattern characterized by slowperformance on the TMT B (Low B). Clusters did not differ on demographic or psychiatric variables. The Above Average cluster had betterperformance on measures of processing speed, working memory, and phonemic fluency compared with the Low B cluster. Results suggestthatasubsetofpatientswithmTBIperformpoorlyonTMTB,whichsubsequentlypredictspoorercognitivefunctioningonseveralotherneuro-psychologicalmeasures.ThissubsetmaybevulnerabletocognitivechangesinthecontextofmTBIandmultiplecomorbiditieswhileanumberofother patients remain cognitively unaffected under the same circumstances. Keywords: Mildcognitive impairment; Statisticalmethods;Assessment