In Reply Hoffmann contends that the clinical measures that were used in our study may not be sensitive to deficits associated with traumatic brain injury (TBI) or chronic traumatic encephalopathy (CTE), pointing to case studies that demonstrated a dissociation between cognitive and behavioral frontal lobe functions, the latter of which are difficult to capture with traditional neuropsychological tests (NPT). We agree that our study’s measures represent an incomplete interrogation of frontal lobe functions and did not include tests of initiation, impulsivity, self-awareness, and apathy. While these functions may be impaired following moderate to severe TBI, there is less evidence that such deficits manifest with mild TBI and concussion.1 However, decades of research have demonstrated the sensitivity of traditional NPT, particularly tests of verbal fluency and delayed word recall, to acute concussion, chronic TBI,2 and dementias of various etiologies, including Alzheimer disease and frontotemporal dementia, both of which are associated with subtle deficits on NPT that may precede a formal clinical diagnosis.3,4 As Hoffmann notes, in individual cases in which deficits are mild, NPT may be of little diagnostic use. Nevertheless, randomized clinical trials have consistently demonstrated group differences between cases and healthy individuals. This is particularly true in large samples such as ours (n = 3904).
Rabinowitz AR, Deshpande SK, Small DS. Sensitivity to the Deficits Associated With Traumatic Brain Injury or Chronic Traumatic Encephalopathy—Reply. JAMA Neurol. 2018;75(1):131–132. doi:10.1001/jamaneurol.2017.3572
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