Diabetes is a disease with a deleterious pathology that currently impacts 4.5 million individuals within the United States. This study examined the ability of a specific neuropsychological battery to identify and classify dementia type, investigated the impact of diabetes on cognition and analyzed the ability of the memory measures of the 7 Minute Screen (7MS) and the Rey-Osterrieth Recall to correctly categorize dementia type when not used in combination with a full battery. The battery in addition to exhaustive patient history, medical chart review and pertinent tests were used in initial diagnosis. Results indicated the battery was sufficient in the identification and classification of dementia type. Within the sample, diabetes did not appear to significantly impact overall battery results whereby only two measures were minimally affected by diabetes. Finally, the memory measures of the 7MS and the Rey-Osterrieth Recall were sufficient to predict membership into the Alzheimer's (AD) and vascular dementia (VD) groups with 86.4% accuracy. The classification percentage dropped to 68.3% with addition of the mild cognitive impairment category. The full battery correctly classified AD and VD dementia 87.5% and appeared to be the most robust.

The Rey-Osterrieth Complex Figure Task (ROCFT) has been a standard in neuropsychological assessment for six decades. Many researchers have contributed administration procedures, additional scoring systems and normative data to improve its utility. Despite the abundance of research, the original 36-point scoring system still reigns among clinicians despite documented problems with ceiling and floor effects and poor discrimination between levels of impairment. This study is an attempt to provide a new method based upon item response theory that will allow clinicians to better describe the impairment levels of their patients. Through estimation of item characteristic curves, underlying traits can be estimated while taking into account varying levels of difficulty and discrimination within the set of individual items. The ultimate goal of the current research is identification of a subset of ROCFT items that can be examined in addition to total scores to provide an extra level of information for clinicians, particularly when they are faced with a need to discriminate severely and mildly impaired patients.

This study utilized the Medical Symptom Validity Test (MSVT) and a set of standard neuropsychological instruments to determine the underlying construct of the MSVT that accounts for effort in mild traumatic brain injury (mTBI) patients by comparing/contrasting mTBI with dementia and an analog simulation. The results indicate that a common underlying neurocognitive construct (memory) exists between mTBI and dementia patients, which may account for poor effort as measured by the MSVT. Other underlying factors emerged for both groups, though they did not point to a common construct. This finding suggests that the overall effect of brain injury in neurologically impaired groups also impacts effort performance as measured by the MSVT. Similarly impaired performance patterns also emerged between mTBI and dementia groups in sub-groups that failed effort measures. Thus, failed effort tests may be a function of more pronounced deficits in these groups, rather than a function of effort. Finally, although similar effort profiles were noted between mTBI and analog simulators, the analog group was unable to mimic the neurocognitive effects of mTBI.