No abstract

No abstract

Exaggeration of cognitive symptoms or poor effort on cognitive testing has been addressed primarily in the traumatic brain injury literature. The present investigation aims to extend the evaluation of effort to the epilepsy monitoring setting, where base rates of failure on effort testing remain unknown for patients with intractable epilepsy (ES), psychogenic nonepileptic seizures (PNES), or both conditions (ES+PNES). In addition, this investigation explores how well four measures of effort (DMT, LMT, TOMM, PDRT) distinguish between these diagnostic groups. Results show that 20% of the combined sample failed one or more effort measure. When examining failure rates for each diagnostic group, 22% of epilepsy patients, 24% of PNES patients, and 11% of ES+PNES patients performed suboptimally on one or more measure of effort. The utility of these effort measures to differentiate between these diagnostic groups appears limited. Further research is needed to clarify the base rate of poor effort in the epilepsy monitoring unit setting in general and in these three diagnostic groups specifically.

The diagnosis of psychogenic nonepileptic seizures (PNES) is complex. Long-term electroencephalogram monitoring with video recording (video EEG) is the most common method of differential diagnosis of epilepsy and PNES. However, video EEG is complex, costly, and unavailable in some areas. Thus, alternative diagnostic techniques have been studied in the search for a diagnostic method that is as accurate as video EEG, but more cost effective, convenient, and readily available. This paper reviews the literature regarding possible diagnostic alternatives and organizes findings into 7 areas of study: demographic and medical history variables, seizure semiology, provocative testing, prolactin levels, single photon emission computed tomography, psychological testing, and neuropsychological testing. For each area, the literature is summarized, and conclusions about the accuracy of the technique as a diagnostic tool are drawn. Overall, it appears unlikely that any of the reviewed alternative techniques will replace video EEG monitoring; rather they may be more successful as complementary diagnostic tools. An important focus for further investigations involves combinations of diagnostic techniques for the differential diagnosis of epilepsy and PNES.

MMPI-2 results from 39 moderately to severely head injured (HI) and 44 community volunteer (CV) participants given instructions to feign symptoms or answer honestly during an analog forensic neuropsychological examination were compared. No significant effects for HI or the interaction between the HI and instruction set (IS) factors were noted on either clinical or selected validity scales (F, Fb, Fp, Ds2, FBS). However, the main effect of IS was significant for both clinical and validity scales (median Cohen's d=1.34 and 1.39, respectively). Most validity scales were characterized by perfect specificity rates but low to modest sensitivity, whereas FBS had both moderate sensitivity and specificity. Logistic regressions showed that the F and Ds2 scales made a significant contribution independent of motivational tests to the identification of feigning during neuropsychological examination.