Neil H. Pliskin

Relationship between confabulation and measures of memory and executive function

Confabulation has traditionally been attributed to a combination of memory impairment and executive dysfunction, but recent models propose that confabulation can result from executive dysfunction alone. One hundred and ten patients with diverse neurologic and psychiatric diagnoses were subdivided into high-, low-, and non-confabulator groups based upon the ratio of confabulations to total responses produced during story recall. Consistent with the combined deficit model, high-confabulators performed significantly worse than the low- and non-confabulators on measures of memory and measures of executive function that assess sustained attention, mental tracking, and set-shifting ability. However, there were no differences between groups on measures of problem-solving, concept formation, and verbal fluency, suggesting a dissociation in executive functions that contribute to confabulation.

Attention and mental processing speed in hemodialysis patients

It has remained unclear whether well-dialyzed patients with end-stage renal disease (ESRD) show persisting neurocognitive deficits, especially in tasks that depend on sustained attention or psychomotor speed. We administered a battery of six attentional measures to 10 stable hemodialysis (HD) patients (age, 61+/-16 years; education, 12.4+/-3.8 years; Kt/V, 1.35+/-0.07) and 10 matched controls with normal renal function (age, 62+/-10 years; education, 11.6+/-1.0 years; estimated creatinine clearance, 92+/-25 mL/min). Results of the Trailmaking Test, Paced Auditory Serial Addition Test, Stroop Test, Digit Span, Continuous Performance Test (CPT), and Gordon Diagnostic System did not differ between groups. We conclude it is unlikely that well-dialyzed patients with ESRD manifest significant uremic neurocognitive deficits in the functional spheres related to sustained attention or mental processing speed.

The Neuropsychological Effects of Electrical Injury: New Insights

Although electricity has been used for commercial purposes since the 19th century, surprisingly little is known about the pathogenesis of neuropsychological and psychiatric changes following electrical injury (EI). As first noted in our review of this area, there primarily have been single case studies and retrospective investigations of EI patients that have been limited by small sample sizes, lack of appropriate control group comparisons, nonrandom selection procedures, and methodological variability.1 Yet, these studies seem to suggest that EI patients can have diverse clinical presentations in both type of symptoms (i.e., ranging from significant cognitive and/or emotional) and time of onset (i.e., immediate vs. delayed). Since our review of the neuropsychological effects of electrical injury first published in this book series in 1994, several new case reports have appeared in the literature that have documented posttraumatic stress disorder following electric shock2 and the presence of parasomnia as a neuropsychiatric complication of electrical injury.3 Additionally, one study surveyed a large support group of lightning and electrical injury survivors for behavioral symptoms4 and several retrospective neuropsychological studies have been published by a group of University of Iowa neuroscientists based on their series of electrical injury patients.5,6 Unfortunately, in our view, the critical factors that influence the neurocognitive and psychiatric consequences of exposure to electricity have not been clearly identified. However, many assumptions about EI are made by mental health professionals despite the lack of empirical evidence. These assumptions include the following: (1) the worse the visible burn, the worse the psychological difficulties that someone will have; (2) low voltage exposures will not cause significant neuropsychological problems; (3) EI patients who experience changes are not premorbidly psychologically stable; or (4) electrically injured patients are faking their difficulties for secondary gain. The purpose of this article is to summarize the new insights gained into the neuropsychological effects of electrical injury based on a series of studies conducted by the University of Chicago Electrical Trauma Program over the past five years,7–11 emphasizing that much more work still needs to be done. The goals of our research program continue to be the clarification of the central nervous system effects of electrical injury as reflected by postinjury neurocognitive and psychiatric functioning as

Neuropsychological Function in Renal Disease and Its Treatment

Our understanding of neuropsychological function in end-stage renal disease (ESRD) and chronic hemodialysis has evolved a great deal in the past 30 years. Early studies in the 1960s and 1970s documented the neurocognitive effects of uremia and chronic renal failure, while investigations in the 1970s and 1980s focused on neurocognitive outcome following initiation of hemodialysis, neuropsychological status in chronic hemodialysis and peritoneal dialysis, and correction for anemia and aluminum toxicity. In the 12 years since this chapter was first published, medical standards of dialysis adequacy have changed dramatically. Thus, many patients studied in the 1960s to 1980s may have been relatively underdialyzed at the time of assessment compared to current standards for dialysis prescription (Lowrie, Laird, Parker, & Sargent, 1981; Gotch & Sargent, 1985; National Kidney Foundation, 1997a, 1997b). Recent investigations quantifying dialysis delivery have provided new insights into the neuropsychological effects of dialysis. Several investigations into the effects of renal transplantation on cognition also have appeared within the past decade.

Verbal fluency task equivalence

Abstract The research and clinical use of the verbal fluency paradigm has been hindered by the paucity of information on the equivalency of the various versions of this measure. Currently, the comparability of the two most commonly used forms of the letter fluency task, the “FAS” and “CFL” tests, is uncertain. The equivalence of these versions was investigated by examining their consistency across and within settings and disease processes. The two verbal fluency tasks were administered to 287 patients at two separate sites as part of a neuropsychological evaluation. Results showed that the CFL and FAS verbal fluency paradigms were equivalent across both settings and diagnostic groups with correlations ranging from .87 to .94. These findings may be useful for both researchers and clinicians who require equivalent measures for repeated testing. Furthermore, the demonstrated equivalency of the two paradigms may facilitate interpretation of research findings across laboratories.

Life after electrical injury. Risk factors for psychiatric sequelae

ABSTRACT: Long‐term cognitive and emotional deficits have been commonly reported in electrical injury (EI) survivors. However, it remains undetermined what factors may lead to the development of such effects in some patients and not in others. In this study, we hypothesized that certain elements of subjective EI experience may predict specific psychiatric sequelae. A group of 73 postacute EI patients were included in this retrospective study. Statistical associations were examined between major psychiatric diagnoses (posttraumatic stress disorder and major depression) and such EI descriptors as having experienced “no‐let‐go” or having been knocked away on contact, as well as loss of consciousness or altered states of consciousness at the scene of the accident (including amnesia for the event). The study results will help physicians determine which patients may be at increased risk of developing psychiatric symptoms and address these issues as part of their total rehabilitation plan.