Neuropsychological Differential Diagnosis

This book is one volume in a series entitled Studies on Neuropsychology, Development, and Cognition. Its authors are well-known and respected researchers and clinicians in the field of neuropsychology. Neuropsychological Differential Diagnosis is intended to be useful for neuropsychologists, students of neuropsychology, and researchers who use neuropsychological tests. It is likely that other mental health professionals looking for rich clinical descriptions of neuropsychiatric syndromes would be disappointed by what this book offers.

The authors assert that researchers and clinicians in neuropsychology employ a subjective bias when selecting tests for use in research or diagnostic test batteries, based on clinical lore, their best understanding of the literature, or theoretical speculation. Their goal in publishing the book is to improve research design and clinical diagnosis in neuropsychology by placing both "on firmer scientific grounds." They aim to do so, they say, by "quantitatively assessing individual test sensitivities" and "generating preserved and impaired ability profiles from different dementia and neuropsychiatric syndromes to guide diagnostic practice."

The first three chapters present the rationale for the book and explain the meta-analytic methodology used to achieve its aims. Readers whose interests and inclinations lie more in the clinical realm than in research might be tempted to skip these chapters and turn directly to those addressing syndrome profiles. However, the authors' explanations of the effect-size estimate d statistic and meta-analysis are lucidly written and can help the reader appreciate how the profiles were generated.

For each neuropsychiatric syndrome, the authors selected multiple published studies that incorporated patient and healthy control groups and subjected the data from these studies to meta-analysis to look for the effect magnitude and sensitivity of specific tests. The results of their efforts are reported for 11 syndromes: dementia of the Alzheimer's type, frontotemporal dementia, primary progressive aphasia, progressive supranuclear palsy, Parkinson's disease, Huntington's disease, multiple sclerosis, major depressive disorder, schizophrenia, obsessive-compulsive disorder, and mild traumatic brain injury.

Chapters devoted to each syndrome provide both a tabular presentation of the rank-ordered sensitivity of many common neuropsychological tests and a discussion of the profile of impaired and preserved neuropsychological domains— attention and concentration, cognitive flexibility and abstraction, memory acquisition, and so forth— associated with each syndrome.

Among the profiles, there are a few surprises that challenge clinical lore and may spur debate and future research. For example, in contrast to many previous literature reviews, meta-analysis of the data associated with mild traumatic brain injury revealed greater prominence of dysfunction on putative measures of frontal-executive function than on measures of attention-concentration.

The final chapter provides succinct profile summaries for each syndrome, facilitating quick comparisons. The authors also propose a neuropsychological test battery for differential diagnosis consisting of tests that likely are familiar to most neuropsychologists, especially those trained in the Boston Process Approach or other flexible battery approaches.

Overall, although the book is rather dry because of its quantitative approach, it is a worthwhile volume for its target audience. As a clinical neuropsychologist, I find the book valuable for its challenges to clinical lore and for the empirical basis it provides for differential diagnosis. As the authors caution, however, the syndrome profiles could change as the body of neuropsychological literature grows.