skillfully handles the still thorny issue of correlation of im- plied M R imaging-defined pathology and clinical disability, without overstepping the boundaries of current knowledge. The final chapter, with Donald W. Paty, is a useful review of the role of MR in modern clinical trials, drawing on the considerable experience and insight of the contributors. Whereas the literature of this burgeoning field may still be encompassed by its active participants, most will benefit from this assessment of the current state of the art. This re- viewer flagged quite a number of pages for future reference. Updated editions of this book can be expected. They would benefit from publication of the figures on a higher grade pa- per and replacement of the earlier, lower resolution images that otherwise nicely complement the text.

jerry S. Wolinsky, MD Houston, T X

Electromyography and Neuromuscular Disorders, Clinical and Electrophysiologic Correlations By David C. Preston and Barbara C. Shapiro Boston, Butterworth-Heinemann, 1998 581 pp, illustrated

The authors have written this book for physicians who per- form and interpret nerve conduction studies and electromyog- raphy in patients with neuromuscular disorders. The text is designed to integrate electrodiagnosis in the evaluation and treatment of patients with neuromuscular disease. It is orga- nized into two main parts. The first sections deal with nerve conduction studies, electromyography, and clinical-electro- physiologic correlation. The second part deals with diseases including mononeuropathy, polyneuropathy, motor neuron disease, radiculopathy, and disorders of neuromuscular trans- mission and muscle. The authors, who direct neuromuscular units, emphasize that these studies extend the neuromuscular examination, and therefore, the interpretation reflects the clinical ability of the examiner. This stresses the point that physicians, who perform these electrodiagnostic studies, must be trained also in neurology and neuromuscular disease. Em- phasis is placed on the specific studies performed in each patient to establish a diagnosis and answer the clinical ques- tions. Because the studies rely on technical equipment and methods, it is also essential that the person performing these studies be well trained and versed in the use and upkeep of the electrophysiologic equipment.

The book is well illustrated and there are excellent pho- tographs of humans with placement of the electrodes both for nerve conduction studies and electromyography. It is un- fortunate that, with the modern technology available, the au- thors still measure nerve action potentials to peek as well as onset. Early studies, without the use of modern electronic averagers, had to measure to peek because of the difficulty with determining the onset of the potential. With current equipment, averaged nerve action potential onset should be visible, allowing accurate measurement to onset. The authors describe common artifacts of the techniques and stress the importance of recording in a warm laboratory with the pa- tient's temperature at 33" to 34°C to avoid cooling artifact. The chapters dealing with the localization of lesions in pe- ripheral nerves, plexus, and roots are excellent and make the text valuable to all clinicians involved in the evaluation of these patients. Each of the chapters has excellent descrip- tions, diagrams, tables, and case reports with specific electro- myographic data. There are excellent discussions of the clin- ical, anatomical, and physiologic correlations. The chapters dealing with muscle disease are not as well presented as those dealing with focal nerve lesions.

The book would be improved if there was further discus- sion of single-fiber electromyography and its value in the evaluation of patients with neurogenic and myopathic disor- ders as well as those with disorders of neuromuscular trans- mission. The appendix would be improved if it included data, from the world literature, of normal values of nerve conduction and motor unit parameters in children and adults of different ages. Normal data, with means and stan- dard deviations, would be of more value than means with greater or less than symbols. The book would be more au- thoritative if there were more references, including the orig- inal reports of normal and abnormal data.

Overall, the book is well written and illustrated, and it fulfills the objectives of the authors to integrate electrodiag- nosis with the clinical evaluation of patients with neuromus- cular disorders. Physicians with the appropriate training and background will enjoy reading this text and using it to help them in their electrophysiologic studies of patients.

Richard F. Mayer, MD Baltimore, M D

430 Annals of Neurology Vol 44 No 3 September 1998