Since Oppenheim1 in 1900 first described this disease, case reports have gradually accumulated until at the time of writing 115 are on record, with 27 anatomic reports, including necropsies and muscle biopsies. A mass of clinical and pathologic material of these proportions appears to be great enough to render a statistical analysis of considerable value, not only in defining the disease more precisely, but in throwing new light on the etiology and in correcting some current misconceptions.
Reviews of the literature have been frequently made by those reporting new cases. It will suffice to mention the more important of these, noting that the last fairly comprehensive study—Thorspecken's—appeared more than four years ago, and that none is based on the statistical method. Batten, in 1903, without mentioning Oppenheim's description, reported three cases under the name of "myopathy—infantile type." Kundt in 1905 described a case