The following quotation from the author's preface and introduction are pertinent!
When a medical method, whether diagnostic or therapeutic, has been generally recognized it easily becomes a matter of routine, being deprived of unceasing critical observation. Indications and contra-indications become blurred. Results are misjudged. Limitations and risks are forgotten. It therefore becomes imperative to analyze now and again the results arrived at, as well as, the risks and indications of the methods employed.... I assumed, to begin with, that these complications (neurological) were rare and, therefore, almost negligible (after spinal anesthesia). I