One of the standards for including a case in statistical calculations is completeness of the needed case. I counted forty-seven cases (from data patients provided on the web) this weekend who are either on a trach or passed away and left complete data for the basics . . . twelve bulbars and thirty-five limb onset . . . thirty-five is approximately two pilot samples (. . . 2x16 patients or 32 patients . . .). Of these thirty-five, two _probably_ are limb onset and another may not have correctly specified their onset date. Whether thirty-five or thirty-three, the median survival is seventy or seventy-four months, respectively. Regarding the possibly inadequately specified onset date, the patient is in the weaker half of the sample and correction, if appropriate, would move them well into the stronger half of the sample and therefore would only strengthen the median for the set. The bulbar median is under review will be further discussed in this thread (there are at least 56 but only twelve pacing and without missing completion data - hence we do not yet have a pilot sample):

http://neurotalk.psychcentral.com/thread224801.html

In principle, pacing patients should be more valuable in clinical studies because the researchers could collect dEMG data from them:

Identification of unexpected respiratory abnormalities in patients with amyotrophic lateral sclerosis through electromyographic analysis using intramuscular electrodes implanted for therapeutic diaphragmatic pacing

http://www.americanjournalofsurgery....598-4/fulltext

In the aforereferenced paper Dr. Onders provides more insight into patients of the original study.

Evaluations including all cases will likely show lower results because they always include all the least successful cases and remain in wait for completion data from those who continue advancing. Early studies are more likely to include patients who are later in the disease process because the treatment was not available to them before they were eligible. As time goes on, patients in the vicinity of a new implant site will be increasingly likely to receive timely implant.