This whole thread is the great risk we all run by trying to specialize in an area we've "studied" under duress for a few days versus dedicating a professional career to it and practicing in front of real, live honest-to-goodness patients.
I know little more than any other average Joe about this area, but I do know the facts of what I've been told from reliable sources in this field versus the unverifiable conjecture:
A properly performed EMG examination does NOT have to be performed in the specific muscle group or area afflicted by motor neuron degeneration to indicate MND or ALS sepcifically. The gold standard (and this is NOT a term thrown around loosley by the medical profession) diagnostic threshold for ALS is that a recognized neuropathy MUST be present in at least 3 of 4 primary nerve groupings for ALS to be considered. Based on every available medical text and verifiable history of ALS patients, this INCLUDES early onset ALS, which STILL VERY MUCH presents in a typical pattern of abnormal EMG findings applied to this neuropathic threshhold. No debate - no ifs ands or buts. So, the manner in which an EMG test is performed, and the number of regions explored, is subject to many other factors than just confirming or ruling out ALS. Based on all that I have been told (and it is only that - second hand knowledge from what I view to be very reliable physician sources), I would agree with the original poster's account from the Yale doctors that most often, anything beyond a complete exploration of 1-2 of the critical nerve regions is usually overkill, intended to offer comfort to the patient or more often, explore and rule out other possible neurological disorders.
I think far too often this site overlooks the vital role other diagnostics play (such as that initial physical exam we all discounted because it felt too arbitrary and "unscientific") in prescribing the course and scope of EMG examination performed by qualified physicians. Very clearly, not all EMG/NCS examinations are identical - they are not intended to be. In many cases, a patient with no pronounced weakness, a lack of verifiable motor impairment, successful physical exam results and no discernable speech impairment DOESN'T need an EMG at all to be properly ruled out of the ALS spectrum, much less a debate on the proper scope of limbs to be tested and regions to be explored. The purpose of the EMG in virtually every full course ALS case, and in the vast majority of suspected early onset instances, is to CONFIRM, NOT FIND. In this regard, it is a possible procedure for an EMG physician to pursue one of many different diagnostic options, including a directional probe of a suspected region (what I believe is being referred to above with the discussion of a doctor "moving the needle around"), which can verify tension and resistance response for a particular group of muscles, or a standard probe of multiple regions (8 to 10 to 12 pokes with limited directional exploration) which is concerned about generalized onset of weakness and nerve degeneration. In any case, any broad inferences about the quality of exam based on number/type of probes is leaving far too many of the tangible variables out of the picture to be reliable, and is probably causing you more stress than benefit.
I'll reiterate what I said in another post on this site, perhaps the most important statement commonly echoed by ALL of my doctors through this experience, from "Joe Neuro" (who we should all have a LOT of faith in still) to physicians at the Mayo Clinic and the Manitoba provincial neurological centers - world recognized specialists in this area. DIAGNOSIS IN THIS AREA (MND/ALS) IS NOT AS MYSTERIOUS AND COMPLICATED AS WE WANT TO MAKE IT OUT TO BE. ALS, because it is a systemic, degenerative disorder of the musculoskeletal system presents in consistent and readily recognized patterns. Because of the correlation of sysmptoms and presentation to the degenration of nerves and cells that cannot be rehabilitated except in remarkably rare instances (i.e.: never, for all intents and purposes), diagnosis does not even reach the level of complexity marked by serious conditions that may regress for periods of time (such as cancer) and/or present in multiple patterns. When you have ALS, you have it, a trained neuro KNOWS it relatively quickly, and the "complicating factors" we all turn up, such as the possibility OUR ALS is not yet fully set in and/or a neuro missed it because he/she was not paying full attention are unfortunately the byproduct of the ingestion of too much incomplete information, from a myriad of incomplete or unreliable sources, interpreted by untrained and sometimes frantic minds. Count me in this group, as I never would have felt the need to travel to these places and/or get a second EMG had I known and trusted then what I do now.
Trust your doctors, resist the urge to scrutinize and "interpret" the means and quality of testing applied to you, and take some time to smile and enjoy your day. Pure numbers and time say you are not afflicted with this terrible disorder.
JG
PS: resist the temptation to get an EMG from someone other than a board certified Neurologist. This will eliminate any last doubt you might reasonably have about the quality of your neurological exam.
