Thank you so much for joining us today. Knowing that we have people from all over the country, including those people presenting today, joining us, I suspect that some of you might be at work or at your home office or listening in the car or even maybe making a meal or just starting to disconnect from work for the evening. So really wherever you are connecting with us today, we are so appreciative of your time. Thank you so much for being here. My name is Deborah Vennessy and I have the distinct honor of working with my dear friends and colleagues on this program organized by Dr. Farron Williams. We have a limited time with you today, so I'm just going to set the stage in regards to the national pandemic and infection control and share just one activity that I worked on with the AANEM. Well you'll hear about two cases, lower extremity cases, Dr. Bill Pease and Dr. Farron Williams, and then Dr. Eric Ensrud will present an upper limb case. I think it's called dirt off the shoulder. You know, the COVID-19 pandemic has certainly had a profound impact on all of us on health care research and health care delivery, and the field of neuromuscular disorders and electrodiagnosis is no exception to this. It's hard to believe, but seven months ago on March 11th, the World Health Organization declared a global pandemic. The CDC and the Centers for Medicare and Medicaid Services recommended prioritizing urgent and emergent visits and procedures. Thus, all in-person visits with a clinician all stopped, leading to more to a virtual care environment and virtual assemblies, as it turns out. Many health care systems across the United States, and certainly across the world, recommended stopping all elective and non-urgent procedures. That included imaging, that included surgeries, and certainly electrodiagnostic testing. Postponing non-essential care was critical at that time for preserving PPE, for preserving staff, maintaining the stock of the PPE, as well as patient care supplies, and ensuring the safety of all of our patients, our community, and health care personnel. Certainly, a small subset of indications for electrodiagnostic testing is genuinely urgent, but in most situations during that time, you know, or during any time, electrodiagnostic testing can't be postponed indefinitely. Back in April, the AANEM received tons of inquiries from its members about how do we postpone electrodiagnostic testing. So at that time, in order to assist the clinicians with triaging all of these electrodiagnostic studies, a group of my colleagues on the Quality and Safety Committee got together and they wrote a practical guidance paper and described a tiered framework to stratify the electrodiagnostic test in regards to acuity and indication. So they really kind of just talked about urgent, non-urgent, and possibly urgent. And that brief paper was written back in April. And then a few weeks later, our committee met for our spring meeting via a video conference on May 9th. And again, during that time, if you can remember back that far, which seems like an eternity ago, you know, at that point we were thinking, like, how are we going to reopen, you know, non-urgent electrodiagnostic testing? So again, there were a lot of questions that were coming in to AANEM. And during our initial video conference meeting, our spring meeting, we considered the scope. We identified a writing group, of which I had the privilege of being part of. And with that group of neurologists and physiatrists, we reviewed data from the CDC, as well as some available institution protocol recommendations. A couple of days after that, next week, on May 15th and 16th, we met via video conference, and then we reviewed it with our executive director. And then it was presented to the board, believe it or not, like the week later, and published in the Muscle & Nerve on May 28th. Now, aside from...that was the fastest I'd ever done anything like that. And the most satisfying part, aside from that, was working collaboratively with a group of neurologists and physiatrists via video conference. It was truly amazing. And just the...I don't...you might not be able to see it, but our little paper, as I said, it's just a practical guidance summary back on May 28th. But we really focused on patient safety, as well as healthcare provider safety. At that time, back in May, we recommended that all patients wear a mask. We still do. We recommended that all patients perform hand hygiene before electrodiagnostic studies. Those of our patients that were coming in that we weren't sure if were COVID, we did recommend screening. We recommended that all providers wear masks, gloves, and then, of course, a shield, as you can see. So we talked a lot about that back in May. We also said that maybe an N95 mask was an option. And if you can remember back in April, May, there still was a question about how much PPE was available. At that time, we recommended that higher risk studies, such as a facial study, that maybe we should consider wearing an isolation gown or an N95 would be acceptable. During our group, we had a lot of discussion about whether we should recommend or strongly recommend, or however we wanted to phrase it, pre-procedure COVID testing. We ended up deciding just on strongly recommended, even though a number of us felt that maybe it would be a better idea to have a pre-COVID test, given the length of time that we are with patients, as opposed to some of my colleagues that do interventional procedures or something like that, or even having a colonoscopy. So that was a major discussion. We also talked and recommended maybe considering disposable electrodes, disposable tape measures, maybe even having a preassembled single use kit for each study. We certainly emphasize social distancing with patients, maybe doing later hours or whatever, and sanitizing. So hard to believe, but back then in July, CDC recommended universal pandemic precautions for caregivers, meaning that we all wear masks, eye shield, with all direct patient contact. And so this was the recommendation back at the end of July. And I don't know what you guys are doing at your institution, but at our institution, we talked about it at the end of July, and since August, we have been wearing all of... With any outpatient procedure or any outpatient visit, surgical mask and shield, especially due to all the respiratory infections. So it's just interesting to share some of the things that we talked about, discussed, and worked collaboratively with AANEM in regards to infection control. I'm sure that we'll continue to do this. And then before I turn it over to, I think, Bill, I just wanted to draw your attention, and you might not be able to see, but in the program, in addition to our awesome challenging electrodiagnostic studies, which you'll hear more of in just a second, there's also gonna be a live session on Friday, November 13th, and it's from 2 to 3 Central Time, where they'll really be talking more about COVID complications. So it's entitled Neuropathies and Neuromuscular Complications of COVID-19 and the Electrodiagnostic Studying. But I just thought it'd be relevant to talk about this, given that we are doing... Having a virtual annual assembly and sharing trying to... How this all came about. So I look forward to hearing from Bill, Farron, and Eric. So I think Bill's up next. Thank you, Dr. Vennesey. I'll represent the AANEM in thanking you for that important work and the ongoing collaboration between the Academy and the AANEM as it relates to electrodiagnostic medicine. But this was a very important time. And thank you all for joining us to this very special version of the annual assembly of the Academy of Pim & Arr, which we trust will be unique in our history, and that we'll have things resolved by the time the next fall meeting rolls around. The case I have for you is an interesting one, and we can learn a lot from reviewing details of a basic case. But as you'll see, it's a special case, at least it is to me. And you'll see why as we move through it. The case begins as I was in the hospital one day and heard an unusual but unique sound coming down the hallway. And it was a foot slap pattern of walking. So I immediately, of course, dashed down the hallway, because seeing an unusual walking pattern is what I do whenever there's an opportunity. And I saw not a patient, but a white coated person coming down the hallway, showing the foot slap. The presentation here, I have no financial disclosures to reveal. And our case, as I suggested, is a retired physician, 87 year old man with chronic lumbar pain, a history of prostate cancer, who has had some paresthesias in his right foot and leg, and ankle dorsiflexion weakness for about six weeks. He has no significant medical history other than the prostate excision five years ago, with no evidence of recurrence of his cancer. On examination, he shows weakness of dorsiflexion and eversion of the right foot, two over five, with normal strength and inversion and eflexion, as well as in all the other major muscles of both lower limbs. There's minimal sensory loss seen on the dorsum of the foot. I suggested to him that a test called an EMG might be helpful in deducing what was wrong with this problem and how best to approach the treatment. And to remind you what we do an EMG for, which is when we want to know if a nerve is working or not in an area, and sometimes this is difficult. There's pain, there's edema, there's restricted motion, there's paresthesias, sometimes hypersensitivity with the paresthesias, and there may be weakness, and a difficult exam is not an unusual occurrence for us. We want to know if it's a peripheral nerve problem or perhaps a central nervous system problem. Certainly, the dropped foot in an 87-year-old is suspect of being a stroke, and that's part of the differential diagnosis. We want to know where the problem is. We want to know if anything else is going on. We'd like to get some quantitative information, if possible, on the severity of the problem. And whenever we can get information about prognosis, especially quantitative information about prognosis, we know that's going to be of interest to the patient, and it'll guide our treatment by being informative in that way as well. So, we talked the patient into this perfectly comfortable test, as we all know, and proceeded to begin with nerve conduction testing. We, of course, checked the fibular nerve, did a motor study recording at the extensor digitorum brevis, and we got a very small amplitude response, 0.2 millivolts. We got a similar response when we stimulated the nerve proximally at the fibular head, and when we stimulated at the knee, we could no longer identify the response. Not an unusual occurrence as we move proximally with a small amplitude response. We calculated a conduction velocity of 34 meters per second and had a distal latency of 6.3. Conduction speeds mildly slowed and suggestive of axonal loss, of course, both the small amplitude and the moderately diminished conduction velocity. We did sensory nerve conduction studies in the right leg and compared the soral nerves side to side. We had a slight delay in the right soral sensory at 4.3, not out of the ordinary for an older gentleman, and a small amplitude response. But again, we weren't surprised by this response, and I show them to you so that you can see. For one thing, the right superficial fibular is shown twice because I often will duplicate the presentation to show that we do, in fact, have a consistent signal. Our recording from that peroneal or fibular sensory nerve had a normal latency of 4.0 and an amplitude of 2.6, which is small but similar to the sural. And when we compared the left sural, we found it slightly larger, but also more delayed in distal latency. All in all, not unusual recordings or significantly abnormal for an 87-year-old. Now, when we think about just the data we have so far, think about what you would already be thinking about your differential diagnosis and whether it would be refined. Certainly, the idea of a stroke is less likely because we wouldn't expect the small amplitude motor response motor response in a stroke as the cause of weakness. We have a very small, almost absent peroneal motor response at the EDB, and we have sparing of the sensory branch of the same nerve. And of course, this comparison, small motor and spared sensory, immediately suggests the possibility of a spinal lesion or radiculopathy. In this case, an L5 lesion would affect these nerve branches specifically. And it is only a lesion that's in the spine, proximal or cranial to the dorsal root ganglion, but affecting the motor branches peripheral to the motor neurons that's going to produce this dichotomy of responses. So, we need more information. We'll move on toward the needle portion of our EMG. And that will show us that we did not identify fibrillations or positive sharp waves. There's no abnormal insertional activity in any of the muscles. We did see abnormal recruitment in the tibialis anterior and extensor hallucis longus. And we saw increased amplitude motor units in the extensor hallucis longus. So, these suggest a chronic lesion with reinnervation in a pattern that suggests a radiculopathy. So, the data is concordant with L5 radiculopathy as we talked about the nerve conduction testing. However, it does not suggest an acute injury here as the cause of weakness. And our history is of an injury only six weeks old. So, what are we going to do now? Why do we have weak dorsiflexion now if we have an old injury and no new axon loss causing spontaneous activity in the muscles? Because these motor units with increased amplitude clearly must be from sprouting and reinnervation. And it must be an older lesion, not showing significant polyphasicity. So, we did an additional motor nerve conduction study of the fibular nerve. We recorded from the tibialis anterior. We got an amplitude of response of 3.5 millivolts, which is just below my normal amplitude for this response when we stimulated at the fibular head. And when we stimulated at the knee, we got only a 0.5 millisecond response. We calculated a 34 meters per second velocity for that segment at the knee. So, now what we see is conduction block. And here are the waveforms that go with the numbers I just showed you. You see the large amplitude, 3.5 millivolt response in the middle of the screen, the fourth trace from the top, and the bottom trace, which is the recording with stimulation at the knee. So, we have conduction block. And conduction block, of course, will correlate with weakness. The signals don't get to the muscle because of the neuropraxic segment of nerve as the nerve is entrapped. This is what we love to see in EMG because it allows us to precisely localize the injury to the nerve as we stimulate proximal and distal to the site of injury. Now, what happens next after we see a neuropraxic lesion? Well, we come back three months later. This individual was, as I said, a medical staff colleague. And we were able to convince him it would be fun, if not enlightening on his injury, to do repeat studies. We repeated the fibular motor nerve to the EDB, and we got the same 0.2 millivolt response and similar findings in terms of distal latency and conduction velocity. With recording from the tibialis anterior on the follow-up study, we now saw a 4 millivolt response from the fibular head. And with stimulation at the popliteal crease, a 3.1 millivolt response. So, we still had some conduction block, but it was only 25% of the lesion rather than not. And so, you see, our strength is 4 over 5 instead of 2 over 5. As the conduction block resolves in a short period of time of just a few months, we see improvement in strength. These are the responses. You see some temporal dispersion, as we now have some segments of the nerve that are conducting quite slowly, and a longer duration response is expected with that temporally dispersed response. And we did a limited EMG this time, but we're interested in whether the tibialis anterior still showed some abnormalities. And in fact, it did. It now shows some evidence of muscular denervation. But they were probably already there. EMG, needle EMG, is quite sensitive to denervation, and we find it now. The motor unit amplitudes were still large, an increase in duration, and we now had some polyphasic motor units because we had some sprouting reinnervation going on in the muscle fibers. So, this is how we handle a nerve entrapment. We always want to stimulate proximal and distal to the point of a suspected entrapment. That's how we're going to find the lesion. We want to be carefully noting amplitude and duration, as well as the latency and conduction velocity of these measurements. And the best measure of prognosis is what the amplitude is with your most distal stimulation. It's important to value the contribution of both sensory and motor components of the nerve conduction study. And remember that the best measure of strength is the response from proximal stimulation, which shows you how much of the axon function is passing through, so that the cranial impulses to the spinal cord can get all the way to the muscle. This is the technique of recording that perineal sensory response I showed you. I do it in a little more proximal location up on the ankle than many other people do, and this worked better for me as a reliable response. It records some of the smaller branches of the fibular nerve as they're just beginning to divide and before they splay out on the dorsum of the foot. Remember that this entrapment of the perineal or fibular nerve happens in the popliteal space between there and the fibular head as it passes between the muscle tendons. Contributing factors are known to be rapid weight loss and crossing legs, both of which are subject of today's case experienced, and repeated squatting, also known as strawberry pickers palsy, can also cause this phenomenon. Eliminate the cause, and the problem usually heals well. It rarely results in a permanent loss. You may need a temporary orthosis, but since there's no sensory loss in the plantar surface of the foot, a custom-molded plastic orthosis is not necessary. The patient usually has protective sensation. A picture demonstrating where the nerve passes by the lateral hamstring tendon and lateral gastrocnemius tendons as it's exiting the knee. A picture of our subject, even with his eyes obscured for privacy, most of you will recognize as Ernie Johnson, my longtime colleague and leader and mentor. May he rest in peace. Muscle strength correlates with the conduction block in neuropraxia and bears no relationship to the velocity of nerve conduction in the segment, and that's what we showed in today's case. After nine months, he had recovered full strength, five out of five, and I can no longer specifically hear him walking down the hallway of our office building. So did we find out what we wanted to know? We found out that the nerve was affected, and in what way the nerve was affected is neuropraxia with some small amount of axon injury and well-airing degeneration as well. We did specify that it's a peripheral nerve problem. We knew exactly where it was with our two points of stimulation, and we did identify that there was also an underlying chronic L5 radiculopathy that provided initial confusion in making this diagnosis, and we measured the severity with quantitative measurements, and we knew we had a good prognosis when our distal stimulation below the fibular head recording the tibialis anterior gave us an amplitude that was almost in the normal range. The prognosis for nerve functional recovery is good whenever we can demonstrate that well-airing degeneration is not happening or is only a small proportion of injury. Thank you for your attention, and I'd welcome any questions if you have them at any time. Thank you. Farron, I think it's your turn. Thank you, Bill. It is my honor to present another challenging case and to be on this program together with my esteemed colleagues from other renowned medical centers. As Bill mentioned, I'm Farron Williams, clinical professor from University of Massachusetts, and I want all of you to think about different diagnostic possibilities as you may all see these cases that don't show up every day because you all have very varied practices, and many of you do focus on spine and lower extremity problems, so I'm going to present another case with lower extremity weakness that presented as a diagnostic dilemma. The patient is a 78-year-old male who presented with pain and with weakness in the lower extremities, and I first saw him about six months after the onset of weakness, which he states started with right thigh pain that progressed to weakness, followed two or three months later with left thigh pain and weakness, to the extent that by the time I saw him, he needed a walker to get around. He was managing somewhat in the house with a cane, and he was able to get to his third floor apartment, but with great difficulty and only because his upper body strength remained intact. He had some urinary urgency and frequency, but no incontinence and no loss of sensation from micturition without bowel problems. He states he's had chronic lower back pain, but that really wasn't any different from his baseline. He told me that he was told he had diabetes mellitus. He wasn't actually so sure about the diagnosis himself, so he wasn't managing that too optimally, and he'd also been told he had no prostate problems. He had been a former smoker with about 40-pack year history of smoking, but had not smoked in 20 years and denied a use ongoing of alcohol. He, as I mentioned, lived on a third floor, which can be challenging. I'm in Worcester, and there are many of what we call triple-deckers that are entirely separate living quarters with three different levels. In fact, he has an ex-wife who helps him that lives on the first floor. He had still been working on a part-time basis, but five days a week at a Walmart. He enjoyed doing that, but he got weak to the point that he could no longer continue to do that, nor could he continue to drive. His ex-wife and others were helping him to get to the store and to go to other places. He had no significant family history. Both parents lived to older ages. His mother may have had congestive heart failure, but died at 87, and his father lived to 99. I saw him first six months after the onset of his initial weakness and pain in the left thigh, and at that time, he had the following strength. He had fairly profound weakness through the hip girdle musculature into the quads and more so the hamstrings and the extensor musculature, but he had fairly good strength still distally. He did, however, progress over the next month, and when I saw him approximately a month later, he now had much more weakness, including in the distal ankle muscles. At that time, I proceeded with electrodiagnostic testing, and he had progressed also with weakness now on the right side. His neurological examination, upper extremities remained 2 plus and symmetrical for deep tendon reflexes. In the lower extremities, he had absent reflexes at both the knees and the ankles. Sensory, he had decreased pinprick, as well as vibratory sensation from mid-shin distally. He had rapid alternating movements and finger to nose intact and symmetrical, and he had no cranial nerve abnormalities. Because of the presentation initially, someone had already done hip scans before I saw him, and they found some nonspecific labral tears. He'd also had lumbar MRI, which revealed multi-level degenerative changes, but no exiting nerve root impingement, no cauda equina abnormalities, no compromise of the fecal sac, and no significant lumbar stenosis. More recently, because of ongoing weakness and thigh pain on the left, someone ordered an MRI of the left femur, which showed some signal intensity changes in the vastus intermedialis and lateralis, but it was felt to be not significant. He did, of note, have hemoglobin A1c, and interestingly, he has some questions about his diabetes diagnosis, but his hemoglobin A1c, the time he was so weak, was around 10. It trended downward to 8, but it still remains quite elevated, with blood sugars in the 150 to 200 range trending downward, never much higher than 200. No other significant laboratory abnormalities. He also, on electrodiagnostic testing, seven months after the onset of the symptoms, had no obtainable serosensory response. Perineal motor responses were as follows. On the right, there was no obtainable response from the EDB, and as Dr. Peace just pointed out elaborately, it's important when you can't get a distal response to record more proximally from the tibialis anterior. He had a very small response from that, 0.1 millivolt, both at the fibular head and above it, with conduction velocity across there of 34 meters per second. And on the left, he did have a distal response, but it was 0.6 millivolt amplitude, 4.8 distal latency, and similar amplitude, approximately 0.5, with conduction velocity between the two sites of 35 meters per second. Tibial motor on the right was 1.4 millivolt for the amplitude, 5.4 distal latency, and on the left, 2.1 millivolt amplitude, 7.3 distal latency. As you can see, better than perineal motor, but still fairly significantly lower than what one would expect as a normal tibial amplitude, and more delayed latency on the left side. Needle EMG findings on the right reveals diffuse spontaneous activity, not only in proximal muscles, but also distal muscles, including no motor units from the tibialis anterior. He also had corresponding decreased recruitment almost throughout, with some discrete recruitment in some muscles, and no motor units detected in gluteus maximus and anterior tibialis. On the left side, similar findings with generalized spontaneous activity in most of the muscles. And on both sides, you might also note he has polyphasic motor units, many in some muscles, few in others. But in most of the muscles, he has polyphasic units, as well as decreased recruitment. Lumbar paraspinals were studied on both sides, and they showed 2 plus fibs and positive waves in both mid and lumbar paraspinals bilaterally. How then do we interpret these findings? Well, for one, we had amplitude changes, no sensory and significant motor amplitude changes, and we had diffuse EMG abnormalities, proximal and distal, and EMG abnormalities in the lumbar paraspinals. The amplitude changes alone suggest he most likely has some sensory motor perforatoropathy from the diabetes, but he has another superimposed process that affects myotomes from different root levels, with evidence on the needle study for both denervation as well as reinnervation. His clinical history suggested an asymmetrical progressive weakness, first proximal, then distal, without bladder or bowel changes. And that together may suggest a diabetic amyotrophy, which is usually a subacute process, but in his case, it progressed over time. And diabetic amyotrophy is often thought to be a polyridiculopathy, but also a plexopathy involving the lower extremities. How does one differentiate? Well, this case demonstrates that that may be difficult, because for one, he has no obtainable sensory response in the lower extremities. And as pointed out earlier, the sensory often help to differentiate a plexopathy from a radiculopathy, since the sensory ganglion is more distal to the foramina. But in his case, since he had no obtainable sensory distally and proximal sensory in the lower extremities are at baseline, very small, it would be challenging to obtain any proximal sensory. Sensory also tend to be smaller and at times unobtainable in older patients, and this gentleman is 78 years old. His amplitude changes suggested axonal loss, and that was confirmed with the needle EMG changes. And these are diffuse. Absence of reflexes doesn't help us that much, because it could be consistent with a radiculopathy or a plexopathy, and also seen with a peripheral neuropathy. It may be less likely a motor neuron disease, because it may present with more hyperreflexia than hyporeflexia. His pattern of weakness, though, is a little unusual, because while he had proximal weakness initially, it progressed to distal. If it had remained proximal, it would be more the usual pattern with a diabetic amyotrophy and could reflect a myopathy, although that is often symmetrical and not asymmetrical. The asymmetrical weakness also is concerning for possible lower motor neuron disease. He had progressive weakness, which could also be lower motor neuron, and one has to consider whether there could be an underlying infectious process, such as an epidural abscess, or also a possible coagulopathy. I have seen a few patients with unusual coagulopathies who have bled into the thigh or other surrounding musculature and have had to compromise or compression of the nerves because of that. So this problem is often referred to as a diabetic radiculoplexopathy superimposed on his diabetic peripheral neuropathy. Etiologies are thought to be ischemic possibly, could affect the lumbar sacral plexus or the nerves themselves at different levels. Some patients have a process such as a multiplex neuritis, mononeuritis, especially which may affect more the femoral nerve, and he could have epidural microvasculitis. Others suspect there could be a metabolic myopathy that helps with that is one of the etiologies for this problem. While most patients recover to some extent over a period of months, some patients may have a much more prolonged course, and it can take one to two years to recover. And in this patient's case, it has now been about one year and two, three months, and he still isn't that much stronger. So he may be in the category of patients who will have some long-term weakness. Fortunately, he has remained strong in his upper extremities to the extent that he is able to climb the three flights of stairs to his dwelling, and he actually recognizes that that's good exercise for him, even though it's hard for him to do it multiple times a day or to do it very fast. For treatment, medical management, we are consultants and physicians first and foremost. So making sure that his blood sugars are controlled and his hemoglobin A1c is controlled with diet and medication, making sure he has someone who monitors and treats those problems is key. He may benefit from physical therapy to help not only with exercises and strengthening, but also to help him with gait patterns and the other things that they may be able to work with him to help him remain more functional. But one cannot emphasize enough, as you know, the importance of doing these home exercises regularly because that's where he resides 24-7. Most importantly, surgery is not indicated. This will not be a problem that will improve with surgery because it's not from a lumbar stenosis or just a single nerve root impingement. He may need pain management. He may need some assistive devices for ambulation, and he also may need an orthotic depending on how much weakness, driving adaptations if it's mostly the right leg, and in rehabilitation, always psychological support. So in conclusion, remember that lower extremity weakness may be multifactorial, affecting one's ability to do functional activities such as stairs and may require a change in the environment. He was fortunate that he could still do the stairs. May limit what he does every day. This patient was older, but he still enjoyed going to work, and he's not able to do that any longer. But the physiatry role is not only to make the diagnosis with the electrodiagnostic capabilities that we all are capable of doing, but to help prevent unnecessary surgery and to educate both the patient and the referring provider about what the prognosis may be for further recovery to help define a most appropriate course of treatment in optimizing his functional recovery and improving his quality of life. And I want everyone to please remember that patients do not follow the textbooks. They are all individuals, and they are different. They present unique challenges to us every day, and I thank you for watching, and I hope next year this will be a live presentation, and I have included a reference at the bottom for some possible treatment options. Thank you so much. All right. Challenging cases for the expert electromyographer. I'm Eric Ensrud from Portland, Oregon, and my case is dirt off the shoulder. We'll get going here. So this is a patient, a 37-year-old nurse practitioner who sent on September 11th a MyChart message to her primary care. She's writing because she injured her left shoulder on August 30th in the morning. After playing with her kids, she heard a popping sound and had some mild tenderness. She went to work, and a few hours later, she began to have significant pain. Couldn't raise her left arm and had pain radiating down to her fingers. And then from the next day onward, she's had daily pain, and she's about 10 days after this onset, that wakes her up at night. It's constant and bothersome and impacts activities. All right. So this is a So she was sent for an EMG, and that was on November 11th. So if we back up here, so the onset was at the beginning of September, end of August. So about 10 weeks after the onset, she had an EMG, 10 to 12 weeks after the onset, she had a first EMG referral. And you can see the exam that they found there. An MRI had already been done that showed some mild rotator cuff tendonitis and labral fraying. Interesting, it showed some signal change in the infraspinatus and supraspinatus, a normal suprascapular notch. And basically, this EMG was normal. Nerve conduction studies were normal, and you can see the needle EMG chart to the right, all the muscles that were sampled, and everything was normal. And they did report that they sampled the supraspinatus and the infraspinatus. So this problem persisted, and about two months later, she was sent for a second EMG. Remember the onset, let's just say it was September 1st. So now we're at January 3rd, four months later, and she's got posterior lateral shoulder pain, you know, increased with lifting and overhead. You can see the exam there. Nerve conduction studies were done again and were normal again. And then look at the needle EMG table there on the right, and everything was normal. And they reported that they looked at the supraspinatus and infraspinatus as well, and they also reported that they looked at the rhomboids and the cervical paraspinals and added on the triceps, everything was normal. Well, this resulted in some, she's being seen by an emergency medicine, sports medicine fellowship trained person, and less than a week later, she said, would you see her as a consult and see her? And so I talked with her, and of note, when she was in that acute pain period, if she tilted her head towards the contralateral side from the left shoulder, she would get sudden shock-like pains in the left shoulder and finger. She didn't get that with tilting the head and neck to the ipsilateral side, towards the left. And the pain pretty much significantly improved over the next couple of weeks after onset, and certainly a month after onset, she no longer had that type of severe pain. However, she's had abnormalities in shoulder function and strength, and that's what they're being asked to see her about. The shoulder doesn't feel normal. She has reduced shoulder function. She's got some pain in the shoulder. In her exam, you can see my MRC scores there from the muscle force, and the most significant thing was that she had really a quite weak infraspinatus at 4 minus, but, you know, elbow flexion and extension were normal. I did some musculoskeletal tests there. The Hawkins sign was negative. The AC joint compression was negative. I couldn't appreciate medial or lateral scapular winging. Light touch was normal, including the outside of the shoulder. Some supraspinatus tests, the drop test, the left was mildly positive. And checking shoulder abduction at 15 degrees, that was 5 out of 5 bilaterally, and it's very unclear that this idea that the supraspinatus does the first 15 degrees of shoulder abduction forces is accurate at all, but because the deltoids already started activating, it's a much stronger muscle. So I didn't do nerve conduction studies on her. They'd been done twice, but I did needle EMG, and you can see I found the biceps was normal, the triceps was normal, the deltoid was normal, but when I went into the supraspinatus, she had 2 plus fibs, and she had significant reinnervation changes, and when I went into the infraspinatus, I had 4 plus fibs and very significant reinnervation changes with markedly decreased recruitment. The rhomboids were normal, and the middle cervical paraspinals were normal. So what's going on here? So this is Parsonage-Turner syndrome. This is the original article, and they found 66 of 136 patients in their case series here were in the hospital with other conditions when the syndrome started, and others had recently recovered from illness. A large number of them had a precipitating factor. You can see the actual table there, anything from lumbar punctures, puncture operations, infections, trauma, anything that, you know, any sort of precipitating cause. What they noticed was rapid development of weakness subsequent to a period of initial pain. A small percentage or small portion, about a third, had sensory changes on exam. Interestingly, a third bilateral in all but the most severe cases improved over months. And by the way, in the interest of full disclosure, those two guys there, they're actually not Parsonage-Turner. I just looked up a couple of old British guys on Google Image, and they all look alike, so I figured I could sneak that one by you. So if you're not familiar with this paper, I really encourage you to be. It almost seems like it's getting a little dated, but it hasn't really, there's not enough knowledge of it. It's the largest study of Parsonage-Turner, about 250 cases. It was done at a national referral center in the Netherlands where everybody was sent in to this center to be evaluated, a very regimented evaluation. And all patients had an attack of acute, painful, patchy brachial or lumbosacral plexopathy that followed a monophasic course. And they included patients with paresis before pain and painless but otherwise typical attacks. And they did, as you can see on the right here, a very regimented and full evaluation, including functional evaluation. And what are these patients like? Well, in their study, what was interesting, almost three-fourths were male, which is unusual for autoimmune. The percentage was right-handed was normal, no preponderance of left-handers. Interestingly, about 20% had a family history of this, mean age of onset, 41 years of age. So they're probably just maybe even starting to make a big dent in their school loans. And the mean time to diagnosis, unfortunately, was 44 weeks. And 62%, two-thirds, received another diagnosis initially, usually cervical radic, rotator cuff tendonitis, or glenohumeral pathology. So what were the characteristics of these attacks? 90%, which means 10% don't, started with typical pain, onset usually over a few hours. You can contrast that with radiculopathy, which starts almost immediately at the time of the herniation and compression of the root. 61% started at night. About a fifth had nerves outside of the brachial plexus. And very interestingly, 7% had phrenic nerve involvement. And over to the right there, I pointed out a paper that Sam Beener from University of Nebraska published last year, very interesting case series in phrenic nerve palsy in patients with neurologic amyotrophy. So if you have patients who have unilateral or bilateral diaphragmatic paresis, you really need to be thinking about this. It probably explains the majority of such cases. About a quarter of the patients had reoccurring attacks. And most of the patients experienced this typical severe pain. Interestingly, almost all patients, the pain was worse at night. It was increased by movement or pressure on the limb. When we talked about her neck bending to the contralateral side, that's stretching the upper plexus, which is just the opposite of what a radiculopathy would be, worsened by ipsilateral bend of the knee. Usually the pain lasted about three weeks. Males couldn't take it as well. It lasted longer. And about two-thirds of pain had subsequent MSK, patients had MSK-type pain, especially in the periscapular region. Quite a bit of adhesive capsulitis, even subluxation. And you can see that quite a few patients had pain that radiated down into the arm, probably leading to the misdiagnosis of cervical radic. Weakness. What I wanted to really point out here is that usually it takes some time for the weakness to mean time of onset, almost two weeks after the pain. And if you'll look at that table four there, what are the most often involved muscles? So, you know, most of these patients have the upper plexus. You can see in the top table there about three-fourths of the upper plexus. So, not surprisingly, the infraspinatus was the most commonly affected muscle at nearly three-fourths, serratus anterior almost as much, and in particular, the supraspinatus as well. So, you can see that particularly, you know, that suprascapular nerve and the long thoracic nerve. And we like to think that they're focal, but those nerves are specific nerves that have specific adhesion molecules that are unique to them all the way down. So, really the attack can occur anywhere along the length of the nerve, and there's a lot of false localization at a specific branch area. So, why are these patients missed? One reason is the way that people check infraspinatus force. Some people, unfortunately, check it the way I'm shown on the left there, where you do it unilateral. You can't have a contralateral control, and the whole trunk rotates. It's much better to check it as on the right there. Bilateral, have the patient hug their elbows into their shoulder, or into their ribcage, and then externally rotate the upper arms, and then push on the forearms, not the fists themselves, because then you'll get the range of motion of the wrist involved, but push on the wrists. And this is a very sensitive test. You've got side-to-side comparison. It's actually great for upper motor neuron pattern weakness, too. Try it on a patient who's had a hemiplegic stroke and says they're not quite back to normal. I think you'll find something there, comparing side-to-side. So why are we missing this? Because the infraspinatus isn't checked, and then also you really need to take the shirt off and look for inferior angle scapular winging, secondary to long thoracic nerve involvement, or serratus anterior. This is especially good to differentiate it from rotator cuff or supraspinatus tendonitis, and you can see this patient there on the left has winging. So sensory symptoms. Most patients report some, but a considerable portion don't. They tend to resolve quite quickly. When they do occur, they're often on the outside of the shoulder, lateral surface of the shoulder arm. So over half reported an antecedent event. Usually it occurred about a week before the attack. Sometimes it occurred hours before and about a fifth, and it could be exercise. It's frequently exercise for you sports medicine people. Surgery is really common. Probably a lot of surgeons are falsely accused of pressure palsies during surgery when what really occurred was this monophasic autoimmune attack. Peripartal is seen quite a bit. Vaccination can cause it. There will likely be, when we get a population-wide COVID vaccination program, which hopefully will occur soon, there are going to be percentages of people, small but meaningful, that develop parsonage turner after this. So be on the lookout for it, especially with the flu vaccinations and hopefully COVID vaccinations coming up. It can even occur after Botox injections for cervical dystonia. Probably for headache as well, although I haven't seen that one. Lab tests. You know, you need to wait to get the best EMG. Usually these are proximal muscles, but best at greater than three weeks after symptom onset. And the problem with EMG is very few patients in general have infraspinatus, supraspinatus, and serratus anterior checked. And if they do, they may be checked incorrectly. I'll mention that. But interestingly, about a third of the patients had a chest x-ray and about one in 20 had elevation of one or both diaphragms due to phrenic nerve involvement. So again, think of this with a phrenic paresis or diaphragmatic paresis. Always think about it in a patient with diaphragm weakness. And you know, almost half of them had a cervical spine MRI. And guess what? Half of the cervical spines in a 41-year-old show degenerative changes, which probably, you know, there's too much spine-centric evaluation and treatment. And you know, you'll find what you're looking for if you're convinced it's a RIDIC. And there's not actually not a really high yield of brachial plexus MRI in these patients unless you do very specialized imaging available very few places in the U.S. for sure. So why did this patient have two EMGs that missed the infraspinatus and supraspinatus? For many years, I ran a lab in Boston that trained a lot of residents in EMG. And I'd see people missing it. And I thought, you know, how can we make sure? So what you really need to do with these muscles is first divide the area between the medial scapular border and the edge of the humerus into thirds. And because these muscles are tapered, both of the needle EMG insertions should be at the border of the proximal and middle third. And first you want to go perpendicular to the scapula when you do the supraspinatus. If you don't go deep enough, you're going to record from a trapezius overlying, which I believe happened in this patient because both the MRI was abnormal signal intensity and the EMG. You need to get all the way down to the bone. You tell the patient it's going to tap the bone, it's going to feel sharp, and then retract a couple of millimeters and you'll be in the supraspinatus, or excuse me, infraspinatus. For the supraspinatus, you need to come in vertically in that groove, that trough between the scapular spine and the scapular body there, and just put the needle down into the bone and back up. And that way you'll be in the supraspinatus and not the trapezius. So again, tell the patient you're going to feel a sharp tap when it taps off the bone. You're not helping them by just getting into the trapezius. And you're not going to cause a pneumothorax and be in the lung when you're using the bone as a protectant to avoid doing that. How about the serratus anterior? You know, that can be a little iffy can it, particularly in patients who have, you know, some subcutaneous adipose tissue and so on. This is a great method from Mayo Clinic. So you find a rib with your fingers, which you can do even when the subcutaneous tissue is there, and then isolate that rib by placing the fingers in the adjacent interspaces. And you do that in the mid or anterior axillary line. And then you tell the patient this needle is going to tap the bone. You'll feel a sharp sensation when it taps the bone. The rib is keeping you from doing a pneumothorax. So you're not being too ginger and getting down, need to get down to the serratus anterior. You tell the patient you're going to tap the rib with the needle and tap the rib with the needle and you'll be in the serratus anterior. So I'm convinced that's what happened with the first two needle EMGs this patient had. So functional recovery is, you know, this is a Dutch study. Almost a quarter of patients weren't able to work at three years or more. That may be related to the very generous system they have for disability in the Netherlands. I think unless it's changed, you get either two-thirds or three-fourths of your previous income for life. But there definitely are some residual problems from the complex shoulder force imbalance from, you know, chronic muscle weakness from incomplete recovery. So here's some graphs here on persistent pain. You know, interestingly, the musculoskeletal pain on the left there is much more common than neuropathic pain. And then, you know, the majority of patients had some weakness in the involved muscles long-term. A small percentage had an MRC-5 score at three years or more. So, you know, is there anything else we can do about this? Well, this is a monophasic immune attack. Do we know about any others of those? Well, how about Bell's palsy, which is a monophasic immune attack on the patient. Here, if you can see, this person has right lower facial weakness. So what do we do with that? We give the patients steroids and have a very significant improvement in ultimate recovery. It's usually a 10-day course of steroids. So, again, this is a paper that probably not enough people are aware of. It was so positive, they were unable to do a double-blind study. This is an open label study, but 50 patients treated within one month of symptom onset. And there's no particular logical reason for one month. But if you think about a monophasic attack and inflammation and resolution, if you do it much after a month, it's probably not going to be very effective. And it's probably more effective the sooner you give it. It's a real simple 13-day course. They use prednisolone, but prednisolone and prednisone are dose equivalent. 60 milligrams a day for a week, and then taper it down by 10 milligrams every day. Once you get to 10, go down by 5. And these are really remarkable results. Median time until pain relief, 12 1⁄2 days versus 20 1⁄2 without the steroids. Recovery of strength within one month was tripled to 18% versus 6.3% without the steroids. And then finally, full functional recovery within the first year. Look at this, 12% with that 13-day steroid course versus 1%. So, please think about this and have a low threshold after discussing the possible risks with a patient to treat with this. So, you know, are you going to see partialness or is this just one of these, you know, zebras that, you know, attendings tend to like to question people about, you know, have you thought about all these strange things? Well, you know, if you don't look for it, you're not going to see it. Do you see anything unusual in that picture there? Obviously, it's a bit outdated, but you know, those of you who live in California, certainly in Oregon here, even in the Midwest and other areas of the country, these are around, these are around a lot more than we would have thought. So, now look for a mountain lion. Do you see a mountain lion there looking at that little kid? I bet a lot of you saw it once you decided you were going to look for it. So, let's look at this paper. We'll try and wrap things up here, but it's a great paper on the incidence of Parsonage-Turner syndrome in a primary care setting of prospective cohort study in a population of 14,000 patients. The annualized incidence rate of Parsonage-Turner was 1 per 1,000, which is about as third, you know, half to third as common as MI and much more common than TIA. So, it's much more common than we realize in medical and surgical treatment is possible if there are focal nerve constrictions. That's kind of experimental at this point, but gaining some momentum. But certainly, acutely, we've already got a treatment that will really help the outcome, the steroid dosing. So, summary and objectives. Think of Parsonage-Turner syndrome early and often with subacute, onset, neck, shoulder, and arm pain. It's not unusual. Examine an EMG, the infraspinatus, certainly. EMG, the supraspinatus. And the patient for the scapular winging, the serratus anterior. Remember the needle orientation when doing needle EMG. Perpendicular to the medial one-third of scapula and tap the scapula with the needle for infraspinatus. Vertical to the scapular, not so much the trough, at the medial between the wing and the scapula body. At the medial third of the scapula and tap the bone in the lowest point of that trough for the supraspinatus. And then straddle the rib with fingers and tap the rib for the serratus anterior. Be careful that your fingers are on either side of the rib. Hold your fingers there and go down to the rib. So, treat, low threshold to treat with a 13-day steroid course. Very effective. Try and start it within 30 days of the onset of symptoms. Advise the patient is for significant recovery at three years. It may be incomplete. Get them into specialized shoulder PT. Don't over-localize to a specific branch point in the brachial plexus. It can be anywhere along the peripheral nerve pathway. There's a great paper that anterior interosseous neuropathy is not at the branch point in the forearm off the main trunk of the median nerve. It's up in the upper arm. So, anyway, thank you very much and please think about Parson's Turner.

neuromuscular disorders

electrodiagnosis

COVID-19 pandemic

electrodiagnostic testing

healthcare professionals

chronic lumbar pain

lower extremity weakness

diabetic amyotrophy

Parsonage-Turner syndrome

neurologic amyotrophy