All right, I am Karim, one of the senior critical care fellows at the Bay State Medical Center in Massachusetts. I'm presenting a case that presented to us with tracheal nodules, no financial disclosures. And we had a 64-year-old male who was referred to the pulmonary clinic by his primary care provider after he was noted to have abnormal CT findings. The CT chest was obtained because the patient had complained of a chronic cough as well as a 10-pound weight loss over the past year. His past medical history was kind of like what we usually see with most of our patients, diabetes, hypertension, hyperlipidemia. He did have a history of asthma, was on ICS as needed. He also had an essential tremor, was on primidone for that. His family history revealed some history of cancer in the mother and sister, but he was unclear exactly what types of cancer. And as far as his dad, he had alcoholic cirrhosis. Social history, he smoked one pack per week for as long as he remembered. He was originally from Puerto Rico and moved to the New York area at the age of nine and then moved fairly recently to Massachusetts. He had worked in factories making gloves and packing and no other occupational exposures that we were able to identify. He denied any other inhalational or drug exposures. So his physical exam was fairly unremarkable except for the known tremor that he had and some coiculoderma that was noted on his neck. Vital signs were also within normal limits. So we started reviewing his imaging. So this was his X-ray, which was fairly unremarkable to us. He did have pulmonary function tests already done. These were the flow volume loops, which were, again, fairly unremarkable. These were the actual numbers, no really signs of obstruction, supranormal FEV1, FBC, no bronchodilator response. His lung volumes were all normal, maybe even supranormal, and he was unable to perform a DLCO maneuver. So we reviewed his CT chest, and then that's when we start seeing these tracheal abnormalities. You can start seeing tracheal thickening, nodules, the wall, mostly anterior and lateral walls with some calcifications. Notably, the lung parenchyma was normal. You can see, again, some of it here, again, mostly in the anterior and lateral walls of the trachea, and completely sparing the posterior membrane of the trachea. And again, as you can see, most of the lung parenchyma was fairly normal. The base is not much really going on there, and not much in the distal areas. So our differential at this point for tracheal nodules, the first one on our differential was TPO, which usually presents with nodular calcifications that spare the posterior wall. Amyloidosis was also on our differential, which usually does involve the posterior membrane as opposed to TPO. Other etiologies were relapsing polychondritis, although he did not have any abnormalities, cartilaginous abnormalities with ears and nose, sarcoidosis, which can have tracheal narrowing, but he did not have any signs of hyaluronidin or mediastinal lymph nodes, granulopathy with polyangitis, but again, no history of renal or lung disease, and then other etiologies such as benign or malignant tumors. So we went ahead and performed a bronchoscopy, and we saw in the trachea these yellowish vascular nodules that were primarily on the anterior walls and the lateral walls, and again, completely sparing the posterior walls. This is another segment. The distal part of the airway survey was fairly unremarkable. So we did obtain biopsies of these nodules and sent them for pathology, and they came back staining positive for Congo red stain and crystal violet stains, which was consistent with amyloidosis. We sent them out for a send-out test liquid chromatography, tandem mass spectroscopy, which again confirmed the presence of amyloid tissue. So pulmonary amyloidosis, I mean, amyloidosis overall is a disorder that is caused by formation of antibodies, kappa and lambda chain proteins that are deposited extracellularly in multiple organs and can cause dysfunction and death. Pulmonary involvement can be limited or systemic. The four patterns that we know of is diffuse pulmonary amyloidosis, nodular, and the less common diffuse tracheobronchial amyloidosis, as well there's a plural amyloidosis. Nodular usually presents like this with unilateral or bilateral nodules that can be, are usually part of localized amyloidosis, but some rare cases of systemic amyloidosis have been published. They are usually sub-plural, well-circumscribed nodules and usually do not cause morbidity and mortality if they're part of the limited disease. The more severe form is diffuse pulmonary amyloidosis, also known as diffuse alveolar septal amyloidosis. And here the amyloid proteins deposit in the alveolar septa and vessels. This is usually part of systemic amyloidosis, can show up as reticular opacities, septal thickening, micronodules, and traction bronchiectasis, and sometimes even honeycombing. This disease can cause pulmonary hypertension, either due to cardiac dysfunction, which can cause group two or sometimes group three if it causes severe ILD. Rarely does it cause group one, but it has been described as well. Usually it has a poor prognosis and chemotherapy is the treatment. It's usually treated as a multiple myeloma. And this is our patient here with tracheobronchial amyloidosis. The least common form of it presents with yellow-white flakes. Usually there's a pattern to the disease. It's either proximal or mid or in the distal airways. In our patient, it was proximal. Usually patients present due to the amyloid deposits causing stenosis of airways. And that can cause cough, hemoptysis, dyspnea, recurrent pneumonias, and wheezing. And management here usually is focused on palliation of these symptoms by monitoring the patients to prevent airway compromise. So usually treatments like debulking, using lasers, or different forceps, or sequential dilation to dilate any airways that are stenosed. Some reports of using radiation and chemotherapy, but usually the standard of care, even though there's not a whole lot of data, is monitoring the airways and doing sequential treatments as needed. And special thanks for my co-authors. And these are my references. OK. I did it. We're off to a good start, I think. Hi, everyone. I'm Laura Jones. I'm a pulmonary transplant fellow from San Antonio, Texas. And I'm going to be talking about light chains with heavy consequences. That's me. I have nothing to disclose. So today we're going to be talking about a rare case of pulmonary light chain deposition disease, which is a mouthful, so I'm going to try to say it as slowly as possible. We're going to talk about the patient's clinical presentation, the ways to diagnose it, and then treatment modalities. So our patient was a very healthy 49-year-old gentleman who presented with a subacute progressive dyspnea, cough, and palpitations. On arrival to the hospital, he was hypertensive, tachycardic. He had bilateral crackles and some lower extremity edema. His labs were significant for normocytic anemia, normal renal and liver panel. His BNP was elevated at 767, and he was noted to have proteinuria and hematuria. These are his images. Chest X-ray is on the left side. He has some bilateral reticular opacities, mostly at the lower bases, but pretty scattered throughout. And then his CT on the right of the screen shows a couple of cystic lesions. And I'd like to point out, I think maybe, I don't know if this is a laser, these little vessels coursing near the cystic lesions, one there and then one a little bit lower right there. And that'll be pertinent later when we discuss the disease itself. He also did have a one-centimeter pulmonary nodule and very tiny pleural effusions. He had a pretty complete rheumatologic workup, but I included only the pertinence. An ANA was negative, and an SSA and SSB were negative. His lambda-free light chain was elevated, and kappa-lambda ratio was reduced. His SPEP had a monoclonal spike in the gamma region, and his electrophoresis had an IgD lambda monoclonal gammopathy. He also had an echo, which showed significantly depressed ejection fraction, as well as global hypokinesis and left ventricular diastolic dysfunction. He subsequently had a left heart cath, which showed non-obstructive disease. He had a bone marrow biopsy, which confirmed the diagnosis of light chain deposition disease. He did not have a biopsy of the pulmonary nodule or the cystic lesions, but we assumed he likely had pulmonary light chain deposition disease. He was treated with chemotherapy for a suspected multiple myeloma, and he did have symptomatic improvement and follow-up, but he did not have a repeat CT of his chest at that time due to financial issues. So light chain deposition disease is extremely rare. It was first found out in 1975, and since then, there have only been 50 reported cases in the literature and a review in 2022. It's associated with monoclonal immunoglobulin deposition, which frequently involves the kidneys, can involve the liver, and very rarely the heart and the lungs. This is a really nice illustration by Sweet et al. On the top left, you can see the light chains in the light green color, which deposit in the alveoli and the vessels and also the airways. On the right of the illustration is an image that shows you the cystic lesion in the center, which usually characteristically has a vessel coursing through the cystic lesion or very near it. And then you can also have nodules, which are associated with eosinophilic material, and they can have calcifications, but it's not necessary. Again, it's an extremely rare disease, mostly associated with men and multiple myeloma, MGUS, and macroglobulinemia. This is our patient's CT. Just to bring it up again, you can see his cystic lesions have vessels that are coursing very near to them. So diagnosis does require a biopsy, and to distinguish it between an amyloid diagnosis, usually you'll see deposits that are granular versus fibrils and amyloid. They do not have an apple grain bifurangence under polarized light, so conga red staining is necessary to help differentiate the two. And this here is what you would see on biopsy. On the left is an H and E stain, and the arrows are pointing to eosinophilic material with giant cells surrounding them. On the right is a conga red stain, which doesn't have any bifurangence. So this would be pulmonary light chain deposition disease. Unfortunately, there's no unified treatment. The goal is to treat the underlying disease, and the goal is to remove abnormal plasma cells and reduction of synthesis and secretion of the light chains. If your patient does have pulmonary disease related to this, usually it's very indolent, slowly progressive, but there have been very few cases of rapidly progressive lung disease. Those patients did go on to receive lung transplant, but unfortunately, they didn't survive long enough to see if the disease recurred in their lungs. So in conclusion, the diagnosis of light chain deposition disease in the lungs is challenging because it's so rare. However, I would really recommend you including it in your differential diagnosis in cystic lung diseases, especially if the cysts are associated with a blood vessel. It's usually associated with lymphoperliferative diseases and Sjogren's syndrome. These are my references. Thank you. Thank you. My apologies. Our moderator had to step out, so you're getting me in its place. So I'm Anissa Das. Next up. Chair of the meeting. Yeah, chair of the meeting, aka pinch hitter. And so Dr. Jones, was that you who just spoke? Yes. Thank you so much. I just want to make sure that I'm on track and I'm doing it. And you were the second speaker because I just came in because I came from another session. Okay. Wonderful. So next up we have Mohamed Saad. Is it Sadiq or Sadiqay? Sadiq. Sadiq. Hey. Welcome. Good morning, everyone. I am excited to be here and share with you this case of silicone embolization syndrome that we recently saw in our clinical practice. I am a second year resident at Nasr Hospital, Philadelphia. I do not have any financial disclosures. Today we'll be learning about recognizing silicone embolization syndrome and possible diagnostic testing and possible treatment options. Liquid silicone, liquid injectable silicone is used for cosmetic augmentation, which is more often off-label use. It can cause serious local and systemic reactions. These local reactions are mostly associated with inflammation, tissue necrosis, and possible infections. Testing effects are usually due to embolization through the bloodstream and to various organs of the body. It can be life-threatening, can go to the brain, can go to the lungs and kidneys. In the U.S., liquid silicone is only used or approved for intraocular use and has not been approved for cosmesis or any other organ in the body. This is different from the silicone implants. This is a liquid silicone polymer. This case was presented to us. She is a 20-year-old female with no significant past medical history, comes to the emergency with shortness of breath. As you can see, her vitals are fairly stable, except for the respiratory rate that she has. EKG was normal in presentation. HSXA was done, which shows alveolar infiltrates. Her labs were significant for mildly elevated T-dimer and mildly elevated leukocyte count. Suspicion for community-acquired pneumonia. She was started on ceftriaxone and azithromycin for possible pneumonia. A CTA was done that showed peripherally located ground-glass opacities, mostly in the lower lobes and the middle lobes. And at this time, she was also deteriorating. She had a high rate of respiration, 38, and she was tachycardic, and she had a fever. Repeat labs were done, increased leukocytosis. She had a lactate of five. It was presumed that she had worsening pneumonia, which was not being covered by antibiotics. She was intubated because she was rapidly deteriorating. And soon after that, she coded. This deterioration was around after 24 hours the next day. She went into cardiac arrest. She was coded, and unfortunately could not survive. This is the post-intubation X-ray. It has worsening alveolar infiltrates. An autopsy was done later on, and it was identified that she had evacuated globular deposits of silicon and interstitial capillaries, interalveolar walls and macrophages, leading to diagnosis of silicon embolization syndrome. As we're discussing, silicon embolization syndrome can affect various organs. It can affect the brain. It can affect the lungs, the kidneys. Usual presentation would be dyspnea, fever, cough, hemoptysis. The way I think about it is like any other embolus, for example, a fat embolus, an ear embolus, or a thrombus going into the lungs, causing all these symptoms and reactions. Silicon embolization syndrome was first identified in transgenders for breast augmentation in 1970s. Although the precise mechanism is unclear, but it is postulated that it goes into the bloodstream and metastasizes to various organs. Most notably, the two most commonly affected organs are the lungs and the brain. These are the microemboli that diffuse to these two organs. For treatment, quite honestly, we are not sure how to treat it. Treatment is mostly supportive, including high-flow oxygen inhalation, mechanical ventilation, and controversial steroids, because it's thought to be inflammatory. And maybe steroids are helpful, but it's not been proven. The patients who do survive pulmonary fibrosis are late sequelae. Literature has shown that neurological complications have been found to be universally fatal. And autopsies have shown that these are microinfarcts in a white matter of the brain, which is basically silicon. In conclusion, history and physical can help us rule out or rule in the disease. Initial suspicion is obviously for a multifocal pneumonia, but if we have a good history, we can probably think about it and include it in our differential diagnosis. And biopsy is most likely the gold standard to diagnose it, because there's probably no other way to see it on imaging. Tissue biopsy is probably the most accurate way to diagnose it. And I would be happy to take any questions with this. Thank you. Well done. Good morning, ladies and gentlemen. It's my great honor to speak to you guys today, the greatest minds in critical care and pulmonary medicine. It's a pleasure to be here. By way of introduction, my name is Dr. Emily Beershen. I'm a second-year internal medicine resident affiliated with Miami Valley Hospital, Gunshof School of Medicine, Dayton, Ohio. Three years ago, I had the privilege of training at the Pulmonary and Sleep Institute with Dr. David Marks in San Antonio during medical school. It was during this time that we encountered a very unique case of systemic disease affecting pulmonary function. I'm very excited to share this case with you today. And I have no disclosures. In June of 2019, a 60-year-old Caucasian male was referred to us by his primary care doctor for shortness of breath. It had started six months prior to that and was somewhat progressive and worsened with exercise, better with rest. He denied any other symptoms at that time. He had pulmonary red flags in his history. He was a former smoker with a 24-pack year history but did have cessation five years prior. He also had a family history of lung cancer in his father. Aside from his pulmonary manifestations, he battled prostate cancer previously but did not undergo radiation. When we evaluated him in the office, he was comfortable in room air, slightly hypertensive but otherwise normal. His physical exam revealed diminished breath sounds on the left lower lung field but otherwise he was clear throughout. Pulmonary function tests in the office showed a reduced total lung capacity to 52% of predicted, reduced FVC to 48% of predicted, and his DLCO was reduced to 69% of predicted. So what was in our differential at that time? Restrictive lung disease, given his low TLC and DLCO. With his history, certainly pulmonary fibrosis was considered in that. Pneumoconiosis at that time, though he had no occupational or social history that fit with that picture. Drug-induced lung damage was also evaluated. We checked his medications, especially given that he was treated for his prostate cancer, but none of those drugs were associated with that. Hypersensitivity pneumonitis was considered as well. And aside from restrictive lung diseases, we also considered pulmonary embolism, lung cancer, and even some obstructive processes, given his smoking history, along with infective causes. So we ordered a chest X-ray. And remarkably, an elevated left hemidiaphragm was evaluated. A paralyzed diaphragm was suspected, and we sent this patient then in for a SNF test. A SNF test is performed under fluoroscopy to allow for real-time observation of the diaphragm during breathing. It's an outpatient procedure. It's performed by interventional radiology. And in a healthy patient, the diaphragm should move caudally during inspiration, indicating normal contraction of the diaphragm. However, in this patient, as we'll observe in a second, during inspiration, the left hemidiaphragm showed cranial migration and paradoxical elevation. And this confirmed our diagnosis of a unilateral paralyzed diaphragm. Equally important to the diagnosis was finding out why this occurred and identifying the etiology of this. So there are many causes of a paralyzed diaphragm, but the majority of causes are caused by a problem with the phrenic nerve and its course. So to further understand the unique nature of this case, please allow me a few minutes to review the diaphragm and the course of the phrenic nerve. The left hemidiaphragm is more vulnerable to trauma and congenital anomalies, which is a reflection of weaknesses in fusion that occurred during development. The left hemidiaphragm is innervated, well, both are innervated by the phrenic nerve, which is one of three diaphragmatic innervations. Though the intercostal and subcostal nerves provide GSA innervation, the general somatic efferent, or motor, is operated solely by the phrenic nerve. Thus, disruption in its course can cause paralyzation. The left phrenic nerve is comprised of C3 to C5 roots, which join and cross over the anterior scalene muscle, as shown above. The nerve then enters the thoracic cavity through the superior thoracic aperture, lateral to the esophagus. It then crosses over the anterior subclavian artery, posterior to the vein, over the aortic arch, and then anterior to the root of the left lung. It then runs on top of the left ventricle over the pericardium and pierces the diaphragm. The right phrenic nerve runs similarly over the right atrium. So interestingly, our patient was also undergoing workup by GI for persistent abdominal pain, and that team had ordered a CT, and that became available shortly after his first appointment with us. Our CT shown here revealed an incidental finding of a markedly enlarged paraesophageal lymph node with further imaging revealing more of these. On the right, I have a picture from the website Radiology Assistant. It's a great map out of the mediastinal lymph nodes. In addition to those shown in the previous slide, he had enlargement of around 2L, if you can see above. And that overlies the course of the phrenic nerve, thus likely compressing it and disrupting its path down to the hemidiaphragm. So with fear of malignancy, as many of these cases turn out to be malignancy, the patient was sent for biopsy with ultrasound-guided fine needle aspiration. In the histopathology, identified similar to this picture here, non-caseating epithelioid granulomatous inflammation consistent with sarcoidosis. We also performed special stains for infective agents, all negative, workup for vasculitis, histo, and tuberculosis were all negative as well. He was given a course of oral steroids and he improved very rapidly. Seven weeks after his first visit in the pulmonary office, he reported normal exercise tolerance and feeling backwards and forward. He had repeat PFTs as well that were normal after his completion of oral steroid course. So in conclusion, paralyzed diaphragm is rare in its own right and has many etiologies. In the case of an unclear cause, though this variance is unique, interruption of the phrenic nerve by physical means should be considered during workup. Some sources. Thank you for your time. Good morning, everyone. I'm Angela, a resident at Englewood Hospital, and I'd like to share with you a case of myelomatous pleural effusions as the initial presentation of my multiple myeloma. I have no financial disclosures, so let's get straight into the case. So this patient is a 71-year-old male who presented for shortness of breath for two weeks who were at rest for a few days. He was given a course of oral steroids and presented for shortness of breath for two weeks who were at rest but worsening on exertion. He also had some chest tightness and difficulty with deep inspiration, and his only other symptoms were multiple areas of pain, particularly in the lower back and pelvis, for which he had outpatient MRI, which showed areas of heterogeneous marrow edema, but was then lost to follow-up. He also had 15 pounds of unintentional weight loss over four months. And review of systems was otherwise unremarkable, and physical exam was remarkable for sinus tachycardia in the 120s and respiratory distress with tachypnea, but without hypoxia. He also had decreased breath sounds in the mid to lower lung fields bilaterally, and EKG had only showed sinus tachycardia. All the other systems were unremarkable. In terms of his labs, CBC was grossly within normal limits, and CMP showed elevated alkaline phosphatase and LDH. Serum and urine protein electrophoresis was also done, with SPEP showing monoclonal spike in the mid-gamma region, and monoclonal IgG gammopathy with elevated capillite chains and elevated kappa lambda ratio in both serum and urine. Chex X-ray only showed some mediastinal and pleural-based opacities, better visualized on the CT, which showed bilateral pleural effusions, as well as a mediastinal mass, which was read as either prominent thymic tissue or a soft-tissue myelomatous lesion. Now, at this point, the plan was for thoracentesis, but there was no good pocket to tap on ultrasound. So he did get an MRI of the abdomen, which showed multiple soft-tissue lesions throughout, notably five centimeters in the liver and nine centimeters in the pancreatic tail. So there were also multiple pleural-based soft-tissue lesions visualized, and there were multiple mixed lytic and sclerotic lesions throughout all the bones. At this point, there was high suspicion for a plasma cell neoplasm, given the SPEP findings, as well as his clinical picture and the imaging, but other differentials included possibly lymphoma, lymphoplasmic acidic lymphoma specifically, and metastatic pancreatic cancer. So the effusions themselves were most likely malignant, given the clinical picture, and echo-ruled out any cardiac etiology. And since the effusions were not able to be tapped, the liver lesion was actually biopsied because it was the most accessible, and partially also due to depression preference. And it showed a plasma cell neoplasm with stains positive for CD45 and 138, both which are markers of plasma cell proliferation. So he did undergo a bone marrow biopsy eventually, showing approximately 40% plasma cells. In the meantime, he had supportive treatment with ipertropium, budesonide, and a mucolytic, but he had further accumulation of these effusions, and he underwent diagnostic and therapeutic torrescentesis, which drained a liter of fluid, after which he had significant symptomatic relief. And the pleural fluid analysis was consistent with an exudative infusion, as we suspected, and cytopathology showed many plasma cells, once again positive for CD138, confirming our diagnosis of myelomatous pleural effusions. So he was initially planned to undergo chemotherapy outpatient, but was readmitted for acute hypoxic respiratory failure from reaccumulation of these malignant effusions, and bilateral pleural catheters were replaced. And he was started on the DVRD chemotherapy regimen inpatient, after which he had significant improvement of the drainage from the catheters, and at four weeks after initiating treatment, he was having minimal drainage from the catheters, and they were able to be removed just six weeks after starting treatment. So when discussing multiple myeloma, the diagnosis of it requires the presence of more than 10% plasma cells in the bone marrow, or a biopsy-proven plasma cytoma, as well as evidence of end-organ damage, either renal failure, hypercalcemia, anemia, or lytic bone lesions, such as our patient. And these soft tissue plasma cytomas typically represent aggressive disease because it shows the ability of the clonal plasma cells to proliferate outside of the bone marrow environment. And there are three main ways that this can develop, either from direct spread after cortical bone disruption, secondly from hematogenous spread, and most rarely from an invasive procedure, such as a bone marrow biopsy itself, or possibly spine surgery in patients with undiagnosed myeloma. And so the diagnosis of myelomatous pleural effusion requires the thoracentesis, but extramedullary disease itself in myeloma is not that uncommon. It can occur up to 10% of cases. Typically, it's in patients who are already diagnosed with myeloma, and it represents a very aggressive disease that is refractory to treatment, and those patients have usually undergone multiple rounds of chemotherapy without success. So the incidence of extramedullary disease in newly diagnosed myeloma is less common, just 0.5 to 4.8%. And now pleural effusions in myeloma can occur from renal or cardiac causes, but in less than 1% of cases, it could be directly attributable to the myeloma itself, and these are myelomatous pleural effusions where plasma cells are found within the fluid. So interestingly, these myelomatous pleural effusions have been attributed to either hematogenous spread or direct invasion from soft tissue pleural-based lesions, but they've also been thought to be due to invasive procedures or thoracic fractures, which might be the case in our patient because the CT did show a healing clavicular fracture. And so as I mentioned, the diagnosis requires thoracentesis with pleural fluid analysis and cytopathology. And previously, pleural biopsy was also done, but it's not really as favorable given the availability of flow cytometry. And so there's no specific treatment of MPE itself, although systemic chemoradiation have been used, as well as pleural catheters for symptomatic relief and drainage, and pleurodesis considered in palliative cases. So why was this case even unique? First of all, MPE is a rare form of extramodular disease in itself. And secondly, most cases have been associated with very refractory, very resistant disease. And all of the cases that have been reported so far had deaths of the patient within four months of onset of effusion. But this patient actually had much improvement in their effusions with just first-line chemotherapy for the multiple myeloma. So in conclusion, it is important to keep a wide differential for new onset pleural effusions, and keeping myelomatous pleural effusions in mind can lead to early treatment of the underlying cause. These are my references. Thank you so much for listening. So, I'm going to be really honest. I had three questions accumulating, and you answered every single one throughout. So you did, it was super thorough. Thank you so much. Thank you. Okay. Our final, but not least, presenter is Dr. Akhinav Raval. And you're going to have to tell me, you can correct me so that I can say your name properly. Say? Akhinav Raval. Okay. Dr. Akhinav Raval. Thank you. And he's speaking on antibody-positive disease presenting as pleuritis, neuromuscular weakness, and respiratory failure. All right. Looks like I'm the only thing that's between you guys and lunch, so let's jump right into it. So today I'll be telling you about glutamic acid decarboxylase 65 antibody-positive disease that actually presented as pleuritis, neuromuscular weakness, and respiratory failure. So I'm Akhinav, there's my picture, nothing to disclose. So in terms of our objectives for the presentation, I'll just be telling you a little bit more about the clinical presentation of this specific disease and the specific distinguishing features that kind of separate it from its other differential diagnoses and specific diagnostic criteria that led to us ultimately making this diagnosis and of course review the available treatments. So we have a 43-year-old wheelchair-bound woman. She presented to the hospital with two days of intermittent inhalational pleuritic pain, hoarseness, periodic muscle spasms, and stiffness of her arms, back, and legs. She was seen just a couple days ago where she established with pulmonology, at which time she was diagnosed with acute pleuritis with an unknown etiology. Prior medical history had been for multiple DVTs and PEs without any evidence of CTEF, in addition to prior rheumatologic disease, and quote-unquote multiple sclerosis, which they had attributed to be the diagnosis that led to her lower muscular weakness with no positive findings. And no history of diabetes mellitus, which I'll get to in a little bit. And family history had also been negative for any autoimmune disease. On physical exam, phytos had been remarkable for she was slightly tachypneic, 20 to 22. She was having rapid, shallow breathing, and she had hypophonic and hoarse speech, decreased muscle tone in bilateral lower extremities. In terms of lab studies, so her VBG had shown a respiratory alkalosis picture with, of course, compensation, and the rest of the lab work had been essentially unremarkable, including even the infectious workup that we had done. And we had also done an extensive autoimmune and rheumatologic workup that had also resulted negative, but a few of which I've shown in terms of the pertinent findings. So this specific lab titer, being the anti-GAD antibody titer, had actually been significantly elevated about four times above the upper limit of normal. So that kind of led us to just looking into a little bit further. Imaging studies-wise, her chest x-ray had essentially been unremarkable. There wasn't any evidence of consolidation or any infiltrates. And imaging studies-wise, CTA of the chest with, without contrast, no evidence of any PE, no fibrosis, MRI of the brain had not been evident for any kind of enhanced lesions, and an EMG that she had done had no evidence of any active denervation. She also had an LP performed that had protein count within normal limits and negative oligoclonal bands. In terms of the pulmonary function tests, it had shown a mixed obstructive and restrictive profile, and it also showed the maximal inspiratory and maximal expiratory pressures to both be reduced, which had actually been suggestive of an underlying neuromuscular weakness. And so that leads us to the disease for which this case is based on. So it's stiff person syndrome, which is actually a part of the anti-glutamic acid decarboxylase disorder spectrum of diseases. So just a little bit overview background of the disease. So it was actually first described by Marcian Woltman in 1956, and it's an autoimmune movement disorder characterized by intermittent stiffness and muscle spasms. The incidence is one case per one million people each year that have been diagnosed with the condition, and the prevalence is about one to two cases per one million. So just seeing that, it's a really rare disease with an even fewer number of documented cases of patients with this condition going on to develop pulmonary complications. So in terms of the pathophysiology, what exactly is it? So we have glutamic acid decarboxylase. It's an intracellular enzyme. It's found in a variety of different cells, some being in the central nervous system, some being in certain muscle cells, and all throughout the body, even within the pancreas. So it's actually autoantibodies to this specific enzyme that we see with the arrow, and that enzyme actually helps to convert glutamate to GABA, and as we know, GABA is more of an inhibitory neurotransmitter. So when you have antibodies to that specific enzyme, you have an excess amount of glutamate, which can precipitate as excessive muscle stiffness and spasms in the muscle cells, and if we reflect on the respiratory component of it, it can also cause, when you have less GABA being produced from glutamate, it's causing less inhibition of the inhibitory Purkinje cells, which then we suspect is leading to that respiratory compromise that our patient presented with. So the antibodies to the specific enzyme are also seen in other conditions, most commonly seen in type 1 diabetes, which our patient did not have, actually. So in terms of differential diagnoses that we certainly had to rule out just based on her clinical presentation, a few of them had been multiple sclerosis, CIDP, Guillain-Barre, and myasthenia gravis. So for multiple sclerosis, the EMG didn't show any evidence of demyelination, and the LP had no oligoclonal bands. In terms of CIDP, sure, it's a relapsing symmetric proximal and distal muscular weakness, but the CSF that I alluded to earlier didn't show any kind of evidence of albuminocytologic dissociation. In terms of Guillain-Barre, she had certain symptoms that were similar, but it actually highlights over a course of four weeks, for which our patient didn't meet in terms of the timeline, and of course, the anti-GQ1 antibody had been negative. And lastly, with myasthenia gravis, she also had negative antibody for that disease as well. So in terms of the diagnostic criteria, so these are the diagnostic criteria of which I've highlighted in blue that our patient had actually met. So of course, stiffness of the axial muscles, which she certainly did, superimposed painful muscle spasms, which she had an intermittent history of, and then EMG evidence of continuous motor unit activity at rest, for which our patient essentially did not have on the EMG, but it's ultimately going to be picked up when the patients are in these active episodes of the disease, so it kind of becomes a little bit more difficult to gauge. And then of course, the high titer of anti-GAD antibodies, and I read in the literature up to about four to five times the upper limit of normal, which according to our workup, the patient did have, and then of course, in absence of an alternative diagnosis, which we ruled out many of the others. So in terms of the treatment, IVIG is known as the first-line immunotherapy, of course in conjunction with GABA-enhancing drugs, just because of the mechanism that we saw a few slides ago. And then of course, if you have patients that are not successful with IVIG, Rituximab has also been shown to be proven in those patients. So in terms of a little bit about the hospital course and how the patient's doing now. So while she was admitted, she was of course stabilized with steroids, and then she received IVIG infusion for six days. Three months after, she was on IVIG three times a week, every three weeks. But at the end of each of those three-week periods, she would continue to have those intermittent muscle spasms, respiratory weakness, and she actually continued to have worsening respiratory weakness and became dependent on NIV. And then six months after, her symptoms were better controlled in terms of she had fewer flares of it, and as a result of still having those symptoms ongoing, she was started on Rituximab in addition to continuing the IVIG infusions. So in terms of the takeaways, of course, early identification and diagnosis of this condition, it's critical as it has a propensity to lead to significant fatal respiratory complications, especially if it remains untreated. And of course, the rarity of this condition with an even fewer number of documented cases of the pulmonary complications, I believe I had seen about four or five in the literature with pulmonary complications, shouldn't necessarily be discounted in terms of a patient presenting with the constellation of symptoms that our patient had. And it's really important to ensure that all the other confounding differential diagnoses have actually been appropriately ruled out to reach more of an accurate diagnosis and, of course, lead to an adequate treatment. And, of course, IVIG is available as first line, and Rituximab is also available for patients who have failed the IVIG infusions. And there's some of the colleagues who have helped out, references, and thank you. What questions do you guys have? Thank you.

stiff person syndrome

muscle spasms

autoimmune disorder

glutamic acid decarboxylase

IVIG

rituximab

respiratory complications

diagnosis