United States

Background: Pigmentary retinal dystrophy (PRD) is a group of inherited disorders involving the progressive degeneration of rod and cone photoreceptors and the retinal pigment epithelium (RPE), which can progress to pigmentary retinopathy (PR). We present a case of PRD in a female pediatric patient with mutations in the PRPH2 and PEX1 genes.

Case Presentation: A 4-year-old female patient presented to the pediatric ophthalmologist with concern for developmental delay and “feeling around for objects” despite full-time glasses wear. Comprehensive evaluation revealed visual acuities of 20/180 in the right eye and 20/270 in the left eye via Teller cards, hyperopia with astigmatism, extensive retinal pigmentation 360° in the mid-periphery, and decreased foveal reflexes that were concerning for macular edema bilaterally. Optical Coherence Tomography of the macula revealed thickened retinal segments and schisis/edema of the outer retinal segments. The patient was also diagnosed with bilateral sensorineural hearing loss. Subsequent genetic evaluation yielded pathogenic homozygous mutation for the PEX1 c.2528G&gt;A, p. (Gly843Asp) gene and a heterozygous mutation for the PRPH2 c.806C&gt;G, p. (Thr269Arg) gene. Treatment for severe macular edema has included topical dorzolamide and intravitreal dexamethasone injection with successful improvement in macular edema and vision.


Discussion: The PEX1 gene mutation is associated with peroxisome biogenesis disorder-Zellweger syndrome spectrum (PBD-ZSS) and resulting retinal dystrophies. Furthermore, the PRPH2 mutation may play a role in macular edema and PRD, as it is implicated in macular degeneration, choroid defects, and photoreceptor dysfunction. This case demonstrates the potential for multiple gene etiologies in a single patient with PRD and the significant resulting visual impairment. Ocular findings in historical cases of PBD-ZSS have consistently included loss of photoreceptors, RPE, and ganglion cells. Retinal pigment dispersion, optic disc pallor and hypoplasia, and narrowed retinal arterioles were also consistently observed. PBD-ZSS has less consistently been associated with cataracts, glaucoma, and corneal clouding. Treatment remains supportive, aiming to control macular edema and correct refractive errors.

AMA Research Challenge 2022

Retinal Dystrophy associated with Peroxisome Biogenesis Disorder-Zellweger Syndrome Spectrum

Background: Pigmentary retinal dystrophy (PRD) is a group of inherited disorders involving the progressive degeneration of rod and cone photoreceptors and the retinal pigment epithelium (RPE), which can progress to pigmentary retinopathy (PR). We present a case of PRD in a female pediatric patient with mutations in the PRPH2 and PEX1 genes.

Case Presentation: A 4-year-old female patient presented to the pediatric ophthalmologist with concern for developmental delay and “feeling around for objects” despite full-time glasses wear. Comprehensive evaluation revealed visual acuities of 20/180 in the right eye and 20/270 in the left eye via Teller cards, hyperopia with astigmatism, extensive retinal pigmentation 360° in the mid-periphery, and decreased foveal reflexes that were concerning for macular edema bilaterally. Optical Coherence Tomography of the macula revealed thickened retinal segments and schisis/edema of the outer retinal segments. The patient was also diagnosed with bilateral sensorineural hearing loss. Subsequent genetic evaluation yielded pathogenic homozygous mutation for the PEX1 c.2528G>A, p. (Gly843Asp) gene and a heterozygous mutation for the PRPH2 c.806C>G, p. (Thr269Arg) gene. Treatment for severe macular edema has included topical dorzolamide and intravitreal dexamethasone injection with successful improvement in macular edema and vision.


Discussion: The PEX1 gene mutation is associated with peroxisome biogenesis disorder-Zellweger syndrome spectrum (PBD-ZSS) and resulting retinal dystrophies. Furthermore, the PRPH2 mutation may play a role in macular edema and PRD, as it is implicated in macular degeneration, choroid defects, and photoreceptor dysfunction. This case demonstrates the potential for multiple gene etiologies in a single patient with PRD and the significant resulting visual impairment. Ocular findings in historical cases of PBD-ZSS have consistently included loss of photoreceptors, RPE, and ganglion cells. Retinal pigment dispersion, optic disc pallor and hypoplasia, and narrowed retinal arterioles were also consistently observed. PBD-ZSS has less consistently been associated with cataracts, glaucoma, and corneal clouding. Treatment remains supportive, aiming to control macular edema and correct refractive errors.

poster

Welcome to the largest national, multi-specialty research event **featuring research from 750 medical students, residents and fellows, and international medical graduates.**


#### Event Details
The 2022 American Medical Association Research Challenge includes a poster symposium hall and a semifinals hall with the top scored research. Log in at any time throughout the event to:
* **View posters and presentations** on a variety of topics and specialties
* **Score posters in the semifinals** to help decide the top five finalists (AMA member exclusive opportunity)
* **Connect with participants** and provide feedback to help advance their research

At the conclusion of this event, the AMA will announce the top five finalists who will advance to the AMA Research Challenge finals, present their research to an elite panel of judges and compete to win a $10,000 grand prize sponsored by Laurel Road.
 

#### Attend Live Forums
**Oct. 20, 6 — 7 p.m. Central**
 **How to plan a career in academic medicine** 
 Learn how to plan a career in academic medicine and get your questions answered. [Access Here](https://underline.io/events/363/lounge)
 
 **Speakers**
![](https://assets.underline.io/uploads/markdown_image/1/image/d5adb133dfc58eb0a6d469e9cedcd5d4.jpg)
Ricardo Correa, MD, EdD
![](https://assets.underline.io/uploads/markdown_image/1/image/5f9437ab87861538bf02b9ca7c0d926e.jpg)
Stuart M. Greenstein, MD
![](https://assets.underline.io/uploads/markdown_image/1/image/05b1b637c99286d558c371f8e8b185ce.jpg)
Stephanie Strohbeen, MD
 
 **Oct. 22, 11 a.m. — Noon Central**
 **How to get published**
 Learn tips to get your research published and get your questions answered. [Access Here](https://underline.io/events/363/lounge)
 
 **Speakers**
![](https://assets.underline.io/uploads/markdown_image/1/image/8ce6235e957d31cb5e6f9097cc6f6972.jpg)
Jessica Li, MD/PhD Candidate
![](https://assets.underline.io/uploads/markdown_image/1/image/9950ef2e0237f54cb3d8280334d42491.jpg)
Charles Lopresto, DO

### Sponsor
AMA would like to thank Laurel Road for sponsoring a $10,000 grand prize for the winner of the AMA Research Challenge. Laurel Road is not involved in the judging or scoring process to select the winner. The winner will be announced on Dec. 7 during the AMA Research Challenge finals. Payment of the grand prize will be directly from Laurel Road. See the AMA Research Challenge Official Rules for terms and conditions.

![](https://assets.underline.io/uploads/markdown_image/1/image/611e331d4a0eba0920f240cfc04b4d77.png)

**There is no registration fee for this event! **

Register to explore research in a variety of topics. AMA members get exclusive access to score posters in the semifinals.

**Please use the link below to register for free if you have not already done so:**

https://www.ama-assn.org/about/events/ama-research-challenge

Registration Is Required

Welcome to the largest national, multi-specialty research event featuring research from 750 medical students, residents and fellows, and international medical graduates.


Background: Klebsiella pneumoniae, a gram-negative anaerobic rod-shaped bacterium, is a rare cause of endogenous endophthalmitis. We describe a case of Klebsiella endophthalmitis presenting with a uniquely rapid time course and evidence of intraocular abscesses.

Case Presentation: 
A 37-year-old Hispanic male, with no known ocular history and a past medical history significant for type 2 diabetes mellitus and recent diagnosis of COVID19, was admitted to the hospital with shortness of breath, chest pain and hyperglycemia. Ophthalmology was consulted due to subjective change in vision in the right eye. On examination, his near visual acuity was 20/40 and 20/25 in the right eye and left eye, respectively. Funduscopic exam was notable for mild macular edema with exudates and scattered intraretinal hemorrhages in the right eye, which was attributed to diabetic retinopathy. 
One day after the ophthalmologic consultation, the patient acutely decompensated requiring intubation and transfer to the MICU. Blood cultures grew gram negative rods speciating to Klebsiella. Two days later, he was noted to have worsening redness in the right eye, and ophthalmology was re-consulted. Fundoscopic exam at this time was limited, but showed inferonasal white-centered hemorrhages. B-scan ultrasound demonstrated vitreous debris with a grossly attached retina. He was started on treatment for endophthalmitis with intravitreal antibiotic injections. 
Subsequent repeat examinations showed continued decreased visual acuity to light perception (LP), then no light perception in the right eye and development of a near total retinal detachment. Goals of care were discussed, and a decision was made to focus on comfort measures for the right eye, less than a month after his initial examination.

Discussion: In contrast to previously published case reports, our patient had a bedside visual acuity of 20/40 upon initial consultation which, within six days of the initial evaluation, worsened to LP. This rapid deterioration of vision is likely a function of the bacteria’s quick doubling time of 2.31 hours. Due to the rapidly progressive nature of Klebsiella endogenous endophthalmitis, we recommend to primary teams to consult ophthalmology for daily funduscopic examinations once blood cultures have confirmed the causative organism.


Unrelenting Vision Loss: The Virulence of Klebsiella pneumoniae

Background:
Posterior labral tears are common in the shoulders of collision athletes and frequently present with instability and dysfunction. These can be successfully stabilized arthroscopically, but it is essential to identify and treat the full extent of the injury, especially in high demand athletes. We present a surgical technique utilized to repair a 180˚ posterior and inferior labrum tear in a professional collision athlete with symptomatic posterior instability.

Indications:
Arthroscopic stabilization of posterior labral tears is indicated in athletes with recurrent instability events and the inability to return to their previous level of play with nonoperative management.

Technique Description:
This arthroscopic 180˚ posterior and inferior labral repair is performed in the lateral decubitus position. An EUA helps guide surgical management, as identifying and treating the full extent of the labral tear is essential for successful management. An accessory posteroinferior 7 o’clock portal is necessary for low posterior anchor placement. Stability is critical in collision athletes so slightly overtightening the shoulder is optimal, and large bites in the capsule allow for an aggressive capsular shift. Multiple suture tapes are utilized per anchor, increasing the number of fixation points in the capsule and labrum, creating a very robust repair. A large spread between sutures in the same anchor is avoided to prevent bunching of the labrum. Percutaneous anchors are placed to completely address superior and anterior extension.

Results
Arner, McClincy and Bradley have shown very successful outcomes following posterior labral repairs in American football players. 93% returned to play with 79% returning at the same level, and 96.5% were satisfied with the procedure. They showed these players can safely return to contact sports at 6 months following surgery. Our patient followed a similar course, returning to professional collision sports at 6 months post op and was very satisfied with his outcome.

Discussion/Conclusions:
Arthroscopic posterior labral repair can be a very successful procedure if the full extent of the labral tear is identified and addressed. Robust fixation and an aggressive capsular shift are the goals in collision athletes.


180˚ Posterior and Inferior Labral Tear in A Professional Collision Athlete with Symptomatic Posterior Shoulder Instability, A Case Report.

Background
Compartment syndrome (CS) is a known and severe complication of extremity injury and can result in permanent loss of limb function and vital organ damage. CS typically develops within 48 hours of injury and may be diagnosed clinically or with direct compartment manometry. Here we will present a polytrauma patient who developed CS 13 days after intramedullary fixation of a tibial diaphysis fracture.

Case Presentation
Our patient was a 38-year-old male who presented to our facility as a level 2 trauma after being struck by a car while on his bicycle. Examination and radiographic studies were significant for left mid-shaft tibia fracture with associated fibular shaft fracture and nondisplaced posterior malleolar fracture, left nondisplaced scapular body fracture, and right distal third clavicle fracture. Left lower extremity was splinted with strict ice and elevation with compartment checks performed every four hours. He underwent percutaneous fixation of the posterior malleolus and intramedullary fixation of the tibial shaft fracture on the morning of hospital day 1 with simple posterior slab splint application. Postoperatively, compartment checks were continued, and he demonstrated no signs or symptoms concerning for compartment syndrome. He presented to clinic on post-operative day 13 with complaints of new onset paresthesia and increasing pain. Splint was removed in clinic where left leg was noted to be very firm to palpation, and patient expressed increased pain with passive motion of the great toe, findings concerning for compartment syndrome. Direct compartment manometry was then performed using Stryker Intra-Compartmental Pressure Monitor System finding compartment pressure as follows: Anterior 49 mmHg, lateral 41 mmHg, superficial posterior 31 mmHg, and deep posterior 30 mmHg. Patient was deemed to have compartment syndrome at this time, and went for urgent four-compartment fasciotomy of the left leg with negative pressure wound therapy device application.

Discussion
Intracompartmental pressure may increase during reduction and intramedullary nailing, but intramedullary nailing is not associated with an increased risk for developing compartment syndrome. Although this patient went on to an uneventful outcome from this fracture and subsequent CS, his experience demonstrates the need for increased suspicion if clinical signs and symptoms are concerning.



Compartment Syndrome in Polytrauma Patient

Background
Talar neck fractures are an uncommon injury, representing less than one percent of bony injuries of the foot (Shamrock & Byerly, 2022). They are associated with high-energy trauma, such as MVCs. Due to the risk of avascular necrosis, recognition and treatment are crucial (Matthews et al., 2022). Surgical treatment employs a dual anteromedial and anterolateral incision approach with open reduction and internal fixation (Lee et al., 2020). Post-traumatic arthritis or osteonecrosis can lead to fair to poor functional outcomes.

Case Presentation
A 23-year-old Asian-American male presented to an urgent care with a chief complaint of right ankle pain after landing awkwardly during a recreational basketball game. The patient had no significant past medical history or medications. Interestingly, he was a first-year medical student.

On examination, the patient was unable to bear weight on his right foot with diffuse pain in his ankle and hindfoot. The right foot had intact skin with edema and ecchymosis to the lateral ankle with limited range of motion and was resting in a slightly plantarflexed and inverted position. Radiographs and CT scans demonstrated a fracture of the right talar neck, warranting a referral to orthopedics. Orthopedics confirmed a talar neck fracture with subtalar subluxation. 

A standard anteromedial and anterolateral approach was used for open reduction internal fixation. Two pilot holes were drilled into both the lateral and medial talar neck and pointed reduction clamps provided reduction. Two 3 mm headless compression screws were placed laterally, and two 4 mm headless compression screws were placed medially through the talar neck. Two 2.5 mm headless compression screws affixed a portion of displaced articular cartilage, achieving anatomic reduction. The patient was placed in a short leg splint and remained non-weight-bearing until seven weeks postoperative. One year postoperative, the patient ambulates with no limitations.

Discussion
This case demonstrates a low-energy mechanism of injury for a talus fracture. This patient presented similarly to an ankle sprain or fracture due to diffuse pain and mechanism of injury. Intolerance to weight-bearing, diffuse pain, and edema warranted radiographs and CT, leading to prompt diagnosis. Surgery sought to improve healing rates while allowing an early range of motion. Despite the high rate of poor outcomes following talar fractures, the patient had an excellent outcome with a full range of motion and normal gait. 

Sources:

1. Shamrock AG, Byerly DW. Talar Neck Fractures. In: StatPearls. Treasure Island (FL): StatPearls Publishing; May 2, 2022.
2. Matthews AH, Davis DD, Fish MJ, Stitson D. Avascular Necrosis. In: StatPearls. Treasure Island (FL): StatPearls Publishing; April 16, 2022.
3. Lee C, Brodke D, Perdue PW Jr, Patel T. Talus Fractures: Evaluation and Treatment. J Am Acad Orthop Surg. 2020;28(20):e878-e887. doi:10.5435/JAAOS-D-20-00116





Medical Student Sustains a Basketball-Related Talus Fracture

Introduction: Total Hip Arthroplasty (THA) is one of the most common orthopedic procedures performed in the United States. With nearly 500,000 cases performed annually, the success rate has been estimated to be around 90-95%. Known complications from THA are classified into early or late stages. The association between arterial thrombotic events such as ischemic colitis (IC) and acute limb ischemia following THA has not been highly reported. 

Case Report: 62-year-old male nine days status post right THA presented to ED for altered mental status. On arrival, BP was 95/57, HR 104, and O2 sat 88% on 10L NC. The bilateral lower extremities were swollen and cool to touch with absent DP pulses. The abdomen was distended with diffuse tenderness. CT abdomen/pelvis was concerning, and the decision to proceed with exploratory laparotomy was made. Upon entry into the peritoneum, foul-smelling, purulent fluid was present. It was evident that the patient had an ischemic left colon in the distribution of the IMA with sparing of the rectum. The ischemic colon was resected, and an ostomy was brought out. Despite aggressive resuscitation attempts, the patient continued to worsen and remained intubated. On postoperative day 7, due to severe acidosis and deteriorating multiorgan failure, the patient's family opted to withdraw care. 

Discussion: To our knowledge, there has been only one published report of mesenteric ischemia following THA. The standard of care following THA to prevent thromboembolism has changed over the last ten years from Warfarin to direct oral anticoagulants (DOAC), with recent literature describing the beneficial efficacy of monotherapy with aspirin. Due to life-threatening complications, strict compliance with VTE prophylaxis is necessary for all post-operative patients.

Conclusion: With THA volume increasing yearly, we aim to emphasize the importance of recognizing these rare and potentially devastating postoperative vascular complications.


Multiple Ischemic Events Following Total Hip Arthroplasty

Novel Surgical Technique to Repair Pediatric Tibial Tubercle Avulsion Fracture,
No Need for Hardware or Casting

Background: 
Lacrimal gland tumors are a rare malignancy with an incidence of about 1 per 1 million people. Epithelial tumors are the most common form representing 50-60% of all lacrimal gland tumors with carcinoma ex pleomorphic adenoma (CEPA) constituting 10% of the epithelial tumors. CEPA is a malignant tumor that arises from benign pleomorphic adenomas. Clinical features include rapid growth causing eyelid and orbital protrusion often accompanied by pain. Mean survival after diagnosis is three years. CEPA may progress to intracranial spreading along with possible metastatic malignancy to the lung, chest, and bone. These malignancies are treated aggressively with a combination of surgical resection, chemotherapy, and radiation. 

Case Presentation: 
A 79-year-old male with a history of right eye exenteration after a childhood injury initially presented to his PCP with a mass on his right lower eyelid. A biopsy was obtained, and pathological results were initially suspicious for squamous cell carcinoma. He was referred to ENT who excised the lesion with intraoperative pathology confirming a negative margin. Pathology results from the excision were consistent with a 3 cm high-grade carcinoma ex pleomorphic adenoma of the lacrimal gland. Three weeks after resection, PET/CT scan showed local recurrence at the inferior resection margin and metastatic disease in a 1B cervical lymph node. The patient underwent combination chemoradiation therapy with complete regression confirmed by PET/CT. Nine months after completing chemoradiation, repeat PET/CT showed two new lung nodules concerning for metastatic disease. The patient did not wish to undergo further testing or treatment and decided to transition to comfort care only. 

Discussion: 
CEPA is an incredibly rare and aggressive tumor about which little is known regarding the preceding oncogenic events in the literature, indicating the need for further research to improve treatments.

Carcinoma Ex Pleomorphic Adenoma: An Extremely Rare Tumor of the Lacrimal Gland

Aggressive natural killer cell leukemia (ANKL) is a rare neoplastic malignancy, especially in pediatric populations with very few cases reported in the literature. It commonly presents with a rapidly declining clinical course and has a median survival of two months. We report the case of a 15-year-old female who presented with fever, hepatosplenomegaly, hemophagocytosis, and disseminated intravascular coagulation (DIC). The patient was ultimately diagnosed with ANKL but died after developing multiorgan failure and DIC prior to the initiation of any treatment. In this case report, we review and discuss the literature concerning the diagnosis and treatment of ANKL in pediatric patients.

A Case Report on Aggressive Natural Killer Cell Leukemia in a Pediatric Patient 

A Sugar of 4: An Unlikely Presentation of Glycogen Storage Disease


Acute liver failure (ALF) is a dynamic clinical condition manifested either by an abrupt or indolent onset of a liver-based coagulopathy and biochemical evidence of hepatocellular injury resulting from rapid deterioration in liver cell function. Acetaminophen overdose is the most common cause of ALF in Western countries and its incidence appears to be increasing. Most acetaminophen overdose patients recover with early N-acetylcysteine (NAC) therapy and supportive care, but regulatory actions are needed to prevent future cases. However, we must consider alternative causes of hepatitis which include HBV infection (7%), autoimmune hepatitis (5%), ischemic hepatitis (4%), and various other causes (5%). We present a 16 y.o. who presented in Acute Liver Injury (ALI) with transaminitis progressing to ALF (INR 2.5, NH4 119 umol/L, ALT 2,812/AST 6,222 U/L). In this case presentation, we aim to highlight the importance of obtaining a thorough history and including the practice of excluding alternative causes. While our patient denied intentionally overdosing on acetaminophen, an acetaminophen level of 24 mcg/mL at ~24 hours is significant. Without the concomitant acute EBV hepatitis (EBV PCR pos, EBV Capsid Ag IgM 96.4, EBV IgG neg), she likely would have experienced less severe liver injury without progression to acute liver failure. The appropriate initiation of intravenous N-acetylcysteine and fomepizole likely played a critical role in halting the progression by blocking further metabolism of acetaminophen by CYP2E1. Perhaps most importantly in delayed presentations, fomepizole inhibits c-Jun-N-terminal Kinase (JNK) which mitigates liver inflammatory responses. NAC may help other causes of ALI/ALF not caused by acetaminophen.

Next from AMA Research Challenge 2022

Unrelenting Vision Loss: The Virulence of Klebsiella pneumoniae

Similar lecture