United States

Distal renal tubular acidosis is an uncommon disorder in adults. The primary defect in distal RTA is
impaired distal acidification. Causes of distal RTA in adults are autoimmune diseases, hypercalciuria, and
medications. This is an interesting case of a young woman found to have distal renal tubular acidosis in
the setting of Sjogren syndrome and nephrolithiasis.

AMA Research Challenge 2023

Distal Renal Tubular Acidosis in the Setting of Sjogren Syndrome and
Nephrolithiasis

poster

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Introduction
Renal medullary carcinoma (RMC) is an exceedingly rare and devastating malignancy that primarily affects adolescents and young adults between the ages of 11 and 39 years with sickle cell trait (SCT) or sickle cell disease. RMC is characterized by early and widespread metastases, leading to late-stage diagnosis and poor prognosis. The tumor suppressor gene SMARCB1/INI1 is inactivated in all cases, resulting in the loss of expression of INI1 protein. RMC also shares similarities with collecting duct carcinoma (CDC), including a predilection for the right kidney and the renal medulla as the epicenter, as well as aggressive clinical behavior.
Case Report
We present the case of a 27-year-old male with a medical history of asthma, HIV, and
nephrolithiasis. The patient presented with worsening right flank pain, testicular swelling, rapid weight loss, and a history of hematuria. Physical examination revealed mild tenderness in the right flank and scrotal edema. Imaging studies demonstrated infiltrative liver lesions, moderate pleural effusion, and renal abnormalities. Biopsy confirmed INI-deficient renal cell carcinoma associated with sickle cell trait. Palliative chemotherapy was initiated. RMC is an exceptionally rare malignancy that is often diagnosed at advanced stages. Loss of INI1 and its correlation with sickle cell trait are diagnostic hallmarks. Our case demonstrates an aggressive and rapidly progressive clinical presentation, including right-sided involvement and metastasis to the liver, lung pleura, cardiac pericardia, and omentum. The treatment options for RMC are limited, and the prognosis remains unfavorable.
Discussion
The discussion highlights the rarity and diagnostic challenges of RMC, which has fewer than 220 reported cases in the literature. RMC is distinguished by the presence of SCT and loss of SMARCB1/INI1 expression. It primarily affects African Americans and shows a right-sided predominance, often presenting with advanced disease and widespread metastases. Clinical manifestations include flank pain, hematuria, abdominal mass, and weight loss. Histologically, RMC displays anastomosing tubules and cords forming microcytic structures with a reticular appearance.
This case report emphasizes the importance of early recognition and prompt management of RMC. Despite its rarity, clinicians should consider RMC in young patients with sickle cell trait presenting with renal abnormalities. Timely collaboration between various medical specialties is essential for tailored therapeutic approaches, considering the aggressive nature of this malignancy. Further research is warranted to explore more effective treatment strategies and improve outcomes for this devastating disease.

INI Deficiency Unveiled: An Aggressive Case of Renal Cell Medullary Carcinoma.

Background: Dural arteriovenous fistulas (dAVF) are abnormal anastomoses between meningeal arteries and dural venous sinuses and have a yearly incidence rate of 0.15 to 0.29 patients per 100,000 people. Typically, dAVF treatment involves an endovascular or microsurgical approach. A hybrid approach combining endovascular and microsurgical treatment, however, may improve patient outcomes. Few reports of hybrid approaches to dAVF embolization are available, thus, we hope to add to the literature with this case report to support this less explored surgical approach.
Case Presentation: We present the case of a female in her late 60s who presented for headaches. Angiography revealed an extensive superior sagittal sinus dAVF with multiple bilateral arterial feeders, including the superficial temporal artery, the occipital artery and the middle meningeal artery. The fistula involved the superior sagittal sinus with cortical venous drainage. Parts of the sinus around the middle third were thrombosed. Initial attempts at coiling were incomplete due to complicated venous access, however, a second surgery using a hybrid
approach resulted in successful obliteration of the dAVF. Eight months post-operatively, she reports improved personality and irritability symptoms, but continued headaches and blurry vision.
Discussion: Cerebrovascular procedures in hybrid rooms have already been widely described in the literature, however this technology is not available in every neurosurgical center and has been mostly used in the treatment of cerebral aneurysm. This case report exemplifies the potential benefit of a hybrid approach in treating high grade (Cognard class IIa and IIb in this case) dAVFs. With more case reports and large-scale clinical studies examining patient outcomes, the hybrid surgical technique may offer promising prognoses to future patients with complex dAVFs.

Treatment of a dural arteriovenous fistulas (dAVF) in a hybrid surgical setting:

Background
Carotid cavernous fistulas (CCF) are a serious condition that involves spontaneous or trauma-induced disruption in the carotid arteries within the cavernous sinus. This disruption causes blood to leak into the sinus, which impedes the function of cranial nerves III, IV, V1, V2, and VI. Early signs of CCF often include proptosis, glaucoma, severe headaches, partial blindness, and conjunctival hyperemia- especially in patients with preexisting conditions such as atherosclerosis, hypertension, diabetes. If left untreated, patients can develop periorbital disfigurement and permanent vision loss. Despite effective methods of diagnosis using angiography and blood vessel repair, this condition is often misdiagnosed due to it making up only 1.5% of endovascular-treated ruptured aneurysms and its similarity in presentation to cerebrospinal fluid (CSF) leaks. Therefore, CCFs have been under-investigated, and additional research is required to delineate the cause, unique features, and proper treatment of this phenomenon.

Case Presentation
Six weeks following an uncomplicated L4-S1 posterior instrumented fusion with partial laminectomy and bilateral facetectomy, a 78-year-old female developed moderate bifrontal headaches and neck discomfort. In the following weeks, the headaches grew severe with periorbital swelling despite a negative brain CT scan and no findings in an exploratory surgery. Worsening symptoms prompted a brain MRI that showed abnormal superior ophthalmic veins. Diagnostic angiography confirmed a left CCF, and the patient was successfully treated via transvenous embolization in the intercavernous sinus and left cavernous sinus. 

Discussion
Carotid-cavernous fistulas (CCF) are pathological shunts between the cavernous sinus and carotid artery or its meningeal branches. Symptoms include conjunctival injection, blurred vision, pulsating proptosis, and cranial nerve six palsy – all of which may be exacerbated with delayed diagnosis. Historically, etiologies of CCFs have included trauma, ruptured ICA aneurysms, connective tissue diseases, or iatrogenic injury. We present the first reported case of a CCF that occurred in conjunction with spine surgery. We describe the association of prolonged operative time in the prone position and development of CCF using radiographical images and thorough clinical workup. We also describe how the clinical history and symptomology originally indicated a dural tear, although subsequent workup led to the diagnosis of CCF. This case demonstrates a difficult diagnosis of CCF and its potential relationship with spinal surgery.


Carotid Cavernous Fistula and Its Association with Spine Surgery

Background
Patients who present with cervical dystonia may also present with cervical myelopathy. This presentation can be problematic because patients with cervical myelopathy need fusion surgery such as an anterior discectomy and fusion (ACDF) to stabilize the spine and prevent damage to the spinal cord. The involuntary tremor caused by cervical dystonia can result in problems with boney fusion in the post-operative period. Deep Brain Stimulation (DBS) provides a potential solution to this problem when more conservative treatments like medication, halo vests, and botulinum toxin fail to reduce tremor.
Case Presentation
A 46-year-old female presented to our center with a chief complaint of neck pain. The patient also presented with bilateral upper extremity radiculopathy, paresthesia, and a myelopathic gait. She had a 15-year history of cervical dystonia and had tried various medications and botulinum toxin injections without resolution of symptoms. In addition to this the patient had cervical myelopathy caused by disc herniation at the C5-C6 and C6-C7 level. Although the patient was a candidate for ACDF, she was advised to have her dystonic tremor treated before ACDF to prevent pseudoarthrosis and hardware failure because of the tremor. The patient underwent bilateral DBS in the Globus pallidus interna (GPi) utilizing an Abbott InfinityTM DBS system. After placement of the DBS-GPi leads, batteries were placed, and the system was turned on which was able to provide significant relief of the patient’s tremor. The patient was followed up at 3 months and had a >75% reduction in her tremors. After the significant reduction in tremor, the patient underwent C5-C6 and C6-C7 ACDF at 6 months post DBS-GPi. The patient reported that the paresthesia had improved significantly, and the weakness had gradually improved at 3 months post ACDF. There was no radiographic evidence of hardware loosening or malalignment.
Discussion
The presentation of both Cervical Dystonia and Cervical Myopathy concurrently is a challenging couple of pathologies to manage. Bilateral DBS-GPi prior to ACDF is a viable strategy for managing these pathologies surgically. 


DBS before ACDF for a patient with Cervical Dystonia and Cervical Myelopathy

Background
Spinal manipulation is one of many therapies for back pain. It is typically done by a chiropractor or physical therapist. A systemic review and meta-analysis concluded that spinal manipulation has moderate-quality evidence for improvement in pain scale and function. However, there is insufficient data for chronic back pain treatment. Like most treatments, there are risks associated with spinal manipulation. While serious adverse effects of spinal manipulation are rare, they include disc herniation, cauda equina syndrome, vertebrobasilar and carotid dissection. The incidence of serious adverse events range between 1/100,000 and 1/6 million manipulations. More commonly, minor complaints (dizziness, lightheadedness, headache, and numbness) are reported following spinal manipulation with rates between 25-60%. In this case, a 50-year-old patient underwent chiropractic spinal manipulation for back pain, resulting in bilateral lower extremity paralysis requiring spinal surgery.
Case Presentation
A 50-year-old male with no past medical history presented with back pain. The patient reported that he had back pain for about a month after lifting a heavy object. He went to the chiropractor for an adjustment two weeks prior to admission. Following the adjustment, he felt better, but the next day he had bilateral leg weakness, numbness, and tingling. He couldn’t walk for two weeks and was using a wheelchair. Sensation was intact. Two days ago, he started experiencing urinary incontinence but no bowel incontinence. On examination, the patient had bilateral leg weakness and saddle anesthesia. Thoracic MRI showed a disc extrusion and epidural hematoma at T10-T11 extending superiorly to the T10 superior endplate and inferiorly to the mid-T11 vertebral body with severe mass effect on the spinal cord and canal stenosis. The patient was started on dexamethasone 4-mg q6-hours. A left thoracotomy, T10-11 left transthoracic corpectomy, and T9-11 anterior-lateral interbody arthrodesis was performed and well tolerated. After two months of inpatient rehab, the patient was able to ambulate using a walker, discharged home, and scheduled for outpatient rehab.
Discussion
This case demonstrates an interesting and rare serious adverse event of spinal manipulation. Generally, it is important to avoid spinal manipulation in patients with documented or suspected disc herniation. In this case, it is unknown whether the patient had a pre-existing herniation but considering that the back pain originally began shortly after lifting a heavy object, it is possible that there was a degree of herniation prior to the chiropractor visit that progressed after the spinal manipulation, causing a mass effect and spinal stenosis.

Thoracic Spine Injury Requiring Neurosurgery following Chiropractic Manipulation: A Case Report

Background
Primary CNS Vasculitis is an extremely rare vasculitis with an incidence of 2.4 cases/million person-years. It can manifest in various ways, including seizures, altered mental state, headaches, and cognitive decline. When different vascular territories are affected across episodes or when headaches are associated with cognitive decline and altered mental status, CNS Vasculitis should be considered. The diagnosis of Primary CNS Vasculitis is challenging due to the potential for
other conditions to mimic it, such as neoplasms like gliomatosis cerebri or intravascular B-cell lymphoma. Our case was complicated by previous treatment for these malignancies.
Case Presentation
In our case, a 35-year-old male with a history of alcohol and cocaine use and seizures presented with transient right hemiparesis, visual deficits, and aphasia. Brain MRI revealed T2 hyperintense lesions in the left cerebral hemisphere. A subsequent neurological workup was negative for encephalitis. Two months later, the patient was admitted again after another seizure, and MRI showed progression of the left-sided brain lesions. A brain biopsy targeting the left superior parietal lobule was inconclusive. The patient underwent chemotherapy and radiation but responded more to steroids, ruling out gliomatosis cerebri. A second biopsy of the left frontal
brain lesion revealed perivascular inflammation with necrosis consistent with vasculitis, although the effects of previous treatment complicated the diagnosis
Discussion
Primary CNS Vasculitis is a rare variant of vasculitis that is still poorly understood, with an unknown etiology and pathogenesis. Immune triggers and genetic predisposition have been identified as potential factors. The disorder primarily affects small and medium-sized vessels in the brain, but spinal cord involvement has also been documented. Clinical presentation varies but commonly includes headache, altered cognition, and hemiparesis. CSF analysis is often abnormal in PCNSV cases. Diagnostic tools like angiography and MRI are helpful but not
sufficient for diagnosis as PCNSV can mimic other disorders like intravascular large B-cell lymphoma and gliomatosis cerebri. Skin biopsy can help rule out the former. Brain biopsy is crucial for a definitive diagnosis, as it has been shown that a significant percentage of cases have an alternate diagnosis following biopsy.Treatment options for PCNSV include a combination of steroids and immunosuppressants, as well as methotrexate, cyclophosphamide, and azathioprine. Prognosis is generally fair, but mortality rates are higher in cases with focal neurological deficits, cognitive impairment, cerebral infarction, and large-vessel involvement. Early detection and treatment can improve the overall
prognosis.

Primary CNS Vasculitis Disguised as CNS Malignancy 


Introduction
The external urethral sphincter reflex is a new neurmonitoring modality used to protect bowel, bladder, and sexual function during surgery. EUSR and bulbocavernosus reflex (BCR) assess the sacral segments of the spinal cord, cauda equina, and sacral nerve roots and provides a functional evaluation of the S2-S4 mediated reflex arc.
Objectives
We present a case study where we demonstrate for the first time the EUSR prognosticating postoperative bladder function independently of bowel function.
Methods
A 59-year-old female with hypertension and type 2 diabetes mellitus presented with a tumor causing cord compression at the T10 level. She underwent a T9-T11 laminectomy for tumor resection with a multimodal neuromonitoring paradigm including motor evoked potentials, somatosensory evoked potentials, EMG, BCR, and EUSR. The BCR and EUSR were activated using needle electrodes placed in the clitoris (cathode) and labia majora (anode) to activate the afferent sensory fibers of the dorsal clitoral nerves. Needle electrodes were placed in the left and right external anal hemisphincters to record the downstream motor component of the BCR. A specialized foley catheter embedded with 3D printed electrodes was used to record from the external urethral sphincter muscle for the EUSR.
Results
Baseline neuromonitoring data was acquired in all modalities except the EUSR. The
laminectomy and tumor resection were uneventful, and almost immediately following tumor removal, the EUSR began to reproduce and remained stable throughout the remainder of the procedure. The final pathology was benign schwannoma, and the patient was discharged intact on post-operative day 8. Follow-up at one month revealed cured urinary incontinence.
Conclusion
While this case study has limitations, it suggests that EUSR may not only provide redundancy to BCR monitoring but may discretely assess pathways associated with bladder function and prognosticate post-operative outcomes. More research with a larger cohort is needed to prove efficacy and statistical significance.

Prognostic Value of Intraoperative External Urethral Sphincter Reflexes in
Intradural Spinal Cord Surgery: A Case Report

Introduction: 

Cavernomas are low-flow vascular lesions made up of a collection of dilated capillaries with an adventitia and endothelial lining (1). Cavernous angiomas make up around 10-15% of all vascular abnormalities of the central nervous system (CNS) (2,3). These lesions can be sporadic or familial, and they have a frequency of 0.5% and an incidence of 0.3-0.7%. Females are somewhat more likely to get these lesions than men (3,4). The optic pathway, which is made up of the optic nerve, chiasm, and optic tract, can be affected in some highly unusual scenarios (2,3,5). Of the CNS cavernous malformations, optic pathway cavernomas make up fewer than 1%.(2,6). It was Uihlein et al. who first described anterior visual pathway CM in the literature in 1958(8). Cavernous malformations of the anterior visual pathway exhibit distinctive changes on MRI, with a hypointense to isointense signal on T1-weighted images and a heterogeneous "popcorn" look on T2-weighted images with mixed bright and dark signals. Gradient-echo T2 sequences enhance this dark signal because of a "blooming effect" brought on by the deposition of haemosiderin inside and around the CM (9).
Seizures are the most prevalent sign of symptomatic CMs in general, however, the symptoms of optochiasmatic CMs can vary, and many individuals remain asymptomatic. (7) . Although less common, progressive vision loss may occur, typically accompanied or preceded by headaches, nausea, and focal impairments. (5,7). The conventional therapy is gross total resection (GTR), which has resulted in symptom relief in the vast majority of patients. (1)

Case Presentation:
This 37-year-old male, a known case of Suprasellar Cavernous Angioma, presented with complaints of right-eye blurring for the past few days with no other symptoms. An MRI brain revealed a suprasellar heterogeneous tumor of <2cm. The patient previously had suprasellar cavernous angioma surgery in 2019. Testing for visual acuity showed 6/24 in the right eye and 6/6 in the left. No other investigative findings were found. The patient has no history of diabetes, hypertension, coronary artery disease, or asthma.
Operation:
LEFT PTERIONAL CRANIOTOMY AND TOTAL EXCISION surgery was performed on the patient. Supine ETGA. The head was secured in place by a three-pin Mayfield head rest. The standard procedure for a left-sided pterional craniotomy was used. The Sylvian fissure had been split. The left optic nerve and internal carotid artery were found to have numerous dense adhesions from earlier surgery that were difficult to dislodge. The tumor had bled and increased in size. A yellowish solid component was found embedded in the chiasm, which had been pushed anteriorly and to the left, along with the Right Optic nerve. Microsurgical excision was performed with care. In order to preserve vision, minute pieces adhered to the underside of the optic apparatus had to be left inside. Dura was reinforced with a patch, and the bone flap was secured using miniplates and a screw. The wound was closed in layers. The patient was treated with antibiotics, antidiabetics, analgesics, antiepileptics, anti-inflammatories, anti-emetics, steroids, gastro protectives, and other supportive measures. Histopathological sections showed brain parenchyma with areas of hemorrhage, dilated congested blood vessels, and haemosiderin laden macrophages leading to a diagnosis of cavernous hemangioma.
Discussion:
Observation:
In this case report, we present the case of a 37-year-old male with recurrent suprasellar cavernous angioma who experienced visual loss. Suprasellar cavernous angiomas are uncommon vascular lesions that can lead to neurological symptoms, including visual disturbances. Timely diagnosis and appropriate management are crucial to prevent irreversible neurological complications.
The patient had a previous history of suprasellar cavernous angioma and had undergone surgical intervention in 2019. However, he developed visual loss, which prompted further evaluation. Magnetic resonance imaging (MRI) revealed a recurrent heterogenous mass measuring less than 2 cm in the suprasellar region. Subsequently, the patient underwent a left pterional craniotomy with the intention of completely excising the mass.
During the surgical procedure, the presence of dense adhesions from the previous surgery posed challenges in separating the adhesions around the left optic nerve and internal carotid artery. Intraoperatively, the tumor was found to have bled and increased in size. Microsurgical excision was performed with careful consideration to preserve visual function. However, due to the adherence of tumor fragments to the undersurface of the optic apparatus, complete removal was not feasible, resulting in residual tumor remaining.
Histopathological examination of the excised tissue confirmed the diagnosis of cavernous hemangioma. The surgical intervention successfully alleviated compression on the optic pathways and improved the patient's visual symptoms. Postoperatively, the patient received a comprehensive treatment regimen, including appropriate antibiotics, antidiabetic agents if needed, analgesics, antiepileptics, anti-inflammatory medications, anti-emetics, steroids, and gastroprotective measures. Long-term follow-up is essential to monitor for tumor recurrence and evaluate visual outcomes. Suprasellar cavernous angiomas present management challenges due to their location and the associated risk of intraoperative bleeding. Surgical resection remains the mainstay of treatment, aiming for complete excision while minimizing damage to critical structures. In situations where complete resection is not attainable, partial resection can still provide clinical benefits.
Early diagnosis and prompt intervention are critical in preventing irreversible neurological complications associated with suprasellar cavernous angiomas. Long-term follow-up is necessary to monitor for tumor recurrence and assess visual outcomes. A multidisciplinary approach involving neurosurgeons, ophthalmologists, and other healthcare professionals is essential for comprehensive management.
In conclusion, our case underscores the significance of timely intervention in cases of recurrent suprasellar cavernous angiomas presenting with visual loss. Surgical resection, despite its challenges, can offer symptomatic relief and improve visual function. Further research is warranted to investigate optimal treatment strategies and long-term outcomes for these rare vascular lesions.
Lessons:
Cavernous hemangiomas of the optic pathway are extremely rare (<1%), and the involvement of the optic nerve in the optic canal is even rarer. Diagnosing cavernous malformations (CMs) of the optic pathway preoperatively is challenging and often can be misdiagnosed. The relevance of this case, therefore, is that in a patient with loss of visual acuity and visual field defects, it is extremely important for clinicians to keep cerebral cavernous malformations in their differential diagnosis. [3]
MRI is the most specific and sensitive imaging modality to diagnose CMs, the mainstay of treatment for which is radical resection. It is a challenging procedure, but usually curative and associated with favorable outcomes. [7]
Surgery for radical resection of the CM is a technically challenging procedure that has a high risk of morbidity and death. The hazards, which include pre- and/or post-operative bleeding, hormone imbalances, and transient or permanent nerve palsies are principally brought on by the complex neuroanatomy of the CS-sellar area. The literature only contains a small number of recorded cases claiming effective total eradication as evident in our case, wherein some minute pieces of the lesion had to be left behind in order to prevent vision loss.
In instances when complete removal implies excessive risks during the perioperative period, surgical reduction with cranial nerve decompression, followed by stereotactic radiosurgery, is currently regarded as the best choice. []
In all cases, the surgeon's experience, anatomical knowledge, and microsurgical skills are important factors that influence the final outcome. [7] With our case, we aim to highlight the importance of early surgical intervention in order to prevent regrowth and fatal complications.

Optic Pathway Cavernous Malformations - A Rare Cause Of Vision Loss

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**Abstract:**



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Distal Renal Tubular Acidosis in the Setting of Sjogren Syndrome and Nephrolithiasis

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INI Deficiency Unveiled: An Aggressive Case of Renal Cell Medullary Carcinoma.

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