PMON79 Supraphysiologic vasopressin-induced receptor desensitization; a case report

Background

Arginine vasopressin (AVP) is a nonapeptide released from the neurohypophysis in response to increases in plasma osmolality, hypovolemia, hypotension, and angiotensin II. V2 receptors, expressed on the basolateral membrane of the renal collecting ducts coupled to the adenylyl cyclase-cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) pathway. PKA increases the synthesis and shuttling of aquaporin 2 water channel containing vesicles (AQMCV) from cytoplasmic vesicles to the luminal surface of the renal collecting ducts (and inhibits the endocytosis of the vesicles), where they are inserted into the apical cell membrane. As a result, AVP increases free water reabsorption from the filtrate and decreases serum osmolality.

There are different protocols for CDI management in post neurosurgical patient, including IV or SQ injections as well as continuous vasopressin drip. Here we discussed a case where prolonged IV drip could probably have caused loss of response to IV DDAVP injections.

Case

Patient is a 46-year-old male admitted with AMS with imaging revealed ruptured anterior communicating artery aneurysm associated with subarachnoid and intra parenchymal hemorrhage. The patient underwent emergent aneurysm coiling and EVD placed. The patient was subsequently started on heparin infusion due to a large frontal lobe clot which was found on cerebral angiogram. The next day, the patient developed acute diabetes insipidus with hypernatremia and polyuria. Repeat head CT demonstrated increased cerebral edema around the frontal clot. The patient underwent right frontal craniotomy for clot evacuation. He patient was subsequently started on vasopressin infusion (ranging from 0.5-6 units/hour) by neurosurgery team for urinary output less than 200 mL/hour. ​Urinary output and sodium level improved and remained stable on infusion. When endocrinology attempted transition to DDAVP IV injections patient responded with severe polyuria to initial 0.5 mcg injection. Eventually patient required 1 mcg IV every 4 hours dosing to maintain normal urine output and required a slow wean off to the standard dose of 0.5 mcg every 8 hours over 14 days.

Discussion

we are presenting a case of CDI associated to SAH who was started on IV infusion of vasopressin, required slow weaning. phenomenon called for slow re-sensitization of the receptors with gradual decreasing of DDAVP dosing. Animal studies have shown that V1 and V2 receptors levels are sensitive to hormone-induced downregulation of hormone receptors. Hypervasopressinemia in rats whose blood vasopressin concentration was experimentally elevated by IV infusion to extraphysiologic levels caused significant desensitization of kidney vasopressin receptors. In another study, IM injection of DDAVP to rats led to a total loss of kidney V receptors. Thus, it is likely that administration of high dose DDAVP IV in this patient induced downregulation of kidney V2 receptors.

Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.

PMON79 Supraphysiologic Vasopressin-Induced Receptor Desensitization: A Case Report

Background

Arginine vasopressin (AVP) is a nonapeptide released from the neurohypophysis in response to increases in plasma osmolality, hypovolemia, hypotension, and angiotensin II. V2 receptors, expressed on the basolateral membrane of the renal collecting ducts coupled to the adenylyl cyclase-cyclic adenosine monophosphate (cAMP)-protein kinase A (PKA) pathway. PKA increases the synthesis and shuttling of aquaporin 2 water channel containing vesicles (AQMCV) from cytoplasmic vesicles to the luminal surface of the renal collecting ducts (and inhibits the endocytosis of the vesicles), where they are inserted into the apical cell membrane. As a result, AVP increases free water reabsorption from the filtrate and decreases serum osmolality. There are different protocols for CDI management in post neurosurgical patient, including IV or SQ injections as well as continuous vasopressin drip. Here we discussed a case where prolonged IV drip could probably have caused loss of response to IV DDAVP injections.

Case

Patient is a 46-year-old male admitted with AMS with imaging revealed ruptured anterior communicating artery aneurysm associated with subarachnoid and intra parenchymal hemorrhage. The patient underwent emergent aneurysm coiling and EVD placed. The patient was subsequently started on heparin infusion due to a large frontal lobe clot which was found on cerebral angiogram. The next day, the patient developed acute diabetes insipidus with hypernatremia and polyuria. Repeat head CT demonstrated increased cerebral edema around the frontal clot. The patient underwent right frontal craniotomy for clot evacuation. He patient was subsequently started on vasopressin infusion (ranging from 0.5-6 units/hour) by neurosurgery team for urinary output less than 200 mL/hour. ​Urinary output and sodium level improved and remained stable on infusion. When endocrinology attempted transition to DDAVP IV injections patient responded with severe polyuria to initial 0.5 mcg injection. Eventually patient required 1 mcg IV every 4 hours dosing to maintain normal urine output and required a slow wean off to the standard dose of 0.5 mcg every 8 hours over 14 days.

Discussion

we are presenting a case of CDI associated to SAH who was started on IV infusion of vasopressin, required slow weaning. phenomenon called for slow re-sensitization of the receptors with gradual decreasing of DDAVP dosing. Animal studies have shown that V1 and V2 receptors levels are sensitive to hormone-induced downregulation of hormone receptors. Hypervasopressinemia in rats whose blood vasopressin concentration was experimentally elevated by IV infusion to extraphysiologic levels caused significant desensitization of kidney vasopressin receptors. In another study, IM injection of DDAVP to rats led to a total loss of kidney V receptors. Thus, it is likely that administration of high dose DDAVP IV in this patient induced downregulation of kidney V2 receptors.

Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.

Intracranial fungal Cladophialophora bantiana infection in a nonimmunocompromised patient: A case report and review of the literature

Background:

Cladophialophora bantiana is a dematiaceous fungus that rarely infects the central nervous system (CNS). It is associated with a mortality rate of over 70% despite treatment.

Case Description:

An 81-year-old female with a remote history of renal cell carcinoma presented with progressive headache and an expressive aphasia for 3 days. Computed tomography imaging revealed a left frontotemporal mass with surrounding vasogenic edema. A left frontotemporal craniotomy was performed and cultures revealed C. bantiana. The initial management with IV voriconazole was unsuccessful and the patient had a recurrence of the cranial infection and developed pulmonary abscesses. Following the addition of oral flucytosine, the patient showed a significant improvement with a complete radiographic resolution of both the cranial and pulmonary lesions.

Conclusion:

C. bantiana involving the CNS is a rare and often fatal disease. Surgical management along with standard antifungal treatment may not provide definitive therapy. The addition of flucytosine to IV voriconazole resulted in a positive outcome for this patient who is alive, living independently 1 year from the original diagnosis. In this rare fungal infection, standard antifungal treatment may not provide adequate coverage and the utilization of additional therapy may be required.

The Impact of 68Gallium DOTA PET/CT in Managing Patients With Sporadic and Familial Pancreatic Neuroendocrine Tumours

OBJECTIVE

Pancreatic neuroendocrine tumours (panNETs) arise sporadically or as part of a genetic predisposition syndrome. CT/MRI, endoscopic ultrasonography and functional imaging using Octreoscan localise and stage disease. This study aimed to evaluate the complementary role of ⁶⁸Gallium (⁶⁸Ga)-DOTA PET/CT in managing patients with panNETs.

DESIGN

A retrospective study conducted across three tertiary UK NET referral centres.

METHODS

Demographic, clinical, biochemical, cross-sectional and functional imaging data were collected from patients who had undergone a ⁶⁸Ga-DOTA PET/CT scan for a suspected panNET.

RESULTS

We collected data for 183 patients (97 male): median (SD) age 63 (14.9) years, 89.1 vs. 9.3% (n=163 vs. 17) alive vs. dead (3 data missing), 141 sporadic vs. 42 familial (MEN1, n=36; 85.7%) panNETs. Non-functional vs. functional tumours comprised 73.2 vs. 21.3% (n=134 vs. 39) (10 missing). Histological confirmation was available in 89% of individuals (n=163) but tumour grading (Ki67 classiifcation) was technically possible only in a smaller cohort (n=143): grade 1, 50.3% (n=72); grade 2, 46.2% (n=66) and grade 3, 3.5% (n=5) (40 histopathological classification either not technically feasible or biopsy not perfomed). 60.1% (n=110) were localised, 14.2% (n=26) locally advanced and 23.5% (n=43) metastatic (4 missing). 224 ⁶⁸Ga-DOTA PET/CT scans were performed in total for: diagnosis/staging 40% (n=88), post-operative assessment/clinical surveillance 53% (n=117) and consideration of peptide receptor radionuclide therapy (PRRT) 8% (n=17) (2 missing). PET/CT results confirmed other imaging findings (53%), identified new disease sites (28.5%) and excluded suspected disease (5%). Overall, ⁶⁸Ga-DOTA PET/CT imaging findings provided additional information in 119 (54%) patients and influenced management in 85 (39%) cases.

CONCLUSION

⁶⁸Ga-DOTA PET/CT imaging more accurately stages and guides treatment in patients with sporadic/familial panNETs with newly diagnosed/recurrent disease.

The NEALS primary lateral sclerosis registry

BACKGROUND AND OBJECTIVE

Primary lateral sclerosis (PLS) is a neurodegenerative disease characterized by progressive upper motor neuron dysfunction. Because PLS patients represent only 1 to 4% of patients with adult motor neuron diseases, there is limited information about the disease's natural history. The objective of this study was to establish a large multicenter retrospective longitudinal registry of PLS patients seen at Northeast ALS Consortium (NEALS) sites to better characterize the natural progression of PLS. Methods: Clinical characteristics, electrophysiological findings, laboratory values, disease-related symptoms, and medications for symptom management were collected from PLS patients seen between 2000 and 2015. Results: The NEALS registry included data from 250 PLS patients. Median follow-up time was 3 years. The mean rate of functional decline measured by ALSFRS-R total score was -1.6 points/year (SE:0.24, n = 124); the mean annual decline in vital capacity was -3%/year (SE:0.55, n = 126). During the observational period, 18 patients died, 17 patients had a feeding tube placed and 7 required permanent assistive ventilation. Conclusions: The NEALS PLS Registry represents the largest available aggregation of longitudinal clinical data from PLS patients and provides a description of expected natural disease progression. Data from the registry will be available to the PLS community and can be leveraged to plan future clinical trials in this rare disease.

Thermoregulation in brain injury

Different mechanisms explain thermoregulatory dysfunction following ischemic stroke, hemorrhagic stroke, and traumatic brain injury. Temperature instability following brain injury likely involves hypothalamic injury, pathologic changes in cerebral blood flow, metabolic derangement, and a neurogenic inflammatory response. Although targeted temperature management (TTM) exerts pleiotropic effects, the heterogeneity of brain injury has hindered identification of patient subsets most likely to benefit from TTM. Early optimism about TTM's role in brain injury has been tempered by the failure of successive clinical trials to show improved patient outcomes. However, given the deleterious effects of fever, aggressive fever management is still warranted in the critically ill neurologic patient.

SOD1 in cerebral spinal fluid as a pharmacodynamic marker for antisense oligonucleotide therapy

BACKGROUND

Therapies designed to decrease the level of SOD1 are currently in a clinical trial for patients with superoxide dismutase (SOD1)-linked familial amyotrophic lateral sclerosis (ALS).

OBJECTIVE

To determine whether the SOD1 protein in cerebral spinal fluid (CSF) may be a pharmacodynamic marker for antisense oligonucleotide therapy and a disease marker for ALS.

DESIGN

Antisense oligonucleotides targeting human SOD1 were administered to rats expressing SOD1G93A. The human SOD1 protein levels were measured in the rats' brain and CSF samples. In human CSF samples, the following proteins were measured: SOD1, tau, phosphorylated tau, VILIP-1, and YKL-40.

PARTICIPANTS

Ninety-three participants with ALS, 88 healthy controls, and 89 controls with a neurological disease (55 with dementia of the Alzheimer type, 19 with multiple sclerosis, and 15 with peripheral neuropathy).

RESULTS

Antisense oligonucleotide-treated SOD1G93A rats had decreased human SOD1 messenger RNA levels (mean [SD] decrease of 69% [4%]) and decreased protein levels (mean [SD] decrease of 48% [14%]) in the brain. The rats' CSF samples showed a similar decrease in hSOD1 levels (mean [SD] decrease of 42% [14%]). In human CSF samples, the SOD1 levels varied a mean (SD) 7.1% (5.7%) after additional measurements, separated by months, were performed. The CSF SOD1 levels were higher in the participants with ALS (mean [SE] level, 172 [8] ng/mL; P<.05) and the controls with a neurological disease (mean [SE] level, 172 [6] ng/mL; P<.05) than in the healthy controls (mean [SE] level, 134 [4] ng/mL). Elevated CSF SOD1 levels did not correlate with disease characteristics in participants with ALS or controls with dementia of the Alzheimer type, but they did correlate with tau, phosphorylated tau, VILIP-1 and YKL-40 levels in controls with dementia of the Alzheimer type.

CONCLUSIONS

SOD1 in CSF may be an excellent pharmacodynamic marker for SOD1-lowering therapies because antisense oligonucleotide therapy lowers protein levels in the rat brain and rat CSF samples and because SOD1 levels in CSF samples from humans are stable over time.

Anti-superoxide dismutase antibodies are associated with survival in patients with sporadic amyotrophic lateral sclerosis

Our objective was to test the hypothesis that aberrantly modified forms of superoxide dismutase (SOD1) influence the disease course for sporadic amyotrophic lateral sclerosis (SALS). We probed for anti-SOD1 antibodies (IgM and IgG) against both the normal and aberrantly oxidized-SOD1 (SODox) antigens in sera from patients with SALS, subjects diagnosed with other neurological disorders and healthy individuals, and correlated the levels of these antibodies to disease duration and/or severity. Anti-SOD1 antibodies were detected in all cohorts; however, a subset of ∼5-10% of SALS cases exhibited elevated levels of anti-SOD1 antibodies. Those SALS cases with relatively high levels of IgM antibodies against SODox exhibit a longer survival of 6.4 years, compared to subjects lacking these antibodies. By contrast, SALS subjects expressing higher levels of IgG antibodies reactive for the normal WT-SOD1 antigen exhibit a shorter survival of 4.1 years. Anti-SOD1 antibody levels did not correlate with disease severity in either the Alzheimer's or Parkinson's disease cohorts. In conclusion, the association of longer survival with elevated levels of anti-SODox antibodies suggests that these antibodies may be protective. By extension, these data implicate aberrantly modified forms of WT-SOD1 (e.g. oxidized SOD1) in SALS pathogenesis. In contrast, an immune response against the normal WT-SOD1 appears to be disadvantageous in SALS, possibly because the anti-oxidizing activity of normal WT-SOD1 is beneficial to SALS individuals.

Body mass index, not dyslipidemia, is an independent predictor of survival in amyotrophic lateral sclerosis

INTRODUCTION

Recent studies have provided conflicting data regarding the role of dyslipidemia in amyotrophic lateral sclerosis (ALS). The aim of this study was to determine whether cholesterol level are an independent predictor of survival in ALS.

METHODS

Cholesterol levels were measured in 427 ALS subjects from three clinical trial databases.

RESULTS

The LDL/HDL ratio did not decrease over time, despite significant declines in body mass index (BMI), forced vital capacity (FVC), and ALSFRS-R. After adjusting for BMI, FVC, and age, the lipid ratio was not associated with survival. There was a "U"-shaped association between BMI and mortality, with the highest survival at 30-35 kg/m(2). The adjusted hazard ratio for the linear association between BMI and survival was 0.860 (95% CI 0.80-0.93, P = 0.0001).

CONCLUSIONS

We found that dyslipidemia is not an independent predictor of survival in ALS. BMI is an independent prognostic factor for survival after adjusting for markers of disease severity.

Some operationalizations of the neodissociation concept and their relationship to hypnotic susceptibility

We operationalized and tested E. R. Hilgard's (1973a, 1977b) neodissociation theory. His work suggested that the dissociation necessary for experiencing hypnotic phenomena may be attributable to a general capacity for dissociation that should be measurable outside of the domain of hypnosis. We used several types of operational definitions and tasks in order to capture a wide range of meanings. The performances of 169 undergraduates on clerical/motor and cognitive tasks in selective attention and divided attention conditions, as well as the degree of incidental learning, were correlated with scores on the Harvard Group Scale of Hypnotic Susceptibility. The results do not support a neodissociation theory despite the study's respectable convergent-discriminant validity. Although conceptual and methodological considerations were noted, the results may indicate an important limitation of the explanatory power of E. R. Hilgard's neodissociation theory.

Some operationalizations of the neodissociation concept and their relationship to hypnotic susceptibility

We operationalized and tested E. R. Hilgard's (1973a, 1977b) neodissociation theory. His work suggested that the dissociation necessary for experiencing hypnotic phenomena may be attributable to a general capacity for dissociation that should be measurable outside of the domain of hypnosis. We used several types of operational definitions and tasks in order to capture a wide range of meanings. The performances of 169 undergraduates on clerical/motor and cognitive tasks in selective attention and divided attention conditions, as well as the degree of incidental learning, were correlated with scores on the Harvard Group Scale of Hypnotic Susceptibility. The results do not support a neodissociation theory despite the study's respectable convergent-discriminant validity. Although conceptual and methodological considerations were noted, the results may indicate an important limitation of the explanatory power of E. R. Hilgard's neodissociation theory.