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Inhaled nitrites have been a substance of recreational use for centuries, primarily among men who have sex with men (MSM). However, there is a lack of awareness of the use of inhaled nitrites in this population and the possible complications and health disparities it carries. In this case report, we present a 62-year-old man with a past medical history of glucose-6 phosphate dehydrogenase (G6PD) deficiency presenting with severe hemolytic anemia and methemoglobinemia after recreational use of inhaled nitrites. The case was complicated with the presence of methemoglobinemia in a patient with G6PD deficiency. This report also aims to increase awareness of the use of nitrites in the MSM population. The use of nitrites is a predictor for high-risk sexual behavior and is associated with positive human immunodeficiency virus (HIV) status.

Previous studies on possible accumulation of gadolinium-based contrast agents (GBCA) in the brain suggest that macrocyclic GBCA are less likely to accumulate than linear GBCA. However, conflicting results have been reported, especially in MS. The aim of this study is to investigate retrospectively the correlation between gadoterate-meglumine (macrocyclic GBCA) use and T1 signal intensity changes (SI) in the dentate nucleus and the GP on unenhanced T1-weighted images in a large cohort of MS patients.Unenhanced T1-weighted images of 232 MS patients who previously received multiple intravenous administrations of 0.1 mmol/kg of gadoterate-meglumine were reviewed. The change in T1 SI ratios of dentate nucleus/central pons (DN/CP) and globus pallidus/centrum semiovale (GP/CSO) was calculated between the first and last MRIs and correlated with age, number of injections, time interval between MRIs, disease duration, activity, and therapy.DN/CP ratio showed no significant changes whereas the GP/CSO ratio showed a significant decrease (p0.0001) between the first and last MRIs. Multivariable analyses of both ratios, controlling for age, disease duration, and time interval between MRIs, showed no significant correlation between the number of gadolinium injections and the differences in DN/CP (standardized beta = -0.018, p = 0.811) or GP/CSO SI ratios (standardized beta = -0.049, p = 0.499).Repeated administration of gadoterate-meglumine in MS patients did not result in increased T1 SI in the DN or the GP. The significant decrease of GP/CSO ratio between the first and last MRIs is not due to gadolinium accumulation but rather to varying MR parameters.

Ever since gadolinium was found to deposit in the brain of patients with normal kidney function by Kanda et al. in 2014, several studies have been conducted to evaluate its effect on the patients' health. However, conflicting results were obtained regarding imaging in gadolinium retention. These finding were attributed to the chelating structure of the administered gadolinium-based contrast agent (GBCA): linear agents were found to accumulate in the dentate nucleus (DN) and the globus pallidus (GP) of subjects even after one dose. There are some contradictory results when assessing macrocyclic agents. In the following article, we review the basis of GBCAs characteristics and their side effects, as well as, the MRI studies that assessed the accumulation of gadolinium in the brain. Based on the results of several studies, in 2017, the European Medicine Agency requested the suspension of the marketing authorizations for three linear GBCAs: gadodiamide (Omniscan®), gadoversetamide (Optimark®) and gadopentate dimeglimine (Magnevist®) and limited the use of gadoxetate disodium (Primovist/Eovist®) and gadobenate dimeglumine (MultiHance®) to hepatic uptake for imaging poorly vascularized hepatic lesions. Accordingly, the FDA did not restrict GBCA use, but will continue to study their safety and urged clinicians to use these agents sparingly. All macrocyclic GBCAs continued however to be used as no available valid evidence linked them to brain gadolinium retention. Regardless of possible accumulation in the brain, there is no evidence to-date that gadolinium retention leads to any disease or disorders in subjects with normal renal function. Further investigations with long-term follow-up are needed.

Objective To explore prospectively through OCT the rate of retinal layer changes in relapsing-remitting multiple sclerosis patients followed up on fingolimod or interferon, as well as the treatments’ differential effects on cognitive tests scores. Methods This prospective observational study enrolled 128 stable RRMS patients treated either with fingolimod (n = 71) or interferon (n = 56). Symbol-Digit Modality Test and retinal OCT scans were obtained at baseline and every 6 to 12 months. A subgroup of patients underwent expanded cognitive tests annually (Brief visual-spatial memory-total recall, BVMT-delayed recall, and Montreal Cognitive Assessment). Retinal-OCT scans were also obtained from 22 age- and sex-matched healthy controls. Mixed effects regression was used to study annualized changes in retinal layers and cognitive function, including differences between treatment groups. Correlations between annualized changes in retinal measurements and cognitive scores were also explored. Results Fingolimod treated patients showed no significant difference in the rate of thinning of all retinal layers when compared to healthy controls and had significantly less GCIPL thinning when compared to interferons. SDMT scores improved similarly among both RRMS treatment groups. However, interferon but not fingolimod treated patients had significant decline in MOCA and total recall scores. We also found correlations between the annualized change in GCIPL thickness and annualized change in MOCA scores, and similar correlations with annualized change in total recall scores. Conclusion Fingolimod has a potential role in reducing retinal neurodegeneration in RRMS. Longitudinal OCT measures appear to be sensitive to changes in cognitive function and may be useful for monitoring neuroprotective therapies.

Background: Inhaled nitrites have been a substance of recreational use for centuries, primarily among men who have sex with men (MSM). However, there is a lack of awareness of the use of inhaled nitrites in this population and the possible complications and health disparities it carries. This case report highlights the use of inhaled nitrites in an MSM male with an emphasis on the complications induced by this product, including severe hemolytic anemia and methemoglobinemia. Followed by a review of both acute therapy and preventative therapy by increasing provider awareness. Case presentation: A 62-year-old man with a past medical history of glucose-6 phosphate dehydrogenase (G6PD) deficiency presented to the emergency department with atypical chest pain. He was tachypneic and hypotensive with laboratory evidence of end organ damage. He had an acute drop in hemoglobin with elevated bilirubin concerning for acute hemolytic anemia. His arterial blood gas was significant for elevated methemoglobin. The patient reported recent use of “poppers” (inhaled nitrite) which is associated with formation of methemoglobin and hemolytic anemia. Given the severity of his symptoms and elevated methemoglobin, he met criteria for methylene blue administration. However, his G6PD deficiency is a contraindication to methylene blue and the patient was treated conservatively with a positive outcome. Conclusion: The following report presents a unique scenario in which a G6PD deficient patient presented with hemolytic anemia and methemoglobinemia after recreational use of inhaled nitrites. The case was complicated with the management challenge of methemoglobinemia in a patient with G6PD deficiency. Prior literature has shown that the use of nitrites is a predictor for high-risk sexual behavior and is associated with positive human immunodeficiency virus (HIV) status. Increasing provider awareness for appropriate counseling is of importance.

Gadolinium-based contrast agent (GBCA) effect on automated segmentation algorithms of subcortical gray matter (GM) is not fully known. The aim of this study is to determine gadolinium effect on the segmentation of the thalamus and whole brain tissue using different automated segmentation techniques. Eighty-four multiple sclerosis (MS) patients underwent an MRI acquisition of two 3DT1-weighted sequences with and without gadolinium injection among which 10 were excluded after image quality check. Manual thalamic segmentation considered as gold standard was performed on unenhanced T1 images. volBrain and FSL-Anat were used to automatically segment the thalamus on both enhanced and unenhanced T1 and the degree of similitude (DICE) values were compared between manual and automatic segmentations. Whole brain tissue segmentation (GM, white matter (WM), and lateral ventricles (LV)) was also performed using SIENAX. A paired samples t test was applied to test the significance of DICE value differences between the thalamic manual and automatic segmentations of both enhanced and unenhanced T1 images. Significant differences (FSL-Anat 1.474% p

A critical step in the diagnosis of multiple sclerosis is to rule out a heterogeneous variety of multiple sclerosis mimickers, which is crucial in the era of powerful immune-modulator treatments. In this review, we discuss the background of toxocariasis in general, present central nervous system Toxocara infection as one of the multiple sclerosis mimickers in the Middle East, and share our experience about the diagnosis and management of this condition. This entity seems very relevant in a region such as the Middle East, where displacement of populations and conflict can result in non-hygienic food and water management bundles. The diagnosis should be entertained, especially when assessing patients with myelopathy. The presence of a single lesion in the spinal cord with inflammatory features should prompt serological testing for Toxocara IgG and IgM in serum and the cerebrospinal fluid. This infection is treatable, with the regimen of high-dose albendazole being one of the most accepted treatments. Although most cases exhibit a good prognosis, some have residual deficits localized to the affected spinal cord level.