ABSTRACT
The cranial nerves (CNs) are responsible for multiple functions, including extraocular mobility, facial sensation and movement, hearing, mastication, tongue movement and sensation, and swallowing. Beyond these vital roles, they can also demonstrate importance in their diagnostic value. Isolated or combined palsies provide insights into potential localizations and various underlying etiologies, including stroke, tumor, and infections that may guide further neurological evaluation. CN VI, the abducens nerve, singularly innervates the lateral rectus muscle, which is responsible for the abduction of the eyes. Despite its long anatomic trajectory, making it susceptible to intracranial injury, an isolated abducens nerve palsy is extremely rare. The most common clinical presentation includes headache, diplopia, and the inability to abduct the afflicted eye. This case report introduces a 71-year-old female with a medical history of malignancy and pancytopenia who presented to the emergency room with complaints of ear pain and swelling and subsequently developed diplopia secondary to unilateral CN VI palsy. Magnetic resonance imaging (MRI) revealed isolated sphenoid sinusitis for which she was clinically asymptomatic. She was treated with a regimen of ampicillin-sulbactam, an oral anti-inflammatory agent, and a tapered course of methylprednisolone with a rapid and complete resolution of the abducens nerve palsy and sinusitis. Acute isolated diplopia is an unusual neurologic condition prompting the need for rapid and thorough investigation. Although exceedingly rare and infrequently cited in the literature, isolated abducens nerve palsies secondary to sphenoid sinusitis should be entertained in the differential diagnosis of this presentation.
ABSTRACT
Background: Hyperoxaluria is typically associated with excessive oxalate intake in the diet, decreased dietary calcium, hyperabsorption of oxalate, or increased endogenous production of oxalate. The disorder spectrum extends from recurrent kidney stones to ESKD. This clinical trial sought to evaluate the effectiveness of an acid stable oxalate decarboxylase (OxDC) to reduce urinary oxalate in healthy subjects on a high-oxalate diet. Methods: In this prospective, double-blind, randomized, placebo-controlled, crossover clinical trial, 33 healthy volunteers were randomized into two crossover sequences separated by a 2-day washout period. A controlled high-oxalate diet (750-800 mg oxalate, 500-550 mg calcium daily) was utilized, and six 24-hour urine collections were measured. Subjects were given approximately 1000 U (micromoles per minute per milligram) of OxDC or placebo with meals three times daily during the 4 days of treatment. Results: Urinary oxalate significantly decreased with OxDC treatment. The baseline corrected within-subject mean reduction in 24-hour urinary excretion (after OxDC dosing versus high-oxalate baseline preceding treatment) was 12.5 mg or 29% (P<0.001). OxDC treatment was effective (>5% reduction) in 31 of 33 subjects (94%). Compared with placebo, OxDC produced a 24% reduction (P<0.001) in 24-hour oxalate excretion. Other urinary parameters (creatinine, uric acid, citrate, magnesium, calcium) were not affected by OxDC. No serious adverse events and no product-related adverse events occurred. Conclusions: An orally administered OxDC is capable of significantly reducing urinary oxalate levels in healthy volunteers on a high-oxalate diet without affecting creatinine clearance, urine creatinine, or other solutes related to supersaturation of calcium oxalate. Clinical Trial registry name and registration number: Evaluation of Nephure, and the Reduction of Dietary Oxalate, in Healthy Volunteers, NCT03661216.
