Recreational Nitrous Oxide-Induced Subacute Combined Degeneration.

Subacute combined degeneration (SCD) is myelopathy caused by vitamin B12 deficiency, leading to demyelination of the dorsal column located in the posterior spinal cord. Despite the high prevalence of recreational nitrous oxide use, its detrimental effects, including significant nerve dysfunction, are insufficiently recognized. We present the case of a 32-year-old male who was brought to the emergency department with complaints of paresthesia of his four extremities and lower extremity weakness. He was found to have B12 deficiency from chronic nitrous oxide abuse and responded positively to intramuscular B12 supplementation. It is important to consider possible nitrous oxide abuse while investigating suspected B12 deficiency, especially in patients presenting with nonspecific myeloneuropathy. Elevated methylmalonic acid (MMA) level is specific for diagnosing B12 deficiency. Prompt diagnosis and treatment can lead to the resolution of the symptoms and prevent further nerve damage.

Generalised myoclonus associated with COVID-19 infection.

Postinfectious generalised myoclonus has been reported after many viral and bacterial infections in the past. Recently, some case reports have described it in the context of COVID-19 infection. Most patients described in these case reports are either critically ill and intubated or have concurrent respiratory symptoms. Herein, we present a case of a 79-year-old man, who was recovering from a recent COVID-19 infection, presented with isolated generalised myoclonus. The patient was treated with levetiracetam, a short course (10 days) of dexamethasone, and required extensive rehabilitation. Outpatient follow-up at 2 months suggested complete resolution of symptoms and levetiracetam was subsequently discontinued. This case highlights that generalised myoclonus can occur as a delayed complication of COVID-19 infection.

A new family of Drosophila balancer chromosomes with a w- dfd-GMR yellow fluorescent protein marker.

We report new w- fluorescent balancers scorable from stage 13 through adulthood that bear a nuclear-localized yellow fluorescent protein marker directly driven by dfd and GMR enhancer elements. The utility of this marker is enhanced by identification of an anti-GFP/yellow fluorescent protein (YFP) serum that is compatible with heat fixation.