Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease (MOGAD) Initially Presenting as Septic Meningoencephalitis in a 16-Year-Old Male.

Background: We describe a case of myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) in a 16-year-old patient who initially presented with clinical features of septic meningoencephalitis. This case outlines the importance of considering a diagnosis of MOGAD in patients who fail to improve with appropriate antimicrobial therapy or show a positive clinical response to glucocorticoids (often used in treatment of meningococcal meningitis). We emphasise the importance of recognising that an infectious prodrome can precede MOGAD. Case description: A 16-year-old male was admitted with vomiting, fever, headache, photophobia and altered mental state. He was treated for meningoencephalitis with initial clinical improvement. Lumbar puncture findings were suggestive of viral meningoencephalitis. During admission the patient went through several periods of transient clinical and biochemical improvement, alternating with periods of symptomatic relapse. On day 17 of admission, he was transferred to a tertiary centre for suspected autoimmune disseminated meningoencephalitis (ADEM) and two days later, he suffered a catastrophic neurological decline with new dysarthria, dysphagia, aphasia, horizontal nystagmus and facial paralysis. He made a remarkable neurological recovery after commencing treatment with IV immunoglobulin, IV methylprednisolone and plasma exchange, with complete resolution of symptoms. Conclusion: MOGAD can run a variable course and present soon after a central nervous system infection, making the diagnosis more challenging. Nonetheless, patients can achieve a full neurological recovery with early recognition, diagnosis and treatment of this rare entity. LEARNING POINTS: Autoimmune encephalitis can be preceded by an infectious prodrome which makes the diagnosis more challenging.Autoimmune encephalitis can run a subacute and fluctuating course with transient periods of symptomatic improvement preceding a rapid neurological decline.Glucocorticoids often used in treatment of patients with meningococcal meningitis may lead to transient symptomatic improvement in patients with autoimmune encephalitis, masking the diagnosis.MRI findings of demyelination in autoimmune encephalitis may lag behind clinical symptoms by days to weeks.

Wildfire plume ageing in the Photochemical Large Aerosol Chamber (PHOTO-LAC).

Plumes from wildfires are transported over large distances from remote to populated areas and threaten sensitive ecosystems. Dense wildfire plumes are processed by atmospheric oxidants and complex multiphase chemistry, differing from processes at typical ambient concentrations. For studying dense biomass burning plume chemistry in the laboratory, we establish a Photochemical Large Aerosol Chamber (PHOTO-LAC) being the world's largest aerosol chamber with a volume of 1800 m3 and provide its figures of merit. While the photolysis rate of NO2 (jNO2) is comparable to that of other chambers, the PHOTO-LAC and its associated low surface-to-volume ratio lead to exceptionally low losses of particles to the walls. Photochemical ageing of toluene under high-NOx conditions induces substantial formation of secondary organic aerosols (SOAs) and brown carbon (BrC). Several individual nitrophenolic compounds could be detected by high resolution mass spectrometry, demonstrating similar photochemistry to other environmental chambers. Biomass burning aerosols are generated from pine wood and debris under flaming and smouldering combustion conditions and subsequently aged under photochemical and dark ageing conditions, thus resembling day- and night-time atmospheric chemistry. In the unprecedented long ageing with alternating photochemical and dark ageing conditions, the temporal evolution of particulate matter and its chemical composition is shown by ultra-high resolution mass spectrometry. Due to the spacious cavity, the PHOTO-LAC may be used for applications requiring large amounts of particulate matter, such as comprehensive chemical aerosol characterisation or cell exposures under submersed conditions.

Bilateral paramedian pontine infarcts: a rare cause of bilateral horizontal gaze palsy.

A 73-year-old man presented to accident and emergency with headache and diplopia. Examination of the eye movements revealed a bilateral complete horizontal gaze palsy. On admission, a CT scan of the brain was performed, which was unremarkable. An MRI of the brain was then performed, which confirmed tiny acute infarcts involving the pons and the right cerebellum. This man was promptly treated with aspirin 300 mg one time per day, as per the stroke pathway. Further diagnostic workup later revealed atrial flutter. This man was therefore commenced on apixaban. The differential diagnoses for bilateral gaze palsy include the following: multiple sclerosis, infarction, haemorrhage and space occupying lesion. Bilateral gaze palsy is often associated with other neurological symptoms.