Bilateral Acute Iris Transillumination (BAIT): A Rare Syndrome Possibly Associated with COVID-19 and Moxifloxacin Use. A Report of 2 Cases.

Bilateral acute iris transillumination (BAIT) is a rare clinical entity, presumed to be associated with preceding upper respiratory tract infection and/or use of certain antibiotics, marked by bilateral acute loss of iris pigment epithelium with pigment dispersion in the anterior chamber and trabecular meshwork, which can cause elevated intraocular pressure and glaucoma, and with iris transillumination and sphincter paralysis which lead to photophobia and blurry vision. We report the first two cases of BAIT in our center which both had a history of preceding COVID-19 (coronavirus disease 2019) and moxifloxacin use. With more awareness, ophthalmologists might diagnose more cases, and thus gain more information regarding the link between COVID-19 and BAIT, which might be underdiagnosed since it is rare or easily misdiagnosed as some more common diseases with similar features.

Redefining the Koizumi model of mouse cerebral ischemia: A comparative longitudinal study of cerebral and retinal ischemia in the Koizumi and Longa middle cerebral artery occlusion models.

Cerebral and retinal ischemia share similar pathogenesis and epidemiology, each carrying both acute and prolonged risk of the other and often co-occurring. The most used preclinical stroke models, the Koizumi and Longa middle cerebral artery occlusion (MCAO) methods, have reported retinal damage with great variability, leaving the disruption of retinal blood supply via MCAO poorly investigated, even providing conflicting assumptions on the origin of the ophthalmic artery in rodents. The aim of our study was to use longitudinal in vivo magnetic resonance assessment of cerebral and retinal vascular perfusion after the ischemic injury to clarify whether and how the Koizumi and Longa methods induce retinal ischemia and how they differ in terms of cerebral and retinal lesion evolution. We provided anatomical evidence of the origin of the ophthalmic artery in mice from the pterygopalatine artery. Following the Koizumi surgery, retinal responses to ischemia overlapped with those in the brain, resulting in permanent damage. In contrast, the Longa method produced only extensive cerebral lesions, with greater tissue loss than in the Koizumi method. Additionally, our data suggests the Koizumi method should be redefined as a model of ischemia with chronic hypoperfusion rather than of ischemia and reperfusion.

Urodilatin reverses the detrimental influence of bradykinin in acute ischemic stroke.

Occlusion of cerebral arteries leads to ischemic stroke accompanied by subsequent brain edema. Bradykinin (BK) is involved in the formation of cerebral edema, and natriuretic peptides (NPs) potentially have beneficial effects on brain edema formation via a still unknown mechanism. The aim of this study was clarifying the mechanisms of action of NPs on BK signaling, and their interactive effects after ischemic brain injury. We used a mouse model for stroke, the middle cerebral artery (MCA) occlusion. Brain lesion and edema were measured by microcomputerized tomography volumetric measurements. To determine the effects of NPs on the BK signaling pathway in the MCAs we measured changes in vessel diameter and membrane potentials in endothelial cells. To determine the effects of NPs on BK signaling pathway in isolated astrocytes and neurons, membrane potentials and intercellular Ca2+ concentrations were measured. Urodilatin inhibited and when applied together with BK, reduced the formation of the ischemic lesion via activation of G-Protein-Signaling Protein Type 4 at the cellular (atrocities, neurons) and blood vessel (endothelial cells and isolated MCA) level as well as in in vivo experiments. The results of this study show the existence of a natural antagonist of BK in the brain, and the possible use of NPs in the treatment of stroke.

Differences in oligoclonal bands and visual evoked potentials in patients with radiologically and clinically isolated syndrome.

The aim of this study was to determine the prevalence of cerebrospinal fluid (CSF) and visual evoked potentials (VEP) abnormalities, and ANA titers in patients with either clinically or radiologically isolated syndrome (CIS and RIS). We gathered records from 330 hospitalized patients diagnosed with CIS/RIS within a 3-year period. Symptoms, CSF findings, VEP and ANA titers were analyzed. Incomplete transverse myelitis was the presenting symptom in 32.7 %, optic neuritis in 22.7 %, brainstem/cerebellar symptoms in 19.4 %, hemispheral symptoms in 2.7 % and multifocal symptoms in 15.2 % of patients in the CIS cohort. We identified 24 (7.3 %) patients with atypical or no symptoms-RIS cohort. Positive oligoclonal bands (OCB) were found in 75.5 % patients. When we divided the patients into CIS and RIS groups, the presence of OCB was 82.4 and 44 %, respectively. VEP were performed in 87.3 % patients and prolonged latencies were found in 39.6 % of them (43.8 and 14.3 % in the CIS and RIS cohort, respectively). ANA were positive in 15.2 % (14.7 and 16 % in the CIS and RIS cohort, respectively) of patients. RIS patients had statistically significant lower percentages of positive OCB and positive VEP (P = 0.002 and 0.001, respectively). Detection of OCB and VEP still has an important role for satisfying the "no better explanation for the clinical presentation" criteria when presented with a patient with a first "radiological" demyelinating episode.

Do we need broad immunological work-up in all patients with CIS?

BACKGROUND: The aim of this study was to determine the prevalence of altered immunological tests and their clinical significance in patients with clinically isolated syndrome (CIS) suggestive of multiple sclerosis (MS). PATIENTS AND METHODS: The information was gathered from medical records of patients hospitalized in the Referral Center for Demyelinating Diseases in the 2008-2010 period. All patients had ANA, ENA profile, ANCA, aCl IgG and IgM, C3, C4, CH50, anti-TPO, AST and RF antibodies tested. RESULTS: From 726 patients with CIS that were reviewed, the complete battery of immunological tests was performed in 418 of them (57.6%), representing our cohort. Altered tests were found in 235 patients (56.2%); 73 (17.4%) had positive antinuclear antibodies, 14 (3.3%) had positive ENA, 47 (11.2%) had positive aCl IgG, 83 (19.8%) had positive aCl IgM, and 13 (3.1%) had anti TPO antibodies. We found no correlation between ANA, aCl IgG or IgM positivity (ANA vs aCL IgG p=0.554; ANA vs aCL IgM p=0.19; aCL IgG vs aCL IgM, p=0.155). None of the patients had any clinical manifestations other than MS symptoms. CONCLUSION: These results indicate that significant number of patients with CIS have altered immunological tests but nevertheless none of them had clinical expression of any other autoimmune disease making them clinically insignificant. In conclusion there is no need to perform extensive immunological work-up in all patients with CIS. Contrary, our results argue for more focused testing rather than a battery of screening tests.