Optical coherence tomography reveals light-dependent retinal responses in Alzheimer's disease.

Spectral-domain optical coherence tomography (SD-OCT) is an accessible clinical tool for measuring structural changes to the retina, and increasingly as a biomarker for brain-predominant neurodegenerative diseases like Alzheimer's. Information about retinal function can also be extracted from OCT images, but is under-studied, with literature examples often employing challenging protocols or requiring specialized hardware. The first goal of this study was to verify that functional retinal imaging was feasible with a commercially-available SD-OCT device and a clinically practical protocol. Inspired by methods from other functional imaging modalities, we acquired images while repeatedly cycling lights on and off, and spatially normalized retinas to facilitate intra- and inter-individual analyses. In eight healthy young adults, light-dependent increases in reflectivity were easily demonstrated at photoreceptor inner and outer segments, changing by ~7% in bright light and ~3% in dim light. Bright light elicited a subtle (~2%) but consistent light-dependent decrease in reflectivity through much of the rest of the retina, including the avascular outer nuclear layer (ONL). We speculated that some of these changes are influenced by glial function - as through water management - a topic of high interest in neurodegenerative diseases that may involve the glymphatic system. Functional abnormalities in patients with antibodies against aquaporin-4 (n â€‹= â€‹3) supported this interpretation. We next compared patients with early-onset Alzheimer's disease (n â€‹= â€‹14) to age-matched controls (n â€‹= â€‹14), revealing that patients had a relatively exaggerated light-induced change in ONL reflectivity (p â€‹< â€‹0.05). Because these measurements can be obtained within 30 â€‹min, regular use in research and limited clinical settings is feasible.

Immunologic mechanisms of fingolimod and the role of immunosenescence in the risk of cryptococcal infection: A case report and review of literature.

BACKGROUND: Fingolimod is a disease-modifying agent used in the treatment of relapsing/remitting multiple sclerosis. In MS clinical studies, the overall rate of infections in fingolimod group was overall similar to placebo, except for slightly more common lower respiratory tract infections and to a lesser extent HSV. Recently, an increasing number of cryptococcal infections associated with a long-term use of this medication have been reported. METHODS: We reviewed literature for cases of cryptococcal infection associated with the use of fingolimod and reported a case at our institution, as well as carefully evaluated the established immune mechanisms of the medication and discussed new insights into its short-term and long-term immunologic effects that may become important in the context of risk of infection. RESULTS: Unique characteristics of cryptococcal pathogen, its immune escape mechanisms, its ability to establish a latent infection with a potential for later reactivation, fingolimod's effects on many lines of immune system, both quantitatively and qualitatively, duration of therapy, and long-term effects of fingolimod, not previously described, in conjunction with effects of natural immunosenescence of the patient population, that appears to be most at risk, may be meaningful in further understanding the risk of infection with long-term use of fingolimod in people of older age.

Estriol combined with glatiramer acetate for women with relapsing-remitting multiple sclerosis: a randomised, placebo-controlled, phase 2 trial.

BACKGROUND: Relapses of multiple sclerosis decrease during pregnancy, when the hormone estriol is increased. Estriol treatment is anti-inflammatory and neuroprotective in preclinical studies. In a small single-arm study of people with multiple sclerosis estriol reduced gadolinium-enhancing lesions and was favourably immunomodulatory. We assessed whether estriol treatment reduces multiple sclerosis relapses in women. METHODS: We did a randomised, double-blind, placebo-controlled phase 2 trial at 16 academic neurology centres in the USA, between June 28, 2007, and Jan 9, 2014. Women aged 18-50 years with relapsing-remitting multiple sclerosis were randomly assigned (1:1) with a random permuted block design to either daily oral estriol (8 mg) or placebo, each in combination with injectable glatiramer acetate 20 mg daily. Patients and all study personnel, except for pharmacists and statisticians, were masked to treatment assignment. The primary endpoint was annualised relapse rate after 24 months, with a significance level of p=0.10. Relapses were confirmed by an increase in Expanded Disability Status Scale score assessed by an independent physician. Analysis was by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT00451204. FINDINGS: We enrolled 164 patients: 83 were allocated to the estriol group and 81 were allocated to the placebo group. The annualised confirmed relapse rate was 0.25 relapses per year (95% CI 0.17-0.37) in the estriol group versus 0.37 relapses per year (0.25-0.53) in the placebo group (adjusted rate ratio 0.63, 95% CI 0.37-1.05; p=0.077). The proportion of patients with serious adverse events did not differ substantially between the estriol group and the placebo group (eight [10%] of 82 patients vs ten [13%] of 76 patients). Irregular menses were more common in the estriol group than in the placebo group (19 [23%] vs three [4%], p=0.0005), but vaginal infections were less common (one [1%] vs eight [11%], p=0.0117). There were no differences in breast fibrocystic disease, uterine fibroids, or endometrial lining thickness as assessed by clinical examination, mammogram, uterine ultrasound, or endometrial lining biopsy. INTERPRETATION: Estriol plus glatiramer acetate met our criteria for reducing relapse rates, and treatment was well tolerated over 24 months. These results warrant further investigation in a phase 3 trial. FUNDING: National Institutes of Health, National Multiple Sclerosis Society, Conrad N Hilton Foundation, Jack H Skirball Foundation, Sherak Family Foundation, and the California Community Foundation.

Optical coherence tomography in Susac's syndrome.

Susac's syndrome is an autoimmune endotheliopathy with predilection for brain, retina and cochlea (Susac, 1994). Optical coherence tomography (OCT) is a non-invasive method, which is increasingly used in the diagnosis of retinal as well as primary central nervous system diseases. OCT is suggested as a useful diagnostic tool in differentiating Susac's syndrome from multiple sclerosis (MS) (Brandt et al., 2012). This report demonstrates the OCT findings in 3 patients with Susac's syndrome in different stages of the disease. The OCT demonstrated decreased retinal nerve fiber layer (RNFL) thickness, which was patchy in nature and more prominent in the nasal quadrants. We also observed loss of the normal foveal contour, which is uncharacteristic for MS. The extent and degree of the OCT abnormalities in our patients correlated with the stage and severity of the disease and correlated with the findings on the visual field studies. We confirm that OCT is a useful diagnostic tool in Susac's syndrome and helps to differentiate it from MS. Furthermore, OCT may be a non-invasive alternative to fluorescein angiography in longitudinal follow up of these patients.

Homonymous hemimacular thinning: a unique presentation of optic tract injury in neuromyelitis optica.

A 42-year-old African American woman with a 5-year history of neuromyelitis optica was found to have an incongruous homonymous hemianopia. Optical coherence tomography (OCT) showed corresponding left homonymous hemimacular thinning. Magnetic resonance imaging of the brain demonstrated a demyelinating lesion in the left optic tract (OT) just anterior to the lateral geniculate nucleus and diffusion tensor magnetic resonance tractography confirmed axonal fiber loss in the left OT. This case illustrates the complementary and confirmatory roles of visual field testing, macular OCT, and neuroimaging in an OT lesion, which caused selective hemimacular thinning through retrograde degeneration.

Retinal Nerve Fibre Layer and Macular Thinning in Spinocerebellar Ataxia and Cerebellar Multisystem Atrophy.

The spinocerebellar ataxias, like all neurodegenerative diseases, lack objective disease- and stage-specific biomarkers. Based on reports of clinically evident optic disc atrophy or retinal disease in some ataxia patients, and the discovery that pre-symptomatic retinal thinning occurs in other neurologic diseases such as multiple sclerosis, we tested the hypothesis that subclinical neuronal or axonal loss in the retina could occur in the degenerative ataxias. Spectral domain optical coherence tomography was performed on 29 ataxia patients with genetically proven spinocerebellar ataxia (SCA) 1, 2, 3, or 6, or multisystem atrophy type C (MSA-C) and 27 age-matched normal subjects. Ataxia patients were assessed using the scale for assessment and rating of ataxia. Compared with normal control subjects, retinal nerve fibre layer (RNFL) thickness was reduced for patients with SCA2 and SCA3, and thickness in the macular region was reduced for all SCAs but SCA2.