Study of nycthemeral variations in blood pressure in patients with non-arteritic anterior ischemic optic neuropathy

PURPOSE

The objective of this study was to analyze the nycthemeral variations in blood pressure (BP) in individuals who presented with non-arteritic anterior ischemic optic neuropathy (NAION).

METHODS

BP was recorded for 24 h (ambulatory blood pressure monitoring, ABPM) in 65 patients with acute NAION. Three definitions of nighttime periods were used: definition 1, 1 a.m.-6 a.m.; definition 2, 10 p.m.-7 a.m.; and definition 3, 10 p.m.-8 a.m. For each of these definitions, patients were classified according to the value of nocturnal reduction in BP into dippers (10-20%), mild dippers (0-10%), reverse dippers (< 0%), and extreme dippers (> 20%).

RESULTS

The proportions of dippers, mild dippers, reverse dippers, and extreme dippers varied significantly depending on the definition chosen. We found the highest number of patients with extreme dipping (23%) when using the strictest definition of nighttime period (definition 1, 1 a.m.-6 a.m.), as compared with 6.2% and 1.5% for the other definitions, respectively. Overall, 13 of 33 patients without known systemic hypertension (39%) were diagnosed with hypertension after ABPM. No risk factor for NAION was associated with the extreme-dipping profile. Finally, the prevalence of systemic hypertension was high (69%).

CONCLUSION

In our population of patients who had an episode of NAION, the proportion of extreme dippers was higher than that usually found in the literature. However, extreme dipping is not a frequent feature of patients with NAION as compared to patients with systemic hypertension. ABPM is recommended for all patients with NAION and unknown history of systemic hypertension.

High diagnostic accuracy of T2FLAIR at 3 T in the detection of optic nerve head edema in acute optic neuritis

OBJECTIVES

Optic nerve head edema (ONHE) detected by fundoscopy is observed in one-third of patients presenting optic neuritis (ON). While ONHE is an important semiological feature, the correlation between ONHE and optic nerve head MRI abnormalities (ONHMA), sometimes called "optic nerve head swelling," remains unknown. Our study aimed to assess the diagnostic accuracy of T2 fluid-attenuated inversion recovery (FLAIR) MRI sequence in detecting ONHE in patients with acute ON.

METHODS

In the present single-center study, data were extracted from two prospective cohort studies that consecutively included adults with a first episode of acute ON treated between 2015 and 2020. Two experienced readers blinded to study data independently analyzed imaging. A senior neuroradiologist resolved any discrepancies. The primary judgment criterion of ONHMA was assessed as optic nerve head high signal intensity on gadolinium-enhanced T2FLAIR MRI sequence. Its diagnostic accuracy was evaluated with both the gold standard of ONHE on fundus photography (FP) and peripapillary retinal nerve fiber layer thickening on optic coherence tomography (OCT).

RESULTS

A total of 102 patients were included, providing 110 affected and 94 unaffected optic nerves. Agreement was high between the different modalities: 92% between MRI and FP (k = 0.77, 95% CI: 0.67-0.88) and 93% between MRI and OCT (k = 0.77, 95% CI: 0.67-0.87). MRI sensitivity was 0.84 (95% CI: 0.70-0.93) and specificity was 0.94 (95% CI: 0.89-0.97) when compared with the FP.

CONCLUSION

Optic nerve head high T2FLAIR signal intensity corresponds indeed to the optic nerve head edema diagnosed by the ophthalmologists. MRI is a sensitive tool for detecting ONHE in patients presenting acute ON.

CLINICAL RELEVANCE STATEMENT

In patients with optic neuritis the high T2FLAIR (fluid-attenuated inversion recovery) signal intensity of the optic nerve head corresponds indeed to optic nerve head edema, which is a useful feature in optic neuritis etiological evaluation and treatment.

KEY POINTS

Optic nerve head edema is a prominent clinical feature of acute optic neuritis and is usually diagnosed during dilated or non-dilated eye fundus examination. Agreement was high between magnetic resonance imaging, fundus photography, and optical coherence tomography. Optic nerve head high T2 fluid attenuation inversion recovery signal intensity is a promising detection tool for optic nerve head edema in patients presenting acute optic neuritis.

Are PHOMS a clinical sign of optic neuritis?

PURPOSE

Assess the prevalence and evolution of PHOMS in optic neuritis.

METHODS

We analysed the medical files of 126 patients included in the OCTON cohort. Patients' medical files, digital retinal images and OCT examinations were reviewed, searching for optic nerve head oedema and PHOMS at the initial presentation and during the follow-up.

RESULTS

We included 102 patients in the final analysis. Twenty-nine (29) eyes had optic nerve head oedema at the initial presentation. PHOMS were found to be present in 8 eyes affected with optic neuritis. All cases of PHOMS were associated with optic nerve head oedema. All the PHOMS decreased in size and disappeared with the improvement of the oedema.

DISCUSSION

Our results show that PHOMS is not a common sign of optic neuritis. We didn't observe any case of PHOMS in the absence of optic nerve head oedema in eyes with optic neuritis. PHOMS seem to be a rare sign of optic neuritis associated to optic nerve head oedema, and they tend to disappear with the improvement of the optic nerve head oedema. We suggest that the presence of PHOMS in optic neuritis eyes with no optic nerve oedema should be a considered warning sign.

Acute optic neuritis: What are the clues to the aetiological diagnosis in real life?

BACKGROUND

Previous cross-sectional studies have reported distinct clinical and radiological features among the different acute optic neuritis (ON) aetiologies. Nevertheless, these reports often included the same number of patients in each group, not taking into account the disparity in frequencies of ON aetiologies in a real-life setting and thus, it remains unclear what are the truly useful features for distinguishing the different ON causes. To determine whether clinical evaluation, ophthalmological assessment including the optical coherence tomography (OCT), CSF analysis, and MRI imaging may help to discriminate the different causes of acute ON in a real-life cohort.

METHODS

In this prospective monocentric study, adult patients with recent acute ON (<1 month) underwent evaluation at baseline and 1 and 12 months, including, high- and low-contrast visual acuity, visual field assessment and OCT measurements, baseline CSF analysis and MRI.

RESULTS

Among 108 patients, 71 (65.7%) had multiple sclerosis (MS), 19 (17.6%) had idiopathic ON, 13 (12.0%) and 5 (4.6%) had myelin oligodendrocyte glycoprotein and aquaporin-4 antibodies, at last follow up respectively.At baseline, the distribution of bilateral ON, CSF-restricted oligoclonal bands, optic perineuritis, optic nerve length lesions and positive dissemination in space and dissemination in time criteria on MRI were significantly different between the four groups (p <0.001). No significant difference in visual acuity nor inner retinal layer thickness was found between the different ON aetiologies.

CONCLUSIONS

In this large prospective study, bilateral visual involvement, CSF and MRI results are the most useful clues in distinguishing the different aetiologies of acute ON, whereas ophthalmological assessments including OCT measurements revealed no significant difference between the aetiologies.

Effectiveness and safety of cataract surgery in laminar air flow device versus traditional scrubs: A 1-year non-inferiority pilot study

Purpose

The study aimed to assess the safety and the non-inferiority of cataract surgery outside an operating room using the Surgicube^®, a mobile laminar airflow (LAF) device.

Settings

This single-center study was conducted at the Rothschild Foundation, Paris, France.

Design

This is a retrospective cross-sectional study.

Methods

All patients operated on for cataracts using the Surgicube^® between February 2020 and February 2021 were included and controlled by a cohort of patients operated on for cataracts in the traditional theater during the same period. Patients with a postoperative follow-up of less than 1 month were excluded. Data collection was carried out using the patient's medical record. The primary endpoint was the evaluation of the number of endophthalmitis in the two groups. The secondary judgment criteria were the analysis of the various complications and the Logmar visual acuity at 1 month in the two groups. All the patients underwent an OCT retinal examination.

Results

A total of 923 randomized patients who underwent cataract surgery between 2020 and 2021 have been included in the study. Among them, 448 patients were operated on using the Surgicube, and 475 patients underwent surgery in the traditional operating room using the same lens phacoemulsification technique. There are no significant differences between the two groups (p > 0.05).

Conclusion

Cataract surgery using the Surgicube^® outside a conventional operating room seems non-inferior to conventional scrub.

Treatment of nonarteritic anterior ischemic optic neuropathy with an endothelin antagonist: ENDOTHELION (ENDOTHELin antagonist receptor in Ischemic Optic Neuropathy)—a multicentre randomised controlled trial protocol

Background

Nonarteritic anterior ischemic optic neuropathy (NAAION) is a major cause of blindness in individuals over 50 years of age, with no available effective treatment. The oral dual endothelin receptor antagonist, bosentan, increases retinal optic nerve head blood flow in healthy humans and glaucoma patients. The objective of this trial is to assess the efficacy of bosentan administered at the acute stage in improving outcomes in NAAION patients.

Methods

ENDOTHELION (ENDOTHELin antagonist receptor in Ischemic Optic Neuropathy) is a phase III, interventional, prospective, multicentre, placebo-controlled randomised double-blind clinical trial. The primary outcome is change in the visual field mean deviation (MD) at 3 months (Humphrey 30-2 SITA standard programme). Secondary outcomes include MD and visual acuity changes up to 24 months, changes in peripapillary retinal nerve fibre and macular ganglion cell layer thickness in the affected eye, as measured by optical coherence tomography, rate of NAAION bilateralisation at 2 years, and quality-of-life. Patients over 50 years of age presenting with typical NAAION of recent onset (less than 21 days) are randomly assigned to either 125 mg oral bosentan or placebo, twice a day, during 8 weeks. Besides visits during the treatment phase, patients attend follow-up visits at 2, 3, 6, 12 and 24 months. The inclusion of patients began in August 2015 at five French University hospital ophthalmology departments and two specialised ophthalmology centres. It is planned to include 86 patients in this trial. To date we have included 72 patients and 49 have completed the full follow-up process.

Discussion

An endothelin receptor antagonist is a potential approach to improving the anatomical and functional prognosis of patients with NAAION. This multicentre double-blind randomised controlled trial is an opportunity to assess (1) the effect of bosentan on the structure and function of the optic nerve in NAAION, at 3 months, (2) the effect of bosentan on the bilateralisation rate at 24 months and (3) the tolerance profile of bosentan in this population.

Trial registration

ClinicalTrials.gov NCT02377271. Registered on March 3, 2015.

Use of Retinal Angiography and MRI in the Diagnosis of Giant Cell Arteritis With Early Ophthalmic Manifestations

BACKGROUND

Giant cell arteritis (GCA) is a vasculitis often revealed by visual signs. Diagnosis is challenging and urgent. Retinal angiography (RA) and MRI allow effective diagnosis. We compared those and proposed an imaging-based approach to diagnose GCA in ophthalmological practice.

METHODS

We conducted a retrospective study based on the data collected from patients suspected to have GCA on ophthalmological findings. Fluorescein (FA) and indocyanine green (ICG) RAs and MRI were performed and compared with final diagnosis.

RESULTS

Among the 41 patients included, 25 were diagnosed with GCA. Sensitivities and specificities of FA and ICG were not different. MRI showed a higher sensitivity and specificity. The approach consisting in performing RA followed by MRI provided a better accuracy.

CONCLUSION

Our study shows that RA can be supplemented by MRI in a specialized center to provide the most accurate diagnosis in GCA revealed by visual signs.

A prospective longitudinal study on prognostic factors of visual recovery and structural change after a first episode of optic neuritis

BACKGROUND

To determine the role of OCT in predicting the final visual and structural outcome, and evaluate the correlation between functional eye outcome and retinal changes, in patients with first episode of optic neuritis (ON).

METHODS

In this prospective study, consecutive adult patients with acute ON underwent ophthalmological evaluation at baseline and 1 and 12 months, including OCT measurements of peripapillary retinal nerve fiber layer (pRNFL), macular ganglion cell and innerplexiform layer, and innernuclear layer thicknesses, high- and low-contrast visual acuity, visual field assessment, and baseline brain MRI. Univariate and multivariate linear regressions were used to assess predictive factors of outcome. Correlations between 12-month visual function and retinal structure were estimated by Spearman coefficients. Two groups of patients were analysed, with or without multiple sclerosis (MS).

RESULTS

Among 116 patients, 79 (68.1%) had MS, and 37 (31.9%) had ON not related to MS (including 19 idiopathic (i.e isolated) ON, and 13 and 5 with myelin oligodendrocyte glycoprotein and aquaporin-4 antibodies, respectively). We found no independent predictive factor of visual and retinal outcome. Analysis of the relationship between the visual field test (mean deviation) and pRNFL thickness demonstrated a threshold of 75.4 μm and 66.4 μm, below which the mean deviation was worse, for patients with MS (p=0.007) and without MS (p<0.001), respectively.

CONCLUSIONS

We found that inner retinal layer measurements during the first month are not predictive of final outcome. The critical threshold of axonal integrity, below which visual function is damaged, is different between patients with and without MS.

Early diffusion-weighted MRI at 3 Tesla detects ischemic changes of the optic nerve in anterior ischemic optic neuropathy

OBJECTIVES

To assess the impact of timing from visual symptoms' onset to diffusion-weighted (DW) 3 T MRI completion to detect ischemic changes of the optic disc and optic nerve in AION patients.

METHODS

This IRB-approved retrospective single-center study included 3 T MRI data from 126 patients with AION and 111 controls with optic neuritis treated between January 2015 and May 2020. Two radiologists blinded to all data individually analyzed imaging. A senior neuroradiologist resolved any discrepancies by consensus. The primary judgment criterion was the restricted diffusion of the optic disc and/or the optic nerve assessed subjectively on the ADC maps. ADC values were also measured. Spearman rank correlations were used to examine the relationships between timing from visual symptoms' onset to MRI completion and both the restricted diffusion and the ADC values.

RESULTS

One hundred twenty-six patients (47/126 [37.3%] women and 79/126 [62.7%] men, mean age 69.1 ± 13.7 years) with AION were included. Restricted diffusion of the optic disc in AION eyes was more frequent in the early MRI group than in the late MRI group: 35/49 (71.4%) eyes versus 3/83 (3.6%) eyes, p < 0.001. ADC values of the pathological optic discs and optic nerves were lower in the early MRI group than in the late MRI group: 0.61 [0.52-0.94] × 10^-3 mm²/s versus 1.28 [1.01-1.44] × 10^-3 mm²/s, p < 0.001, and 0.74 [0.61-0.88] × 10^-3 mm²/s versus 0.89 [0.72-1.10] × 10^-3 mm²/s, p < 0.001, respectively.

CONCLUSIONS

DWI MRI showed good diagnostic performance to detect AION when performed early after the onset of visual symptoms.

KEY POINTS

• Restricted diffusion of the optic disc in eyes affected by AION was significantly more likely to be observed in patients who had undergone MRI within 5 days after onset of visual symptoms. • ADC values of the pathological optic discs and optic nerves were significantly lower in patients who had undergone MRI within 5 days after onset of visual symptoms of AION: 0.61 × 10^-3 mm²/s versus 1.28 × 10^-3 mm²/s, p < 0.001, and 0.74 × 10^-3 mm²/s versus 0.89 × 10^-3 mm²/s, p < 0.001, respectively. • The optimal threshold for timing from visual symptoms' onset to MRI completion to detect restricted diffusion of the optic disc and/or optic nerve was 5 days, with an AUC of 0.88 (CI_95%: 0.82-0.94).

Validation of a multimodal algorithm for diagnosing giant cell arteritis with imaging

PURPOSE

The purpose of this study was to identify which combination of imaging modalities should be used to obtain the best diagnostic performance for the non-invasive diagnosis of giant cell arteritis (GCA).

MATERIALS AND METHODS

This IRB-approved prospective single-center study enrolled participants presenting with a suspected diagnosis of GCA from December 2014 to October 2017. Participants underwent high-resolution 3T magnetic resonance imaging (MRI), temporal and extra-cranial arteries ultrasound and retinal angiography (RA), prior to temporal artery biopsy (TAB). Diagnostic accuracy of each imaging modality alone, then a combination of several imaging modalities, was evaluated. Several algorithms were constructed to test optimal combinations using McNemar test.

RESULTS

Forty-five participants (24 women, 21 men) with mean age of 75.4 ± 16 (SD) years (range: 59-94 years) were enrolled; of these 43/45 (96%) had ophthalmological symptoms. Diagnosis of GCA was confirmed in 25/45 (56%) patients. Sensitivity and specificity of MRI, ultrasound and RA alone were 100% (25/25; 95% CI: 86-100) and 86% (19/22; 95% CI: 65-97), 88% (22/25; 95% CI: 69-97) and 84% (16/19; 95% CI: 60-97), 94% (15/16; 95% CI: 70-100) and 74% (14/19; 95% CI: 49-91), respectively. Sensitivity, specificity, positive predictive and negative predictive values ranged from 95 to 100% (95% CI: 77-100), 67 to 100% (95% CI: 38-100), 81 to 100% (95% CI: 61-100) and 91 to 100% (95% CI: 59-100) when combining several imaging tests, respectively. The diagnostic algorithm with the overall best diagnostic performance was the one starting with MRI, followed either by ultrasound or RA, yielding 100% sensitivity (22/22; 95% CI: 85-100%) 100% (15/15; 95% CI: 78-100) and 100% accuracy (37/37; 95% CI: 91-100).

CONCLUSION

The use of MRI as the first imaging examination followed by either ultrasound or RA reaches high degrees of performance for the diagnosis of GCA and is recommended in daily practice.

Vascular origin in acute transient visual disturbance: A prospective study

BACKGROUND AND PURPOSE

This study was undertaken to validate a clinical score of vascular origin in patients with acute transient visual disturbances (TVDs) without diplopia.

METHODS

We conducted a prospective study in an ophthalmology emergency department and a transient ischemic attack (TIA) clinic. Patients underwent clinical evaluation including a tailored questionnaire, brain, vascular, and ophthalmologic investigations, and 3-month follow-up. TVDs were classified according to vascular or nonvascular origin by three independent experts based on all clinical, cerebrovascular, and ophthalmologic investigations, but blind to the questionnaire results. A clinical score was derived based on clinical variables independently associated with a vascular origin, and was externally validated in an independent cohort.

RESULTS

An ischemic origin of TVD was found in 45% (67/149) of patients in the derivation cohort. Age and six questions were independently associated with an ischemic origin. A nine-point score (≥70 years old = 2; monocular visual loss = 2; black or white vision = 1; single episode = 1; lack of headache = 2; diffuse, constricted, altitudinal, or lateralized visual loss pattern on drawings = 1) showed good discriminative power in identifying ischemic origin (c-statistic = 0.82) and was replicated in the validation cohort (n = 130, 25% of ischemic origin, c-statistic = 0.75). With a score ≥ 4, sensitivity was 85% (95% confidence interval = 68-95) and specificity was 52% (95% confidence interval = 41-62). In both cohorts, ophthalmologic evaluation found a vascular cause in 4% and was noncontributive in 85%. After 3 months, no patients had a stroke, TIA, or retinal infarct.

CONCLUSIONS

Our score may assist in predicting a vascular origin of TVD. Ophthalmologic evaluation, when not readily available, should not delay the neurovascular evaluation.

Pediatric Eye Injuries by Hydroalcoholic Gel in the Context of the Coronavirus Disease 2019 Pandemic

Importance

The coronavirus disease 2019 (COVID-19) pandemic has made alcohol-based hand sanitizers (ABHS) widely available in public places. This may warrant determining whether cases of unintentional ocular exposure are increasing, especially in children.

Objective

To describe the epidemiologic trend of pediatric eye exposures to ABHS and to report the severity of the ocular lesions.

Design, Setting, and Participants

Retrospective case series conducted from April 1, 2020, to August 24, 2020. Cases were retrieved from the national database of the French Poison Control Centers (PCC) and from a pediatric ophthalmology referral hospital in Paris, France. Cases of ocular exposure to chemical agents in children younger than 18 years during the study period were reviewed. Cases of ABHS exposure were included.

Exposures

The following data were collected: age, sex, circumstances of exposure, symptoms, size of the epithelial defect at first examination, time between the incident and re-epithelialization, and medical and/or surgical management.

Main Outcomes and Measures

Comparison of the number of eye exposures to ABHS in children between April to August 2020 and April to August 2019.

Results

Between April 1 and August 24, 2020, there were 7 times more pediatric cases of ABHS eye exposures reported in the PCC database compared with the same period in 2019 (9.9% of pediatric eye exposures in 2020 vs 1.3% in 2019; difference, 8.6%; 95% CI, 7.4-9.9; P < .001). The number of cases occurring in public places increased in 2020 (from 16.4% in May to 52.4% in August). Similarly, admissions to the eye hospital for ABHS exposure increased at the same period (16 children in 2020 including 10 boys; mean [SD] age, 3.5 [1.4] years vs 1 boy aged 16 months in 2019). Eight of them presented with a corneal and/or conjunctival ulcer, involving more than 50% of the corneal surface for 6 of them. Two cases required amniotic membrane transplant.

Conclusions and Relevance

These data support the likelihood of an increasing number of unintentional ocular exposures to ABHS in the pediatric population. To maintain good public compliance with hand disinfection, these findings support that health authorities should ensure the safe use of these devices and warn the parents and caregivers about their potential danger for children.

Dominant mutations in MIEF1 affect mitochondrial dynamics and cause a singular late onset optic neuropathy

Inherited optic neuropathies are the most common mitochondrial diseases, leading to neurodegeneration involving the irreversible loss of retinal ganglion cells, optic nerve degeneration and central visual loss. Importantly, properly regulated mitochondrial dynamics are critical for maintaining cellular homeostasis, and are further regulated by MIEF1 (mitochondrial elongation factor 1) which encodes for MID51 (mitochondrial dynamics protein 51), an outer mitochondrial membrane protein that acts as an adaptor protein to regulate mitochondrial fission. However, dominant mutations in MIEF1 have not been previously linked to any human disease. Using targeted sequencing of genes involved in mitochondrial dynamics, we report the first heterozygous variants in MIEF1 linked to disease, which cause an unusual form of late-onset progressive optic neuropathy characterized by the initial loss of peripheral visual fields. Pathogenic MIEF1 variants linked to optic neuropathy do not disrupt MID51's localization to the outer mitochondrial membrane or its oligomerization, but rather, significantly disrupt mitochondrial network dynamics compared to wild-type MID51 in high spatial and temporal resolution confocal microscopy live imaging studies. Together, our study identifies dominant MIEF1 mutations as a cause for optic neuropathy and further highlights the important role of properly regulated mitochondrial dynamics in neurodegeneration.

Visual field loss and structure-function relationships in optic neuritis associated with myelin oligodendrocyte glycoprotein antibody

BACKGROUND

A paradoxical discrepancy between severe peripapillary retinal nerve fiber layer (pRNFL) atrophy and good visual outcome had been reported in patients with myelin oligodendrocyte glycoprotein-immunoglobulin G (MOG-IgG)-associated optic neuritis (ON). However, only visual acuity (VA) was assessed.

OBJECTIVES

To study visual field (VF) outcomes of patients with MOG-IgG-associated ON and evaluate the correlation between functional eye outcome and retinal structural changes assessed by optical coherence tomography.

METHODS

The records of 32 patients with MOG-IgG-associated ON who underwent ophthalmological examination at least 12 months after ON onset were reviewed. Degree of VF disability was determined by mean deviation (MD).

RESULTS

At final assessment (median, 35 months), 4.2% of 48 affected eyes (AE) had VA ⩽ 0.1, 40% had abnormal MD, and among AE with final VA ⩾ 1.0, 31% had mild to moderate damage. Thinning of the inner retinal layers was significantly correlated with MD impairment. Analysis demonstrated a threshold of pRNFL thickness (50 µm), below which MD was significantly worse (mean, -2.27 dB vs -17.72 dB; p = 0.0003). ON relapse was significantly associated with poor visual outcome assessed by MD.

CONCLUSION

Functional impairment measured with VF is not rare, and MD assessment better reflects actual structural damage.

Mutations in the m-AAA proteases AFG3L2 and SPG7 are causing isolated dominant optic atrophy

OBJECTIVE

To improve the genetic diagnosis of dominant optic atrophy (DOA), the most frequently inherited optic nerve disease, and infer genotype-phenotype correlations.

METHODS

Exonic sequences of 22 genes were screened by new-generation sequencing in patients with DOA who were investigated for ophthalmology, neurology, and brain MRI.

RESULTS

We identified 7 and 8 new heterozygous pathogenic variants in SPG7 and AFG3L2. Both genes encode for mitochondrial matricial AAA (m-AAA) proteases, initially involved in recessive hereditary spastic paraplegia type 7 (HSP7) and dominant spinocerebellar ataxia 28 (SCA28), respectively. Notably, variants in AFG3L2 that result in DOA are located in different domains to those reported in SCA28, which likely explains the lack of clinical overlap between these 2 phenotypic manifestations. In comparison, the SPG7 variants identified in DOA are interspersed among those responsible for HSP7 in which optic neuropathy has previously been reported.

CONCLUSIONS

Our results position SPG7 and AFG3L2 as candidate genes to be screened in DOA and indicate that regulation of mitochondrial protein homeostasis and maturation by m-AAA proteases are crucial for the maintenance of optic nerve physiology.

A new association: acute macular neuroretinopathy in acute optic neuritis

Background

Acute optic neuritis (AON) is a common optic nerve disease leading to retrograde degeneration of optic nerve axons, reflected by thinning of the inner retinal layers on optical coherence tomography. On the contrary, acute macular neuroretinopathy (AMN) type 2 is a rare outer retinal disorder that leads to thinning of the outer nuclear layers and is diagnosed by multimodal imaging. The aim of this study was to report a new association between these two diseases.

Methods

Patients with a first episode of optic neuritis were invited to participate in a study that involved optical coherence tomography evaluation at baseline and the following 1, 3, 6 and 12 months. All the study patients underwent ophthalmologic evaluation that comprised of visual acuity, visual field and multimodal imaging as well as orbital and brain Magnetic Resonance Imaging. A diagnosis of multiple sclerosis was made according to the 2010 McDonald criteria.

Results

Six of the 114 patients with acute optic neuritis also had acute macular neuroretinopathy, of whom three were positive for myelin oligodendrocyte glycoprotein antibodies (MOG‐Abs), two had relapsing–remitting multiple sclerosis and one had clinical isolated syndrome.

Conclusion

Our study suggests that it is imperative to check for associated AMN in cases of AON, especially those associated with MOG‐Abs.

[Raxone in the Leber optical neuropathy: Parisian experience]

INTRODUCTION

Leber's Hereditary Optic Neuropathy (LHON) causes a rapid and severe decrease in visual acuity. Raxone^® (Idebenone, Santhera) is the only drug to have a European Marketing Authorization for the treatment of this optic neuropathy. It can be proposed in the first months after the onset of this optic neuropathy, according to an international consensus meeting.

PATIENTS AND METHODS

Retrospective study of the efficacy of Raxone^® on the visual acuity of patients with genetically confirmed LHON who were followed in four Parisian hospitals. The primary endpoint is the best recovery of LogMar visual acuity between baseline and the end of follow-up. The secondary endpoints are the evolution of LogMar visual acuity of the best eye at baseline and change in LogMar visual acuity for each eye considered separately.

RESULTS

Seventeen patients, three women and 14 men, mean age 34.2 years, naive to treatment with Raxone^® were included in this study. The mean duration of treatment was 11.0±6.6 months. A mitochondrial DNA mutation was found in all patients. Only 2 had the 14484 mutation. A recovery of better LogMar visual acuity was found at the end of the treatment for 4 eyes (23.5 %), and a deterioration was observed for 8 (47.0 %). Only 2 eyes (11.7 %) with the best visual acuity at baseline improved. On the other hand, 17.6 % of the eyes considered separately had an improvement in their LogMar visual acuity at the end of the treatment.

CONCLUSION

The results confirm the trend of Raxone^® treatment to improve patients' visual acuity. Given the recommendations of a consensus conference, this treatment should be started early after the onset of LHON. It is therefore important to look for this diagnosis in the presence of any hereditary optic neuropathy, in order to be able to initiate this treatment.

A novel method of inducing endogenous pupil oscillations to detect patients with unilateral optic neuritis

Purpose

To use and test a new method of inducing endogenously generated pupillary oscillations (POs) in patients with unilateral optic neuritis (ON), to describe a signal analysis approach quantifying pupil activity and to evaluate the extent to which POs permit to discriminate patients from control participants.

Method

Pupil size was recorded with an eye-tracker and converted in real time to modulate the luminance of a stimulus (a 20° disk) presented in front of participants. With this biofeedback setting, an increasing pupil size transforms into a high luminance, entraining a pupil constriction that in turn decreases the stimulus luminance, and so on, resulting in endogenously generated POs. POs were recorded for 30 seconds in the affected eye, in the fellow eye and in binocular conditions with 22 patients having a history of unilateral ON within a period of 5 years, and with 22 control participants. Different signal analysis methods were used to quantify the power and frequency of POs.

Results

On average, pupil size oscillated at around 1 Hz. The amplitude of POs appears not to be a reliable marker of ON. In contrast, the frequency of POs was significantly lower, and was more variable over time, in the patients’ affected eye, as compared to their fellow eye and to the binocular condition. No such differences were found in control participants. Receiver operating characteristic analyses based on the frequency and the variability of POs to classify patients and control participants gave an area under the curve of 0.82, a sensitivity of 82% (95%CI: 60%-95%) and a specificity of 77% (95%CI: 55%-92%).

Conclusions

The new method used to induce POs allowed characterizing the visual afferent pathway defect in ON patients with encouraging accuracy. The method was fast, easy to use, only requiring that participants look ahead, and allows testing many stimulus parameters (e.g. color, stimulus location, size, etc).

Stress-induced flexibility and individuality in female and male zebra finch distance calls

Vocal recognition is central to the coordination and organization of behavior in pair-bonding species such as zebra finches. Zebra finches' vocalizations are individualized and support acoustic discrimination processes. Physiological states - such as the ones involved in emotional stress - can modify vocal production and consequently the structure of vocalizations. These modifications might signal the state of the caller but also impair individual recognition processes. This may represent a signaling trade-off, especially in contexts where both pieces of information can be critically important, for example when mates use calls to reunite after social isolation. Here we study the impact of a stress on the individual vocal signature in both female and male zebra finch distance calls. We built a manually curated database of distance calls of several individuals (both females and males) recorded in control and stress conditions. The stress was induced either by social isolation of the bird or using exogenous corticosterone. We developed a machine learning approach to assess the impact of stress on the individual characterization of calls. We show that while calls' spectral structure is significantly modified by stress, it still allows for the correct classification of calls to the caller. Moreover, we also show that the stress-induced modification of calls' structure is not a 'general feature signal' that can be detected as a 'stress' signal regardless of identity. Thus, female and male zebra finch calls' structure show stress-induced flexibility that stays within the range of individual vocal signatures.

Nerve excitability changes related to muscle weakness in chronic progressive external ophthalmoplegia

OBJECTIVE

To explore potential spreading to peripheral nerves of the mitochondrial dysfunction in chronic progressive external ophthalmoplegia (CPEO) by assessing axonal excitability.

METHODS

CPEO patients (n=13) with large size deletion of mitochondrial DNA and matching healthy controls (n=22) were included in a case-control study. Muscle strength was quantified using MRC sum-score and used to define two groups of patients: CPEO-weak and CPEO-normal (normal strength). Nerve excitability properties of median motor axons were assessed with the TROND protocol and changes interpreted with the aid of a model.

RESULTS

Alterations of nerve excitability strongly correlated with scores of muscle strength. CPEO-weak displayed abnormal nerve excitability compared to CPEO-normal and healthy controls, with increased superexcitability and responses to hyperpolarizing current. Modeling indicated that the CPEO-weak recordings were best explained by an increase in the 'Barrett-Barrett' conductance across the myelin sheath.

CONCLUSION

CPEO patients with skeletal weakness presented sub-clinical nerve excitability changes, which were not consistent with axonal membrane depolarization, but suggested Schwann cell involvement.

SIGNIFICANCE

This study provides new insights into the spreading of large size deletion of mitochondrial DNA to Schwann cells in CPEO patients.

Gut: An underestimated target organ for Aluminum

Since World War II, several factors such as an impressive industrial growth, an enhanced environmental bioavailability and intensified food consumption have contributed to a significant amplification of human exposure to aluminum. Aluminum is particularly present in food, beverages, some drugs and airbone dust. In our food, aluminum is superimposed via additives and cooking utensils. Therefore, the tolerable intake of aluminum is exceeded for a significant part of the world population, especially in children who are more vulnerable to toxic effects of pollutants than adults. Faced with this oral aluminum influx, intestinal tract is an essential barrier, especially as 38% of ingested aluminum accumulates at the intestinal mucosa. Although still poorly documented to date, the impact of oral exposure to aluminum in conditions relevant to real human exposure appears to be deleterious for gut homeostasis. Aluminum ingestion affects the regulation of the permeability, the microflora and the immune function of intestine. Nowadays, several arguments are consistent with an involvement of aluminum as an environmental risk factor for inflammatory bowel diseases.

Progressive Ataxia and Palatal Tremor: Think about POLG Mutations

Background

Progressive ataxia and palatal tremor (PAPT) can be observed in both acquired brainstem or cerebellar lesions and genetic disorders.

Phenomenology shown

PAPT due to mutation in POLG, the gene encoding the mitochondrial DNA polymerase.

Educational value

POLG mutation should be considered in patients with PAPT, particularly when additional clues such as a sensory neuronopathy or an ophthalmoplegia are present.

Open-angle glaucoma and paraoptic cyst: first description of a series of 11 patients

We report 11 patients who were referred to our institution for severe open-angle glaucoma who had a paraoptic cyst on MR imaging. All cysts were extraoptic and retrolaminar; most were deforming the adjacent optic nerve. Cysts had a high signal on T2 and FLAIR sequences, and a variable signal on T1 and variable echogenicity, suggesting different proteinaceous content. Arterial vascularization of the optic nerve was normal. Cyst volumes were inversely correlated with the severity of glaucoma on the same eye (P < .01-.05, Spearman correlation coefficient). We hypothesized that such cysts may reflect a valve mechanism, which would allow preservation of the translamina cribrosa pressure and thus could preserve visual function. The rarity of this association, together with the frequent mass effect of the cyst on the optic nerve, stresses the necessity of long-term follow-up in these patients.

Optic neuritis: from magnocellular to cognitive residual dysfunction

Optic Neuritis (ON) has been associated to both parvocellular dysfunction and to an alteration of the magnocellular pathway. After objective visual field and acuity recovery, ON patients may complain about their vision suggesting a residual subclinical deficit. To better characterize visual abnormalities, 8 patients recovering from a first ON episode as well as 16 healthy controls performed a simple detection task and a more complex categorization task of images presented in low spatial frequencies (to target the magnocellular system) or in high spatial frequencies (to target the parvocellular system) or of non-filtered images. When completing the tasks with their (previously) pathologic eye, optic neuritis patients showed lower accuracy compared to controls or to their healthy eye for low spatial frequency images only. Conjointly, the longest reaction times were observed with the previously pathologic eye regardless the type of images and to a greater extent in the categorization task than in the detection task. Such data suggest two distinct, although associated, types of residual dysfunction in ON: a magnocellular pathway alteration and a more general (magno and parvocellular) visual dysfunction that could implicate the cognitive levels of visual processing.

Optic neuritis revealing Kikuchi-Fujimoto disease

Kikuchi-Fujimoto disease is a rare systemic disease with uncommon neurological involvement. We report the case of a 30-year-old Asian woman who presented a rapidly progressive loss of vision. Magnetic resonance imaging (MRI) of the optic nerve revealed an inflammation of the left optic nerve with chiasmatic involvement, without any encephalic or medullar lesion. Thoracic computed tomography scan showed bilateral axillary lymphadenopathy. Analysis of a biopsy of the axillary lymph node showed typical histological findings of Kikuchi-Fujimoto disease. There was no clinical or biological sign of associated systemic lupus erythematosus. The patient spontaneously recovered normal visual acuity in 4 weeks, with resolution of MRI abnormalities. No optic neuritis relapse or neurological event occurred in a 3-year follow-up. To our knowledge this is the first case of optic neuritis associated with Kikuchi-Fujimoto disease.

Relapsing optic neuritis: a multicentre study of 62 patients

Background:

Optic neuritis (ON) may be the first symptom of a central nervous system demyelinating, systemic or infectious disease but few patients experience recurrent episodes and have a negative workup.

Objective:

This disorder, named relapsing optic neuritis (RON), is poorly described in the literature and still presents a particular challenge in diagnosis and management.

Methods:

We describe the clinical, laboratory, magnetic resonance imaging (MRI) and disability course of RON in a French cohort of 62 patients, based on a multicentre, retrospective, observational study.

Results:

In our cohort, we identified two distinct groups of RON patients. The first is characterised by relapsing inflammatory optic neuritis (RION, 68%), which is non-progressive, whereas the second presented as a chronic relapsing inflammatory optic neuritis (CRION, 32%), which is progressive. We have noted more cases with steroid dependence in the CRION group than the RION group (42% vs 10%). The long-term visual prognosis was more severe in CRION patients and neuromyelitis optica-immunoglobulin G (NMO-IgG)-positive patients.

Conclusion:

RON is likely a separate entity corresponding to an autoimmune disease that differs from multiple sclerosis (MS), NMO and vasculitis. We provide a new classification system based on a better understanding of RON which could allow an improved management by early treatment of poor prognosis forms.

Social experience affects neuronal responses to male calls in adult female zebra finches

Plasticity studies have consistently shown that behavioural relevance can change the neural representation of sounds in the auditory system, but what occurs in the context of natural acoustic communication where significance could be acquired through social interaction remains to be explored. The zebra finch, a highly social songbird species that forms lifelong pair bonds and uses a vocalization, the distance call, to identify its mate, offers an opportunity to address this issue. Here, we recorded spiking activity in females while presenting distance calls that differed in their degree of familiarity: calls produced by the mate, by a familiar male, or by an unfamiliar male. We focused on the caudomedial nidopallium (NCM), a secondary auditory forebrain region. Both the mate's call and the familiar call evoked responses that differed in magnitude from responses to the unfamiliar call. This distinction between responses was seen both in single unit recordings from anesthetized females and in multiunit recordings from awake freely moving females. In contrast, control females that had not heard them previously displayed responses of similar magnitudes to all three calls. In addition, more cells showed highly selective responses in mated than in control females, suggesting that experience-dependent plasticity in call-evoked responses resulted in enhanced discrimination of auditory stimuli. Our results as a whole demonstrate major changes in the representation of natural vocalizations in the NCM within the context of individual recognition. The functional properties of NCM neurons may thus change continuously to adapt to the social environment.