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.
To report the use of Spectralis High Magnification Module (HMM) as part of multimodal imaging in Multiple Evanescent White Dot Syndrome (MEWDS).
HMM imaging showed a blurry mosaic pattern ...corresponding to MEWDS-related photoreceptors’ lesions. These abnormalities remained detectable at later stages of the disease while other imaging modalities were negative.
HMM can be a useful technique to monitor the structure of the outer retina during the different stages of MEWDS.
We show that the topes of a complex of oriented matroids (abbreviated COM) of VC-dimension d admit a proper labeled sample compression scheme of size d. This considerably extends results of Moran and ...Warmuth on ample classes, of Ben-David and Litman on affine arrangements of hyperplanes, and of the authors on complexes of uniform oriented matroids, and is a step towards the sample compression conjecture – one of the oldest open problems in computational learning theory. On the one hand, our approach exploits the rich combinatorial cell structure of COMs via oriented matroid theory. On the other hand, viewing tope graphs of COMs as partial cubes creates a fruitful link to metric graph theory.
Nyldon words Charlier, Émilie; Philibert, Manon; Stipulanti, Manon
Journal of combinatorial theory. Series A,
10/2019, Letnik:
167
Journal Article, Web Resource
Recenzirano
Odprti dostop
The Chen-Fox-Lyndon theorem states that every finite word over a fixed alphabet can be uniquely factorized as a lexicographically nonincreasing sequence of Lyndon words. This theorem can be used to ...define the family of Lyndon words in a recursive way. If the lexicographic order is reversed in this definition, we obtain a new family of words, which are called the Nyldon words. In this paper, we show that every finite word can be uniquely factorized into a lexicographically nondecreasing sequence of Nyldon words. Otherwise stated, Nyldon words form a complete factorization of the free monoid with respect to the decreasing lexicographic order. Then we investigate this new family of words. In particular, we show that Nyldon words form a right Lazard set.
Giant cell arteritis (GCA) is a large vessel vasculitis associated with a risk of permanent ophthalmologic complications. Data about diplopia prognosis in GCA are scarce. This study was designed to ...better characterize diplopia in newly diagnosed GCA patients.
All consecutive patients diagnosed with GCA from January 2015 to April 2021 in a French tertiary ophthalmologic center were retrospectively reviewed. GCA diagnosis relied on a positive temporal artery biopsy or high-definition MRI.
Among 111 patients diagnosed with GCA, 30 patients (27%) had diplopia. Characteristics of patients with diplopia were similar to other GCA patients. Diplopia resolved spontaneously in 6 patients (20%). Diplopia was attributed to cranial nerve palsy in 21/24 patients (88%), especially third (46%) and sixth cranial nerve (42%). Ocular ischemic lesions occurred in 11 of the 30 patients with diplopia (37%); 2 patients developed vision loss after initiation of corticosteroids. In the remaining 13 patients, diplopia resolved after treatment onset in 12 patients (92%) with a median delay of 10 days. Patients treated intravenously tended to have a quicker improvement than those treated orally, but with a similar resolution rate of diplopia at 1 month. Two patients had relapse of diplopia at 4 and 6 weeks after an initial treatment course of 24 and 18 months, respectively.
Diplopia is a rare feature at GCA diagnosis, but should raise clinician suspicion for GCA when associated with cephalic symptoms and prompt the initiation of corticosteroids to prevent ocular ischemic complications.
We investigate the structure of two-dimensional partial cubes, i.e., of isometric subgraphs of hypercubes whose vertex set defines a set family of VC-dimension at most 2. Equivalently, those are the ...partial cubes which are not contractible to the 3-cube $Q_3$ (here contraction means contracting the edges corresponding to the same coordinate of the hypercube). We show that our graphs can be obtained from two types of combinatorial cells (gated cycles and gated full subdivisions of complete graphs) via amalgams. The cell structure of two-dimensional partial cubes enables us to establish a variety of results. In particular, we prove that all partial cubes of VC-dimension 2 can be extended to ample aka lopsided partial cubes of VC-dimension 2, yielding that the set families defined by such graphs satisfy the sample compression conjecture by Littlestone and Warmuth (1986) in a strong sense. The latter is a central conjecture of the area of computational machine learning, that is far from being solved even for general set systems of VC-dimension 2. Moreover, we point out relations to tope graphs of COMs of low rank and region graphs of pseudoline arrangements.
Abstract Objective To determine whether motor unit number index (MUNIX) is pertinent to monitor the effect of intravenous immunoglobulins (IVIg) in multifocal motor neuropathy (MMN). Methods MUNIX ...was assessed longitudinally in 7 MMN patients and 17 healthy controls in the abductor pollicis brevis (APB) and abductor digiti minimi (ADM) muscles. A MUNIX sum-score and a compound muscle action potential (CMAP) sum-score were calculated by summing up the scores of APB and ADM. MMN patients were evaluated on the first day of IVIg infusion, 5 MMN patients were evaluated 22 days after IVIg infusion, and 3 MMN patients were evaluated 1 month after two IVIg infusions. Results Intraclass correlation coefficient of the MUNIX sum-score in healthy controls was 0.85, showing good test–retest reproducibility. MUNIX and CMAP sum-scores were lower in MMN patients than in healthy controls (p < 0.01 and 0.02, respectively). MUNIX sum-score improved in three of the five patients 22 days after IVIg infusion and in two of the three patients 1 month after 2 IVIg infusions, whereas CMAP sum-score improved in only one patient in both evaluations. Conclusions In this preliminary study, MUNIX seems to be a reliable and sensitive tool to monitor the short-term efficiency of IVIg in MMN. Significance MUNIX can help monitor IVIg treatment in MMN.
To report the occurrence of paracentral acute middle maculopathy (PAMM) in giant cell arteritis (GCA), describe its features and outcomes, and identify risk factors associated with PAMM in patients ...with GCA.
Review of medical records of patients with GCA who were examined in the Rothschild Foundation Hospital. Patients were divided into three groups: GCA with PAMM (Group 1), GCA with ophthalmic involvement but without PAMM (Group 2), and GCA without ophthalmic involvement (Group 3). We analyzed the data for age, sex, medical history, laboratory testing, visual acuity, and posterior segment vascular involvement.
Among the 96 patients who met the inclusion criteria, 52 had ophthalmic involvement, and 16 patients were included in Group 1 (GCA with PAMM). In this subgroup, the mean age was 81.6 years and was found to be older than other groups. The visual prognosis was similar between Groups 1 and 2. Of the 20 eyes with PAMM, 35% were also associated with homolateral anterior ischemic optic neuropathy. No statistical difference was found in initial symptoms, signs, and laboratory testing.
Paracentral acute middle maculopathy is frequently observed lesions in ocular GCA. Patients can present with isolated findings of PAMM as the only indication of GCA. Optical coherence tomography of the macula should be routinely performed in patients with suspected GCA, specifically if they complain of visual changes, to look for signs of ischemia in the middle layers of the retina. Isolated PAMM should raise suspicion for GCA in patients at risk.
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