Retinal arterial but not venous tortuosity correlates with facioscapulohumeral muscular dystrophy severity

Gastrointestinal and genitourinary symptoms in facioscapulohumeral muscular dystrophy: Prevalence and impact

INTRODUCTION/AIMS

Anecdotally, patients with facioscapulohumeral muscular dystrophy (FSHD) describe gastrointestinal (GI) and genitourinary (GU) symptoms. We explored the prevalence of GI and GU symptoms and their impact on quality of life (QOL) in people with FSHD compared to healthy household controls.

METHODS

In this descriptive, cross-sectional study, we emailed a survey exploring GI and GU symptoms to all FSHD Society patient contacts (n = 3507). We invited those with FSHD and unaffected household controls to respond. Non-parametric statistics were used to compare symptom frequency and impact of symptoms between respondents with FSHD and household controls. Within the FSHD group, symptom frequency was assessed relative to measures of disease progression (need for ambulatory or respiratory support).

RESULTS

Surveys from 701 respondents (652 with FSHD) ≥18 years old were included in analysis. Those with FSHD had symptoms affecting both GI and GU systems more frequently than controls using ordinal rating of symptom frequency. Within the FSHD group, more advanced disease was associated with increased symptom frequency. QOL was negatively impacted by the GI and GU symptoms. There was no difference between groups in use of medications to treat these symptoms.

DISCUSSION

Recognition and treatment of GI and GU symptoms in people with FSHD, particularly those with more advanced disease, could improve QOL. Additional investigation is required to confirm these findings and understand the physiology.

Artificial Intelligence for Evaluation of Retinal Vasculopathy in Facioscapulohumeral Dystrophy Using OCT Angiography: A Case Series

Facioscapulohumeral muscular dystrophy (FSHD) is a slowly progressive muscular dystrophy with a wide range of manifestations including retinal vasculopathy. This study aimed to analyse retinal vascular involvement in FSHD patients using fundus photographs and optical coherence tomography-angiography (OCT-A) scans, evaluated through artificial intelligence (AI). Thirty-three patients with a diagnosis of FSHD (mean age 50.4 ± 17.4 years) were retrospectively evaluated and neurological and ophthalmological data were collected. Increased tortuosity of the retinal arteries was qualitatively observed in 77% of the included eyes. The tortuosity index (TI), vessel density (VD), and foveal avascular zone (FAZ) area were calculated by processing OCT-A images through AI. The TI of the superficial capillary plexus (SCP) was increased (p < 0.001), while the TI of the deep capillary plexus (DCP) was decreased in FSHD patients in comparison to controls (p = 0.05). VD scores for both the SCP and the DCP results increased in FSHD patients (p = 0.0001 and p = 0.0004, respectively). With increasing age, VD and the total number of vascular branches showed a decrease (p = 0.008 and p < 0.001, respectively) in the SCP. A moderate correlation between VD and EcoRI fragment length was identified as well (r = 0.35, p = 0.048). For the DCP, a decreased FAZ area was found in FSHD patients in comparison to controls (t (53) = -6.89, p = 0.01). A better understanding of retinal vasculopathy through OCT-A can support some hypotheses on the disease pathogenesis and provide quantitative parameters potentially useful as disease biomarkers. In addition, our study validated the application of a complex toolchain of AI using both ImageJ and Matlab to OCT-A angiograms.

A pediatric case report and literature review of facioscapulohumeral muscular dystrophy type1

RATIONALE

Early-onset facioscapulohumeral muscular dystrophy (FSHD) is defined as facial weakness before the age of 5 and shoulder weakness before the age of 10. Early-onset facioscapulohumeral muscular dystrophy is relatively rare in the clinic. This onset is relatively early, the symptoms are serious, and it is likely to be accompanied by retinal vascular disease, sensorineural deafness, epilepsy and other extramuscular multisystem diseases. We report the clinical characteristics of 2 patients with early-onset facial and shoulder brachial muscular dystrophy to improve clinicians' understanding of this particular condition.

PATIENT CONCERNS

We report 2 pediatric patients with FSHD type 1. Patient 1 is an 11-year-old boy with reduced facial expression for 9 years and proximal muscle weakness for 6 years. Patient 2 is a 4-year and 6-month-old girl with developmental delay for 3 years and facial weakness for 1 year.

DIAGNOSIS

According to the clinical manifestations and molecular genetic testing (such as Southern blot analysis), the patients were diagnosed with early-onset FSHD1.

INTERVENTIONS

The patients received cocktail therapy (vitamin B1 tablets, vitamin B2 tablets, vitamin B6 tablets, vitamin C tablets, vitamin E tablets, idebenone tablets, etc.) to improve their muscle metabolism.

OUTCOMES

Both patients' condition did not improve after being given cocktail treatment. According to a recent follow-up, the symptoms of facial weakness and proximal muscle weakness were aggravated.

LESSONS

Early-onset FSHD presents early and has frequent systemic features, and it is a severe subtype of FSHD. Early identification and genetic diagnosis should be performed to improve patient prognosis.

Evaluation of Macular Retinal Vessels and Histological Changes in Two Cases of COVID-19

The purpose of this study was to assess vascular and histological alterations in two COVID-19 and three control post-mortem retinas. The macular areas of flat-mounted samples were processed for immunofluorescence. Lectin and collagen IV positive vessels were captured under confocal microscopy, and endothelium loss and tortuosity were analyzed. Expression of ACE2 (angiotensin-converting enzyme 2) (the receptor for SARS-CoV-2), Iba1 (ionized calcium-binding adaptor molecule 1) and GFAP (glial fibrillary acidic protein) were quantified in retinal sections. The number of lectin vessels in COVID-19 retinas decreased by 27% compared to the control (p < 0.01) and the tortuosity increased in COVID-19 retinas (7.3 ± 0.2) vs. control retinas (6.8 ± 0.07) (p < 0.05). Immunofluorescence analysis revealed an increase in ACE2 (2.3 ± 1.3 vs. 1.0 ± 0.1; p < 0.0001) and Iba1 expression (3.06 ± 0.6 vs. 1.0 ± 0.1; p < 0.01) in COVID-19 sections whereas no changes in GFAP were observed. Analysis of the COVID-19 macular retinal tissue suggested that endothelial cells are a preferential target of SARS-CoV-2 with subsequent changes through their ACE2 receptor expression and morphology. Thus, microglial activation was hyperactive when facing an ensuing immunological challenge after SARS-CoV-2 infection.

DUX4 expressing immortalized FSHD lymphoblastoid cells express genes elevated in FSHD muscle biopsies, correlating with the early stages of inflammation

Facioscapulohumeral muscular dystrophy (FSHD) is an incurable disorder linked to ectopic expression of DUX4. However, DUX4 is notoriously difficult to detect in FSHD muscle cells, while DUX4 target gene expression is an inconsistent biomarker for FSHD skeletal muscle biopsies, displaying efficacy only on pathologically inflamed samples. Immune gene misregulation occurs in FSHD muscle, with DUX4 target genes enriched for those associated with inflammatory processes. However, there lacks an assessment of the FSHD immune cell transcriptome, and its contribution to gene expression in FSHD muscle biopsies. Here, we show that EBV-immortalized FSHD lymphoblastoid cell lines express DUX4 and both early and late DUX4 target genes. Moreover, a biomarker of 237 up-regulated genes derived from FSHD lymphoblastoid cell lines is elevated in FSHD muscle biopsies compared to controls. The FSHD Lymphoblast score is unaltered between FSHD myoblasts/myotubes and their controls however, implying a non-myogenic cell source in muscle biopsies. Indeed, the FSHD Lymphoblast score correlates with the early stages of muscle inflammation identified by histological analysis on muscle biopsies, while our two late DUX4 target gene expression biomarkers associate with macroscopic inflammation detectable via MRI. Thus, FSHD lymphoblastoid cell lines express DUX4 and early and late DUX4 target genes, therefore, muscle-infiltrated immune cells may contribute the molecular landscape of FSHD muscle biopsies.

Differentiation of Brain Tumor Microvasculature From Normal Vessels Using Optical Coherence Angiography

BACKGROUND AND OBJECTIVES

Despite rapid advances and discoveries in medical imaging, monitoring therapeutic efficacy for malignant gliomas and monitoring tumor vasculature remains problematic. The purpose of this study is to utilize optical coherence angiography for vasculature characterization inside and surrounding brain tumors in a murine xenograft brain tumor model. Features included in our analysis include fractional blood volume, vessel tortuosity, diameter, orientation, and directionality.

STUDY DESIGN/MATERIALS AND METHODS

In this study, five tumorous mice models at 4 weeks of age were imaged. Human glioblastoma cells were injected into the brain and allowed to grow for 4 weeks and then imaged using optical coherence tomography.

RESULTS

Results suggest that blood vessels outside the tumor contain a greater fractional blood volume as compared with vessels inside the tumor. Vessels inside the tumor are more tortuous as compared with those outside the tumor. Results indicate that vessels near the tumor margin are directed inward towards the tumor while normal vessels show a more random orientation.

CONCLUSION

Quantification of vascular microenvironments in brain gliomas can provide functional vascular parameters to aid various diagnostic and therapeutic studies. © 2021 Wiley Periodicals LLC.

Relationship between retinal vessel tortuosity and oxygenation in sickle cell retinopathy

Background

Reduced retinal vascular oxygen (O₂) content causes tissue hypoxia and may lead to development of vision-threatening pathologies. Since increased vessel tortuosity is an early sign for some hypoxia-implicated retinopathies, we investigated a relationship between retinal vascular O₂ content and vessel tortuosity indices.

Methods

Dual wavelength retinal oximetry using a commercially available scanning laser ophthalmoscope was performed in both eyes of 12 healthy (NC) and 12 sickle cell retinopathy (SCR) subjects. Images were analyzed to quantify retinal arterial and venous O₂ content and determine vessel tortuosity index (VTI) and vessel inflection index (VII) in circumpapillary regions. Linear mixed model analysis was used to determine the effect of disease on vascular O₂ content, VTI and VII, and relate vascular O₂ content with VTI and VII. Models accounted for vessel type, fellow eyes, age and mean arterial pressure.

Results

Retinal arterial and venous O₂ content were lower in SCR (O_2A = 11 ± 4 mLO₂/dL, O_2V = 7 ± 2 mLO₂/dL) compared to NC (O_2A = 18 ± 3 mLO₂/dL, O_2V = 13 ± 3 mLO₂/dL) subjects (p < 0.001). As expected, O₂ content was higher in arteries (15 ± 5 mLO₂/dL) than veins (10 ± 4 mLO₂/dL) (p < 0.001), but not different between eyes (OD: 12 ± 5 mLO₂/dL; OS:13 ± 5 mLO₂/dL) (p = 0.3). VTI was not significantly different between SCR (0.18 ± 0.07) and NC (0.15 ± 0.04) subjects, or between arteries (0.18 ± 0.07) and veins (0.16 ± 0.04), or between eyes (OD: 0.18 ± 0.07, OS:0.17 ± 0.05) (p ≥ 0.06). VII was significantly higher in SCR (10 ± 2) compared to NC subjects (8 ± 1) (p = 0.003). VII was also higher in veins (9 ± 2) compared to arteries (8 ± 5) (p = 0.04), but not different between eyes (OD: 9 ± 2; OS: 9 ± 2) (p = 0.2). There was an inverse linear relationship between vascular O₂ (13 ± 5 mLO₂/dL) content and VII (9 ± 2) (β = -0.5; p = 0.02).

Conclusions

The findings augment knowledge of relationship between retinal vascular oxygenation and morphological changes and potentially contribute to identifying biomarkers for assessment of retinal hypoxia due to SCR and other retinopathies.

Vascular retinal biomarkers improves the detection of the likely cerebral amyloid status from hyperspectral retinal images

Introduction

This study investigates the relationship between retinal image features and β-amyloid (Aβ) burden in the brain with the aim of developing a noninvasive method to predict the deposition of Aβ in the brain of patients with Alzheimer's disease.

Methods

Retinal images from 20 cognitively impaired and 26 cognitively unimpaired cases were acquired (3 images per subject) using a hyperspectral retinal camera. The cerebral amyloid status was determined from binary reads by a panel of 3 expert raters on ¹⁸F-florbetaben positron-emission tomography (PET) studies. Image features from the hyperspectral retinal images were calculated, including vessels tortuosity and diameter and spatial-spectral texture measures in different retinal anatomical regions.

Results

Retinal venules of amyloid-positive subjects (Aβ+) showed a higher mean tortuosity compared with the amyloid-negative (Aβ−) subjects. Arteriolar diameter of Aβ+ subjects was found to be higher than the Aβ− subjects in a zone adjacent to the optical nerve head. Furthermore, a significant difference between texture measures built over retinal arterioles and their adjacent regions were observed in Aβ+ subjects when compared with the Aβ−. A classifier was trained to automatically discriminate subjects combining the extracted features. The classifier could discern Aβ+ subjects from Aβ− subjects with an accuracy of 85%.

Discussion

Significant differences in texture measures were observed in the spectral range 450 to 550 nm which is known as the spectral region known to be affected by scattering from amyloid aggregates in the retina. This study suggests that the inclusion of metrics related to the retinal vasculature and tissue-related textures extracted from vessels and surrounding regions could improve the discrimination performance of the cerebral amyloid status.

Ophthalmological findings in facioscapulohumeral dystrophy

Ophthalmological abnormalities in facioscapulohumeral dystrophy may lead to treatable vision loss, facilitate diagnostics, could help unravelling the pathophysiology and serve as biomarkers. In this study, we provide a detailed description of the ophthalmological findings in a well-defined cohort of patients with facioscapulohumeral dystrophy using state of the art retina imaging techniques. Thirty-three genetically confirmed patients (aged 7-80 years) and 24 unrelated healthy controls (aged 6-68 years) underwent clinical ophthalmological examination, fundus photography, optical coherence tomography/angiography, genotyping and neurological examination. All patients had normal corrected visual acuity and normal intraocular pressure. In 27 of the 33 patients, weakness of the orbicularis oculi was observed. Central retinal pathology, only seen in patients and not in healthy controls, included twisting (tortuosity) of the retinal arteries in 25 of the 33 patients and retinal pigment epithelium defects in 4 of the 33 patients. Asymmetrical foveal hypoplasia was present in three patients, and exudative abnormalities were observed in one patient. There was a correlation between the severity of retinal tortuosity and the D4Z4 repeat array size (R 2 = 0.44, P < 0.005). Follow-up examination in a subgroup of six patients did not show any changes after 2 years. To conclude, retinal abnormalities were frequent but almost always subclinical in patients with facioscapulohumeral dystrophy and consisted primarily of arterial tortuosity and foveal abnormalities. Retinal tortuosity was seen in the retinal arterioles and correlated with the D4Z4 repeat array size, thereby providing clinical evidence for an underlying genetic linkage between the retina and facioscapulohumeral dystrophy.

The boy who lost his smile: facioscapulohumeral dystrophy in the head and neck

BACKGROUND

Facioscapulohumeral dystrophy is the third most common muscular dystrophy and the one most likely to present primarily in the head and neck.

METHODS

In this report, we present a case of a young child with subtle progressive bilateral facial weakness whose workup ultimately led to this diagnosis. Paralysis in this disorder is secondary to worsening muscle atrophy, which typically progresses in a cephalad to caudad direction. Despite facial paralysis being a key and early component of this illness, no prior descriptions in the otolaryngology literature exist.

DISCUSSION

The case described is unusual in that the patient initially presented to a community otolaryngologist. In addition to workup, the disease characteristics, head and neck manifestations, and prognosis are discussed.

Infantile facioscapulohumeral muscular dystrophy revisited: Expansion of clinical phenotypes in patients with a very short EcoRI fragment

Contrary to the classical form, infantile facioscapulohumeral muscular dystrophy (FSHD) usually denotes a severe phenotype and is frequently associated with extramuscular involvements. To elucidate the genotype-phenotype correlation in this severe subgroup, we identified a cohort of nine patients with infantile FSHD who also carried a very short (10-13kb) EcoRI fragment. Their current age ranged from 8 to 33 years and age of onset ranged from 0.4 to 5 years. One patient even manifested his first FSHD-related symptoms at as early as 5 months of age, including inability to smile, poor response to call, and infantile spasms. To date, four patients were wheelchair-bound and six patients had asymmetric weakness. Sensorineural hearing loss and abnormal fundoscopic findings were observed in eight and all of patients respectively. Three with the smallest EcoRI fragments (10-11kb, with normal length being 50-300kb) had mental retardation. Two of these had epilepsy. Cardiac arrhythmias were found in five patients. Restrictive ventilatory defects were observed in seven patients, with one progressing to chronic respiratory failure. Two had swallowing difficulties; one of these required gastrostomy. We identified several rarely reported phenotypes in infantile FSHD, including cardiac arrhythmia, respiratory insufficiency, and swallowing difficulties. There seems to be a correlation between the severity of phenotype and the very short EcoRI fragment in the chromosome 4q35 region. We conclude that the high frequency of multi-organ involvements in this severe FSHD variant suggests the need for an early and multidisciplinary intervention.

Retinal vessel tortuosity measures and their applications

Structural retinal vascular characteristics, such as vessel calibers, tortuosity and bifurcation angles are increasingly quantified in an objective manner, slowly replacing subjective qualitative disease classification schemes. This paper provides an overview of the current methodologies and calculations used to compute retinal vessel tortuosity. We set out the different parameter calculations and provide an insight into the clinical applications, while critically reviewing its pitfalls and shortcomings.