Objective To describe the incidence and types of adult-onset strabismus in a geographically defined population. Design Retrospectively reviewed population-based cohort. Participants All adult (≥19 years of age) residents of Olmsted County, Minnesota diagnosed with new-onset adult strabismus from January 1, 1985, through December 31, 2004. Methods The medical records of all potential cases identified by the resources of the Rochester Epidemiology Project were reviewed. Main Outcome Measures Incidence rates for adult-onset strabismus and its types. Results Seven hundred fifty-three cases of new-onset adult strabismus were identified during the twenty-year period, yielding an annual age- and gender-adjusted incidence rate of 54.1 cases (95% confidence interval 50.2–58.0) per 100,000 individuals ≥ 19 years of age. The four most common types of new-onset strabismus were paralytic (44.2% of cases), convergence insufficiency (15.7%), small angle hypertropia (13.3%), and divergence insufficiency (10.6%). The incidence of adult-onset strabismus overall and its four most common forms significantly increased with age (p<0.001 for all), with a peak incidence in the eighth decade of life. The lifetime risk of being diagnosed with adult-onset strabismus was 4.0% in females and 3.9% in males. Conclusions Paralytic strabismus was the most common subtype of new-onset adult strabismus in this population-based cohort. All of the most common forms of adult-onset strabismus increased with age, especially after the sixth decade of life. Further characterization of strabismus types found in this study is warranted to better define this common disorder.

Introduction A calpain-3 (CAPN3) gene heterozygous deletion (c.643_663del21) was recently linked to autosomal dominant (AD) limb-girdle muscular dystrophy. However, the possibility of digenic disease was raised. We describe 3 families with AD calpainopathy carrying this isolated mutation. Methods Probands heterozygous for CAPN3 c.643_663del21 were identified by targeted next generation or whole exome sequencing. Clinical findings were collected for probands and families. Calpain-3 muscle Western blots were performed in 3 unrelated individuals. Results Probands reported variable weakness in their 40s or 50s, with myalgia, back pain, or hyperlordosis. Pelvic girdle muscles were affected with adductor and hamstring sparing. Creatine kinase was normal to 1,800 U/L, independent of weakness severity. Imaging demonstrated lumbar paraspinal muscle atrophy. Electromyographic findings and muscle biopsies were normal to mildly myopathic. Muscle calpain-3 expression was reduced. Discussion This study provides further evidence for AD calpainopathy associated with CAPN3 c.643_663del21. No pathogenic variants in other genes known to cause myopathy were detected.

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PurposeRNA toxicity from CTG trinucleotide repeat (TNR) expansion within noncoding DNA of the transcription factor 4 (TCF4) and DM1 protein kinase (DMPK) genes has been described in Fuchs' endothelial corneal dystrophy (FECD) and myotonic dystrophy, type 1 (DM1), respectively. We prospectively evaluated DM1 patients and their families for phenotypic FECD and report the analysis of CTG expansion in the TCF4 gene and DMPK expression in corneal endothelium.MethodsFECD grade was evaluated by slit lamp biomicroscopy in 26 participants from 14 families with DM1. CTG TNR length in TCF4 and DMPK was determined by a combination of Gene Scan and Southern blotting of peripheral blood leukocyte DNA.ResultsFECD grade was 2 or higher in 5 (36%) of 14 probands, significantly greater than the general population (5%) (P < 0.001). FECD segregated with DM1; six of eight members of the largest family had both FECD and DM1, while the other two family members had neither disease. All DNA samples from 24 subjects, including four FECD-affected probands, were bi-allelic for nonexpanded TNR length in TCF4 (<40 repeats). Considering a 75% prevalence of TCF4 TNR expansion in FECD, the probability of four FECD probands lacking TNR expansion was 0.4%. Neither severity of DM1 nor DMPK TNR length predicted the presence of FECD in DM1 patients.ConclusionsFECD was common in DM1 families, and the diseases cosegregated. TCF4 TNR expansion was lacking in DM1 families. These findings support a hypothesis that DMPK TNR expansion contributes to clinical FECD.

It is imperative in the corona virus disease 2019 (COVID-19) pandemic that we serve our patients by implementing teleneurology visits for those who require neurologic advice but do not need to be seen face-to-face. The authors propose a thorough, practical, in-home, teleneurologic examination that can be completed without the assistance of an on-the-scene medical professional, and can be tailored to the clinical question. We hope to assist trainees and practicing neurologists doing patient video visits for the first time during the COVID-19 pandemic, focusing on what can, rather than what cannot, be easily examined.