Eggenberger, Eric

AbstractThe evaluation of the dizzy patient is complicated by many common pitfalls. The patient's description of symptoms and the standard neurologic examination are often nonspecific or unrevealing, and neuroimaging is most often normal. Over the past several years, research has demonstrated that a refocusing of history taking results in more reliable and diagnostically helpful information. This can guide a targeted expansion of the exam, often with an emphasis on eye movements.

Introduction: Retinal microvascular abnormalities have been associated with stroke, but their association with dementia and death is less well described. We tested the hypothesis that retinopathy is associated with stroke, dementia, and age-adjusted mortality. Methods: Data were obtained from the US National Health and Nutrition Examination Surveys from 2005 to 2008, with linked mortality through 2015. Severity of retinopathy was defined as no retinopathy, mild nonproliferative retinopathy (NPR), moderate-severe NPR, and proliferative retinopathy. Logistic regression models were performed to evaluate the relationships between retinopathy, stroke, and dementia, respectively. Independent relationships between retinopathy and all-cause mortality were assessed using Cox regression models, before and after adjusting for covariates. All analyses were adjusted for the complex survey design. Results: Of 5,543 participants aged ≥18 years with gradable retinal imaging, 696 had retinopathy, 289 had stroke, and 597 had dementia. Mean age of subjects was 56.3 ± 11.7 years. Retinopathy was associated with higher risk of stroke (adj OR 2.39, P <0.001) and dementia (adj OR 1.68, P =0.005). Over a median duration of 118 months (IQR 111-125), there was a dose-dependent relationship between severity of retinopathy and all-cause mortality (adjusted hazard ratios were 1.0, 1.5, 2.4, 3.4 across retinopathy severity; P =0.021). The Figure shows the age-adjusted cumulative mortality curves by retinopathy severity. Conclusions: Participants with retinopathy have a greater than 2-fold increase in stroke risk and a 1.7-fold increase in dementia risk. Having more severe retinopathy confers a higher risk of death after adjusting for age and vascular risk factors. The retina may serve as a tissue biomarker in intervention trials for cerebrovascular and neurodegenerative diseases.

Fatal familial insomnia (FFI) is a rare inherited prion disease characterized by sleep, autonomic, and motor disturbances. Neuro‐ophthalmological abnormalities have been reported at the onset of disease, although not further characterized. We analyzed video recordings of eye movements of 6 patients with FFI from 3 unrelated kindreds, seen within 6 months from the onset of illness. Excessive saccadic intrusions were the most prominent findings. In patients with severe insomnia, striking saccadic intrusions are an early diagnostic clue for FFI. The fact that the thalamus is the first structure affected in FFI also suggests its role in the control of steady fixation. ANN NEUROL 2021;89:823–827

PolyQ ATXN3 is a pharmacodynamic marker for SCA3, and a SNP associated with the expanded allele may serve to specifically target mutant ATXN3 .