A unique retinal epitheliopathy is associated with amyotrophic lateral sclerosis/Parkinsonism‐Dementia complex of Guam

Abstract Background The aim of this work was to examine whether a linear retinal pigment epitheliopathy is associated with the amyotrophic lateral sclerosis/parkinsonism‐dementia complex of Guam. Methods A total of 918 Guamanian Chamorros, with and without amyotrophic lateral sclerosis/parkinsonism‐dementia complex, were examined cross‐sectionally for linear retinal pigment epitheliopathy (LRPE). Overall, 239 Guamanians, who were neurologically asymptomatic, were followed for up to 20 years to determine the risk of developing amyotrophic lateral sclerosis/parkinsonism‐dementia complex. Results The epitheliopathy was present in 59.7% (117 of 196) patients with amyotrophic lateral sclerosis/parkinsonism‐dementia complex, but in only 24.7% (178 of 722) of subjects who were neurologically asymptomatic (age‐ and sex‐adjusted risk difference: 35.0%; 95% confidence interval [CI]: 27.5‐42.6; p < 0.0001). Prospectively, 15 of 50 cases with epitheliopathy developed amyotrophic lateral sclerosis/parkinsonism‐dementia complex, compared to 4 of 189 cases without epitheliopathy (age‐ and sex‐adjusted hazard ratio: 13.1; 95% CI: 4.0‐43.1; P < 0.0001). Conclusion Amyotrophic lateral sclerosis/parkinsonism‐dementia complex is associated with an LRPE and predicts future neurological disease. Identifying the cause of this retinopathy could provide an understanding about the pathogenesis of amyotrophic lateral sclerosis/parkinsonism‐dementia complex and related diseases. © 2015 International Parkinson and Movement Disorder Society