Faculty Bibliography

OBJECTIVE:Investigations have found associations of homonymous thinning of the macular ganglion cell/ inner-plexiform layer (GCIPL) with demyelinating lesions in the post-chiasmal visual pathway among patients with multiple sclerosis (MS). Retinal thinning may also occur through retrograde trans-synaptic degeneration, a process by which lesions in post-geniculate visual pathway structures lead to thinning of the GCIPL across thalamic synapses. The purpose of our study was to determine the frequency of homonymous hemimacular thinning that occurs in association with post-chiasmal visual pathway demyelinating lesions in patients with MS and other demyelinating diseases. METHODS:Adult patients with demyelinating diseases (MS, neuromyelitis optica spectrum disorder [NMOSD], myelin oligodendrocyte glycoprotein antibody disease (anti-MOG)) who were participants in an ongoing observational study of visual pathway structure and function were analyzed for the presence of hemimacular GCIPL thinning on OCT scans. Brain MRI scans were examined for the presence of post-geniculate visual pathway demyelinating lesions. RESULTS:Among 135 participants in the visual pathway study, 5 patients (3.7%) had homonymous hemimacular GCIPL thinning. Eleven patients (8.1%) had a whole+half pattern of GCIPL thinning, characterized by hemimacular thinning in one eye and circumferential macular thinning in the contralateral eye. All but one patient with homonymous hemimacular thinning had demyelinating lesions in the post-geniculate visual pathway; however, these lesions were located in both cerebral hemispheres. CONCLUSION/CONCLUSIONS:Homonymous hemimacular thinning in the GCIPL by OCT is associated with post-chiasmal visual pathway demyelinating lesions but it appears to be a relatively uncommon contributor to GCIPL loss. Patients with this pattern of GCIPL often fail to complain of hemifield visual loss. Future studies with prospective and detailed MR imaging may be able to more closely associate demyelinating lesions in anatomically appropriate regions of the post-chiasmal visual pathways with homonymous hemimacular thinning.

OBJECTIVE:Tests of rapid automatized naming (RAN) have been used for decades to evaluate neurological conditions. RAN tests require extensive brain pathways involving visual perception, memory, eye movements and language. To the extent that different naming tasks capture varied visual pathways and related networks, we developed the Staggered Uneven Number (SUN) test of rapid number naming to complement existing RAN tests, such as the Mobile Universal Lexicon Evaluation System (MULES). The purpose of this investigation was to determine values for time scores for SUN, and to compare test characteristics between SUN and MULES. METHODS:We administered the SUN and MULES tests to healthy adult volunteers in a research office setting. MULES consists of 54 color photographs; the SUN includes 145 single- and multi-digit numbers. Participants are asked to name each number or picture aloud. RESULTS: = 0.43, P = .001). Learning effects between first and second trials were greater for the MULES; participants improved (reduced) their time scores between trials by 5% on SUN and 16% for MULES (P < .0001, Wilcoxon signed-rank test). CONCLUSION/CONCLUSIONS:The SUN is a new vision-based test that complements presently available picture- and number-based RAN tests. These assessments may require different brain pathways and networks for visual processing, visual memory, language and eye movements.

A 73-year-old woman with 3 years of monocular visual distortion and progressive binocular diplopia. She was found to have a comitant left hypertropia due to an epiretinal membrane causing inferior foveal drag. Displacement of the fovea from an epiretinal membrane is a likely under-recognized cause ocular cause of a comitant binocular diplopia.

OBJECTIVE:The Mobile Universal Lexicon Evaluation System (MULES) is a test of rapid picture naming that captures extensive brain networks, including cognitive, language and afferent/efferent visual pathways. MULES performance is slower in concussion and multiple sclerosis, conditions in which vision dysfunction is common. Visual aspects captured by the MULES may be impaired in Parkinson's disease (PD) including color discrimination, object recognition, visual processing speed, and convergence. The purpose of this study was to compare MULES time scores for a cohort of PD patients with those for a control group of participants of similar age. We also sought to examine learning effects for the MULES by comparing scores for two consecutive trials within the patient and control groups. METHODS:MULES consists of 54 colored pictures (fruits, animals, random objects). The test was administered in a cohort of PD patients and in a group of similar aged controls. Wilcoxon rank-sum tests were used to determine statistical significance for differences in MULES time scores between PD patients and controls. Spearman rank-correlation coefficients were calculated to examine the relation between MULES time scores and PD motor symptom severity (UPDRS). Learning effects were assessed using Wilcoxon rank-sum tests. RESULTS: = 0.37, P = .02). Learning effects were greater among patients with PD (median improvement of 14.8 s between two MULES trials) compared to controls (median 7.4 s, P = .004). CONCLUSION/CONCLUSIONS:The MULES is a complex test of rapid picture naming that captures numerous brain pathways including an extensive visual network. MULES performance is slower in patients with PD and our study suggests an association with the degree of motor impairment. Future studies will determine the relation of MULES time scores to other modalities that test visual function and structure in PD.