Objective A cross-sectional study was performed to evaluate whether quantitative oculomotor measures correlate with disease severity in late-onset GM2 gangliosidosis (LOGG) and assess cognition and sleep as potential early nonmotor features. Methods Ten patients with LOGG underwent quantitative oculomotor recordings, including measurements of the angular vestibulo-ocular reflex (VOR), with results compared to age- and sex-matched controls. Disease severity was assessed by ataxia rating scales. Cognitive/neuropsychiatric features were assessed by the cerebellar cognitive affective syndrome (CCAS) scale, Cerebellar Neuropsychiatric Rating Scale, and sleep quality evaluated using subjective sleep scales. Results Oculomotor abnormalities were found in all participants, including 3/10 with clinically normal eye movements. Abnormalities involved impaired saccadic accuracy (5/10), abnormal vertical (8/10) and horizontal (4/10) pursuit, reduced optokinetic nystagmus (OKN) responses (7/10), low VOR gain (10/10), and impaired VOR cancellation (2/10). Compared to controls, the LOGG group showed significant differences in saccade, VOR, OKN, and visually enhanced VOR gains. Severity of saccadic dysmetria, OKN, and VOR fixation-suppression impairments correlated with ataxia scales (p Conclusions Cerebellar oculomotor abnormalities were present in all patients with LOGG, including those with normal clinical oculomotor examinations. Saccade accuracy (dorsal cerebellar vermis localization), fixation suppression, and OKN gain (cerebellar flocculus/paraflocculus localization) correlated with disease severity, suggesting that quantitative oculomotor measurements could be used to track disease progression. We found evidence of the CCAS, suggesting that cerebellar dysfunction may explain the cognitive disorder in LOGG. Sleep impairments were prevalent and require further study.

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Quantitative oculomotor and nonmotor assessments in late-onset GM2 gangliosidosis

The GM2 gangliosidoses: Unlocking the mysteries of pathogenesis and treatment.

Magnetic resonance imaging and spectroscopy in late-onset GM2-gangliosidosis.

Oromandibular dystonia (OMD) is a clinical problem which is commonly encountered in the practice of movement disorders. OMD results from a variety of genetic and acquired etiologies and can occur as an isolated manifestation, or as part of an isolated generalized or a combined dystonia syndrome. There are only very few systematic reviews on this condition which often causes significant disability. We review here the etiology, clinical features, diagnostic approach and management of OMD. 

Oromandibular dystonia – A systematic review

Case Report of Acquired Stuttering After Soccer-Related Concussion: Functional Magnetic Resonance Imaging as a Prognostic Tool.

Late-onset Tay-Sachs disease (LOTS) is a rare autosomal-recessive genetic disorder caused by insufficient activity of the lysosomal enzyme, beta-hexosaminidase A, resulting in intracellular accumulation of gangliosides in the central nervous system. Clinical manifestations can include unsteadiness in gait, muscle weakness, cognitive dysfunction, psychiatric disturbance, and dysarthric speech. The variable presentation of these symptoms, combined with the late onset of the disease, often results in misdiagnosis. We present video of 3 sibling cases of LOTS in which a dysarthric stutter was the sole presenting symptom in order to better characterize the phenotype of this disease.

https://movementdisorders.onlinelibrary.wiley.com/doi/pdf/10.1002/mdc3.12194

Kristina K. Grim

Papers

Dysarthria and Stutter as Presenting Symptoms of Late-Onset Tay-Sachs Disease in Three Siblings.