Saccadic Impairments in Patients with the Norrbottnian Form of Gaucher’s Disease Type 3

• Published in: Frontiers in Neurology
• Main Authors: Josefine Blume, Stanislav Beniaminov, Cecilia Kämpe Björkvall, Maciej Machaczka, Per Svenningsson
• Format: Article in Journal/Newspaper
• Language: English
• Published: Frontiers Media S.A. 2017
• Subjects: Gaucher’s disease; Norrbottnian form; saccades; eye movements; antisaccades; Neurology. Diseases of the nervous system; RC346-429; Northern Sweden
• Online Access: https://doi.org/10.3389/fneur.2017.00295; https://doaj.org/article/d64073d3448b4b3a82f6f0f63b9cc8e2

BackgroundChronic neuronopathic Gaucher’s disease type 3 (GD3) is relatively frequent in northern Sweden. Besides multiple other neurological symptoms, horizontal gaze palsy or oculomotor apraxia is common in GD3.ObjectiveTo characterize the saccades in patients with Norrbottnian GD3 with respect to their neurological and cognitive status using a computer-based eye-tracking technique.MethodsHorizontal and vertical reflexive saccades as well as antisaccades of nine GD3 patients [4M/5F; 41.1 ± 11.0 years; modified severity scoring tool (mSST): 9.3 ± 5.4; Montreal Cognitive Assessment (MoCA): 24.0 ± 4.2] and age-matched controls were analyzed using EyeBrain T2, a head-mounted binocular eye tracker. Systematic clinical assessment included the mSST, a valid tool for monitoring the neurological progression in GD3 and MoCA.ResultsIn Norrbottnian GD3 patients, gain, peak, and average velocity (107.5°/s ± 41.8 vs. 283.9°/s ± 17.0; p = 0.0009) of horizontal saccades were reduced compared to healthy controls (HCs). Regarding vertical saccades, only the average velocity of downward saccades was decreased (128.6°/s ± 63.4 vs. 244.1°/s ± 50.8; p = 0.004). Vertical and horizontal saccadic latencies were increased (294.3 ms ± 37.0 vs. 236.5 ms ± 22.4; p = 0.005) and the latency of horizontal reflexive saccades was correlated with the mSST score (R2 = 0.80; p = 0.003). The latency of antisaccades showed association to MoCA score (R2 = 0.70; p = 0.009). GD3 patients made more errors in the antisaccade task (41.5 ± 27.6% vs. 5.2 ± 5.8%; p = 0.005), and the error rate tended to correlate with the cognitive function measured in MoCA score (p = 0.06).ConclusionThe mean age of 41 years of our GD3 cohort reflects the increased life expectancy of patients in the Norrbottnian area compared to other GD3 cohorts. Marked impairment of horizontal saccades was evident in all patients, whereas vertical saccades showed distinct impairment of downward velocity. Latency of reflexive saccades was associated with the severity of neurological ...