Ganglion Cell Complex Thinning in Young Gaucher Patients: Relation to Prodromal Parkinsonian Markers.

Background: Patients with Gaucher disease (GD) have an increased risk for parkinsonism. Retinal thinning has been described in parkinsonism as an early nonmotor feature. Scarce reports have addressed retinal thickness changes in GD.

Objectives: The objectives of this study were to compare ganglion cell complex (GCC) thickness in adolescents and young adults (AYAs) with GD with healthy control subjects, and to correlate it with the presence of parkinsonian features (PFs), clinical prodromal markers of parkinsonism, severity score index (SSI), and glucosylsphingosine (Lyso-GL-1).

Methods: This study included 48 AYAs with GD (11-29 years), 11 with manifest PFs (Group 1) and 37 with no PFs (Group 2), and 48 matched healthy control subjects (Group 3). Age of GD onset, disease duration, medication history, history of constipation, SSI, and hematological assessment were done. Neurocognitive evaluation included Parts I, II, and III of the Unified Parkinson's Disease Rating Scale (UPDRS), Wechsler Adult and Intelligence Scale and Wechsler Intelligence Scale for Children, Beck Depression Inventory (BDI), rapid eye movement sleep behavior disorder (RBD) scale, Munich Parasomnia Screening scale, and the olfactory dysfunction scale. Molecular analyses of the acid GBA gene and Lyso-GL-1 were done. Participants underwent full ophthalmological examination and optical coherence tomography with GCC thickness measurement.

Results: GCC was significantly thinner in Group 1 than in Groups 2 and 3 (P < 0.001), whereas no significant difference was found between Groups 2 and 3 (P = 0.977). In addition, a significant interocular GCC thickness difference was found among the studied AYAs with GD (P = 0.007). GCC correlated positively with total intelligence quotient (P < 0.001) and negatively with Lyso-GL-1 (P = 0.019), UPDRS (P = 0.004), and BDI (P = 0.029), but not with SSI (P = 0.874), GD type (P = 0.85), or genotype (P = 0.842). A significant negative relationship was found between GCC thickness and PFs (P = 0.001), parasomnia (P = 0.003), constipation (P = 0.031), RBD (P = 0.044), and hyposmia (P = 0.033).

Conclusions: GCC thinning may be a promising biomarker for central nervous system neurodegeneration that has the potential to monitor early PFs among people with GD. © 2020 International Parkinson and Movement Disorder Society.