Phenotypic effect of GBA1 variants in individuals with and without Parkinson's disease: The RAPSODI study.

BACKGROUND: Variants in the GBA1 gene cause the lysosomal storage disorder Gaucher disease (GD). They are also risk factors for Parkinson's disease (PD), and modify the expression of the PD phenotype. The penetrance of GBA1 variants in PD is incomplete, and the ability to determine who among GBA1 variant carriers are at higher risk of developing PD, would represent an advantage for prognostic and trial design purposes. OBJECTIVES: To compare the motor and non-motor phenotype of GBA1 carriers and non-carriers. METHODS: We present the cross-sectional results of the baseline assessment from the RAPSODI study, an online assessment tool for PD patients and GBA1 variant carriers. The assessment includes clinically validated questionnaires, a tap-test, the University of Pennsyllvania Smell Identification Test and cognitive tests. Additional, homogeneous data from the PREDICT-PD cohort were included. RESULTS: A total of 379 participants completed all parts of the RAPSODI assessment (89 GBA1-negative controls, 169 GBA1-negative PD, 47 GBA1-positive PD, 47 non-affected GBA1 carriers, 27 GD). Eighty-six participants were recruited through PREDICT-PD (43 non-affected GBA1 carriers and 43 GBA1-negative controls). GBA1-positive PD patients showed worse performance in visual cognitive tasks and olfaction compared to GBA1-negative PD patients. No differences were detected between non-affected GBA1 carriers carriers and GBA1-negative controls. No phenotypic differences were observed between any of the non-PD groups. CONCLUSIONS: Our results support previous evidence that GBA1-positive PD has a specific phenotype with more severe non-motor symptoms. However, we did not reproduce previous findings of more frequent prodromal PD signs in non-affected GBA1 carriers.

New-onset seizures in older people: Clinical features, course and outcomes.

OBJECTIVE: The incidence of epilepsy increases with age. With current demographic trends, this presents a healthcare challenge. We investigated the clinical spectrum of first seizures, evaluated neuroimaging and EEG findings, and determined clinical outcomes, including anti-seizure medication (ASM) response in older people. In addition, we sought to understand the relative effects of age and frailty on ASM response. METHODS: A retrospective single centre cohort study of 207 cases ≥60 years' old, 113 of whom were eventually diagnosed with a first seizure in a specialist epilepsy clinic. RESULTS: 65/113 (57.5%) presented with either focal aware or focal impaired awareness seizures. Stroke was the most common aetiological association (31.9%, 36/113), and odds of seizure recurrence did not significantly differ between aetiologies. 55/86 (64.0%) who started an ASM had no seizure recurrence. 14/48 (29.2%) who underwent EEG had epileptiform abnormalities, however EEG result directly affected management in only 4/48 (8.3%). The most common MRI findings were small vessel disease (37/93, 39.8%), stroke (27/93, 29.0%) and global atrophy (14/93, 15.1%). Increasing age and frailty did not affect the odds of seizure recurrence or of experiencing ASM side effects. Severity of small vessel disease or atrophy did not affect odds of seizure recurrence. CONCLUSION: Our data inform the management of first seizures in older people and provisionally support the use of ASMs in patients with increasing age and frailty, despite concerns over polypharmacy and comorbidity. Our findings should be replicated in larger cohorts.