GBA-associated PD presents with nonmotor characteristics

To evaluate whether there exists distinct characteristics in glucocerebrosidase (GBA)-associated Parkinson disease (PD) with regard to motor and nonmotor symptoms as well as imaging characteristics assessed by transcranial sonography (TCS).

Twenty patients with PD with heterozygous GBA mutations (N370S, L444P) (GBA-PD) in comparison to 20 patients with sporadic PD negative for GBA mutations (sPD) were included. We assessed motor impairment with the Unified Parkinson's Disease Rating Scale-III. Nonmotor symptoms were evaluated using the Montreal Cognitive Assessment, Neuropsychiatric Inventory, revised form of the Beck Depression Inventory, Parkinson Disease Sleep Scale, Sniffin' Sticks, and Unified Multiple System Atrophy Rating Scale items 9-12. TCS imaging was used to detect morphologic characteristics.

Patients with GBA-PD more often had a variety of nonmotor symptoms, namely dementia, neuropsychiatric disturbances, and autonomic dysfunction, and had more severe cases, than patients with sPD. They also demonstrated a higher prevalence of a reduced echogenicity of the brainstem raphe assessed by TCS.

Especially nonmotor symptoms seem to be very common in GBA-PD. Further studies are needed to validate these observations in order to better understand the pathogenesis of GBA-PD and develop specific therapeutic concepts.