Timely referral for device-aided therapy in Parkinson's disease. Development of a screening tool.

BACKGROUND: Timely referral of Parkinson's disease (PD) patients to specialized centers for treatment with device-aided therapies (DAT) is suboptimal. OBJECTIVE: To develop a screening tool for timely referral for DAT in PD and to compare the tool with the published 5-2-1 criteria. METHODS: A cross-sectional, observational study was performed in 8 hospitals in the catchment area of a specialized movement disorder center in the Northern part of the Netherlands. The target population comprised PD patients not yet on DAT visiting the outpatient clinic of participating hospitals. The primary outcome was apparent eligibility for referral for DAT based on consensus by a panel of 5 experts in the field of DAT. Multivariable logistic regression modelling was used to develop a screening tool for eligibility for referral for DAT. Potential predictors were patient and disease characteristics as observed by attending neurologists. RESULTS: In total, 259 consecutive PD patients were included, of whom 17 were deemed eligible for referral for DAT (point prevalence: 6.6%). Presence of response fluctuations and troublesome dyskinesias were the strongest independent predictors of being considered eligible. Both variables were included in the final model, as well as levodopa equivalent daily dose. Decision curve analysis revealed the new model outperforms the 5-2-1 criteria. A simple chart was constructed to provide guidance for referral. Discrimination of this simplified scoring system proved excellent (AUC after bootstrapping: 0.97). CONCLUSIONS: Awaiting external validation, the developed screening tool already appears promising for timely referral and subsequent treatment with DAT in patients with PD.

Striatal FDOPA uptake and cognition in advanced non-demented Parkinson's disease: a clinical and FDOPA-PET study.

This study sought to determine the nature of the relationship between cognition and striatal dopaminergic functioning in 28 patients with advanced Parkinson's disease (PD) using fluorodopa Positron emission tomography (FDOPA-PET) and neuropsychological test scores. Mental flexibility was related to putamen activity while mental organization (executive memory and fluency) was related to caudate FDOPA uptake. Interestingly, the caudate may be more important in the mental components of executive functioning, while the putamen may be more important in the motor components of executive functioning.

Striatal dopaminergic activity (FDOPA-PET) associated with cognitive items of a depression scale (MADRS) in Parkinson's disease.

Motor symptoms form the hallmark of Parkinson's disease (PD), although other features such as depression are often present. Currently-used depression rating scales measure affective and somatic symptoms. These somatic symptoms of depression can also be core PD symptoms, suggesting an overlap of symptoms between depression and PD. Using in vivo radiotracer methods, striatal dopaminergic dysfunction is found in both PD and depression. This study investigates to what extent the overlapping symptoms of depression and PD are associated with the striatal dopaminergic dysfunction typical of PD. Symptoms of depression were assessed in 23 PD patients who did not have major depression according to the Montgomery-Asberg depression rating scale (MADRS; cut-off < 18) and according to a trained psychologist who interviewed all patients. The striatal dopaminergic activity of patients was assessed with FDOPA-PET. Dopaminergic activity of the putamen and caudate nucleus was associated with MADRS total score and specifically with the symptom 'Concentration difficulties'. These results suggest that the typical striatal dopaminergic dysfunction of PD can cause symptoms that can also be categorized as symptoms of depression. In particular, cognitive symptoms measured with a depression rating scale may be based on the dopaminergic dysfunction of the striatum in PD patients.