Improving Parkinson's Disease Care through Systematic Screening for Depression.

BACKGROUND: Depression is common in Parkinson's disease (PD) but is underrecognized clinically. Although systematic screening is a recommended strategy to improve depression recognition in primary care practice, it has not been widely used in PD care. METHODS: The 15-item Geriatric Depression Scale (GDS-15) was implemented at 5 movement disorders clinics to screen PD patients. Sites developed processes suited to their clinical workflow. Qualitative interviews with clinicians and patients provided information on feasibility, acceptability, and perceived utility. RESULTS: Prior to implementation, depression screening was recorded in 12% using a formal instrument; 64% were screened informally by clinical interview, and no screening was recorded in 24%. Of 1406 patients seen for follow-up care during the implementation period, 88% were screened, 59% using the GDS-15 (self-administered in 51% and interviewer administered in 8%), a nearly 5-fold increase in formal screening. Lack of clinician or staff time and inability to provide the GDS-15 to the patient ahead of the visit were the most commonly cited reasons for lack of screening using the GDS-15; 378 (45%) patients completing the GDS-15 screened positive for depression, and 137 were enrolled for a 12-month prospective follow-up. Mean GDS-15 scores improved from 8.8 to 7.0 (P < 0.0001) and the 39-item Parkinson's Disease Questionnaire emotional subscore from 42.2 to 36.7 (P = 0.0007). CONCLUSIONS: Depression screening in PD using a formal instrument can be achieved at much higher levels than is currently practiced, but there are barriers to implementing this in clinical practice. An individual site-specific process is necessary to optimize screening rates.

Deep brain stimulation effect on anterior pallidum reduces motor impulsivity in Parkinson's disease.

BACKGROUND: Deep Brain Stimulation (DBS) of the subthalamic nucleus or globus pallidus internus is used to treat the motor symptoms of Parkinson's disease. The former can worsen impulsive and compulsive behaviors after controlling for the reduction of dopaminergic medications. However, the effect of pallidal DBS on such behaviors in PD patients is less clear. OBJECTIVE/HYPOTHESIS: We hypothesized that greater stimulation spread to the pallidum with prefrontal connectivity would reduce motor impulsivity. METHODS: Seven Parkinson's patients with stable globus pallidus internus DBS settings for 3 months, disease duration of 13 ± 1.3 years, and Montreal Cognitive Assessment of 26.8 ± 1.1 each had two stimulation settings defined based on reconstructions of lead placement and volume of tissue activation targeting either a dorsal or ventral position along the DBS electrode but still within the globus pallidus internus. Subjects performed a stop signal reaction time task with the DBS turned off vs. on in each of the defined stimulation settings, which was correlated with the degree of stimulation effect on pallidal subregions. RESULTS: A shorter distance between the volume of tissue activation and the right prefrontally-connected GPi correlated with less impulsivity on the stop signal reaction time task (r = 0.69, p < 0.05). Greater volume of tissue activation overlap with the non-prefrontally-connected globus pallidus internus was associated with increased impulsivity. CONCLUSION: These data can be leveraged to optimize DBS programming in PD patients with problematic impulsivity or in other disorders involving impulsive behaviors such as substance use disorders.