Faculty Bibliography

Cognitive impairment in Parkinson's disease (PD) is related to the reorganization of brain topology. Although drug challenge studies have proven how levodopa treatment can modulate functional connectivity in brain circuits, the role of chronic dopaminergic therapy on cognitive status and functional connectivity has never been investigated. We sought to characterize brain functional topology in mid-stage PD patients under chronic antiparkinson treatment and explore the presence of correlation between reorganization of brain architecture and specific cognitive deficits. We explored networks topology and functional connectivity in 16 patients with PD and 16 matched controls through a graph theoretical analysis of resting state-functional MRI data, and evaluated the relationships between network metrics and cognitive performance. PD patients showed a preserved small-world network topology but a lower clustering coefficient in comparison with healthy controls. Locally, PD patients showed lower degree of connectivity and local efficiency in many hubs corresponding to functionally relevant areas. Four disconnected subnetworks were also identified in regions responsible for executive control, sensory-motor control and planning, motor coordination and visual elaboration. Executive functions and information processing speed were directly correlated with degree of connectivity and local efficiency in frontal, parietal and occipital areas. While functional reorganization appears in both motor and cognitive areas, the clinical expression of network imbalance seems to be partially compensated by the chronic levodopa treatment with regards to the motor but not to the cognitive performance. In a context of reduced network segregation, the presence of higher local efficiency in hubs regions correlates with a better cognitive performance.

Background/UNASSIGNED:Women with Parkinson's disease (PD) are more likely to be older, have greater disease severity and comorbidities, and yet are less likely to receive care from a neurologist, as compared with men with PD. Within the PD population, homebound individuals are a particularly vulnerable group facing significant barriers to care, yet within this understudied population, sex-related differences have not been reported. Purpose/UNASSIGNED:To identify and describe differences in homebound men and women with advanced PD and related disorders, participating in an interdisciplinary home visit program. Patients and methods/UNASSIGNED:This was an exploratory analysis of homebound patients seen between February 2014 and July 2016 using data collected via in-person interviews and chart review. Results/UNASSIGNED:=0.05). Conclusion/UNASSIGNED:The role of the caregiver in facilitating safe aging-in-place is crucial. Among homebound individuals with advanced PD, women were far more likely to live alone. The absence of a spouse or care partner may be due in part to variable sex-based life expectancies. Our findings suggest that homebound women with advanced PD may face greater barriers to accessing support.

Over the last decades, psychophysical and electrophysiological studies in patients and animal models of Parkinson's disease (PD), have consistently revealed a number of visual abnormalities. In particular, specific alterations of contrast sensitivity curves, electroretinogram (ERG), and visual-evoked potentials (VEP), have been attributed to dopaminergic retinal depletion. However, fundamental mechanisms of cortical visual processing, such as normalization or "gain control" computations, have not yet been examined in PD patients. Here, we measured electrophysiological indices of gain control in both space (surround suppression) and time (sensory adaptation) in PD patients based on steady-state VEP (ssVEP). Compared with controls, patients exhibited a significantly higher initial ssVEP amplitude that quickly decayed over time, and greater relative suppression of ssVEP amplitude as a function of surrounding stimulus contrast. Meanwhile, EEG frequency spectra were broadly elevated in patients relative to controls. Thus, contrary to what might be expected given the reduced contrast sensitivity often reported in PD, visual neural responses are not weaker; rather, they are initially larger but undergo an exaggerated degree of spatial and temporal gain control and are embedded within a greater background noise level. These differences may reflect cortical mechanisms that compensate for dysfunctional center-surround interactions at the retinal level.

OBJECTIVE:To assess the safety and efficacy of intradetrusor onabotulinum toxin A injections for the treatment of overactive bladder (OAB) in patients with Parkinson's disease (PD). METHODS:All PD patients who underwent intradetrusor injections of onabotulinum toxin A (BoNT-A) for storage symptoms between 2010 and 2017 were included in a retrospective study. A 100 U dose of BoNT-A (Botox®, Allergan Irvine, CA) was used for the first injection in all patients. The primary endpoint was clinical success defined as any subjective improvement in OAB symptoms self-assessed by the patients 4 weeks after the injections. RESULTS:Out of 24 patients analyzed, 19 reported improvement of their OAB symptoms 4 weeks after the first injection (79.2%) with complete resolution of urgency urinary incontinence in seven patients (29.1%; P < 0.001). The average post-void residual (PVR) increased significantly after the first injection from 17.6 to 125.3 mL (P < 0.001). Three of the patients had to start clean intermittent catheterization (CIC) after the first injection (12.5%). Out of 49 injections in total, only five caused incomplete bladder emptying requiring the use of CIC (10.2%). Higher pre-injection PVR was significantly associated with both a lower chance of symptomatic improvement (P = 0.04) and a higher risk of incomplete bladder emptying with institution of CIC (P = 0.047). CONCLUSION/CONCLUSIONS:Intradetrusor injections of BoNT-A 100 U appeared as a safe and effective option in PD patients with OAB symptoms and a low PVR before the injection. Higher preoperative PVR was the strongest predictor of both treatment failure and postoperative urinary retention requiring CIC.

Though abnormalities of visuospatial function occur in Parkinson's disease, the impact of such deficits on functional independence and psychological wellbeing has been historically under- recognized, and effective treatments for this impairment are unknown. These symptoms can be encountered at any stage of the disease, affecting many activities of daily living, and negatively influencing mood, self-efficacy, independence, and overall quality of life. Furthermore, visuospatial dysfunction has been recently linked to gait impairment and falls, symptoms that are known to be poor prognostic factors. Here, we aim to present an original modality of neurorehabilitation designed to address visuospatial dysfunction and related symptoms in Parkinson's disease, known as "Art Therapy". Art creation relies on sophisticated neurologic mechanisms including shape recognition, motion perception, sensory-motor integration, abstraction, and eye-hand coordination. Furthermore, art therapy may enable subjects with disability to understand their emotions and express them through artistic creation and creative thinking, thus promoting self-awareness, relaxation, confidence and self-efficacy. The potential impact of this intervention on visuospatial dysfunction will be assessed by means of combined clinical, behavioral, gait kinematic, neuroimaging and eye tracking analyses. Potential favorable outcomes may drive further trials validating this novel paradigm of neurorehabilitation.

Parkinson's disease (PD) is a complex, multisymptom, neurodegenerative disease affecting primarily older adults. With progression, many individuals become homebound and removed from coordinated, expert care, resulting in excess morbidity, mortality, and healthcare expenditures in acute care settings and institutions. Home visit care models have achieved the triple aim of improving individual and population health while reducing costs in many frail, community-dwelling geriatric cohorts. This study details a novel, interdisciplinary home visit program specifically designed for individuals with PD and related disorders and their family caregivers built upon best practice principles in the care of multimorbid older adults. At each quarterly home visit, a movement disorders-trained neurologist, social worker, and nurse work in parallel with the individual and caregiver to complete a history, physical, detailed medication reconciliation, psychosocial needs assessment, and home safety assessment. A comprehensive, person-centered plan is agreed upon, referrals to community resources are made, standardized documentation is shared, and follow-up communication is instituted. In the first 2 years, 272 visits were conducted with 85 individuals who represent one of the oldest, most disabled PD populations reported. Satisfaction with and retention in the program were high. This study represents the first translation of the success of interdisciplinary and home-based geriatric care models to a population with a specific neurological disease. Preliminary evidence supports the need for such programs in vulnerable populations. Future studies will prospectively assess person-centered outcomes, the effect of using telemedicine on sustainability, and cost effectiveness.