Objective: (1) To determine the brain connectivity pattern associated with clinical rigidity scores in Parkinson's disease (PD) and (2) to determine the relation between clinically assessed rigidity and quantitative metrics of motor performance.

Background: Rigidity, the resistance to passive movement, is exacerbated in PD by asking the subject to move the contralateral limb, implying that rigidity involves a distributed brain network. Rigidity mainly affects subjects when they attempt to move; yet the relation between clinical rigidity scores and quantitative aspects of motor performance are unknown.

Methods: Ten clinically diagnosed PD patients (off-medication) and 10 controls were recruited to perform an fMRI squeeze-bulb tracking task that included both visually guided and internally guided features. The direct functional connectivity between anatomically defined regions of interest was assessed with Dynamic Bayesian Networks (DBNs). Tracking performance was assessed by fitting Linear Dynamical System (LDS) models to the motor performance, and was compared to the clinical rigidity scores. A cross-validated Least Absolute Shrinkage and Selection Operator (LASSO) regression method was used to determine the brain connectivity network that best predicted clinical rigidity scores.

Results: The damping ratio of the LDS models significantly correlated with clinical rigidity scores (p = 0.014). An fMRI connectivity network in subcortical and primary and premotor cortical regions accurately predicted clinical rigidity scores (p < 10(-5)).

Conclusion: A widely distributed cortical/subcortical network is associated with rigidity observed in PD patients, which reinforces the importance of altered functional connectivity in the pathophysiology of PD. PD subjects with higher rigidity scores tend to have less overshoot in their tracking performance, and damping ratio may represent a robust, quantitative marker of the motoric effects of increasing rigidity.

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3672800PMC
http://dx.doi.org/10.3389/fneur.2013.00067DOI Listing

Publication Analysis

Top Keywords

clinical rigidity
24
rigidity scores
20
brain connectivity
12
motor performance
12
rigidity
11
parkinson's disease
8
determine brain
8
lds models
8
connectivity network
8
predicted clinical
8

Similar Publications

Fenestrated/branched endovascular aortic repair emerges as the primary therapeutic modality for intricate aortic pathologies encompassing the paravisceral and thoracoabdominal segments, where bridging stent grafts (BSGs) play a vital role in linking the primary aortic endograft with target vessels. Bridging stent grafts can be categorized mainly into self-expanding stent grafts (SESGs) and balloon-expandable stent grafts (BESGs). Physiological factors significantly influence post-complex endovascular aortic repair BSG behaviour, impacting clinical outcomes of SESGs and BESGs in different but overlapping ways.

View Article and Find Full Text PDF

Background: The clinical characteristics, therapy, and outcome of Fournier Gangrene (FG) in patients using sodium-glucose cotransporter-2 inhibitors (SGLT2i) were examined in this systematic review.

Methods: Without a publication year restriction, we searched PubMed, ScienceDirect, and Cochrane. Additionally, we manually searched bibliographies using the terms "Fournier's gangrene" and "SGLT2 inhibitors.

View Article and Find Full Text PDF

Objective: Federated research networks, like Evolve to Next-Gen Accrual of patients to Clinical Trials (ENACT), aim to facilitate medical research by exchanging electronic health record (EHR) data. However, poor data quality can hinder this goal. While networks typically set guidelines and standards to address this problem, we developed an organically evolving, data-centric method using patient counts to identify data quality issues, applicable even to sites not yet in the network.

View Article and Find Full Text PDF

Purpose: Ultrahypofractionation presents challenges for a subset of high-risk prostate cancer patients due to the large planning target volume (PTV) margin required for the seminal vesicles. Online adaptive radiation therapy could potentially reduce this margin. This paper focuses on the development, preclinical validation, and clinical testing of online adaptive robotic stereotactic body radiation therapy for this patient group.

View Article and Find Full Text PDF

Purpose: The present study aims at exploring the effect of pitch, loudness, vowel, and voice condition on supraglottic activity among female participants with voice disorders and among female participants with normal voices.

Methods: Forty-four volunteers were recruited. Inclusion criteria for the dysphonic group were: 1) age between 20 and 50 years, 2) reporting at least 1 year-long history of voice problems, 3) moderate or severe dysphonia.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!