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Background: The subthalamic nucleus (STN) is considered a key structure in motor, behavioral, and emotional control. Although identification of the functional topography of the STN has therapeutic implications in the treatment of the motor features of Parkinson's disease (PD), the details of its functional and somatotopic organization in humans are not well understood.
Objective: The aim of this study was to characterize the functional organization of the STN and its correlation with the motor outcomes induced by subthalamotomy.
Methods: We used diffusion-weighted imaging to assess STN connectivity patterns in 23 healthy control subjects and 86 patients with PD, of whom 39 received unilateral subthalamotomy. Analytical tractography was used to reconstruct structural cortico-subthalamic connectivity. A diffusion-weighted imaging/functional magnetic resonance imaging-driven somatotopic parcellation of the STN was defined to delineate the representation of the upper and lower limb in the STN.
Results: We confirmed a connectional gradient to sensorimotor, supplementary-motor, associative, and limbic cortical regions, spanning from posterior-dorsal-lateral to anterior-ventral-medial portions of the STN, with intermediate overlapping zones. Functional magnetic resonance imaging-driven parcellation demonstrated dual segregation of motor cortico-subthalamic projections in humans. Moreover, the relationship between lesion topography and functional anatomy of the STN explains specific improvement in bradykinesia, rigidity, and tremor induced by subthalamotomy.
Conclusions: Our results support an interplay between segregation and integration of cortico-subthalamic projections, suggesting the coexistence of parallel and convergent information processing. Identifying the functional topography of the STN will facilitate better definition of the optimal location for functional neurosurgical approaches, that is, electrode placement and lesion location, and improve specific cardinal features in PD. © 2021 International Parkinson and Movement Disorder Society.
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http://dx.doi.org/10.1002/mds.28862 | DOI Listing |
J Thromb Thrombolysis
September 2025
Central Laboratory of Yongchuan Hospital, Chongqing Medical University, No. 439, Xuanhua Road, Yongchuan District, Chongqing, 402160, China.
In vitro assessment of the inhibitory effect of antiplatelet drugs on platelet aggregation is frequently employed to guide personalized antiplatelet therapy in clinical practice. However, existing methods for detecting platelet aggregation rely heavily on high concentrations of exogenous agonists, which may obscure part of the inhibitory effect of antiplatelet drugs and lead to an underestimation of their effects. This study validates a novel analytical strategy for evaluating the effects of antiplatelet drugs by quantifying the microscopic three-dimensional morphological parameters of platelet aggregates formed through spontaneous aggregation on a glass surface.
View Article and Find Full Text PDFJ Refract Surg
September 2025
The College of Medicine, Taibah University, Medina, Saudi Arabia.
Purpose: To present a case of synthetic intrastromal corneal ring segment (ICRS) intrusion secondary to necrosis and migration, managed by implantation of corneal allogenic intrastromal ring segments (CAIRS) within the preexisting tunnel.
Methods: A 24-year-old man with known keratoconus underwent bilateral ICRS implantation. He presented with blurred vision in the right eye 6 weeks after the procedure.
J Refract Surg
September 2025
Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, China.
Purpose: To evaluate axis-dependent visual and refractive outcomes of small incision lenticule extraction (SMILE) in patients with interocular astigmatic axis discordance.
Methods: Seventy-five patients (150 eyes) with interocular astigmatic axis discordance were included in the study. Based on interocular axis combinations, patients were stratified into three cohorts: with-the-rule (WTR)/against-the-rule (ATR) (n = 19), WTR/oblique astigmatism (OA) (n = 39), and ATR/OA (n = 17).
J Refract Surg
September 2025
Purpose: To discuss the technique and outcome of what the authors called the "flap-in-flap" technique and report its safety as a procedure for correction of post-laser in situ keratomileusis (LASIK) myopic regression.
Methods: Seven eyes of 4 patients were included in this study. All patients had previously undergone LASIK for compound myopic astigmatism using the Moria M2 micro-keratome (Moria) 8 to 12 years prior to presentation.
J Refract Surg
September 2025
Department of Refractive Surgery, Aier Eye Hospital, Jinan University, Guangzhou, Guangdong, China.
Purpose: To report the refractive outcome of femtosecond laser-assisted lenticule intrastromal keratoplasty (LIKE) in correcting moderate to high hyperopia. Intraoperative effective optical zone (EOZ), centration offset, and postoperative higher order aberrations (HOAs) were analyzed to better understand factors affecting postoperative outcomes.
Methods: This was a prospective, consecutive case series study of LIKE for correcting hyperopia in one department from 2018 to 2023.