Movimientos Anormales

Chorea and Levodopa-Induced Dyskinesia in Corticobasal Syndrome: Two Case Reports with Pathological Insights and Literature Review

2025-05-11T00:00:00Z

Chorea and Levodopa-Induced Dyskinesia in Corticobasal Syndrome: Two Case Reports with Pathological Insights and Literature Review Medina Escobar, Alex; Rossi, Malco Damián; Richer, Maxime; Gautreau, Sylvia; Lang, Anthony E. Background: Corticobasal syndrome (CBS) is a rare, clinically heterogeneous form of atypical Parkinsonism. Hyperkinetic movements, aside from myoclonus and dystonia, have rarely been reported in CBS. Cases: We present two patients with CBS, one with pathologically confirmed corticobasal degeneration (CBD) and generalized chorea, and another with probable CBS and Levodopa-induced dyskinesia (LID). Case 1 exhibited late-onset generalized chorea, which was preceded by several years of dystonia, rigidity and apraxia affecting the right upper limb. Case 2 presented with dystonia, cortical sensory loss, and apraxia in the left upper limb, while LID affected the face and the right side of the body. Literature review: A systematic review of published cases of chorea or levodopa-induced dyskinesia (LID) in CBS was performed. The literature search was executed in PubMed from its inception for cases of chorea or LID associated with CBS. Twelve patients were identified across eight studies. Only five cases of pathologically confirmed CBD with chorea were found; chorea developed after 4 years of disease progression. Conclusions: Chorea and LID are rare but may represent late manifestations of CBS. The exact mechanisms are unclear; they may relate to variability in anatomical involvement, particularly relative sparing of the GPi. Greater understanding of topographical disease progression may improve diagnostic precision and phenotypic classification in CBS and related tauopathies.

The Role of Basal Ganglia Theta Oscillations in Predicting the Onset of Levodopa-Induced Dyskinesias

2025-10-11T00:00:00Z

The Role of Basal Ganglia Theta Oscillations in Predicting the Onset of Levodopa-Induced Dyskinesias Wilken, Miguel; Granda, Luna; Cruz, Ivonne; Rossi, Malco Damián; Cerquetti, Daniel; Merello, Marcelo Background: Levodopa-induced dyskinesias (LIDs) are an important burden for patients with Parkinson's disease (PD), yet their mechanisms remain incompletely understood. Objective: The objective of this study was to investigate the temporal and spatial relationship between local field potential (LFP) changes and dyskinesia development in PD. Methods: We recorded bilateral subthalamic LFPs, electromyography, and accelerometry in patients with PD with peak-dose LIDs undergoing deep brain stimulation (DBS) surgery. Apomorphine was administered to induce dyskinesias, and recordings continued for 200 seconds postonset. Spectral power changes were analyzed over time and mapped to the DBS "sweet spot." A machine-learning algorithm detected dyskinetic movements. Results: In 9 of 36 patients, dyskinesias were preceded by a bilateral beta power decrease (P < 0.001) and contralateral theta increase (P = 0.02), followed by gamma elevation (P = 0.03). These changes peaked in the DBS sweet spot. Conclusions: Our results provide insights into the sequential nature of beta, theta, and gamma oscillatory changes. Theta activity may serve as a key biomarker for adaptive DBS. © 2025 International Parkinson and Movement Disorder Society.

Quantitative Assessment of Proprioceptive Force Perception in Parkinson’s Disease Using a Sensor-Based Grip Task

2025-10-16T00:00:00Z

Quantitative Assessment of Proprioceptive Force Perception in Parkinson’s Disease Using a Sensor-Based Grip Task Martínez de Sucre, M. Nahuel; Bianchi, Gianfranco; Wilken, Miguel; Cruz Molina, Cecilia; Noel, Gabriel; Andrés, Daniela Parkinson’s disease (PD) is characterized by progressive motor and sensorimotor deficits, including impairments in proprioception and grip force control. Despite their clinical relevance, these alterations are rarely evaluated quantitatively. In this study, we present a portable, sensor-based system designed to assess proprioceptive force perception in PD through a structured grip force protocol. Participants performed a three-phase task involving visually guided and unguided contractions at 50% of their maximum voluntary contraction (MVC). Signals were acquired at 250 Hz and processed offline to extract multiple performance metrics, including root mean squared error (RMSE), standard deviation, average percentage distance to the 50% MVC target, and the slope during the plateau region. Data were analyzed from 19 patients with PD and 32 healthy controls. Results showed that PD patients consistently applied less force than the 50% MVC target during the phase without visual feedback and exhibited greater deviations during sustained contractions (plateau region). Statistically significant group differences revealed characteristic patterns of error consistent with proprioceptive dysfunction, particularly in the average percentage distance between the applied force and the 50% MVC target during the plateau region (p < 0.02, Kolmogorov–Smirnov test). These findings support the potential of quantitative tools to identify sensorimotor alterations in PD and contribute to clinical assessment protocols.

Analysis of DBS Outcome by MDS-UPDRS Severity Levels: Comparison with Changes on MDS-UPDRS III

2025-06-22T00:00:00Z

Analysis of DBS Outcome by MDS-UPDRS Severity Levels: Comparison with Changes on MDS-UPDRS III Castillo Torres, Sergio Andrés; Cruz, Ivonne; Rossi, Malco Damián; Wilken, Miguel; Cerquetti, Daniel; Merello, Marcelo Background: MDS-UPDRS Severity Levels (SLs), derived from clinician- and patient-rated scales, remain underused to evaluate response to subthalamic deep brain stimulation (STN-DBS) in patients with Parkinson's disease (PD). Objectives: To evaluate MDS-UPDRS SL as markers of STN-DBS response. Methods: SLs were categorized as mild, moderate, or severe using established cut-off points for Parts II, III Off, and IV. Improvement was defined as a decrease in at least one SL. Part III Off improvement was correlated to quality-of-life scales and used to predict SL improvement using ROC Curve analysis. Results: A total of 51 patients (34.1% female, aged 58.9 ± 10.2 years, disease duration 12.3 ± 4.1 years) were evaluated 12 months after surgery. MDS-UPDRS III Off changes over 30% predicted SL improvements in MDS-UPDRS II (AUC = 0.83, p = 0.015) and IV (AUC = 0.89, p = 0.001). Conclusion: Our findings suggest that improvement in MDS-UPDRS SL are potential markers of STN-DBS response. With an MDS-UPDRS part III improvement around 30% predicting SL improvement.