Parkinson’s disease involves widespread neurodegeneration that extends far beyond the basal ganglia, giving rise to a diverse range of non-motor symptoms that frequently emerge before motor onset. These include autonomic dysfunction, cognitive decline, neuropsychiatric disturbances, sleep-related disorders, and sensory deficits. Here, we synthesize current evidence on the anatomical, neurochemical, and network-level mechanisms that drive these symptoms, and we examine how they shape disease progression and clinical heterogeneity. We highlight the limitations of dopamine-centric models and advocate for a framework that treats non-motor symptoms as the disorder’s primary, mechanistically distinct features. We also discuss how emerging technologies—such as multi-omic profiling, artificial intelligence, and network neuroscience—enable earlier identification, stratification of non-motor phenotypes, and the development of precision-based therapeutic strategies. Recognizing non-motor symptoms as central to Parkinson’s disease redefines how the disorder should be diagnosed, studied, and treated.

Advanced magnetic resonance imaging (MRI) techniques are transforming the study of movement disorders by providing valuable insights into disease mechanisms. This narrative review presents a comprehensive overview of their applications in this field, offering an updated perspective on their potential for early diagnosis, disease monitoring, and therapeutic evaluation. Emerging MRI modalities such as neuromelanin-sensitive imaging, diffusion-weighted imaging, magnetization transfer imaging, and relaxometry provide sensitive biomarkers that can detect early microstructural degeneration, iron deposition, and connectivity disruptions in key regions like the substantia nigra. These techniques enable earlier and more accurate differentiation of movement disorders, including Parkinson’s disease, progressive supranuclear palsy, multiple system atrophy, corticobasal degeneration, Lewy body and frontotemporal dementia, Huntington’s disease, and dystonia. Furthermore, MRI provides objective metrics for tracking disease progression and assessing therapeutic efficacy, making it an indispensable tool in clinical trials. Despite these advances, the absence of standardized protocols limits their integration into routine clinical practice. Addressing this gap and incorporating these techniques more systematically could bring the field closer to leveraging advanced MRI for personalized treatment strategies, ultimately improving outcomes for individuals with movement disorders.

Transcranial Magnetic Stimulation (TMS) serves as a crucial tool in evaluating motor cortex excitability by applying short magnetic pulses to the skull, inducing neuron depolarization in the cerebral cortex through electromagnetic induction. This technique leads to the activation of specific skeletal muscles recorded as Motor-Evoked Potentials (MEPs) through electromyography. Although various methodologies assess cortical excitability with TMS, measuring MEP amplitudes offers a straightforward approach, especially when comparing excitability states pre- and post-interventions designed to alter cortical excitability. Despite TMS's widespread use, the absence of a standardized procedure for such measurements in existing literature hinders the comparison of results across different studies. This paper proposes a standardized procedure for assessing changes in motor cortical excitability using single-pulse TMS pre- and post-intervention. The recommended approach utilizes an intensity equating to half of the MEP's maximum amplitude, thereby ensuring equal likelihood of amplitude increase or decrease, providing a consistent basis for future studies and facilitating meaningful comparisons of results. • A method for assessing changes in motor cortical excitability using single-pulse TMS before and after a specified intervention. • We recommend using an intensity equal to half of the MEP's maximum amplitude during evaluations to objectively assess motor cortical excitability changes post-intervention.

Parkinson’s disease encompasses a spectrum of motor and non-motor manifestations, with the latter often preceding motor symptoms and influencing disease trajectory. Sensory dysfunction, sleep-related disorders, autonomic impairment, neuropsychiatric symptoms, and cognitive decline reflect widespread neurodegeneration involving the brainstem, limbic system, and peripheral nervous system. Hyposmia and visual dysfunction are emerging as early biomarkers, while chronic pain and paraesthesias indicate central and peripheral nociceptive dysregulation. Sleep-related disorders, particularly REM sleep behaviour disorder and insomnia, frequently arise in the prodromal phase, highlighting disruptions in circadian regulation and neuroanatomical integrity. Neuropsychiatric symptoms—including depression, anxiety, apathy, and hallucinations—result from complex dysregulation of dopaminergic, serotonergic, and noradrenergic pathways, compounding disease burden and impairing quality of life. Autonomic dysfunction, affecting cardiovascular, gastrointestinal, thermoregulatory, and genitourinary systems, underscores the systemic nature of the disease. Despite growing recognition of these non-motor features, treatment strategies remain limited, constrained by a dopamine-centric therapeutic framework that does not fully address broader neurobiological dysfunction. The lack of reliable biomarkers hampers early diagnosis and precision medicine approaches, while the conventional dichotomy between motor and non-motor symptoms has hindered the development of integrative treatment paradigms. While previous reviews have examined individual non-motor manifestations in detail, this article provides a comprehensive synthesis, offering a clinically relevant perspective for medical students, primary care physicians, and non-specialists. Recognizing non-motor symptoms as core disease manifestations rather than secondary sequelae is essential to refine diagnostic criteria and develop targeted therapies. Parkinson’s disease is a complex, multisystem neurodegenerative disorder that necessitates a paradigm shift in research priorities and clinical management. A broader, integrative perspective is required to redefine how the disease is understood, taught, and treated, ensuring that motor and non-motor symptoms are addressed to improve patient outcomes.

Brain-Computer Interfaces (BCIs) offer the potential to facilitate neurorehabilitation in stroke patients by decoding user intentions from the central nervous system, thereby enabling control over external devices. Despite their promise, the diverse range of intervention parameters and technical challenges in clinical settings have hindered the accumulation of substantial evidence supporting the efficacy and effectiveness of BCIs in stroke rehabilitation. This article introduces a practical guide designed to navigate through these challenges in conducting BCI interventions for stroke rehabilitation. Applicable regardless of infrastructure and study design limitations, this guide acts as a comprehensive reference for executing BCI-based stroke interventions. Furthermore, it encapsulates insights gleaned from administering hundreds of BCI rehabilitation sessions to stroke patients. • Presents a comprehensive methodology for implementing BCI-based upper extremity therapy in stroke patients. • Provides detailed guidance on the number of sessions, trials, as well as the necessary hardware and software for effective intervention.