Parkinson's disease: muscle rigidity at the heart of a new scientific perspective
Parkinson’s disease affects around 300,000 people in Italy, and its incidence is rising steadily worldwide.
Muscle rigidity, one of the main symptoms of the condition, has been less well studied than other symptoms, such as tremor and slowness of movement (bradykinesia).
A new study published today in the journal Brain compiles, analyses and summarises all the published evidence on the subject, providing an up-to-date and in-depth overview of the phenomenon.
The study, coordinated by Antonio Suppa, director of the Neurodegenerative Diseases Unit within the Department of Human Neuroscience at Sapienza University, opens up new avenues for the diagnosis and treatment of the condition, starting with a re-evaluation of the role of muscle rigidity.
In particular, the researchers systematically addressed three key aspects of the phenomenon: the correct definition of stiffness, a reliable method of measurement, and the identification of the biological mechanisms that underlie it.
The study, which is the result of collaboration with some of the world’s leading experts in the field of neuroscience from leading institutions in Europe and the United States, also highlights the limitations of clinical observation alone and proposes an integrated approach incorporating advanced diagnostic techniques.
These methods enable more objective and reproducible measurements of muscle stiffness.
With regard to the biological mechanisms underpinning the phenomenon, the research confirms the decisive role played by dopamine deficiency in the basal ganglia – the brain’s ‘control centre’ – but also highlights that the mechanisms through which this deficiency leads to rigidity are not yet fully understood. Among the most innovative findings, the authors propose certain neurophysiological biomarkers of rigidity, opening up new avenues for the study of the disease.
“The research carried out as part of the activities of the Laboratory of Experimental Neurology, Neuroengineering and Telemedicine,” says Antonio Suppa, “confirms Sapienza’s role as a leading centre for research into neurodegenerative diseases. I am also pleased to note that the publication is dedicated to the memory of Professor Mark Hallett, one of the world’s leading experts in the field of neurophysiology, who passed away recently.”
A better understanding of muscle rigidity in Parkinson’s disease means improving the quality of diagnosis, monitoring the condition and developing increasingly personalised treatments.
References: Suppa A, Zampogna A, Vivacqua G, Falletti M, Asci F, Marinelli L, Trompetto C, Currà A, Hallett M, Obeso JA, Rothwell J. Rigidity in Parkinson's disease. Brain (2026) DOI: 10.1093/brain/awag129.
Further Information
Antonio Suppa – Department of Human Neuroscience