Clinical Phenotypes and Progression of Parkinson’s Disease

Parkinson’s disease (PD) is a progressive neurodegenerative disorder characterised by a spectrum of motor and non-motor clinical phenotypes. The classical motor signs—bradykinesia, rigidity, resting tremor and postural instability—can present in varying combinations, giving rise to tremor-dominant, akinetic-rigid and postural instability gait difficulty subtypes. Non-motor manifestations such as cognitive impairment, mood disturbances, autonomic dysfunction and sleep disorders frequently precede or accompany motor symptoms, contributing substantially to patient disability and reduced quality of life. Age at onset emerges as a key stratifier: individuals with early-onset PD (<50 years) often experience slower motor progression but a higher burden of levodopa-induced dyskinesias, while late-onset patients tend towards more rapid functional decline and cognitive deterioration. Underpinning these clinical phenotypes are distinct molecular and network alterations, from blood and brain transcriptomic signatures to disrupted functional connectivity across motor and cognitive circuits. Longitudinal assessment of motor scales, non-motor symptom inventories and health-related quality of life metrics emphasises the heterogeneous trajectories of disease, highlighting the need for tailored therapeutic strategies and precise prognostic biomarkers.

Research from Nature Portfolio

Recent transcriptomic analyses have revealed that stress-response pathways in the caudate nucleus and endothelial signalling in the putamen correlate with specific motor and cognitive complications. Peripheral blood profiles mirror these brain signatures, offering a minimally invasive window into disease progression and the molecular distinction between early- and late-onset PD. Complementing this, a large population-based cohort study has demonstrated that higher age at onset is generally associated with faster motor decline and diminished health-related quality of life, except for levodopa-related fluctuations, which are less pronounced in older patients. These findings underscore the interplay between ageing processes and PD pathophysiology, informing the design of age-adaptive management protocols.

Clinical Phenotypes and Progression of Parkinson’s Disease publication trend

The graph below shows the total number of articles in clinical phenotypes and progression of parkinson’s disease across all publications each year (not limited to Nature Index journals).

Technical terms

Bradykinesia: A slowness of voluntary movement, a cardinal motor feature of PD.

Dyskinesia: Involuntary, erratic movements often arising as a complication of long-term levodopa therapy.

Transcriptomic signature: The pattern of gene expression in a tissue or cell type that reflects underlying molecular processes.

Functional connectivity: The synchronisation of activity between different brain regions, assessed by neuroimaging.

Health-related quality of life (HRQoL): A multidimensional measure of a patient’s perceived physical, emotional and social well-being.

References

1. Blood transcriptomic signatures associated with molecular changes in the brain and clinical outcomes in Parkinson’s disease. Nature Communications (2023).
2. Different risks of early-onset and late-onset Parkinson disease in individuals with mental illness. npj Parkinson's Disease (2024).
3. Abnormal intra- and inter-network functional connectivity of brain networks in early-onset Parkinson’s disease and late-onset Parkinson’s disease. Frontiers in Aging Neuroscience (2023).
4. Impact of age at onset on symptom profiles, treatment characteristics and health-related quality of life in Parkinson’s disease. Scientific Reports (2022).
5. Shaping the course of early-onset Parkinson’s disease: insights from a longitudinal cohort. Neurological Sciences (2023).