Adaptive structural changes in the motor cortex and white matter in Parkinson's disease

Area of Science:

• Neuroscience
• Neuropathology
• Movement Disorders

Background:

• Parkinson's disease (PD) involves dopaminergic pathway loss affecting motor control.
• Motor cortex abnormalities are linked to clinical PD development.
• PD progression includes silent, prodromal, and clinical motor stages.

Purpose of the Study:

• To investigate structural changes in the primary motor cortex and corticospinal tract during PD progression.
• To correlate these changes with different stages of Parkinson's disease.

Main Methods:

• Analysis of longitudinal clinical and cross-sectional pathological cohorts.
• Utilized 18F-FP-CIT positron emission tomography and diffusion tensor imaging.
• Histological examination of motor cortex white matter.

Main Results:

• Prodromal PD patients showed increased fractional anisotropy in motor cortex and corticospinal tract, indicating adaptive structural changes.
• Histology revealed axonal disorientation, α-synuclein accumulation, and oligodendrocyte changes in motor cortex white matter.
• No neuronal loss in the motor cortex was observed, but early increases in neurofilament and myelin proteins were associated with α-synuclein.

Conclusions:

• Structural changes in the primary motor cortex and corticospinal tract occur early in PD, starting in the prodromal motor stage.
• These adaptive changes may contribute to motor symptoms as Parkinson's disease advances.