[11C](R)-PK11195 Positron Emission Tomography Imaging of Skull Inflammation in Isolated Rapid-Eye-Movement Sleep

Andreas Myhre Baun1, Michael Firbank2, Rainer Hinz3

  • 1Department of Nuclear Medicine, Aarhus University Hospital, Aarhus, Denmark.

Abstract

Insights

Skull bone marrow inflammation is elevated in patients with isolated rapid-eye-movement sleep behavior disorder (iRBD), an alpha-synucleinopathy. This study provides the first in vivo evidence of this skull-meningeal immune axis activation in prodromal disease.

Area of Science:

  • Neuroimmunology
  • Neuroinflammation
  • Parkinson's Disease Research

Background:

  • Skull bone marrow serves as a specialized immune compartment for the meninges.
  • Emerging evidence links skull marrow activity to neuroinflammation in early Parkinson's disease.
  • In vivo assessment of skull marrow in alpha-synucleinopathies was previously lacking.

Purpose of the Study:

  • To evaluate skull and meningeal inflammatory activity in patients diagnosed with isolated rapid-eye-movement sleep behavior disorder (iRBD).
  • To investigate the role of the skull-meningeal immune axis in prodromal alpha-synucleinopathies.

Main Methods:

  • Utilized longitudinal [11C](R)-PK11195 positron emission tomography scans.
  • Compared 20 iRBD patients with 19 healthy controls.
  • Assessed skull marrow activation in vivo.

Main Results:

  • iRBD patients exhibited 22.87% higher global skull inflammation compared to controls, particularly in frontal regions.
  • Observed inflammation progression over a 3-year follow-up period.
  • Skull inflammation did not correlate with phenoconversion to Parkinson's disease.

Conclusions:

  • Presents the first in vivo evidence of skull marrow activation in an alpha-synucleinopathy.
  • Supports the involvement of the skull-meningeal immune axis in iRBD.
  • Links peripheral and central inflammation in prodromal Parkinson's disease.