Handwriting patterns in isolated rapid eye movement sleep behaviour disorder.

Area of Science:

• Neurology
• Sleep Medicine
• Movement Disorders

Background:

• Handwriting changes are early indicators of Parkinson's disease (PD).
• Isolated rapid eye movement sleep behaviour disorder (iRBD) is a strong predictor of future PD.
• Handwriting alterations in iRBD require further investigation for early PD detection.

Purpose of the Study:

• To evaluate handwriting characteristics in individuals with iRBD.
• To develop a rating scale for identifying early clinical hallmarks of PD in iRBD patients.

Main Methods:

• A cross-sectional study compared 33 individuals with polysomnography-confirmed iRBD to 29 controls.
• Participants completed a handwriting task (sentence copying).
• A graphologist developed a scale assessing features like micrographia, tremor, and pen pressure; experts also provided global assessments.

Main Results:

• Individuals with iRBD exhibited slower writing speeds compared to controls.
• Key differentiating features in iRBD included hidden tremor, sentence slope, and pen pressure.
• The developed handwriting scale demonstrated higher classification accuracy for iRBD than expert global assessment (AUC 0.76 vs 0.62).

Conclusions:

• Writing speed, tremor, pen pressure, and sentence slope are significant handwriting features in iRBD.
• These features may represent early patterns indicative of prodromal Parkinson's disease.
• Further research is warranted to refine these handwriting markers for early PD detection.