Repetitive exposure to prismatic adaptation in post-stroke optic ataxia: a single case study exploring behavioural...

Area of Science:

• Neuroscience
• Cognitive Rehabilitation
• Visuomotor Control

Background:

• Prismatic adaptation (PA) involves visuomotor shifts using prisms, engaging brain networks including parietal regions.
• Optic Ataxia (OA) is a disorder affecting visually guided reaching, often linked to parietal lesions.
• Previous studies show mixed results on PA effectiveness in OA patients.

Purpose of the Study:

• To investigate behavioral and neurofunctional changes in an Optic Ataxia patient undergoing leftward PA as cognitive rehabilitation.
• To explore the impact of PA on visuomotor coordination and brain network reorganization in an OA patient.

Main Methods:

• A left hemisphere stroke patient with OA underwent ten sessions of leftward PA.
• Behavioral assessments of reaching movements were conducted.
• Resting-state fMRI, including network dispersion, functional gradients, and dynamic edge-centric analysis, was used to assess neurofunctional changes.

Main Results:

• The patient showed improved reaching with the contralesional hand in the ipsilesional hemifield post-PA.
• fMRI revealed significant hemispheric asymmetry with increased network segregation and dispersion in the left hemisphere.
• Dynamic analysis indicated reduced entropy in the visual network and increased entropy in attention/control networks, correlating with structural disconnections.

Conclusions:

• Repetitive PA can lead to behavioral improvements in OA patients.
• PA induces significant neurofunctional reorganization, particularly in the left hemisphere, involving both static and dynamic network changes.
• This study highlights the utility of advanced fMRI techniques in understanding functional recovery mechanisms after PA in OA.