Mechanisms underlying neglect recovery after prism adaptation

Area of Science:

• Neuroscience
• Rehabilitation Medicine
• Cognitive Psychology

Background:

• Hemispatial neglect is a debilitating condition often resulting from brain injury.
• Prism adaptation (PA) shows promise for improving neglect, but treatment response varies.
• Predictors for successful PA treatment in neglect patients are not fully understood.

Purpose of the Study:

• To identify behavioral and neuroanatomical predictors of recovery following prism adaptation in neglect patients.
• To investigate how PA reorganizes low-order visuo-motor behavior and high-order visuo-spatial representation.
• To explore the relationship between lesion location and treatment outcomes.

Main Methods:

• 16 neglect patients received 10 daily PA sessions; 8 controls received cognitive stimulation.
• Assessments included neglect severity and oculo-motor responses before, and at 1 week, 1 month, and 3 months post-treatment.
• Neuroanatomical data (lesion location) were analyzed in relation to behavioral outcomes.

Main Results:

• PA led to lasting neglect recovery and visuo-motor reorganization (error reduction, after-effects).
• Early error reduction within the first week predicted neglect recovery and improved oculo-motor responses.
• Severe occipital lesions correlated with poor error reduction, limited recovery, and reduced oculo-motor improvement.

Conclusions:

• PA-induced visuo-motor reorganization resets the oculo-motor system, enhancing visuo-spatial representation and improving neglect.
• Early behavioral changes during PA are crucial predictors of treatment success.
• Neuroanatomical factors, particularly occipital lesion severity, significantly influence PA efficacy.