Exploring bradyphrenia in Huntington's disease using the computerized test of information processing (CTiP)

Area of Science:

• Neuroscience
• Cognitive Science
• Neurology

Background:

• Bradyphrenia, characterized by slowed mental processing, is observed in conditions like Parkinson's disease and schizophrenia.
• Its presence and characteristics in Huntington's Disease (HD) remain largely uncharacterized.
• Understanding bradyphrenia in HD is crucial for comprehensive disease management.

Purpose of the Study:

• To investigate the presence and progression of bradyphrenia in individuals with Huntington's Disease.
• To utilize the Computerized Test of Information Processing (CTiP) for objective assessment of cognitive processing speed in HD.
• To establish a quantifiable measure of bradyphrenia in HD patients across different disease stages.

Main Methods:

• A cohort of 211 participants, including individuals at various stages of HD (0-3) and healthy controls (HC), were assessed.
• The CTiP, comprising Simple Reaction Time (SRT), Choice Reaction Time (CRT), and Semantic Search Reaction Time (SSRT) subtests, was administered.
• Motor-corrected reaction times were calculated by subtracting SRT from CRT and SSRT to operationalize bradyphrenia.

Main Results:

• Significant differences in motor-corrected CRT vs SSRT were observed within HD-ISS and HC groups (p < 0.0001).
• The magnitude of these processing speed deficits increased progressively with advancing HD disease stage (p < 0.0001).
• Receiver Operating Characteristic (ROC) analysis demonstrated that motor-corrected differences could significantly distinguish advanced HD stages (2+3) from early stages (0+1) (AUC = 0.72, p < 0.0001).

Conclusions:

• This study provides evidence for bradyphrenia in Huntington's Disease, with deficits worsening as the disease progresses.
• The CTiP offers a reliable method for quantifying these processing speed impairments in HD.
• The identified bradyphrenia has significant implications for daily functioning in HD patients and warrants further investigation.