Screening for cognitive dysfunction in Huntington's disease with the clock drawing test

Area of Science:

• Neurology
• Neuropsychology
• Genetics

Background:

• Huntington's disease (HD) is a genetic neurodegenerative disorder.
• Cognitive impairment is a key feature of HD, impacting quality of life.
• Early detection of cognitive dysfunction is crucial for management.

Purpose of the Study:

• To evaluate the clock drawing test (CDT) as a screening tool for cognitive impairment in HD mutation carriers.
• To assess the accuracy and reliability of the CDT in this population.
• To compare CDT performance with established cognitive assessments.

Main Methods:

• The CDT was administered to 65 HD mutation carriers.
• Performance was scored using Shulman and Freund systems.
• Correlations with MMSE, SDMT, Verbal Fluency, and Stroop tests were analyzed.
• Receiver-operator characteristic (ROC) analyses determined optimal cut-off scores.

Main Results:

• High inter-rater reliability was observed for both CDT scoring systems (ICC > 0.90).
• CDT showed moderate to high correlations with executive cognitive functioning (mean ρ = 0.75).
• CDT demonstrated good sensitivity (0.82) and specificity (0.79) for cognitive dysfunction.

Conclusions:

• The clock drawing test is a suitable and accurate screening instrument for cognitive dysfunction in HD.
• Its ease of use and speed make it practical for clinical settings.
• The CDT is particularly effective in identifying deficits in executive cognitive functioning.