Validation of the Thai version of the short Boston Naming Test (T-BNT) in patients with Alzheimer's dementia and mild cognitive impairment: clinical and biomarker correlates.

OBJECTIVES

Impairments in the Boston Naming Test (BNT), which measures confrontational word retrieval, frequently accompanies Alzheimer's dementia (AD) and may predict a more rapid progression of illness. This study aims to validate the Thai version of the 15-item BNT (T-BNT) in participants with AD and amnestic mild cognitive impairment (aMCI) and to externally validate the T-BNT using clinical and biomarker measurements.

METHODS

This cross-sectional study recruited patients with AD, diagnosed according to NINCDS-ADRDA criteria (n = 60), aMCI, diagnosed using the Petersen criteria (n = 60), and healthy controls (n = 62). We examined the internal consistency, concurrent and discriminant reliability of the T-BNT. We also assessed the Mini Mental State Examination (MMSE), the Verbal Fluency Test (VFT) and the Word List Memory (WLM) tests and measured apolipoprotein E polymorphism and serum levels of folic acid, high-density lipoprotein cholesterol (HDL) and triglycerides.

RESULTS

This study validated a 10-item T-BNT (10T-BNT), which yielded good internal consistency (0.92), a one-factor unidimensional structure, and adequate concurrent and discriminant validity. Lower scores on the 10T-BNT highly significantly predict AD, but not aMCI, and are positively associated with VFT and WLM test scores. Furthermore, lowered 10T-BNT scores are significantly associated with the ApoE4 allele, lower folate levels and an increased triglyceride/HDL-cholesterol ratio.

CONCLUSIONS

This study validated the 10T-BNT and the total score on this scale is strongly associated with AD, impairments in semantic and episodic memory and biomarkers, which are known to modify memory via different mechanisms.