Use of the Behavioral Dyscontrol Scale-2 (BDS-2) to measure executive dysfunction in FXTAS

Area of Science:

• Neuroscience
• Genetics
• Radiology

Background:

• Fragile X-associated Tremor/Ataxia Syndrome (FXTAS) is a neurodegenerative disorder linked to the FMR1 gene premutation.
• FXTAS is characterized by mRNA toxicity, leading to cognitive decline and distinct brain changes visible on MRI.
• The Behavioral Dyscontrol Scale-2 (BDS-2) assesses executive function, but its correlation with neuroanatomical changes in FXTAS requires further investigation.

Purpose of the Study:

• To investigate the relationship between scores on the Behavioral Dyscontrol Scale-2 (BDS-2) and Magnetic Resonance Imaging (MRI) findings in individuals with FXTAS.
• To determine if BDS-2 scores correlate with neuroanatomical markers of neurodegeneration in FXTAS patients.

Main Methods:

• Correlation and linear regression analyses were employed.
• The study included 56 FMR1 premutation carriers, with and without FXTAS.
• BDS-2 scores were compared with MRI total scores, white matter hyperintensities, MMSE, and CANTAB subtests.

Main Results:

• MRI scores showed a significant negative correlation with BDS-2 total scores (r = -0.66, p < 0.0001).
• This association remained significant after controlling for CGG repeat length, sex, and age (β = -0.36, p = 0.002).
• Executive function subtests of the CANTAB positively correlated with MRI scores, while MMSE showed a negative correlation.

Conclusions:

• The BDS-2 is a valuable tool for assessing executive dysfunction in FXTAS, demonstrating a clear link with neuroimaging markers.
• Findings support the clinical utility of BDS-2 as a complementary measure alongside traditional cognitive and automated executive function tests in FXTAS management.
• The study highlights the importance of integrating behavioral assessments with neuroimaging for a comprehensive understanding of FXTAS.