Cognitive and behavioral changes in Huntington disease before diagnosis

Area of Science:

• Neuroscience
• Genetics
• Clinical Neurology

Background:

• Huntington disease (HD) presents with phenotypic manifestations detectable over 15 years before motor diagnosis.
• Standardized definitions for HD and its premanifest (prodromal) stages are essential for advancing clinical care and research globally.

Purpose of the Study:

• To summarize cognitive and psychiatric changes in premanifest Huntington disease (prodromal HD).
• To discuss the implications of these findings for future research and clinical understanding of prodromal HD.

Main Methods:

• Review and synthesis of cognitive and psychiatric assessments in individuals with premanifest HD.
• Analysis of changes over time in cognitive and behavioral measures.

Main Results:

• Earliest cognitive deficits in prodromal HD are observed in tests like the Symbol Digit Modalities Test and Stroop.
• Cognitive changes become widespread in later prodromal stages, with the most significant decline near motor diagnosis.
• Psychiatric and behavioral symptoms worsen over time in prodromal HD, impacting independent capacity despite lower assessment scores compared to cognitive changes.

Conclusions:

• Consistent definitions of HD and its prodromal stages are vital for global research and clinical practice.
• Understanding early cognitive and psychiatric changes is critical for managing Huntington disease progression.
• Psychiatric and behavioral symptoms, though less pronounced in testing, are highly debilitating in premanifest Huntington disease.