Two different phenomena in basic motor speech performance in premanifest Huntington disease

Area of Science:

• Neuroscience
• Speech-Language Pathology
• Genetics

Background:

• Dysarthria is a frequent symptom in Huntington disease (HD).
• Early detection of functional changes in premanifest HD (preHD) is crucial for monitoring disease progression.
• Speech parameters, particularly speech timing, are sensitive indicators of neurological function.

Purpose of the Study:

• To objectively analyze speech parameters, focusing on speech timing in connected speech and nonspeech verbalizations.
• To investigate speech characteristics in individuals with premanifest Huntington disease (preHD).

Main Methods:

• Cross-sectional pilot study involving 28 preHD mutation carriers and 28 healthy controls.
• Participants performed reading and syllable repetition tasks.
• Computerized acoustic analysis of speech rate and regularity, correlated with clinical and MRI-based brain atrophy data.

Main Results:

• PreHD participants exhibited significantly higher variability in syllable repetition compared to controls (Cohen's d = 1.46).
• Increased speech rate was observed in preHD individuals (Cohen's d = 1.19), correlating with reduced volume in speech-related brain regions.
• Speech rate also correlated with disease burden, estimated onset, and cognitive scores.

Conclusions:

• Speech rate and regularity measurements may serve as valuable tools for monitoring subclinical disability in preHD.
• Potential huntingtin-dependent developmental processes in the brain might explain some observed speech performance variations.