Localization of stuttering based on causal brain lesions

Area of Science:

• Neuroscience
• Neurology
• Speech and Language Pathology

Background:

• Stuttering, affecting 1% of adults, causes communication difficulties and social anxiety.
• It can be developmental or acquired due to brain damage, offering insights into its neural basis.
• Acquired neurogenic stuttering following stroke provides a unique model to study stuttering's neuroanatomy.

Purpose of the Study:

• To investigate the neuroanatomical substrate of stuttering using acquired and developmental stuttering datasets.
• To identify a common brain network associated with acquired stuttering using lesion network mapping.
• To determine the relevance of this network to developmental stuttering.

Main Methods:

• Utilized three datasets: literature case reports (n=20), a clinical cohort (n=20), and developmental stuttering adults (n=20).
• Applied lesion network mapping to stroke-induced acquired stuttering datasets to identify common lesion locations.
• Correlated grey matter volume within the identified network with stuttering impact in developmental stuttering.

Main Results:

• Lesions causing acquired stuttering consistently mapped to a network centered around the left putamen, including the claustrum and amygdalostriatal transition area.
• This acquired stuttering network was reproducible across independent stroke datasets (PFWE < 0.05).
• In developmental stuttering, grey matter volume in the left posteroventral putamen, claustrum, and amygdalostriatal transition area correlated with stuttering severity (PFWE < 0.05).

Conclusions:

• Acquired neurogenic stuttering is associated with a specific brain network centered in the left putamen, claustrum, and amygdalostriatal transition area.
• This lesion-based network is also relevant to developmental stuttering, indicated by its association with symptom severity.
• Suggests a shared neuroanatomical basis for stuttering across different etiologies.