Clinical anatomic study of pure dysarthria

Area of Science:

• Neurology
• Neuroimaging
• Stroke Medicine

Background:

• Dysarthria, a speech disorder, can result from various neurological conditions.
• Lacunar infarcts are small strokes often associated with specific syndromes.
• The precise localization of brain lesions causing pure dysarthria requires detailed neuroimaging.

Purpose of the Study:

• To investigate the neuroanatomical correlates of pure dysarthria.
• To determine the role of internal capsule infarcts in causing dysarthria.
• To evaluate the relationship between dysarthria, facial weakness, and limb clumsiness.

Main Methods:

• Computed tomography (CT) and magnetic resonance imaging (MRI) were performed on nine patients with pure dysarthria.
• Lesion locations were identified and categorized within the internal capsule and surrounding white matter.
• Clinical symptoms, including dysarthria, facial weakness, and limb involvement, were documented.

Main Results:

• Eight of nine patients had infarcts in the internal capsule (anterior limb, genu, or adjacent corona radiata).
• One patient had a bulbar motor cortex infarct.
• Transient dysarthria with poor articulation was universal; associated symptoms included contralateral facial weakness and, in three cases, transient finger involvement (dysarthria-clumsy hand variants).

Conclusions:

• Infarcts in the internal capsule are a common cause of pure dysarthria.
• The dysarthria-clumsy hand syndrome can be considered a variant of a broader stroke syndrome, not exclusively a lacunar syndrome.
• Neuroimaging is crucial for identifying the specific stroke locations responsible for dysarthria.