Which neuroimaging finding would support a post-stroke AOS diagnosis?

Which neuroimaging finding would support a post-stroke AOS diagnosis?

• A. Left hemisphere lesions in speech planning areas such as the inferior frontal gyrus, insula, or premotor cortex.
• B. Right hemisphere lesions in the occipital lobe.
• C. Bilateral cerebellar lesions.
• D. No lesions.

Answer: (A)

The important idea is that post-stroke Apraxia of Speech arises from damage to the brain regions that plan and program speech movements. When imaging shows a lesion in the left hemisphere’s speech-planning network—particularly the inferior frontal gyrus, insula, and premotor cortex—it supports an AOS diagnosis. These left-side areas are key for sequencing and articulatory planning, so damage there disrupts the motor plan for producing speech, leading to the characteristic halting, effortful, and sometimes inconsistent speech despite preserved language comprehension. In contrast, a lesion in the right occipital lobe would affect vision rather than speech planning; bilateral cerebellar lesions can cause coordination and timing problems (dysarthria or ataxia) but not the classic planning-specific errors of AOS; and having no lesions would not explain a post-stroke motor speech disorder.

The important idea is that post-stroke Apraxia of Speech arises from damage to the brain regions that plan and program speech movements. When imaging shows a lesion in the left hemisphere’s speech-planning network—particularly the inferior frontal gyrus, insula, and premotor cortex—it supports an AOS diagnosis. These left-side areas are key for sequencing and articulatory planning, so damage there disrupts the motor plan for producing speech, leading to the characteristic halting, effortful, and sometimes inconsistent speech despite preserved language comprehension.

In contrast, a lesion in the right occipital lobe would affect vision rather than speech planning; bilateral cerebellar lesions can cause coordination and timing problems (dysarthria or ataxia) but not the classic planning-specific errors of AOS; and having no lesions would not explain a post-stroke motor speech disorder.