Anatomoclinical correlations of the aphasias as defined through computerized tomography: exceptions

Area of Science:

• Neuroscience
• Neurolinguistics
• Clinical Neurology

Background:

• Classical aphasia localization models propose distinct brain regions for fluent and nonfluent speech.
• Exceptions to these models are crucial for understanding brain plasticity and language processing.

Purpose of the Study:

• To determine the frequency of exceptions to classical aphasia localization in Italian adults.
• To correlate clinical aphasia classifications with lesion sites identified via computerized tomography (CT).

Main Methods:

• 267 right-handed, literate, adult Italian native speakers with focal vascular left-hemisphere lesions underwent CT scans.
• Lesions were mapped, and patients were classified as nonfluent aphasic, fluent aphasic, or nonaphasic.
• Anatomoclinical correlations were performed on 207 patients (excluding those with negative CT or only deep lesions).

Main Results:

• 36 out of 207 patients (17.4%) presented unexpected findings.
• Seven cases showed fluent aphasia with anterior CT lesions.
• Six cases exhibited nonfluent aphasia with posterior CT lesions.

Conclusions:

• A significant frequency of exceptions to classical aphasia localization exists.
• These findings challenge strict anatomical models and highlight the complexity of language representation in the brain.
• Further research is needed to understand the mechanisms underlying these atypical language-lesion correlations.