Aphasia type, age and cerebral infarct localisation

Area of Science:

• Neurology
• Neuroscience
• Stroke Research

Background:

• Stroke patients with nonfluent aphasia are often younger than those with fluent aphasia.
• The reasons for this age-related difference in aphasia type are debated.
• Potential factors include age-related changes in language area organization or stroke localization.

Purpose of the Study:

• To investigate whether the age difference in aphasia types (nonfluent vs. fluent) is due to age-related changes in language area organization or stroke location.
• To analyze the relationship between patient age, infarct localization, and aphasia type after ischemic stroke.

Main Methods:

• Analysis of a prospective stroke database (n=423) of ischemic stroke patients with computed tomography (CT)-confirmed infarcts.
• Classification of language disturbance (no aphasia, nonfluent aphasia, fluent aphasia) and infarct localization (anterior/posterior) in the acute phase.
• Statistical analysis (chi-squared test) to compare age groups (<51 vs. >70 years) regarding aphasia type and infarct location.

Main Results:

• Nonfluent aphasia predominated in younger patients (<51 years), while fluent aphasia was more common in elderly patients (>70 years) (P=0.005).
• Posterior infarcts were more frequent in elderly patients (P=0.002).
• Age did not influence the proportion of atypical cases (lesions without aphasia) or atypical infarct localizations for aphasia types.

Conclusions:

• The higher prevalence of fluent aphasia in older stroke patients is associated with a greater proportion of posterior infarcts in this age group.
• The study does not support the hypothesis of age-related changes in the anatomico-functional organization of language areas influencing aphasia type.
• Stroke localization, rather than age-dependent neural reorganization, appears to be the primary driver of the observed age-related differences in aphasia types.