Alexia is loss of the ability to read words. Prosody, the quality of rhythm and emphasis that adds meaning to speech, is usually influenced by both hemispheres but sometimes by the nondominant hemisphere alone. Large frontal-temporal lesions cause global aphasia with severe defects in comprehension and expression. However, bedside interaction usually suffices. Wernicke's aphasia indicates an abnormality of the posterolateral left temporal and inferior parietal language region.
Anomia indicates a posterior temporoparietal abnormality or degeneration.
Spontaneous Wernicke-like aphasia with the ability to repeat heard language results from interruptions of pathways that link frontal and temporal lobe language areas. Prognosis and Treatment Recovery from aphasia depends on several factors, including the size and location of lesions, the degree of language impairment, and, to a lesser degree, age, education, and systemic health. After that age, most recovery occurs within the first 3 mo, but improvement continues to a variable degree up to a year. As a rule, comprehension improves more than the language function. In such persons, specific injuries to either hemisphere can cause aphasia, but nearly all recover rapidly.