Nonetheless, it is possible to associate lesions in certain areas with particular speech defects. As age increases, some healthy elderly persons, even those without cognitive impairment, tend to use fewer words and may make semantic errors. If poor auditory or visual function is noted, further testing is required. Thus, pulmonary function testing and breathing exercises may be indicated. Aphasia is the most common speech disorder among the elderly, followed by dysarthria.
Some authorities use the terms mixed aphasia and global aphasia interchangeably.
However, in general, mixed aphasia refers to less severe global aphasia. Other classifications exist, an indication that aphasia is never purely receptive or purely expressive. No classification is completely satisfactory. Recovery from aphasia, if it occurs, is most pronounced during the first 3 months after brain injury. Rehabilitation focuses on establishing the most effective means of communication.