Diagnosis

Diagnosis is difficult for many reasons, including inconsistencies in definition and interpretation of aphasic syndromes. For example, a physician may not be able to distinguish a particular error of articulation as being resultant of aphasia, apraxia (programming error), or dysarthria (execution error). The lines of demarcation are often blurred from one disorder to another (Bradshaw & Mattingley, 1995; Axer, Jantzen, Berks, Sudfeld, & Keyserlingk, 2000). Even information concerning the exact symptoms and characteristics of various syndromes (including aphasia) is currently widely debated (Kosslyn & Koenig, 1995; Axer et al., 2000). The fine details of the information contained within this research report may change as more scientific discoveries are made; however, the basic concepts are valid and the characteristics presented appear to be the general rule among afflicted patients.

            Post-stroke aphasia can now be predicted using PET scans, which can show functional problems even in intact regions. The PET scan evaluates the levels of metabolic activity within the brain to determine the extent of the damage. The metabolic rates measured shortly after stroke correlate with follow up tests conducted two years later, and can predict eventual onset of aphasia, though diagnosis may not be specific and precise at this point in time (Karbe, 1995). This is somewhat limited, however, due to the uncertainty of the pathophysiology of post-acute stages of stroke (Small, 2000).