Several standardized tests are
commonly used in the diagnosis of aphasia. Some of these are
the Minnesota Test for Differential
Diagnosis (MTDDA), the Porch Index of Communicative Ability
(PICA), and the Boston Diagnostic Aphasia
Examination (BDAE).
The
MTDDA was developed by Schuell in 1965.
This comprehensive test assesses the patient's strengths and
weakness in all language modalities.
The
PICA (Porch, 1967) samples fewer language
behaviors than the MTDDA. However, it is known for its
elaborate scoring system, which allows the examiner to
differentiate between responses elicited with different
degrees of cueing, various types of errors, and also to note
the immediacy of the response.
The
BDAE, developed by Goodglass and Kaplan
in 1972, has been revised twice, in 1983 and 2001. I was
one of the reviewers for the new
edition. It's good, but perhaps a bit lengthy for many patients. While much of the previous
edition has been retained the new edition has significant
changes/improvements. It consists of more than 40 subtests
divided into the following sections: fluency,
conversation/expository speech, auditory comprehension,
articulation, recitation and music, repetition, naming,
paraaphasia, reading, and writing. It also has extended
subtests that include narrative speech/fables, auditory
comprehension, repetition, naming, reading, writing and
praxis. It can often make a determination whether or not the aphasic has Broca's aphasia, Wernicke's aphasia, or another.The severity of a patient's aphasia can be rated on
a scale from one to seven based on speech and language
characteristics as well as auditory comprehension. The
Boston
Naming Test, a test for anomia which was
developed to be used along with the BDAE, is the
supplementary instrument most often used in the evaluation
of aphasia. The new edition can quantify the severity of the
word finding problem and can help the clinician determine
whether and to what extent the patient can recognize the
picture he/she has failed to name.
The administration
of any of the above standardized aphasia batteries can be
time-consuming. In practice, it is best to try to quickly
test all aspects of language, including auditory
comprehension, oral expression, reading and writing, during
an evaluation. In some facilities, patients only stay for a
day or two, and it is necessary to quickly gather enough
information to write any reports that may be required. Also,
it is important to remember that standardized tests are just
one way to sample the patient's performance. A set of tasks
devised by the clinician may provide an equally valid basis
for establishing therapy goals. A standardized test should
be viewed as a checklist (this was suggested some years ago
by Joseph Keenan, 1975, who had an excellent procedure
manual that is out of print). Checklists are used to
evaluate all aspects of language, and thus ensure that the
examiner does not forget to evaluate any important areas of
functioning. In my practice I seldom have the opportunity to
administer a complete diagnostic aphasia exam. I am
pleased that the authors of the Boston have developed a
short form with its own set of stimulus cards.