Primary diagnostic methods are
listening to the patient's speech and observing oral motor
movements. Present a series of speech and oral motor tasks
to the patient. Apraxia is caused by lesions in Broca's area. Of course, damage to Broca's area can also
cause Broca's aphasia. As Broca's aphasia is a non-fluent
form of the disorder in which speech is labored, choppy and
poorly articulated, it may be hard to differentiate between
this syndrome and apraxia. One instrument that can help a
clinician to make this distinction is the Token Test
(DeRenzi & Vignolo, 1966). This test has five parts
involving the manipulation of objects of different colors,
shapes and sizes. It tests receptive grammar by requiring
the patient to follow instructions like "put the red square
on the yellow circle." Since patients with Broca's aphasia
have difficulty comprehending grammatical morphemes like the
preposition "on" they will do poorly on the test. Apraxics without aphasia,
on the other hand, will have no difficulty following the
commands unless they have limb apraxia and therefore cannot
volitionally follow commands. Another test I have given routinely
is the Boston Examination for Aphasia. It's a good test that
just got better (2001). I was a reviewer for Williams and Wilkins
Publishing Company to look closely at new edition and was
favorably impressed.
It should be noted
that a patient may well have both apraxia and Broca's
aphasia.
Both limb and oral
apraxia may be mistakenly diagnosed as an auditory
comprehension deficit.
Non-Speech
Tasks
Begin
with vowel production. Go all the way around the vowel
triangle (quadralateral). Now have the patient perform
diadochokinetic tasks: repeat /p/, /t/, /k/ then /ptk/
several times (rapid alternating task).
Speech
tasks
- produce words
of progressively increasing length (e.g. hope, hopeful,
hopefully; thick, thicker, thickening;); apraxic patients
performance tends to deteriorate as words increase in
length;
- repeat several
multisyllabic words three times (e.g. butterfly,
butterfly, butterfly); production may improve with some
apraxic patients;
- repetition of
sentences
- conversation
- picture
description
- oral
reading
- counting to
20
- days of the
week
- months of the
year
Motor Speech
Evaluation
(suggested by Wertz et al., 1984, p. 98):
This
is a screening tool which should take less than 20 minutes
to administer. Three steps may be required to obtain useful
data. If the patient does not respond in such a way as to
give diagnostic information, repeat the stimuli. If the
second response is still ambiguous, cue (e.g. "Listen, watch
me, and do what I do").
Scoring the Motor
Speech Evaluation can be descriptive:
Use
"A" for apraxic productions, "P" for paraphasias, "D" for
dysarthria, "U" for nondiagnostic errors, "O" for other
errors, and "N" for normal responses. It can also utilize
the PICA 16- point scale, or narrow or broad phonetic
transcription.
The tasks are
conversation, vowel prolongation, repetition of monosyllable
/p /, /t /, /k /; repetition of those in sequence,
repetition of multisyllabic words; multiple trials with the
same word; repetition of words that increase in length;
repetition of monosyllabic words that contain the same
initial and final sound; repetition of sentences; counting
forward and backward; picture description; repetition of
sentences used volitionally to determine consistency of
production; and oral reading.
Generally, apraxic
patients will reveal their deficits in conversation by
producing apraxic articulatory errors and abnormal prosody.
Usually they have no problem with vowel prolongation or
repeating single monosyllables. With the sequence of /ptk/,
there may be initiation difficulty, substitution, omission,
or rearrangement of the syllables; slow rate; equal and even
stress; stops, starts, and reattempts to produce the
sequence. Similar errors should be evident with
multisyllabic words and short phrases. Repeated trials on
the same word may show inconsistent errors. Words of
increasing length should show more errors on the longer
words. Monosyllabic words beginning and ending with the same
sound may show more errors in initial position, but not
necessarily. Sentences and picture description will produce
apraxic errors in articulation and prosody. Counting forward
and backward contrasts automatic speech versus volitional
speech, with more errors expected on the latter. Having the
patient repeat sentences he/she produced earlier allows the
examiner to check for consistency, with the apraxic expected
to be inconsistent. Oral reading of the "Grandfather
Passage," which contains most of the sounds of English,
allows comparison with repetition tasks and more volitional
tasks.
Some oral movement
tasks (suggested by Darley, 1978 and DeRenzi et al, 1966;
cited in Meitus & Weinberg, p. 269): (use verbal
instruction alone at first; if patient cannot perform, then
demonstrate and observe his/her imitation)
- stick out your
tongue
- puff or
blow
- pucker up your
lips
- try to touch
your nose with the tip of your tongue
- bite your
lower lip
- whistle
- move your
tongue in and out of your mouth
- lick your
lips
- clear your
throat
- click your
teeth together once
- smile
- click your
tongue as if imitating the sound of a galloping
horse
- chatter your
teeth as if you are cold
- try to touch
your chin with the tip of your tongue
- cough
- puff out your
cheeks
- wiggle your
tongue from side to side
- show how you
would kiss someone
- alternately
pucker and smile
- yawn
The clinician
should make qualitative judgments of the patient's
performance, eg., consider the presence of:
- accurate
movement patterns preceded by trial and error
- searching
movements of the tongue or lips
- accurate
movement preceded by pauses
- crude,
awkward, erratic, or extraneous oro-facial
movements
- overall
gesture patterns which are grossly acceptable, but
defective in terms of amplitude, accuracy, or
speed
- perseverated
movement
Commercial
Instruments Available
Apraxia Battery for Adults (ABA) by
Barbara Dabul (1979)
Dworkin-Culatta
Oral Mechanism Examination, (1980)
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