BROCA'S APHASIA

(expressive aphasia, motor aphasia):

Sufferers of this form of aphasia exhibit the common problem of agrammatism.  For them, speech is difficult to initiate, non-fluent, labored, and halting. Similarly, writing is difficult as well. Intonation and stress patterns are deficient. Language is reduced to disjointed words and sentence construction is poor, omitting function words and inflections (bound morphemes). For example, in the following passage, a Broca's aphasic patient is trying to explain how he came to the hospital for dental surgery:

Yes... ah... Monday... er... Dad and Peter H... (his own name), and Dad.... er... hospital... and ah... Wednesday... Wednesday, nine o'clock... and oh... Thursday... ten o'clock, ah doctors... two... an' doctors... and er... teeth... yah.^[1]

In extreme cases, patients may be only able to produce a single word. The most famous case of this was Paul Broca's patient Leborgne, nicknamed "Tan", after the only syllable he could say. Even in such cases, over-learned and rote-learned speech patterns may be retained -- for instance, some patients can count from one to ten, but cannot produce the same numbers in ordinary conversation.

While word comprehension is generally preserved, meaning interpretation dependent on syntax and phrase structure is substantially impaired. This can be demonstrated by using phrases with unusual structures. A typical Broca's aphasic patient will misinterpret "the dog is bitten by the man" by switching the subject and object.  Patients who recover go on to say that they knew what they wanted to say but could not express themselves. Residual deficits will often be seen.

Characteristics

ü     Speech is telegraphic, meaning that articles, conjunctions, prepositions, auxiliary verbs and pronouns (function words) and morphological inflections (e.g. plurals, past tense), are omitted. In addition, nouns, verbs, adjectives and adverbs (content words) may be retained. Output can be restricted to noun-verb combinations. There is often a concomitant “apraxia of speech” (AOS).

ü     Sentence length is short. Average utterance length (MLU) is typically about 2. In extreme cases, the patient may only be able to produce single word utterances.

ü     Syntax and morphology are affected; only the most basic and over-learned grammatical forms are produced (often limited to nouns and verbs).

ü     Speech is labored and slow.

ü     Melodic Contour is flat.

ü     Articulatory Agility is impaired. Potential problems include:

o       Simplification of consonant clusters (e.g. t/st, p/spl).

o       Distortion of consonants.

o       Substitutions are infrequent.

o       Literal Paraphasias may occur:

§         Literal Phonological paraphasia – More than half of the spoken words said correctly.  Errors consist of mispronunciation, syllables out of sequence, etc.  (e.g. "I slipped on the lice (ice) and broke my arm.")

ü     Repetition is typically impaired, falling at about the middle of the Boston Diagnostic Aphasia Examination (BDAE) scale. (Repetition and spontaneous speech are impaired to about the same degree in Broca's aphasia.)

ü     Word retrieval is impaired.

ü     Auditory Comprehension is superior to expressive language but is impaired.

ü     Ability to understand grammatical morphemes will be affected. (Markers such as the past participle 'ed used in the past tense,  the present participle 'ing' used in the present progressive, or third person singular 's').

ü     Hemiplegia/Hemiparesis of the right side is common (remember, the language center is in the left hemisphere for more than 90% of the population) The face and arm are most likely to be affected due to the organization of the motor strip.

ü     Apraxia frequently accompanies this type of aphasia due to damage to area 44/45.  This poorly articulated speech shows up most frequently in longer words and phrases.

ü     Broca's aphasics typically have low frustration tolerance. They are aware of their errors and may respond to them with a catastrophic reaction which might include weeping.

ü     Broca's aphasics tend to demonstrate a scarcity of speech output, often impairing or delaying accurate assessment and diagnosis.

ü     Typically there is better recovery of language function in Broca's than in any of the other aphasia syndromes.