Assessing Aphasia and Neurogenic CDs

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Assessing Aphasia and Neurogenic CDs
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Localizationists

• Franz Gall (early 1800s)
• Paul Broca (1850s) a neurologist----articulate
  speech located in the posterior-inferior frontal
  lobe
• Karl Wernicke (1874) a German neuropsychiatrist
  published work on sensory aphasia lesions in
  the posterior temporal lobe

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Anti-localizationists

• Marie Jean-Pierre Florens (colleague of Gall!)
  was the first
• John Hughlings Jackson (NHNSND) a British
  neurologistearly 1900s
• Henry HeadBritish neurologist---1920s
• Equipotentialists
• Lead to theories of cerebral dominance

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Language and Cerebral Dominance

• Left hemisphere dominance for sph/lang was
  Broca---early thoughts were that left and right
  halves of the brain were mirror images on one
  another
• Symmetry notion lasted until Goodglass and
  Kaplan, Penfield and Roberts (1950s)!!
• Confusion about function right handed people
  were left hemisphere dominant

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Therefore,

• Left handed people must be right hemisphere
  dominant?????
• Only a theory based upon case studies
• Maybe from an effort to equalize
  theories---make things symmetrical
• Think of theories of phonation---honest!
• (neurochronaxic theory!)

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50s researchers noticed

• Both left and right handed people had similar
  problems after brain injury
• We learned from the early sodium amytal studies
  that a small of people are right hemisphere
  dominant
• Most adults are left hemisphere dominant for
  sph/language
• The question is how are we born?
• Think cerebral plasticity

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Implications of cerebral plasticity

• Younger injuries have greater opportunity to
  improve
• Older patients recover less language function
  than younger patients
• The older the patient at the time of injury the
  more severe the persistent consequences of the
  injury

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Connectionists

• These theories focus on function of areas
  surrounding the injury in the case of language
  impairment
• The periSylvian region of the left frontal lobe
  is sometimes called the anterior language zone
• Important for planning and executing language
  speech, writing, and maybe gestures
• The periSylvian region in the left temporal
  lobes is the posterior language zone
• For comprehending and formulating linguistic
  messages with accurate syntax and semantic
  structures

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Anterior Language Zone

• Posterior frontal lobe, just anterior to the
  motor strip
• Holds the location of Brocas area the motor
  speech planning site
• Brocas area responsible for planning
  organizing speech movements for the primary motor
  cortex
• Injury here produces Brocas aphasia

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Posterior Language Zone

• Located in the posterior superior left temporal
  lobe
• a.k.a. Wernickes area
• Sometimes called the auditory association cortex
• Important for storage and retrieval of mental
  representations for words, word meanings,
  grammatical and linguistic rules

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Remember the connectionists?

• Wernickes gets most of its input from the
  primary auditory cortex (Heschls Gyrus)
• Function of the primary auditory cortex is
  perception and discrimination of auditory stimuli
• If a tree falls in the woods and there is no one
  there to hear it.

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More connectionists

• Wernickes and Brocas are connected by a large
  bundle of nerve fibers (a fasciculus)
• Runs between the mid temporal lobe and the
  frontal lobe via the parietal lobe
• The arcuate fasciculus is the primary route by
  which linguistic messages formulated in
  Wernickes are transmitted forward to Brocas area

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The angular gyrus

• At the junction of the temporal, parietal and
  occipital lobes
• Important for processes in reading and writing
• Damage to the angular gyrus causes
• Alexia reading impairment
• Agraphia writing impairment

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Language Functions

• Comprehension of speech
• Spontaneous speech
• Repetition
• Oral Reading
• Writing
• Gestural responses to spoken commands

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Fluency

• Important to understanding the connectionist
  model because connectionist aphasia syndromes are
  divided into fluent and non-fluent types.
• Relationship between speech fluency,
  paraphasia, repetition and language comprehension.

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Fluent (aphasic patients) have normal or near
normal speech rates and use a variety of
different grammatical constructions function
words and grammatical inflections are present,
and usually syntactically appropriate. Intonation
patterns are present and usually appropriate.
Nonfluent (aphasic patients) have slow and
labored speech. The variety of grammatical
constructions is often restricted and intonation
may be reduced or absent function words and
grammatical affixes may be omitted, and patients
may rely a lot on nouns (Howard Hatfield, 1987,
p. 147).
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Connectionist Aphasia Syndromes

• Fluent
• Damage posterior to the Rolandic Fissure
• Sph flows smoothly and effortlessly
• Fluent aphasic spkrs. Usually manipulate rate,
  intonation, and stress

• Non Fluent
• Damage anterior to the Rolandic Fissure
• Sph is halting and made with great effort
• Rate is slower than normal, intonation is
  limited, stress is missing (diminished)

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Paraphasias

• errors in speaking produced by speakers with
  aphasia (Brookshire)
• 2 forms literal and verbal paraphasia
• Literal paraphasia phonologic (phonemic)
  errors----tootbrust for toothbrush
• Verbal paraphasia semantic errors (usually
  related to the term) as in knife for fork
• Sports talk play was admiral defense had
  pronouns
• NOTE literal paraphasia vs. apraxia

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Repetition

• Variations in speech repetition and language
  comprehension are indicators of several fluent
  aphasia syndromes

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Classical Aphasia Syndromes

• Brocas aphasia
• Wernickes aphasia
• Global aphasia
• Conduction aphasia
• Transcortical motor aphasia
• Transcortical sensory aphasia
• Mixed aphasia
• Disconnection syndromes

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Brocas aphasia

• Expressive, motor or anterior aphasia
• Because of proximity to the motor strip (face,
  hand and arm) and because descending pyramidal
  fiber tracts run alongside Brocas area pts
  with Brocas display right-sided hemiplegia or
  hemiparesis

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Brocas area

• Lower part of the premotor cortex just anterior
  to the primary motor cortex
• Premotor cortex plans skilled voluntary
  movements for the motor cortex in both
  hemispheres
• Brocas area is adjacent to motor cortex of the
  face thus it is the speech motor planner

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Speech style

• Slower rate, laborious movement, halting
• Long pauses between words sometimes even within
  words
• Lacking intonation
• Misarticulations are common some consonants and
  vowels are distorted
• Short phrases usually missing functor words I.e.,
  conjunctions, prepositions and articles

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Speech style Brocas

• Missing functor words causes the description of
  agrammatic sometimes called telegraphic
• Next slide is from from a patient describing a
  picture from the Boston Diagnostic Aphasia
  Examination (BDAE). The Cookie Theft.

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A sample of Broca-type speech
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Brocas aphasia Writing

• Pts. Write as they speak slowly and laboriously
• Strings of content words sprinkled with
  misspellings, distortions/omissions of letters.
• Poor form, maybe due to hemiplegia (forced to use
  non-dominant hand)
• Usually print not cursive slanted writing

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Brocas writing style
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Brocas comprehension

• Comprehension is better than speech or write
• Although Brocas pts tend to be slow readers
  (careful testing will probably show both reading
  and listening impairments)
• Repair strategy is usually preserved, e.g., they
  make attempts to correct errors in sph or writing

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Brocas comprehension

• Tend to be good tx candidates because they are
  usually cooperative
• error awareness sometimes leads to emotional
  lability
• Usually remember goals from day to day

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Wernickes aphasia

• Also has other names sensory aphasia, receptive
  aphasia and posterior aphasia
• Salient feature impaired comprehension of
  spoken and printed verbal materials
• If severe, pt may be unable to comprehend simple
  spoken or written material
• Mild/moderate get the basic idea but tend to
  miss the details

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Wernickes

• Often dont associate sound (or sight) of words
  and their meanings
• Difficulty with semantic distinctions e.g., know
  difference between small vs. tiny, good vs.
  wonderful, etc.
• Often display problems with short term retention
  and recall for verbal material
• Tend to do poorly on digit recall, recall lists,
  etc

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Wernickes

• Performance tends to deteriorate when
  instructions are longer, more verbal

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Wernickes speech

• Unlike Brocas, Wernickes patients speech is
  usually smooth, even well formed grammatically
• Speech seems less effortful sometimes even long,
  syntactically correct utterances with proper
  prosody
• May see some delay when there is difficulty with
  word recall

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Speech sounds good, eh?

• Not.
• Speech is usually typified with verbal
  paraphasias (sometimes literal paraphasias, too)
• Ferbus lalo! Neologisms
• Strings of neologisms jargon
• Essentially, Wernickes aphasics produce empty
  speech it lacks meaning
• Usually filled with stuff or things or
  pronouns
• Even circumlocute!

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Wernickes speech style
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Wernickes handwriting style
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Logorrhea

• Some Wernickes patients will talk copiously
  until you MUST interrupt them
• Due to circumlocution and poor self monitoring
  skills

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Wernickes writing

• Yup, it resembles their speech writing is
  better in that the letters are well formed, they
  write with ease and it is legible
• Most will use cursive
• Handwriting is mechanically normal but ----it
  lacks content
• Paraphasias in speech usually show up in writing,
  too
• Yeah, logorrhea happens in writing, too.

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Wernickes candidacy

• Patients are usually alert, attentive and likely
  to stay on the task at hand
• Mild forms usually know their errors
• Moderate forms rarely notice errors nor attempt
  to repair errors
• Cant stay on task in testing and tx procedures
• Conversational speech is tangential

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• Auditory comprehension problems complicate all
  communication trials
• Pragmatics/turn taking is usually preserved

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Concommitants

• Wernickes patients are not usually hemiplegic
  (unless there is involvement of the motor strip--
  global aphasia)
• Lesions deep in the temporal lobe may destroy
  portions of the visual cortex
• Causes contralateral visual field loss