Acquired Language Disorders

Question 1

Describe a lesion to the frontal lobe.

Answer 1

• Lack of inhibition to behaviours
• May have normal intelligence + memory
• Personality change (impulse control, quick
  temper, irritability)
• Difficulty carrying out consciously
  organized activities

Question 2

Describe a right sided lesion to the temporal lobe.

Answer 2

Non-verbal memory –> visual memory deficits

Question 3

Describe a right sided lesion to the parietal lobe.

Answer 3

• Complex perceptual disorders of
  spatial orientation, body schema
  (where your body is in space),
  memory
• Hemispatial neglect = neglect
  opposite side of body

Question 4

Describe the function of the primary motor cortex.
What lobe?
Damage = ?

Answer 4

• Located anterior to central sulcus –> precentral gyrus
• Each hemisphere controls motor function on opposite side of body
• Controls voluntary movements of skeletal muscle by generating motor
  commands directly to cranial + spinal nerves
• Speech, hand, finger movements + hand-eye coordination
• Damage to this area brain damage or spinal cord injury = hemiplegia

Question 5

Describe the function of the premotor cortex.
What lobe?
Damage = ?

Answer 5

• Located anterior to primary motor cortex - frontal lobe
• Guide voluntary body movements + integrates sensory input

Question 6

Describe the function of the supplementary motor cortex.
What lobe?
Damage = ?

Answer 6

• Located behind premotor cortex (frontal lobe)
• Involved in planning complex motor movements
• Regulates movements under internal control (sequence of movements from memory that are learned/repetitive)

Question 7

Describe the function of the supplementary motor cortex.
What lobe?
Damage = ?

Answer 7

• Located in anterior frontal lobe
• Higher aspects of motor control + planning/execution of behavior
• Cognitive functions à control of behavior, abstract thinking, reasoning

Question 8

Describe Broca’s area
What lobe?
Damage = ?

Answer 8

• Important in speech production –> control motor movement for speech production
• Well-articulated fluent speech
• Damaged –> motor speech problems (lost ability to speak despite comprehension)
• Located in inferior frontal gyrus in left hemisphere of frontal lobe

Question 9

Describe what the left and right side of the temporal lobes are responsible for.

Answer 9

RIGHT side = auditory association analyzes nonverbal stimuli (music, prosody)

LEFT side = auditory association analyzes speech sound (person recognize words/sentences)

Question 10

What to expect with a right sided temporal lobe lesion?

Answer 10

Non-verbal memory –> Visual memory deficits

Question 11

Describe the difference between the primary, secondary, and association areas of the cerebral cortex.

Answer 11

PRIMARY:
- Most sensory information first arrives
- Primary motor area sends commands to muscles

SECONDARY:
- Higher order visual, somatosensory + auditory
areas
- Located near primary area
- Information further processed

ASSOCIATION AREAS:
- Prefrontal, limbic, parietal-temporal-
occipital areas
- Not exclusively to sensory or motor info
o Higher mental processing
o Composed of regions that receive inputs from 1 or more modalities
o Reasoning
o Memory

Question 12

Describe Herschel’s Gyrus.
Location
Damage =

Answer 12

Dorsal surface of superior temporal gyrus + buried within Sylvian fissure
- Primary auditory cortex + auditory association cortex
- Damage = pure word deafness (inability to understand words but preserved recognition of nonverbal sounds)

Question 13

Describe the primary auditory cortex.
Location
Damage =?

Answer 13

Located on superior temporal gyrus
o Receives sound from acoustic nerve
o Damage = hearing loss (cortical deafness)

Question 14

Describe Wernicke’s area.
Location?
Damage = ?

Answer 14

Located in posterior part of superior temporal gyrus in left hemisphere
o Critical to understanding written + oral language
o Encircles auditory cortex on Sylvian fissure = auditory language association
o Damage = impaired language comprehension, speech can be meaningless, but maintain natural rhythm + syntax

Question 15

Describe the Primary somatosensory cortex.
Location?

Answer 15

Located in postcentral gyrus
o All modalities of somatic sensation are received here
o Primary sensory area that integrates + controls somatic sensory impulses

Question 16

Describe the angular gyrus.
Location?

Answer 16

Located posterior inferior parietal lobe
o Involved in processing of auditory/visual input + language comprehension
o Processes letters with corresponding sounds à grapheme (letter) + phoneme
(sound)
o Important for reading, writing, abstract thinking, calculation (math)

Question 17

Describe the supramarginal gyrus.
Location?

Answer 17

Located inferior lateral parietal lobe
o Semantic + phonological processing à involves in reading (meaning + phonology)
o Symbolic integration for writing

Question 18

What happens if the corpus callosum is damaged?

Answer 18

Corpus callosum = Thick band of myelinated fibers that connect 2 hemispheres (commissural fibers)

Damage = disconnect 2 hemispheres - problems with naming, reading mvmnt)

Question 19

Describe the Circle of Willis.
Where is it located?
What is its purpose?

Answer 19

Located in the vertebral arteries.
Provides safety mechanism b/c if 1 artery gets blocked, the circle will still provide blood to brain
o Communication system between 2 carotids + vertebral system
o Allows blood to circulate in both directions

Question 20

Describe the 3 cerebral arteries. Damage?

Answer 20

ANTERIOR CEREBRAL ARTERY:
- Distributed throughout medial surface of cortex (extending posteriorly into parietal lobe)
- Prefrontal lobe symptoms = impaired thinking, reasoning, planning

MIDDLE CEREBRAL ARTERY:
- Supplies entire lateral surface of cortex + frontal lobe
- Main vessels within Sylvian fissure
- Supplies motor + sensory areas involved in speech, hearing, language
- Damage = weakness, paralysis of limbs + face on opposite side of body

POSTERIOR CEREBRAL ARTERY:
- Covers medial surface of occipital lobe + base of temporal lobe
- Supplies primary visual area
- Damage to basilar artery = total blindness + cerebellar symptoms

Question 21

What can you expect when brain doesn’t receive blood for:
5-8 seconds
25 seconds
6 minutes

Answer 21

5-8 seconds = unconscious
25 seconds = Eliminate neural activity
6 minutes = Permanent brain damage

Question 22

Difference between embolic vs thrombotic ischemic stroke?

Answer 22

Embolic = clot within an artery formed somewhere other than in the brain, will travel bloodstream to the brain

Thrombotic = diseased/damages cerebral arteries become blocked by a blood clot within the brain

Question 23

Difference between hemorrhagic stroke: Intracerebral, Subarachnoid, Aneurysm

Answer 23

Intracerebral = bleeding into brain tissue, rupture of intracranial artery + blood accumulates

Subarachnoid = blood vessel outside the brain ruptures (subarachnoid space fills with blood)

Aneurysm = weakness in blood vessel wall

Question 24

Anterior brain regions vs posterior brain regions related to language

Answer 24

Anterior brain regions = Language output
Posterior brain regions = Reception of language

Question 25

Symptoms seen in non-fluent, fluent and subcortical aphasias

Answer 25

NON-FLUENT APHASIA o Lesion in anterior dominant left hemisphere (frontal lobe) o Verbal expression impaired o Limited, agrammatic, effortful, halting, slow speech with impaired prosody FLUENT APHASIA o Lesions in posterior language area in dominant left hemisphere (temporal + parietal lobe) o Intact fluency but less meaningful speech o Speech well-articulated with good prosody + phrase length SUBCORTICAL APHASIA o Basal ganglia --> anomia, Broca, Wernicke, transcortical motor o Thalamic --> fluent aphasia with paraphasia + comprehension deficits - Word finding problem - Naming problem - Limited verbal output - Neologism o Cerebellum --> limited fluency, mild anomia, agrammatism, mild speech comprehension

Question 26

Describe Broca's aphasia: - Location - Blood supply - Symptoms

Answer 26

Location: posterior part of inferior frontal gyrus of left hemisphere Blood supply: middle cerebral area o Speech is effortful, nonfluent, consisting of short phrases or single words o Vary from complete loss of speech to a mild deficit characterized by word finding diffculties o Telegraphic speech (agrammatism) = all small function words are absent, patient uses mainly nouns + verbs o Single words better than sentence production o Automated verbal sequences, cursing or emotional speech are usually preserved o Writing impairment similar to speech impairment o Comprehension is relatively spared o Comprehension deficits regarding complex syntactic structures o Repetition of words or sentences, reading aloud, naming + writing also affected o Phonemic paraphasias occasionally observed o Some suffer from Apraxia of speech

Question 27

Describe Global aphasia: - Location - Symptoms

Answer 27

All aspects of language severely impaired (expressive + receptive) because the perisylvian region damaged o Severe motor + sensory deficits = deficits in right half of body o Speech is nonfluent à limited to stereotypic utterances o Overlearned, automatized sequences are sometimes preserved o Comprehension, naming, repetition, reading, writing are severely impaired o Little to no functional speech

Question 28

Describe Wernicke's aphasia: - Location - Symptoms

Answer 28

o Location = posterior part of superior temporal region o Lesion of the posterior left perisylvian region o Severe case = Jargon aphasia o Diffculty in understanding language while the ability of verbal expression remains unaffected o Extent of comprehension problems vary among patients o Verbal output is fluent (preserved syntax), but characterized by: - Phonemic paraphasia - Semantic paraphasia - Neologisms - Empty speech - Rich content words are reduced in frequency - Severe anomia Unable to monitor their own verbal output b/c comprehension deficit o Anosognosia = patient unaware of their language disorder à hinders rehabilitation o Clients do not attempt to correct themselves o Repetition, naming, reading aloud, writing is impaired

Question 29

Describe Conduction aphasia: - Location - Symptoms

Answer 29

Repetition is compromised o Speech remains relatively fluent, characterized by: - Phonemic paraphasias - Word finding difficulties o Patients aware of verbal paraphasia = try to correct themselves (produce phonemic variations of target word) o Comprehension is generally spared = some patients have problems understanding complex syntactic structures o Deficits in naming + writing o Reading aloud is impaired à better comprehension with silent reading o Motor and/or sensory deficits may be present

Question 30

Describe Anomic aphasia: - Location - Symptoms

Answer 30

Patients’ inability to find names of people or objects o Patient aware of the nature of an object, but unable to name it upon request o Verbal output is fluent, characterized by: - Word finding difficulties - Frequent pauses - Circumlocutions o Phonemic + semantic paraphasias are rare o Repetition, comprehension, reading aloud are spared

Question 31

Describe the transcortical aphasias Location Symptoms

Answer 31

Disproportionately preserved capacity of repetition b/c isolation of speech areas from rest of cortex MOTOR APHASIA o Nonfluent speech with preserved comprehension + relatively spared naming o Reading aloud + writing are impaired o Phonemic paraphasias observed in some cases o Parrot-like echoing of everything heard (echolalia) o Mild dysarthria, sensory, motor disorder may be present o May be the sequel of a recovered Broca’s aphasia = lack of initiative + akinetic mutism SENSORY APHASIA o Speech is fluent but meaningless or unintelligible (jargon) with many paraphasias + neologisms o Comprehension of oral + written language, naming, reading, writing are severely impaired o Preserved ability to repeat words + sentences o Echolalia is present in some cases = during assessment patient automatically repeats what the examiner says MIXED o Motor + sensory transcortical aphasia symptoms o Speech is nonfluent o Comprehension, naming, writing, reading are severely impaired o Preserved repetition of words + sentences = in the form of echolalia

Question 32

What are the specializations of each hemisphere of the brain? What do they do together?

Answer 32

RIGHT HEMISPHERE: Non-verbal aspects of language o Prosody o Narrative o Inference o Spatial processing o Perceptual information processing LEFT HEMISPHERE: Speech o Reading o Writing o Math o Language related sounds They are both required for language processing

Question 33

Describe sign language aphasia.

Answer 33

Deaf people can acquire aphasia d/t lesion in the left hemisphere (same as oral language users) BEFORE aphasia = patients could pantomime + understand an action AFTER aphasia = unable to produce or understand the sign despite the similarity of the gesture/sign o Language is heavily dependent on the left hemisphere (whether output is verbal or sign language)

Question 34

Structural vs Functional MRI

Answer 34

STRUCTURAL MRI o Detailed measurement of volume, shape, position of brain tissue o Subcortical structures (brain beneath cerebral cortex) o White matter (myelinated axons) o Gray matter (cell bodies) o MRI scan can identify various structures + tissues --> time of onset of vascular lesion FUNCTIONAL MRI o Detect brain activity in response to external stimuli (during performance of various tasks) o Changes in blood flow o Location of neural activity (spatial resolution)

Question 35

What are neurologic and individual factors that contribute to a patient's prognosis for recovering from aphasia?

Answer 35

Predicting prognosis is a complex task because there are many neurological and personal factors that must be considered. NEUROLOGIC FACTORS Size of injury o Site of lesion o Severity = Initial severity more important predictor of recovery than lesion size o Type of aphasia = Individuals with expressive (nonfluent) aphasia have better prognosis than receptive (fluent) aphasia INDIVIDUAL FACTORS: Age = Younger patients have better outcome than older individuals o Education o Handedness o Health status o Race o Socioeconomic status - Type of stroke has moderate influence on the recovery progress - Gender is NOT a good prognostic indicator of recovery

Question 36

Which hemisphere is associated with a better recovery?

Answer 36

- Better recovery is associated with left hemisphere reorganization of language skills, following temporary right hemisphere increase in activity. - However, R hemisphere can take over the processing of some linguistic functions after a L hemisphere stroke - R hemisphere activation does not guarantee a significant improvement in language skills (varying degrees of success)