Speech and language Flashcards
Intracarotid test
used in pts with intractable epilepsy being considered for surgical tx for epilepsy
catheter is routed into internal carotid and barbiturate injected to left or right side resulting in anestesia of greater part of hemisphere
pt has language tests to measure how well the unanaestetized hemi can perform them
invasive test and only for ind with pre-exsisting brain fnx abnormatilies so this test may not be a good representation of population as a whole
Intracarotid test
new imaging tech. Based on changes in ratio of oxyHb to deoxyHb in brain from moment to moment
fMRI
cognitive activity correlated w/ change in this ratio that are involved in performing the activity
used to identify regions activated by cognitive task… is noninvasive and used in healthy
fMRI
90% of population, Dextrals
right handed
10% of population, Sinistrals
left handed
Atypical dominance patterns include
‘bilateral’ and ‘right’ hemisphere dominance
more common in left handed relative to right handed individuals
Atypical dominance patterns
most pts w/out early damage regardless of handedness are left-hemi dominant
left-hemi dominant
incidence of atypical dominance ________in ind w/ early brane damage, ESPECIALLY for those w/ left or mixed handedness
increases dramatically
fMRI results
1. show the area of language activation include what 4 regions?
( see variability w/in individual pts.)
left frontal, temporal and parietal regions and rt cerebellum
More pts w/ epilepsy show __________ compared to healthy
symmetrc and rt hemisphere dominance
More variability in ind with early or late brain damage
EARLY
Simular dominance patterns found in health leftys and lefy epileptics with______ onset brain damage
LATE
lefty epileptic pts with evivdence of EARLY damage
see atypical dominance (crossed-dominance or symmetric dominance) which is high and associated with shift in handed: pathological left-handedness
In left hemisphere, devo of langauge after injury depends on
age at time of injury
Damage Early in life (before 1 yr)
a. develops language functions but usually has a generalize decline intelligence
Damage between 1-5
a. language devos typically but occurs at expense of development of non-linguistic skills (viso-spatial)
b. lang devo occurs in regions usually devoted to devo of non-linguistics and ‘crowds’ those areas
Damage After 5
a. specific abnormalities of lang skills that are apparent—implies the brain plasticity decreases w/ age
Selective injury to ant or post speech zones causes
shift of function associated w/ that zone only.
injury to core or central speech zone may cause a
complete shift in languate fnx to the right hemi; called crossed-dominance
Cerebral dominance and left-handedness
atypical speech representation is more frequent in lefty and ambidextrous then rightys
healthy ind w/ no left-handed 1st degree relatives (negative familial sinistrality) have more typical lang representation
Which is more predictive of atypical dominance family history of left-handedness
family history
Negative correlation between LI and age suggests
langauge processing more symettric w/ age
Damage to far anterior or poster results in
no shift in language
Damage tosomewhat anterior regio or centered around region of speech see
a complete shift in language
Anterior region of language zone is key for
retrival/syntax/exresspive aspect~ damage we see shit of anterior funx
Damage to posterior or middle language zones:
Shift of posterior speech function when more posterior/middle damage we see comprehension affected
Do both hemis involving language look the same?
hemis aren’t mirrior images of each other in either morphology or funx—see minor shape dif in cylvian fissure and occipital lobe
How are hemis organized?
Hemis are organized dif in terms of how the perform secondary and tertiary levels of fnxs (like multi-modal funxs such as hand-eye coordination)
Lateralization of fnx is relative and complementary and______ with age before pubery and______ thereafter
increases
decrease
Disorders of speech all involve
malfunction of muscles of speech articulation!
How are disorders of speech and disorders of language different (aphasias)
they are different from language disorders (aphasia) that you can get w/out the other and has own correlates
can be psychological or neuro
neuro: IG occurs in context of syndrome such as akinetic mutism (thought to be d/t failure to initiate action)
Mutism
Mutism can result from:
Extensive bifrontal brain disease or bilateral lesions in SUPPLEMENTARY motor area responsible
D/t injury to peripheral NS enervating muscles of vocal chords and ≠ sound production
Aphonia
Able to produce vocal sounds (grunts, groans, sound like features) but cant generate speech
Aphemia
Aphemia is considered a
disconnected syndome
d/t white matter lesion beneath Broca’s area that severs the final output path for speech production
Aphemia
impaired capacity to articulate speech~ more about muscles of speech or discordination
Dysarthria
All aphasias can be classified by integrity of speech:
fluency/comprehension and repetition
Most important classification of integrity of speech
fluency is more important to focus on… heslp us localize brain dysnfunction to anterior or posterior regions
Non-fluent aphasias—occur with dysfnx to
ANTERIOR regions
Fluent aphasias—occur with dysfnx to
POSTERIOR brain regions
Fluency;
evaluated on 3 dimensions
Phrase length (maximum number of words per utterance)
Degree of apparent effort in production of speech
Prosody—preservation of melodic elements of speech
Nonfluent speech characterized by
contains less then 3 words in utterance, labroius in produciton and monotonic
Evaluation of fluency:
a. ask pt open ended questions or to describe complex picture (Boston Asphasia Exam)
Global aphasia
fluency:
comprehension:
repetition:
fluency: none
comprehension: none
repetition: none
when functions of both anterior and posterior aspects of core language zones impaired
Isolation of speech
fluency:
comprehension:
repetition:
fluency: none
comprehension: none
repetition: intact
Brocas
fluency:
comprehension:
repetition:
fluency: none
comprehension: intact
repetition: none
Transcortical motor:
fluency:
comprehension:
repetition:
fluency: none
comprehension: intact
repetition: intact
Wernickes
fluency:
comprehension:
repetition:
fluency: intact, paraphaisias present
comprehension: none
repetition: none
Transcortical sensory
fluency:
comprehension:
repetition:
fluency: Yes, paraphiasias present
comprehension: none
repetition: intact
Conduction
fluency:
comprehension:
repetition:
fluency: yes, paraphiasias present
comprehension: intact
repetition: none
Nominal, anomic amnesic
fluency:
comprehension:
repetition:
fluency: intact
comprehension: intact
repetition: intact
fluency: none
comprehension: none
repetition: none
when functions of both anterior and posterior aspects of core language zones impaired
Global aphasia
nonfluent aphasia that has profound impairment in speech articulation. Repetition speech impared d/t articulaiton difficulties
Brocas
Transcortical motor aphasis:
lesion to the premotor region or SMA
Transcortical aphasias: repetition is
PRESERVED
Transcortical sensory aphasia:
fluent aphasia associated with langague comprehension deficits at word level
Transcortical sensory aphasia lesion IG is at
- lesions IG at angular gyrus or post and infereior temporal lobe
- repetition is preserved
Isolation aphasia:
when lesions of both transcortical motor and sensory aphasia present
when lesions of both transcortical motor and sensory aphasia present
Isolation aphasia
effectively isolates core speech zones from remainder of hemisphere
Isolation aphasia
Conduction aphasia: fluent aphasia associated with
profound impairment in repetition speech but preserved comprehension
-repetition deficit d/t impairment in auditory storage buffer needed to repeat speech sounds or perhaps the transmission path (arcuate fasciculus) btwn speech sound recognition and articulation centers
Conduction aphasia
The cortical zones in temporal, parietal and frontal regions that lie outside of the peri-Sylvain zone also makes
significant contributions to linguistic fnxs.
