language

Question 1

what are the main language regions and connective tracts in the brain?

Answer 1

broca’s area:
– pars opercularis and triangularis of the inferior frontal gyrus
– production of speech

wernicke’s area:
– posterior superior temporal gyrus
– comprehension of written and spoken language

ventral fibre bundles:
– connects temporal lobe to prefrontal cortex via external capsule
– maps sound to meaning

dorsal fibre bundles:
– connects temporal lobe to premotor cortex via arcuate and superior longitudinal fascicle
– maps sound to articulation

Question 2

what is aphasia?

what is it’s most common cause?

Answer 2

aphasia is the loss of speech

aphasia impacts all language modalities :
reading, writing, production, comprehension

cerebrovascular stroke in the left hemisphere is the most common cause of aphasia
in particular, ischemic stroke to the left MCA is responsible for ~80% of cases

Question 3

do certain leisons induce certain deficits?

Answer 3

no, lesions have little value in predicting or potential recovery

different brain regions can compensate for the lesion by executing the same task

Question 4

describe what occurs at the time of injury and at the different stages of recovery

Answer 4

TIME OF INJURY:
– core infarct (local tissue destruction) → loss of function
– penumbra (surrounding tissue) is intact but has reduced blood flow
– severe impairments observed

ACUTE:
– days - weeks
– tissue reperfusion = damage to tissue when blood supply returns after ischemia or lack of oxygen

SUB-ACUTE:
– weeks - months
– reorganisation of structure and functional relationships

CHRONIC:
– 6-12+ months
– establishing new pathways and compensatory mechanisms

the more time passed, the more training and activation of brain is required for improvement i.e. there is less spontaneous recovery

Question 5

what is diaschisis?

Answer 5

diaschisis is a sudden loss of function in a anatomically intact portion of the brain that is connected to a distant, but damaged, brain area

Question 6

is treatment still effective in the chronic phase of aphasia?

Answer 6

yes

improvements and neuroplastic reorganisation are still possible with highly intensive treatment in the chronic phase

effect size of treatments in chronic phase are much smaller compared to earlier phases of recovery