Aphasia

arteriovenous malformation (AVM)

-Capillary network between arteries and veins is absent -Vessels are twisted and tangled -usually detected when a seizure, headaches or hemorrhage occurs -arteries and veins not formed correctly- happens during brain development so it is congenital

Transient Ischemic Attack (TIA)

-a "mini stroke" that mimics the effects of a complete stroke -a temporary disruption of blood flow -symptoms usually last less than 1 hour -a risk sign of CVA with 20% chance of suffering a CVA during the first year after a TIA and a 30-60% chance within 5 years -this is a temporary blockage of a cerebral artery, leading to death of brain cells and permanent loss of certain functions

Norman Geschwind

-an approach to disturbances in function which is not based on the assessment of symptoms as the result of a local lesion, but which considers the observed disturbances to the result of dissociation of brain systems -1970s

ischemic stroke

-an arterial vessel is occluded, reducing or stopping the flow of blood through that artery -arteriosclerosis: thickening or hardening of the arterial wall causing reduction of elasticity of the vessel- this is caused by proliferation of cells (blood platelets, fatty deposit) along the wall (clogging by fat due to potentially bad eating) -thrombus: accumulation of cells results in deterioration of the vessel wall, increasing vessel rigidity (less flexible) blood has to work harder to push through the artery (build up of fatty tissue/cells in wall eventually blocking) -embolus: extraneous material in the vessel (guck that has built up) has broken away, traveled through the vessel and becomes lodged in some part of the brain

Boston Classification System of aphasia

-check slides

transcortical

-damage is outside of the typical language area

categories of classification

-fluency: how much do they say? More than 4 words per utterance? -comprehension: everyone with aphasia has difficulty comprehending if they are pushed hard enough, but when given simple instructions, some will definitely do better than others. -repetition: can they repeat something said to them? Very telling when using for testing, don't have to find the word but have to use phonology, memory, etc.

nonfluent aphasia

-global, mixed transcortical, Broca's, transcortical motor -very limited in what they are saying

Ludwig Lichtheim

-illustrated Wernicke's model. and established an approach to brain-behavior-relationships -created the house model looking at how motor, auditory, and everything else may connect -language isn't specifically only in one spot -i.e. functional specialization of brain regions -focused on connections between brocas and wernicke's areas (white matter tract: arcuate fasiculus)

Paul Broca

-in 1861, Broca provided the first scientific evidence of specific cognitive function localization -he had a patient, leborgne, who was only able to say "tan, tan, tan..." after having suffered a stroke -autopsy indicated damage to the posterior 2/3 of the inferior frontal gyrus -Broca determined that this was the "seat of the ability to articulate language"

Carl Wernicke

-in 1874, he had 2 patients who had difficulty understanding language after having suffered strokes -autopsy indicated damage to the superior temporal gyrus (posterior part) which then became known as the region that is crucial for language comprehension

types of stroke

-ischemic: blockage of blood vessels, lack of blood flow to affected area -hemorrhagic: rupture of blood vessels, leakage of blood in affected area

hemorrhagic stroke

-rupture of a vessel in the brain -aneurysm: a dilated blood vessel that involves stretching of all layers of the arterial wall. seen particularly at branches of the internal carotid artery system or other branching points -when an aneurysm bursts, that is when a hemorrhagic stroke happens -brain damage results from the burst vessel -people often don't know they have an aneurysm

Aphasia

-the term aphasia literally means "without speech" or "loss of language" -a disruption in using and understanding language following a neurological injury or disease (but they do know language) -NOT related to intellectual decline or sensori-motor defects (e.g. hearing loss) -therefore, diagnosis of aphasia is not typically applied to patients with TBI, non-dominant (right) hemisphere brain damage, or dementing disease because those have defecits in cognitive domains other than language (these things affect more than just language areas so cognitive effects are seen) -there is a difference between knowing language and being able to use it -not a loss of intellect, but can look that way due to inability to use language -acquired language impairment

fluent aphasia

-wernicke's, transcortical sensory, conduction, anomic (without naming- cannot come up with words- this is the mildest form)

speech vs. language

Speech: Production of sound, more physical and anatomical. the way we produce sounds Language: Communication, the content of the language. the way you communicate what you are thinking

parasylvian cortex

area around the sylvian fissure and if damage occurs in this region, we know it will affect language

what causes aphasia?

cerebrovascular accident (CVA- aka stroke "brain attack") -ischemic vs. hemorrhagic stroke -this is acquired so the person with it generally developed and used language just fine before the stroke occurred

global aphasia

inability to understand language or communicate orally -most severe kind

Heschl's gyrus

primary auditory cortex -endpoint of auditory pathway: hear a sound and make an association -wernicke's area is behind it

Phonology

the sound system of the language, including the sounds that are used and how they may be combined (rule-based)