Aphasia in adults (1)
Aphasia Defn
Aphasia aetiology
Lang code
Defn: links set of ling forms to aspects of meaning
Types
Segmental level
Lexical level
Sentence level
Discourse level
Basic form of lexical item: phonemes of word, organisation into syllables. BUT can sound diff depending on speaker, phonemes char by distinctive features, acceptable phoneme combinations
Makes contact w concepts, categories
Consists of lexical items that designate objects, abstract concepts, actions, properties
Words combine into syntactic structures
Relates ideas w/i, across sentences- can make inferences
Info about general topic discussed, temporal order of events
Acquired comm disorder caused by brain damage, char by impairment of lang modalities: speak, listen, read, write; loss of lang bcos brain damage. Invisible disability that affects communication
Impt facts
Neurogenic
Acquired
Problems with usage of lang
X problem sensation, motor fn, intellect
Damage to areas of brain that are mainly responsible for lang: usually left hemisphere
Mainly caused by stroke (cerebrovascular accident)
Ischaemic (block)
Haemorrhagic (bleed)
Other causes
Brain tumour, abnormal growth
Surgically remove brain tissue
Infection (meningitis, encephalitis)
Head trauma (gunshot wound)
To say to caregivers: "Aphasia is a lang difficulty caused by injury to the brain. It affects comm. Aphasia can make it hard to unds words, to speak, to write and to read. Ppl with aphasia are still intelligent. They know what they want to say, have difficulty getting the words out.
Prevalence
Define stroke: sudden onset of neurological deficit bcos of abrupt interruption of flow in blood vessels to the brain, caused generally by occlusion, rupture of the blood vessel
Processes in comm.
Level I: Ideation (dementia)
Level 2: symbolisation (aphasia)
Level 3: Translation (apraxia of speech)
Level 4: Execution (dysarthria)
Multimodal disorder involving: auditory comprehension, written comprehension, verbal expression, written expression, gestural response to spoken commands, other symbolic items eg. numbers, money, telling time, music notation, stop lights, sirens etc
Aphasia vs. dysphasia
a=without
dys=disordered
BUT we use aphasia to refer to dysphasia because it is confused with dysphagia
Stroke risk factors
Can be controlled
Out of control
Age
Genetic predisposition
Pre-existing health conditions
Cholesterol lvls
Substance abuse
Obesity
Gender
Healthy lifestyle
1/3 people develop aphasia post stroke
1/6 aduits 55-75 y/o
Related to location & size of lesion
Interruption in cerebral blood supply.
Results in necrosis=death of tissue
Anatomy
Internal carotid arteries
Anterior cerebral artery (supplies mostly medial portions of frontal, parietal lobes)
Middle cerebral artery (biggest branch of ICA, supplies areas including lateral surface of frontal, parietal, temporal lobes)
Damage to Left MCA is freq cause of aphasia
Occlusion
80%-cerebrovascular disease
15% cardiogenic embolism
5% others: embolism starting from lungs, arms, legs
Terms to define
Thrombosis: arterial blockage bcos build up of fatty plaque blocks blood flow to brain.
Thrombolysis: used to breakdown blood clots, used for ischaemic stroke. AKA tissue plasminogen activator
Embolus: clot that forms/piece of fatty plaque that breaks off somewhere else in circulatory system, travels to block off smaller artery that supplies blood to the brain
Transient ischemic attack- small, temporary (5-30min) disruption of blood flow to brain that X cause permanent brain damage. May rapidly dev limb weakness, slurred speech, visual abnormalities, dizziness, confusion, mild aphasia. Ppl with TIA have increased risk of having a stroke
Stroke due to cerebral artery bursting, causing blood to escape, flood surr brain tissue
Aneurysm: weak spot on blood vessel, causes vessel to dilate
Arteriovenous malformation (AVM): Congenital morphological defect resulting in abnormal cluster of arteries directly connecting to veins, often enlarges over time is at a risk of rupture. Congenital defect in comm links b/w arteries, veins that results in weakened arterial walls, may lead to haemorrhagic stroke
Defn of stroke: sudden onset of neurological deficit caused by deficiency in blood flow to brain due to blockage of cerebral artery
Locations: intra-cerebral, extra cerebral- subarachnoid
Haematoma: accumulation of clotted blood in space created by haemorrhage
Associated deficits
Motor deficits: hemiparesis-muscle weakness, hemiplegia- paralysis. Apraxia
Concomittant cognitive problems: 1) attention problems- neglect (more common in RHD), 2) memory problems, 3) executive fn problems (more complex lang problems), 4) sensory deficitis- rmb to check for visual field deficits and agnosias (X able to name an object that is presented visually but recognising it upon touch)
Degenerative neurological disorders (PD, MS)
Can co-occur w dysarthria, apraxia etc