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