Stroke and Language

Question 1

what is a stroke/what causes it?

Answer 1

When blood supply is disrupted

Question 2

risk factors

Answer 2

o Old age
o High BP
o Obesity
o Lack of exercise
o Poor diet
o Smoking
o Inflammation
o Prior/family history
o Stress
o Men more likely than women but women live longer so have more ‘exposure’

Question 3

Ischaemic stroke:

Answer 3

• Most common (85%)
• Artery blocked by blood clot
• Cell death from hypoxia and lack of glucose
• Secondary excitotoxicity

Question 4

Haemorrhagic stroke:

Answer 4

• Artery breaks or leaks
  o Hypertension, aneurysm, etc
• Cell death from raised intracranial pressure and inflammation
  o Also hypoxia and lack of glucose
  o Secondary excitotoxicity

Question 5

Glutamate – excitotoxicity causes neuronal cell damage

explain the process

Answer 5

1. Stroke
2. Glutamate neurons die due to hypoxia
3. Release large amounts of glutamate into extracellular space
4. (Over) stimulation of nearby neurons
   a. All glutamate receptors activated
   b. Massive calcium influx
   c. Activates proteases and endonucleases
5. Kills neuron…
6. …which releases large amounts of glutamate into extracellular space
7. (Go to Step 4)

Question 6

consequences of stroke

Answer 6

• Depends on the brain region damaged and which hemisphere it is in

Question 7

Hemineglect:

Answer 7

• Ignoring senses/signals/things on one side (can’t see them)

Question 8

Neglect

Answer 8

sign of posterior parietal cortex damage
- Normally on the right hemisphere
o So affects sensory processing on the left
o Right hemisphere attends to left + right
o Left hemisphere attends only to right

Question 9

• Sensory neglect

Answer 9

o incoming sensory information from the contralateral hemispace is ignored

Question 10

• Conceptual neglect

Answer 10

o neglect of the body and the external world in the contralateral hemifield

Question 11

• Hemiasomatognosia

Answer 11

o patient denies that affected side of body belongs to them

Question 12

• Motor neglect

Answer 12

o fewer movements in the contralateral space

Question 13

role of right parietal cortex

Answer 13

Sensory and spatial processing

Question 14

role of Left posterior parietal cortex

Answer 14

spatial awareness and planning

Question 15

apraxia

Answer 15

difficulty in performing motor tasks even though primary motor pathways intact

Question 16

Ideomotor apraxia

Answer 16

difficulty in responding to motor instructions

Question 17

Ideational apraxia

Answer 17

difficulty in conceptualising motor tasks

Question 18

Gerstmann Syndrome:

Answer 18

• Arises from damage to the Inferior Parietal Lobe
  o On the dominant (normally left) side
• E.g. from a stroke affecting the relevant branches of the MCA
• Dysgraphia/agraphia – problems writing
• Dyscalculia/acalculia – problems with maths
• Finger agnosia – problems distinguishing fingers
• Left-right disorientation

Question 19

agnosia

Answer 19

inability to recognise sensory stimuli

Question 20

damage to Inferior Temporal Cortex

Answer 20

o Visual agnosia (“Psychic blindness”)
 Patient can see, but not identify
o Prosopagnosia (Face Blindness) - Fusiform gyrus
 inability to recognise individuals from their faces. Patients can describe the constituent parts of the face and can identify the subject by voice, clothes and other cues

Question 21

damage to Middle Temporal Cortex

Answer 21

o Movement agnosia (Akinetopsia)
 Cannot distinguish between moving and stationary
 World is a series of ‘still images’

Question 22

• Dysarthria

Answer 22

difficulty moving the muscles of the face and tongue that mediate speaking

Question 23

aphasia

Answer 23

difficulty in naming objects, repetition of words is impaired

Question 24

Wernickes area:

Answer 24

• Brodmann 22 (L)
• Understanding language

Question 25

Wernickes aphasia:

Answer 25

- Unable to understand language - Fluent speech, but makes no sense o (assuming Broca’s area intact) o Little repetition o Adequate syntax and grammar o Contrived or inappropriate speech - Damage to Wernicke’s area o Often as a result of a stroke o Branches of the Middle Cerebral Artery - Also called fluent, sensory or receptive aphasia - Patients are not really aware of the deficit

Question 26

Brocas area:

Answer 26

- Brodmann 44 and 45 (L) - Creating language

Question 27

Broca’s aphasia:

Answer 27

- Few problems understanding language o Assuming Wernicke’s Area intact - Difficulty constructing their own o Halting speech – makes sense? o Repetitive o Disordered syntax + grammar o Disordered structure of individual words - Also called non-fluent, motor, expressive, or production aphasia - Damage to Broca’s area o Often as a result of a stroke o (Different) branches of the Middle Cerebral Artery

Question 28

Articulate fasciculus (L):

Answer 28

- Connects broca’s and wernickes areas

Question 29

Conduction aphasia:

Answer 29

- Can normally understand and produce language o Assuming broca’s and wernicke’s area are intact - Repetition and sequencing are impaired - Phonemic errors o Smole rather than smile o Gar rather than jar - Patient is aware

Question 30

Anomia (anomic aphasia):

Answer 30

- Difficulty in naming objects o Almost all other language is OK o Knows what the object is, what it is used for  (so different to agnosia) o Presents as a ‘tip of the tongue’ problem - Can arise from damage to left Arcuate Fasciculus and Brodmann Area 22 (mild) and possibly temporal/parietal cortices o Tho may feature in other aphasias

Question 31

Treatment for aphasias:

Answer 31

- Long-term prognosis is good - Speech therapy (learn how to manage deficits) - Plasticity within and around damaged areas - Right hemisphere compensation

Question 32

- Right hemisphere communication disorder:

Answer 32

o Language is normally OK-ish o Prosody can be impaired (Aprosodia)  Flat, and emotionless language  Difficulty understanding emotions in language  Humour, sarcasm, reduced recognition and use o ‘Pragmatic difficulties’  Misunderstand context and ‘big picture’  Difficulties taking turns o More likely overshadowed by other deficits  E.g. neglect in right PPC