Lecture 2 - Stroke Flashcards
Define a stroke
Neural dysfunction that results from a disruption of blood supply to the brain or part of the brain
What are the 2 main types of stoke? Define them.
Occlusive: blood clot
Haemorrhagic: burst artery - blood leaking out
Over \_\_\_\_\_\_ people in England and Wales have a stroke pa. Of stroke sufferers, about: 1/3 likely to : 1/3 likely to : 1/3 likely to :
Over 130,000 people in England and Wales have a stroke pa.
Of stroke sufferers, about:
1/3 likely to die within the first 10 days
1/3 likely to recover within one month
1/3 likely to be left disabled + needing rehabilitation.
Ischemia: Infarction: Occlusion: Thrombus: Embolus:
Ischemia- reduction in blood supply
Infarction- area of cell death caused by ischemia
Occlusion- closure of blood vessel
Thrombus- occluding blood clot
Embolus- clot (or other deposit) from distant region
Atherosclerosis :
Aneurysm :
Anastomoses:
Transient ischaemic attack (TIA) :
Atherosclerosis - build-up of lipid on artery inner lining
Aneurysm - swelling of arterial wall (could bleed)
Anastomoses - connections between arteries
Transient ischaemic attack (TIA) – mini stroke, recover completely within 24 hrs, warning sign of stroke?
The brain is:
- __% body weight and receives __% -cardiac output - 0.75-1.0 L/min
- consumes __% total O2
The brain is:
- 2% body weight and receives 15% -cardiac output - 0.75-1.0 L/min
- consumes 20% total O2
How is blood flow regulated (in general)?
Changes in systemic blood pressure accompanied by constriction (e.g. in hypertension) or dilation of arterioles (hypotension) in brain to maintain cerebral blood flow constant
Increased brain metabolism results in (lower/higher)O2, ___CO2 and ____pH producing dilation of cerebral arterioles and ___blood flow (mainly via interstitial acid pH affecting vascular smooth muscle cells)
Increased brain metabolism results in lower O2, higher CO2 and lower pH producing dilation of cerebral arterioles and increasing blood flow (mainly via interstitial acid pH affecting vascular smooth muscle cells)
What are the 3 major arterial sources for the brain?
- Internal cartoid artery
- Anterior spinal artery
- Basilar artery
What allow venous drainage from the brain?
Internal jugular veins
What are the arteries making up the circle of willis?
Anterior cerebral artery (left and right)
Anterior communicating artery
Internal carotid artery (left and right)
Posterior cerebral artery (left and right)
Posterior communicating artery (left and right)
Where does the anterior cerebellar artery send blood?
- Frontal lobes
- Parietal lobes
- Medial surfaces
- Parietal-occipital border
- Corpus callosum
Where does the middle cerebellar artery send blood to?
- Frontal lobe
- Parietal lobe
- Temporal lobe
- Lateral surfaces
- Corpus callosum
- Internal capsule
- Thalamus
Where does the posterior cerebellar artery send blood?
- Occupital lobe
- Temporal lobe
- Midbrain
- Posterior end of corpus callosum
- thalamus
- Subthalamic nucleus
- Optic radiation
- choroid plexus of lateral ventricle
What are some symptoms of stroke associated with the anterior cerebral artery? (e.g. to limbs/speech/memory/vision)
- Paralysis of contralateral foot/leg
- Sensory loss in contra foot/leg
- Motor aphasia to speech initiation
- Dysarthria - impaired motor supply to nuclei supplying muscles involved in speech
What are some symptoms of stroke associated with the middle cerebral artery? (e.g. to limbs/speech/memory/vision)
- Paralysis of contralateral face/arm
- Sensory loss in contra face/arm
- If left/dominant side: Broca’s aphasia or Wernicke’s aphasia
- If right/non-dominant side: contralateral neglect syndrome
- Internal capsule affected - affects eye movements
What are some symptoms of stroke associated with the posterior cerebral artery? (e.g. to limbs/speech/memory/vision)
- Contralateral loss of pain, temperature (brain stem)
- Ballism (unexpeected limb movements) (subthalamic nuclei affected)
- Memory deficits (medial temporal lobe)
- Contralateral hemianopia with macula sparing
- Difficlty in face recognition (inferior parts of tempral lobe)
What is neglect syndrome?
Patients act as if portions of their world doesn’t exist. There is spacial neglect as well as hemi-paresis. Is normally a consequence of brain trauma e.g. Stroke. More commonly associated with damage to right hemisphere
What is wallenberg syndrome?
Caused by thrombosis of the vertebral or posterior inferior cerebellar artery.Occlusion of PICA damages dorsolateral medulla (brain stem).
Damage to nucleus ambiguus causes hoarseness, difficulty swallowing.
Damage to lateral spinothalamic tract leads to contralateral loss of pain and temperature sense in the trunk and limbs
Interruption of central sympathetic pathway to spinal cord produces _______ syndrome
Horner’s syndrome:
What are the facial features of Honer’s syndrome?
combination of drooping of the eyelid (ptosis)
constriction of the pupil (miosis), sometimes accompanied by decreased sweating (anhidrosis) of the face on the same side.
The lateral spinothalamic tract transmits ____ and ____
The anterior spinothalamic tract (or ventral spinothalamic tract) transmits ____ and ____.
The lateral spinothalamic tract transmits pain and temperature.
The anterior spinothalamic tract (or ventral spinothalamic tract) transmits crude touch and firm pressure.
What are the signs of Wallenburg syndrome? (contralateral and Ipsilateral)
Contralateral signs:
Loss of pain and temperature sensation from the body (lateral spinothalamic tract)
Ipsilateral signs:
Loss of pain and temperature sensation from the face (spinal trigeminal tract and nucleus)
Loss of taste from tongue (solitary tract and nucleus)
Horseness and difficulty swallowing (nucleus ambiguus, roots of cranial nerves IX, X)
Limb - lack of coordination (cerebellar peduncle)
Also:
vertigo (vestibular nuclei)
What treatment would be done if someone presented with a stroke (think different treatments for different stroke causes)
–Brain scan
and then…….
-Treatment of blood clots: clot-busters (tissue plasminogen activator (tPA))
-Surgical removal of atherosclerotic deposit: accessibility considerations
-Intracerebral hemorrhage: surgical removal of blood clot
-Ruptured aneurysm: tying off aneurysm to prevent further bleeding
What is optogenic neuronal stimulation?
neurones in layer V of motor cortex bioengineered to express a bacterial channelrhodopsin which allows them to be selectively depolarised by laser light via implanted optical fibre
Regular stimulation of motor cortex (light)
