Week 3 -Cerebrovascular Disorders and TBI Flashcards
What are the two main forms of stroke?
Ischaemic
Hemorrhagic
What are the two types of traumatic brain injury?
Closed head injury
Penetrative head injury
What are the two stages of brain damage?
Primary injury:
damage occurring at the time of the impact
Secondary injury:
secondary effects of physiological processes initiated by the primary injury
Angela is a victim of strangulation and develops brain damage due to a lack of oxygen. What is she suffering from?
Anoxia/ Hypoxia
How much normal cardiac output does the brain use?
15% of normal cardiac output
What are the two vessels involved in the arterial supply of blood to the brain?
Internal carotid arteries
Vertebral arteries
What are the main divisions of the internal carotid system?
Middle cerebral artery
Anterior cerebral artery
What are the main divisions of the vertebral-basilar system?
Basilar artery
Posterior cerebral arteries (PCA)
What combination of arteries, which is often compared to a ‘circle’ shape, is critical for cerebral blood flow?
Circle of Willis
What are the different kinds of obstructive (ischaemic) stroke?
Cerebral thrombosis
Cerebral embolism
Transient ischemic attacks (TIAs)
What are the different kinds of hemorrhagic strokes?
Aneurysm
Hypertensive hemorrhage
Arteriovenous malformations
What is a cerebrovascular accident (CVA)?
A vascular disorder that results in brain injury
What is ischemia in relation to strokes and related disorders?
Insufficient or lack of blood flow to the brain
What is an infarction?
tissue death due to inadequate blood supply
What is an infarct?
Area of damaged or dead tissue from infarction
What is a penumbra?
Tissue surrounding infarct which may recover or die
What is excitotoxicity?
Excess activity in glutamate signaling pathways (excitatory) (NMDA receptors) resulting in cell death
What is Oedema?
Swelling of brain
Dwight is in the office and all of a sudden, he experiences weakness/numbness of his face, arms, and leg on the left side of his body. He also has difficulty speaking and understanding, is dizzy, has a loss of vision, and a headache. What is Dwight experiencing?
A stroke
Dwight survives his stroke, however, it is unsure how well he will recover. What factors are involved in stroke recovery?
Type of stroke
Size of blood vessel
Remaining intact vessels
Premorbid factors
Location
What are the two main types of stroke?
Obstructive (ischaemic) stroke
Hemorrhagic stroke
Dwight’s stroke was caused by a fatty plaque that caused a blockage of a blood vessel. What kind of stroke did he have?
An obstructive (ischaemic) stroke
Stanley had a stroke which was a result of bleeding into brain tissue (or a rupture of a blood vessel), this was because there was a weakening or malformation in the vessel wall. What kind of stroke did Stanley have?
Haemorrhagic stroke
What can cause ischaemic strokes?
Thrombosis
Embolism
What is a thrombotic stroke?
It is an ischaemic stroke caused by the occlusion of a blood vessel by a thrombus (clump of cells/tissue), often arteriosclerosis plaque.
What is an embolic stroke?
An ischaemic stroke, caused by the occlusion of blood vessels by embolism which has broken off from thrombosis in a larger blood vessel (often from the peripheral circulatory system).
How long does it take for an ischaemic stroke to fully develop?
can occur suddenly, 30mins
30% of cases occur over hours/days
What is the recovery rate for obstructive (ischaemic) strokes?
80%
Where do most thrombotic strokes occur?
Internal carotid or vertebral basilar arteries
Strokes have _____ effects on function.
Unilateral
What are the unilateral effects of obstructive (ischaemic) strokes?
Hemiparesis
Hemiplegia
Aphasias (left)
Unilateral neglect (often right)
What is hemiparesis?
Weakness in the vertical half of the body
What is hemiplegia?
Complete paralysis of vertical half of body
- At 1 month, most have perceptual deficits as well, typically to hemispace to the side opposite to the lesion
What are aphasias (left)?
Expressive/receptive language disorders
- Speech fluency returns within one month, if at all
What is hemispatial neglect?
Failure to attend to space at the opposite side of the lesion following unilateral damage to the brain
What is a transient ischaemic attack?
An episode of temporary obstruction of a blood vessel lasting less than 24hrs, many lasting only minutes and 50% lasting <1 hr.
What are the two types of transient ischaemic attacks?
- Those lasting <45 min with no evidence of infarct on CT
- Those lasting >45 min (average 6hrs or more) and show radiological evidence of infarction (CITS - cerebral infarction with transient signs)
Michael experiences a transient ischaemic attack. What is the likelihood that he will develop a full-blown stroke?
30% of people will develop a full-blown stroke within the first months of a TIA.
What are the risk factors that may have caused Stanley to develop a hemorrhagic stroke?
Hypertension/high blood pressure (chief risk factor)
Chronic use of oral anticoagulants (aspirin)
Cocaine and/or excessive alcohol use
Stanley is addicted to alcohol and often treats himself to a bag of cocaine. The next morning, he feels hungover so he takes excessive amounts of aspirin. His behaviours could cause him to develop a stroke. What kind of stroke is he most likely to develop?
Haemorrhagic stroke
What are the two primary mechanisms that cause arterial haemorrhage?
- Weakening of a vessel due to pathological aberrations secondary to hypertension (77-88% of cases)
- Rupture associated with vascular abnormalities, such as aneurysm, arteriovenous malformation (AVM), tumor or deficient coagulation of blood.
What are the characteristics of an aneurysm that can cause risk for a ruptured aneurysm?
Women and older patients
Symptomatic aneurysms (>10mm)
Basilar artery aneurysms
Jim has a severe headache is nauseous and vomiting. He also has a stiff neck and focal neurological pain. What is happening to Jim?
Aneurysm
What is the mortality rate of an aneurysm?
50% within the first month
What brain areas are most affected by a hypotensive haemorrhage?
Thalamus
Basal ganglia
brainstem
Which haemorrhages tend to involve blood vessels at the base of the cerebral hemispheres?
Haemorrages associated with hypertension
What are arteriovenous malformations (AVMs)?
AVMs are tangled masses of arteries and veins of congenital origin which grow, usually gradually and much like a tumour
What is locked in syndrome?
A rare disorder frequently caused by ischaemic or haemorrhagic stroke in the basilar artery.
Loss of all motor function with the exception of eye movement
Cognition and consciousness remain fully intact.
What is a penetrating head injury?
The skull is fractured, exposing the brain and allowing the entry of foreign matter (eg gunshot wound).
What is a closed head injury (CHI)?
non‐penetrative blow to the head. Common causes include MVA, assaults, falls and sports. Can also be percussive (eg blast injuries).
What are the two stages of TBI?
Primary injury
Secondary injury
What is a primary injury of a TBI?
Damage occurring at the time of impact
What is a secondary injury associated with TBI?
secondary effects of physiological processes initiated by the primary injury
What is a contact force in relation to a primary injury?
(force of impact) is predominant cause of damage in static injuries where head is still and receives a blow. Rapid inward deformation of skull (may fracture) with compensatory outward deformation in adjacent areas, followed by rebound effects.
What are the inertial forces associated with a primary injury?
Translational acceleration
Rotational acceleration
Angular acceleration
Coup injury
Contre-coup injury
Diffuse axonal injury
What is translational acceleration?
Head moves in a straight line with brain centre of gravity
What is rotational acceleration?
Brain rotates around centre of gravity eg. sports
What is angular acceleration?
Combination of translational and rotational forces
What is a coup injury?
A site of initial impact
What is a contre-coup injury?
The brain rebounds against the opposing side of skull, causing further damage
What is a diffuse axonal injury?
Rapid deceleration forces lead to widespread damage throughout the brain. Axons get torn, twisted and broke.
In relation to primary injury, what are intra-cranial hemorrhages?
Large blood vessels may be torn on impact, these haemorrhages create haematomas within the skull:
What are the different kinds of haematomas are created by haemorrages?
Epidural haematomas (EDHs)
Subdural haematomas (SDHs)
Intracerebral haematomas (ICHs)
What are epidural haematomas (EDHs)?
Between skull and dura matter. Often due to contact injury. Most often arterial
What are subdural haematomas?
Between dura matter and arachnoid membrane. Produced by torn veins or brains surface and inner side of dura
What are intra-cerebral haemaomas?
Formations within the brain
Usually occur in frontal and temporal lobes, but also basal ganglia
and cerebellum.
Often result from rupture of blood vessels in the brain and are
associated with DAI.
Delayed traumatic ICH occur within 72 hrs post‐injury.
Brain swelling, cell death, hypoxia, dysregulation of the blood-brain barrier and infection are examples of what kind of injury?
A secondary injury
What is a cerebral oedema?
Excess fluid in the brain leading to swelling of the brain and intracranial pressure (ICP).
What are the two kinds of oedemas?
Vasogenic
Cytotoxic
What is a vasogenic oedema?
Occurs when damage to the brain and surrounding membranes leads to increased extracellular fluid.
What is a cytotoxic oedema?
Occurs when a neuron’s (brain cell) membrane pump fails, leading to increased intracellular fluid.
What is the process of cell death?
Necrosis
Apoptosis
What is necrosis?
Passive death of cells as a result of damage. Occurs within hours of injury. Leads to inflammation and possible damage of surrounding cells.
What is apoptosis?
Programmed death (active self destruction) that occurs when cell is damaged. Requires sufficient resources and may take days. No inflammation or damage to surrounding cells.
What is the apoptotic process?
- cell shrinks
- material is divided into vesicles
- scavenger cells clean up the debris
What are three key indicators of injury severity?
- Length of loss of consciousess
- Depth of coma, measured y glasgow coma scale
- Length of post traumatic amnesia
How is the depth of a coma measured?
Glasgow Coma scale
What are some problems with estimating the severity of a TBI?
- Time of assessment
- Reliability of information
- Medical intervention
(Ventilation/analgesics/anaethetics) - Drug/alcohol use
- Dementia/elderly
What are some cognitive problems associated with TBI?
Attention and concentration • Speed of information processing • Memory (short term and long term) • Executive function ‐ Motivation ‐ Planning ‐ Inhibition ‐ Decision making • Word‐finding and speech production impairment
What are some emotional and behavioural effects of TBI?
Lack of emotional control (eg anger outbursts)
• Emotional lability
• Emotional blunting
• Lack of emotional awareness (reduced empathy)
• Disinhibition
• Failure to pick up on social cues
• Lack of insight/awareness
• Change in sex drive (increase or decrease)
• Personality changes (mostly secondary to the above)
What are some psychosocial outcomes of TBI?
- Relationships – increased strain on, or total breakdown of relationships
- Work – reduced capacity, poor decision making
- Social activities – withdrawal from activities and/or change in
What are some clinical outcomes of TBI?
- Depression
- Anxiety
- Personality disorders • PTSD
What brain structure in ischemic strokes was associated with specific cognitive domains in a study done by Sagnier et al (2019)?
fronto-temporo-insula with basal ganglia and thalamus
What artery supplies blood to the lateral surface of the cortex (in particular, the frontal-parietal areas)?
middle cerebral artery
What deficits are associated with stokes on the right side of the brain?
Visuospatial
What deficits are associated with stokes on the left side of the brain?
Language
What are some unilateral effects of obstructive (Ischaemic) stroke?
Hemiparesis
Hemiplegia
Aphasias (left)
Unilateral neglect (often right)
Why does hemispatial neglect occur?
Unilateral damage to the brain
Most commonly to the right hemisphere’s parietal lobe
What are the several kinds of mechanical forces that have been identified as causing closed head injuries?
Contact forces
Inertial forces (translational acceleration, rotational acceleration, agular acceleration)
Coup injury
contre-coup injury
diffuse axonal
Intracerebral haematomas are often associated with _______?
Diffuse Axonal Injuries
