Brain Damage Flashcards
What are the two broad types of cerebrovascular disorders that can lead to brain damage?
The two broad types are hemorrhagic stroke (cerebral haemorrhage) and ischaemic stroke (cerebral ischemia)
What are the main mechanisms that can cause cerebrovascular disorders - differences between hemorrhagic and Ischaemic strokes?
The main mechanisms include cerebrovascular injury, such as rupture of a blood vessel leading to bleeding (hemorrhagic stroke)
and disruptions in blood supply caused by thrombosis, embolism, or arteriosclerosis (Ischaemic stroke).
What neurotransmitter is involved in ischemia-induced brain damage?
Glutamate, the brain’s most excitatory neurotransmitter, is involved in ischemia-induced brain damage.
What are the two types of cell death that can occur in brain damage?
The two types are apoptosis, which is an active but gradual self-destructive process. It is an adaptive process limiting brain damage. A cell body shrinks and remainder neurons die, any debris is cleared.
Necrosis, which is a passive and fast but more generally destructive process whereby neurons swell up and break.
What is the pathomechanism of brain injury and broadly the two primary classifications?
The mechanism is typically shearing, stretching and tearing at the neuron level.
The two classifications are penetrating head injury and close head injury
What is the difference between primary and secondary impact in closed head injury?
Primary impact refers to the initial force applied to the head (coupe), while secondary impact refers to the brain hitting the opposite side of the skull due to the movement of the brain within the skull (contra coupe).
What is a concussion in the context of traumatic brain injury?
A concussion is a disturbance of consciousness without evidence of structural damage, and it can have significant impacts on brain functioning, particularly in the case of repeated concussions.
What is a cerebral haemorrhage?
It is bleeding within the brain tissue, and it can cause the collection of blood in the convex or dish-shaped part of the brain.
What are some imaging findings associated with closed head injury?
Imaging findings may show contusions (damage to the cerebral circulatory system resulting in internal bleeding), collections of blood around the cisterns and fissures of the brain, and bleeding within the brain tissue itself.
What is the qualities of subdural hematoma in the brain?
Cresent-shaped
Blood collection between dura and arachnoid mater
Tear in bridging veins
Alcoholics and elderly are prone
What are the qualities of an epidural hematoma?
Biconvex (lens) shaped
Blood between dura and skull
Tearing of middle meningeal artery
Adolescents and young adults (trauma)
What are the qualities of a subarachnoid haemorrhage?
Blood in circle of Willis, cisterns, and fissures
Rupture of berry aneurysm
Polycystic kidney disease (risk factor)
What are the qualities of intracerebral haemorrhage?
Blood in parenchyma and ventricles
Hypertensive vasculopathy
Territory of penetrator arteries
Is it better to have a brain injury as a child or an adult?
Brain injuries in children can have a greater impact on development and organisation, while injuries in adults may lead to a narrowing gap in trying to recover compared to their peers.
What are the classifications of severity for traumatic brain injury (TBI)?
The classifications of severity include Glasgow Coma Scale (GCS), loss of consciousness (LOC), and post-traumatic amnesia (PTA).
Most TBI’s are classified as mild, with a smaller percentage classified as moderate or severe.
What are the four neuroplastic responses to brain damage?
The four responses are neural degeneration, neural regeneration, neural reorganisation, and recovery of brain function
What is Anterograde and retrograde degeneration and how does it occur?
Anterograde degeneration = distal portion of a neutron degenerates quickly
retrograde degeneration may affect the proximate portion depending on the reaction of the cell body.
What is Transneuronal degeneration and how does it occur?
where degeneration is transmitted from damaged neurons to intact neurons via synaptic connections.
Is neural regeneration successful in mammals and higher vertebrates?
Neural regeneration is not successful in mammals and higher vertebrates, except for in the peripheral nervous system (PNS) where it is possible to some extent.
What are the factors that determine the course of neural regeneration in the PNS?
The nature of the injury determines whether regeneration axons can grow through intact Schwan cell myelin sheaths (if intact) - yellow neuron to yellow neutron.
Grow into incorrect sheaths and incorrect destinations (if the nerve is severed and ends are separated) - blue neuron connection severed, cannot connect to blue so connects to yellow neuron.
Or no meaningful regeneration will occur (if ends are widely separated) - all neurons that are severed will tangle their axons, leaving the neuron with no axon terminal.
What is neural reorganisation and where has it been observed?
It is the reorganisation of primary sensory and motor systems following damage to peripheral nerves or primary cortical areas. Examples include remapping of V1 neurons in animals and the larger auditory and somatosensory cortex in vision-impaired humans.
What are the mechanisms of neural reorganisation?
release from inhibition strengthens existing connections, and collateral sprouting results in new connections.
Why is the recovery of brain function poorly understood?
It is difficult to differentiate between compensation and true recovery, as improvements can be influenced by factors such as reduction in brain swelling after injury.
explain and outline long-term consequences of repeated impact forces (chronic traumatic encephalopathy) (i.e., CTE).
Repeated concussions or subconcussyve impacts lead to CTE, a neurodegenerative condition associated with cognitive, emotional, and behavioural impairments.
