L1+2 TBI and Medical Conditions of the Head Flashcards
(81 cards)
1
Q
What does TBI stand for?
A
Traumatic Brain Injury
2
Q
What does FPOT refer to?
A
Frontal, Parietal, Occipital, Temporal (main skull bones)
3
Q
What does DAP represent?
A
Dura mater, Arachnoid membrane, Pia mater (meninges layers)
4
Q
What is CSF?
A
Cerebrospinal Fluid
5
Q
What does ICP stand for?
A
Intracranial Pressure
6
Q
What is CPP?
A
Cerebral Perfusion Pressure
7
Q
What does MAP stand for?
A
Mean Arterial Pressure
8
Q
What do TPR/PVR refer to?
A
Total/Peripheral Vascular Resistance
9
Q
What does CO stand for?
A
Cardiac Output
10
Q
What is DAI?
A
Diffuse Axonal Injury
11
Q
What does CNS stand for?
A
Central Nervous System
12
Q
What is RAS?
A
Reticular Activating System
13
Q
What is coup-contrecoup?
A
Injury pattern at impact site and opposite side
14
Q
What is vasogenic edema?
A
Fluid leakage from blood vessels into brain tissue
15
Q
What is cytotoxic edema?
A
Cellular swelling due to neuronal injury/death
16
Q
What is hypoxia?
A
Insufficient oxygen
17
Q
What does hypercapnia/hypercarbia mean?
A
Excessive carbon dioxide
18
Q
What is ischemia?
A
Insufficient blood flow
19
Q
What does herniation/coning refer to?
A
Brain displacement through foramen magnum
20
Q
What is Cushing’s triad?
A
Hypertension, bradycardia, irregular respirations
21
Q
What is the blood pressure formula?
A
BP = CO × TPR
22
Q
How is mean arterial pressure (MAP) calculated?
A
MAP = Diastolic BP + 1/3 Pulse Pressure
23
Q
What is pulse pressure?
A
Pulse Pressure = Systolic BP - Diastolic BP
24
Q
How is cerebral perfusion pressure (CPP) calculated?
A
CPP = MAP - ICP
25
What is a primary traumatic brain injury?
Direct damage to the brain from initial trauma caused by mechanical forces such as acceleration/deceleration, blunt force, or penetrating injuries.
26
What is the difference between focal and diffuse brain injuries?
Focal injuries occur at specific locations (e.g., contusions, hemorrhages), while diffuse injuries involve widespread damage throughout the brain (e.g., DAI, concussion).
27
What is the coup-contrecoup mechanism?
Injury occurs at the site of impact (coup) AND on the opposite side of the brain (contrecoup) as the brain bounces within the skull.
28
Why may TBI manifest with dysfunctions unrelated to site of injury?
Due to contrecoup injuries, diffuse axonal injury, or secondary effects like increased ICP affecting distant brain regions.
29
What is an epidural hemorrhage?
Bleeding between the skull and dura mater, typically arterial, rapid-developing and high-pressure.
30
What is a subdural hemorrhage?
Bleeding between the dura and arachnoid membrane, typically venous, often slower-developing, common in elderly.
31
What is a subarachnoid hemorrhage?
Bleeding between the arachnoid and pia mater, often arterial with poor prognosis if traumatic.
32
What is an intracerebral hemorrhage?
Bleeding within brain tissue itself from ruptured small vessels, causing damage through irritation and increased ICP.
33
What is a diffuse axonal injury (DAI)?
Widespread damage to axons throughout the brain caused by rotational/shearing forces.
34
Why is DAI particularly damaging?
It affects communication between brain regions, disrupts multiple functions simultaneously, often involves vital brainstem areas, and has limited recovery potential.
35
How does hemorrhage cause brain injury?
By direct irritation to brain tissue, increasing ICP, compressing blood vessels causing ischemia, and potentially leading to brain herniation.
36
What is a secondary brain injury?
Damage resulting from complications following initial trauma, such as ischemia, hypoxia, edema, and inflammation.
37
What is the Munroe-Kellie hypothesis?
The skull contains a fixed volume of brain (80%), blood (10%), and CSF (10%); any increase in one component must be matched by decrease in another or ICP rises.
38
What happens to CPP if ICP increases?
CPP decreases as blood vessels get compressed, reducing blood flow to brain tissue and potentially causing ischemia.
39
Why is mean arterial pressure (MAP) a useful measure?
It represents average pressure during cardiac cycle, better reflecting organ perfusion than systolic pressure alone.
40
What is the purpose of the CNS ischemic response?
It's a last-ditch effort to preserve blood flow to vital brain centers during increased ICP.
41
What causes vasodilation of cerebral blood vessels in TBI?
Increased CO₂ (hypercapnia) and hypoxia from reduced cerebral blood flow.
42
How does vasodilation affect ICP?
It paradoxically increases ICP by increasing blood volume within the skull, creating a vicious cycle.
43
What are the three stages of Cushing's reflex?
1) Hypertension from sympathetic activation, 2) Bradycardia and widened pulse pressure from baroreceptor response, 3) Irregular breathing from brainstem compression.
44
What is the significance of Cushing's triad?
It indicates terminal stage of increased ICP and potential imminent herniation.
45
What is brain herniation?
Displacement of brain tissue through foramen magnum due to elevated ICP, compressing vital brainstem centers.
46
What are the normal and critical values for ICP?
Normal: 0-15 mmHg; Abnormal: 20 mmHg; Severe: 40 mmHg; Herniation: 50 mmHg
47
What are the normal and critical values for CPP?
Normal range: 70-100 mmHg; Brain ischemia develops below 40 mmHg
48
Calculate MAP for blood pressure 120/80.
Pulse pressure = 120-80 = 40; MAP = 80 + (1/3 × 40) = 80 + 13.3 = 93.3 mmHg
49
What physical signs indicate increased ICP?
Decreasing level of consciousness, Cushing's triad (hypertension, bradycardia, irregular respirations), pupil dilation, abnormal posturing
50
What is the most common cause of secondary brain injury?
Ischemia (insufficient blood flow to the brain)
51
52
What is the difference between a stroke and a TIA?
A stroke causes permanent brain damage with deficits persisting beyond 24 hours, while a TIA is temporary with symptoms resolving within 24 hours and no permanent damage.
53
What percentage of strokes are ischaemic vs haemorrhagic?
80% ischaemic, 20% haemorrhagic.
54
What are the two main types of ischaemic strokes?
Thrombotic (53%) and embolic (31%).
55
What are the two main types of haemorrhagic strokes?
Intracerebral haemorrhage (10%) and subarachnoid haemorrhage (6%).
56
What happens to the brain after 2-4 minutes without oxygen?
Glucose and glycogen stores are exhausted.
57
What happens to the brain after 4-5 minutes without oxygen?
Cellular ATP stores are depleted.
58
What is the ischaemic penumbra?
Salvageable tissue surrounding the ischaemic core in a stroke that may recover with timely intervention.
59
What is the most common cause of embolic strokes?
Atrial fibrillation.
60
What is a subarachnoid haemorrhage?
Bleeding into the space between the arachnoid membrane and pia mater surrounding the brain, often from a ruptured aneurysm.
61
What is the primary symptom of a subarachnoid haemorrhage?
"Worst headache ever" followed by decreased level of consciousness and vomiting.
62
Where do aneurysms commonly occur in the brain?
In the Circle of Willis.
63
What is Bell's Palsy?
Temporary paralysis of the facial nerve (cranial nerve VII) causing facial muscle weakness on one side.
64
What is the difference between aphasia and dysarthria?
Aphasia is a partial or total loss of language skills, while dysarthria is a speech disorder with imperfect articulation.
65
What is the difference between focal and generalised seizures?
Focal seizures begin in one specific area of the brain, while generalised seizures begin simultaneously in both cerebral hemispheres.
66
What is status epilepticus?
A seizure lasting longer than 30 minutes or multiple seizures without recovery, considered a medical emergency.
67
What are the phases of a tonic-clonic seizure in order?
Aura → Loss of consciousness → Tonic phase → Hypertonic phase → Clonic phase → Postictal phase.
68
What is the postictal state?
The period following a seizure characterized by altered consciousness, drowsiness, confusion, and amnesia, typically lasting 5-60 minutes.
69
What is the cause of 50% of epilepsy cases?
Idiopathic (no known cause).
70
What is meningitis?
Inflammation of all three layers of meninges in the brain and spinal cord.
71
What is the approximate death rate for bacterial meningitis?
7-30%.
72
What happens in the brain with continued inadequate oxygenation?
Brain cells start to infarct (die).
73
What is a lacunar stroke?
Small, deep infarcts in non-cortical parts of brain due to occlusion of small penetrating arteries.
74
What is the FAST acronym used for?
To assess stroke symptoms: Face, Arm, Speech, Time.
75
What is hydrocephalus?
Abnormal buildup of CSF in brain ventricles.
76
What does the AEIOUTIPS mnemonic stand for?
Acidosis/Alcohol, Epilepsy, Infection, Overdose, Uraemia/Under-dose, Trauma/Tumour/Toxin, Insulin, Psychosis/Poison, Stroke/Seizure.
77
How much of the body's oxygen consumption is used by the brain?
20%, despite being only 2% of body weight.
78
What percentage of cardiac output does the brain receive?
15% of resting cardiac output.
79
What is an absence seizure?
A generalised non-convulsive seizure characterized by a blank stare, brief unresponsiveness, typically occurring in children.
80
What is excitotoxicity?
Cell death caused by excessive release of excitatory neurotransmitters.
81
What are automatisms in the context of seizures?
Involuntary, repetitive actions during a seizure such as lip-smacking or hand movements.
