LECTURE FINAL COPY Flashcards
1
Q
CEREBROVASCULAR DISEASE
A
NEW TOPIC
2
Q
Under normal circumstances, the brain receives _____
A
15% of the cardiac output and utilized fought 20% of the oxygen consumed by the body
3
Q
What is the most sensitive hypoxic organ?
A
The brain
4
Q
What are the 3 major categories of cerebrovascular disease?
A
- Parenchymal injuries
- Infarcts (ischemic stroke)
- Hemorrhage’s (hemorrhagic stroke)
5
Q
What are “Parenchymal injuries” associated with cerebrovascular disease?
A
Parenchymal injuries associated with a generalized with a generalized reduction in blood flow, including global hypoxia - ischemic encephalopathy
- LEAST COMMON
6
Q
What are “Infarcts” associated with cerebrovascular disease?
A
Infarcts (ischemic stroke) caused by local vascular obstruction
- zone of NECROSIS due to oxygen deficiency
7
Q
How common is “Infarcts (ischemic stroke)” in cerebrovascular disease?
A
Makes up 80% of all CVD (MC)
8
Q
What are hemorrhages (hemorrhagic stroke) associated with cerebrovascular disease?
A
Within the brain parenchyme or subarachnoid space
- Makes up 15% of all CVD
9
Q
What is a hemorrhage?
A
An escape of blood from a ruptured vessel
10
Q
What is ischemia?
A
A restriction of blood supply to tissue causing a shortage of oxygen and glucose
11
Q
What is an infarct?
A
Tissue death (necrosis) due to lack of oxygen
12
Q
When does Ischemic stroke occur?
A
When an artery to the brain is blocked
13
Q
What are the 2 types of ischemic stroke?
A
Lacunar infarction and thrombosis of cerebral arteries
14
Q
Lacunar infarction makes up ____
A
8-9% of all ischemic infarction
15
Q
Lacunar infarction is associated with ?
A
Hyaline arteriosclerosis **
16
Q
What happens during Lacunar infarction?
A
Dramatic narrowing of the lumen of arterioles = reduced blood flow to the brain
17
Q
What does Lacunar infarction affect?
A
MIDBRAIN
18
Q
What type of infarction do people have subtle manifestations and don’t realize they have it?
A
Lacunar infarction
19
Q
Thrombosis of cerebral arteries is due to ______
A
Atherosclerosis
20
Q
What is thrombosis of cerebral arteries associated with?
A
Atheroma accumulate in the walls - activation of the platelet plug, thrombus formation, necrosis of tissue
21
Q
In thrombosis of cerebral arteries, what happens if the thrombus breaks off?
A
If thrombus tears and becomes an embolism, it goes with blood flow to vessels who have small lumen - leads to development of thromboembolism
22
Q
What are the most common areas of atheroma ?
A
- Bifurcation of the CC artery
- Bifurcation of the internal carotid artery
- Middle cerebral artery
23
Q
Where is the bifurcation of the common carotid artery?
A
Divided into int/ext at the level of C5
24
Q
Where is the bifurcation of the internal carotid artery?
A
Divided into ant/middle cerebral artery
25
What is the most vulnerable area for ischemic stroke (atheroma)?
Middle cerebral artery ***
26
Liquefaction necrosis results from?
Cerebrovascular disease
27
What is liquefactive necrosis?
Replacement of damaged brain by neuralgia = GLIOSIS
28
What are the sources of thromboemboli in the brain?
Left sided heart failure
- mitral stenosis
- subacute bacterial endocarditis
- MI
29
What is Transient Ischemic Attack (TIA)?
Sequelae of thrombosis - resolution
30
What happens in Transient Ischemic Attack (TIA)?
Development of temporary ischemic stroke - patient develops manifestations of stroke and loss of motor function/speech/eyesight
(UNILATERAL)**
31
What is the duration of Transient Ischemic Attack (TIA)?
Lasts several minutes and the symptoms go away
32
What is a major symptom of TIA?
Loss of vision explained by Involvment of opthalmic artery
33
What is important diagnosis in TIA associated with the opthalmic artery thrombosis?
Aka AMAUROSIS FUGAX
- Temporary unilateral loss of vision
- Similar symptoms
34
What is the treatment of opthalmic artery thrombosis (aka AMAUROSIS FUGAX) associated with TIA?
Anticoagulant
35
Hemorrhagic stroke subcategory:
Intracerebral aka parenchymal aka hypertensive (long term)
36
What is intracerebral/parenchymal/hypertensive Hemorrhagic Stroke associated with?
Hyaline arteriosclerosis
37
What is the mechanism of injury with intracerebral/parenchymal/hypertensive - Hemorrhagic stroke?
In the case of long term hypertension, development of hyaline arteriosclerosis, replacement of normal vascular wall with hyaline tissue weakening of the vascular wall
38
What does intracerebral aka parenchymal aka hypertensive - Hemorrhagic Stroke lead to?
Death of parenchyme
39
What is the most dangerous part of high BP?
Hemorrhagic stroke
- Intracerebral aka parenchymal aka hypertensive
- Sudden increase or decrease of BP
40
What is the development sequence of hemorrhagic stroke?
1. Dramatic pressure into adjacent tissue which results in
compression of walls in ventricle and formations of
non-communicating hydrocephalus
2. Development of poisoning of brain tissue by blood
▪ Because blood gets outside of the vessels- poisonous for the
nervous tissue
3. Pressure atrophy of brain tissue
▪ Usually results in death
▪ If survival, there is scar tissue formation
41
What happens from subarachnoid hemorrhagic stroke?
Rupture of multiple aneurysms that develop within several cerebral arteries (circle of Willis)
42
What is an aneurysm?
Pouching of vascular wall
43
Where does subarachnoid hemorrhagic stroke go?
Goes into subarachnoid space (not cerebral tissue)
- Does not result in death of neural tissue, just blood in the subarachnoid space
44
What is the etiology of subarachnoid hemorrhagic stroke?
Hypertension may be involved, but it is genetic
45
What is the way in which subarachnoid hemorrhagic strokes occur?
The middle layer of arteries are weakened and eventually leads to destruction of the elastic fibers and slow formation of pouching
- usually occurs in bifurcations
46
When does a subarachnoid hemorrhage occur
Usually before 50 y.o.
47
What are the 2 examples of subarachnoid hemorrhage?
1. Berry aneurysm
| 2. Congenital giant aneurysm
48
Aka of Berry Aneurysm :
Saccular Aneurysm
49
What does Berry Aneurysm cause?
Papilledema
- Berry A. Is most vulnerable to rupture (> 1cm)
50
Congenital Giant Aneurysm aka
Giant Aneurysm
| Diameter = > 1cm, up to 5 cm
51
What are the symptoms of congenital Giant aneurysm ?
Similar to space occupying lesions (headache, papilledema, nausea, vomiting )
- MUST BE REMOVED
52
Aneurysms are most vulnerable to rupture between _____
4-7 mm
53
CNS TRAUMA
NEW TOPIC
54
What is the major factor of CNS trauma ?
Car accidents
55
What is a hematoma?
Collection of blood outside of the vessels
56
What are the 3 major categories of CNS trauma?
1. Epidural hematoma
2. Subdural Hematoma
3. Brain Traumatic Injury (parenchyme)
57
Know your layers ->
(Superficial to deep)
- Dura mater
- Arachnoid mater
- Pia mater
58
What is an epidural hematoma?
Normally no space between the skull and dura > in this case, arterial hemorrhage pushes against the dura and creates space at the expense of the cranial fossa
59
What artery does blood leak from in an epidural hematoma?
Meninges arteries - middle meningeal artery
60
Will you have increased hydrostatic P in epidural hematoma?
YES
- Along with compression of brain tissue
61
What swells during epidural hematoma?
Swelling of white matter - accumulation of fluid around axons
- loss of brain function
- prevents/diminishes neural activity
62
What happens to the brain during Epidural Hematoma?
Shift of brain to the other side fo skull
- Noncommunicating hydrocephalus is possible
63
What are the types of Herniations that can occur during Epidural hematoma ? **
1. Subfalcine Herniation
2. Transtentorial (Uncal, uncinate) herniation
3. Cerebellar Tonsilar Herniation
64
What happens during Subfalcine herniation?
- Compression of the anterior cerebral artery
| - Compression of the cingulate gyrus against the fall Cerebri
65
What results from a Transtentorial (Uncal, uncinate) herniation?
Compression of free margin of temporal lobe against tentorium cerebelli
66
What gets compressed during Transtentorial (Uncal, uncinate) herniation ?
Compression of CN III =
Palsy of CN III **
67
What are the results of Transtentorial (Uncal/uncinate) herniation?
- Paralysis of sphincter papilla muscle responsible for narrowing pupil
- Ipsilateral pupil dilation
- Results in permanent dilation of pupil on the same side of herniation
68
What is ipsilateral pupil dilation?
Mydriasis aka Blown Pupil
69
What herniation is more serious, Subfalcine or Transtentorial?
Transtentorial
70
What is the most serious herniation associated with Epidural hematoma?
Cerebellar Tonsilar Herniation
71
What happens during Cerebellar Tonsilar Herniation ?
Herniations of cerebellar tonsils and brainstem into foramen magnum (can result in death)
72
What gets compressed during Cerebellar Tonsilar herniation
- Midbrain
| - Cardiovascular and respiratory centers compressed = can lead to parathesis/ cardiopulmonary arrest
73
What can cerebellar Tonsilar herniation lead to?
Secondary brainstem hemorrhage
- aka duret hemorrhage
- develops in pons
- arterial hematoma
74
What is a severe consequence of cerebellar Tonsilar herniation ?
Lost consciousness in 15-25 min and die within 45 min
75
Where is the most dangerous place for an epidural hematoma?
Temporal bone
76
Why is the temporal bone the most dangerous place for an epidural hematoma?
Middle meningeal artery (largest of meningeal arteries)
77
What is the sequence of Epidural Hematoma?
1. Trauma
2. Break of skull
3. Cuts meningeal A.
4. Increases hydrostatic P.
5. Convexity
6. Swelling
7. Death (highly likely)
78
What is affected in Subdural hematoma?
Superior cerebral veins
79
Aka of superior cerebral veins =
Bridging veins
- carries blood from the brain to superior sagittal sinus to be drained: major blood collector of brain
80
What does Subdural hematoma result from?
Results from rupture of bridging veins due to sudden change of head velocity
81
What is the MOI in Subdural hematoma?
Trauma to head, law of inertia, the brain still has room to move when skull is impacted, creates tearing/shearing force
82
What happens during a Subdural hematoma?
Leakage fo blood in Subdural space
- venous hematoma
83
What exactly happens with a Subdural hematoma, what causes damage?
Direct contact of blood with the brain - leads to dysfunction and atrophy of the brain tissue
84
When will you see signs and symptoms for Subdural hematoma?
24-48 hours and a 2nd trauma could be fatal (why athletes who experience this trauma should continue playing)
85
What are the 2 types of Subdural hematoma?
1. Acute
| 2. Chronic
86
What happens with acute Subdural hematoma?
Sudden change of head velocity that develops in the normal brain (normal people falling)
87
What happens with Chronic Subdural hematoma?
Usually develops in elderly people with brain atrophy
- typical with Alzheimer’s , Parkinson’s, and Huntington’s
88
What are the things associated with brain traumatic parenchymal injury?
- concussion
- Diffuse Axonal injury
- contusion
- laceration (aka traumatic brain hemorrhage)
- Basilar skull fracture
89
What happens during a brain traumatic parenchymal injury?
Damage of brain in different degree and severity
- MC cause of post traumatic dementia
90
What is brain traumatic parenchymal injury associated with?
Concussion
91
What is concussion clinical syndrome?
Characterized by immediate and transient loss of neurological function secondary to mechanical forces
92
What is concussion characterized by?
2 factors: loss of consciousness and amnesia
93
What is amnesia?
Temporary loss of memory of events prior to, during, and after they occur
94
What system is affected with concussion associated with brain traumatic parenchymal injury ?
Reticular Activating System (temporary function loss of RAS with concussion)
- Set of neurons which connect various parts of the brain with one another and negatively effected by trauma
95
What is the most common cause of post traumatic dementia?
Diffuse Axonal injury
96
What happens during diffuse Axonal injury ?
Elongation of white matter - stretching
- may result in tear of white matter structures
97
Where does diffuse Axonal injury normally occur?
In posterior portions of brainstem and cervical spine
98
What is the MOI with diffuse Axonal injury?
Acceleration-deceleration trauma
(Car accident whiplash*)
- Shaken baby syndrome
99
What do you see within Diffuse Axonal injury?
Subinclusions found in area of axon tear, due to accumulation of proteins (micro tears in white matter), amyloid protein precursor-Axonal spheroids
- aka AXONAL SWELLING
100
What disease would you see with Diffuse Axonal injury ?
Alzheimer’s disease
101
What happens with contusion?
Hemorrhage’s in the Superficial brain parenchyma caused by blunt trauma - anatomical damage to brain tissue
(More serious than concussion )
102
What are the 2 types of contusions?
Coup and contra coup
103
What is coup contusion characterized by?
Damage of brain underneath area of impact
- mobile impact force on immobile head
104
What is contra coup contusion characterized by?
Damage of brain on opposite side of impact
- Mobile head runs into immobile object (person runs into wall)
105
What is laceration aka
Traumatic brain hemorrhage
106
What happens during laceration?
Tear of brain tissue (and therefore blood vessels)
** DONT CONFUSE WITH STROKE
107
What are the 2 types of hemorrhage associate with laceration?
1. Traumatic Subarachnoid hemorrhage
| 2. Intracerebral/parenchymal hemorrhage
108
What happens during traumatic subarachnoid hemorrhage?
Leakage of blood in subarachnoid space as a result of trauma - develops in superficial areas
109
What happens during intracerebral/parenchymal hemorrhage?
Leakage of blood in brain tissue as a result of trauma
110
What happens with a basilar skull fracture?
Fracture of orbital plates of frontal bone or greater wing of sphenoid development of bilateral periorbital hemorrhage (bruising of both eyes) and rhinorrhea (runny nose for no reason)
- Raccoon sign
111
What are the 2 types of fracture associated with Basilar skull fracture?
Fracture of orbital plates of frontal bone or greater wing of sphenoid
Fracture of pyramid of temporal bone or anterior aspect of the occipital bone
112
What happens during the 2nd type of fracture during basilar skull fracture?
Fracture of pyramid of temporal bone or anterior aspect of the occipital bone - development of battle sign (bruising behind ear)
- leakage of CSF from ear > otorrhea
113
What can happen as a result of basilar skull fracture?
Development of an infection of the CNS - antibiotics would be prescribed
