Chapter 16- Disorders of CNS, PNS and NMJ Flashcards
1
Q
What can alter CNS function?
A
Traumatic injury
Vascular disorders
Tumour growth
Infections
Inflammatory processes
2
Q
What is affected by alterations PNS function?
A
Nerve route, plexus, nerve themselves or neuromuscular junction
3
Q
What is the primary cause of death and disability in individuals under age 40 in Canada?
A
Traumatic brain injury (TBI)
4
Q
30% of all TBIs are sustained by what group?
A
Children and youth
-Many caused by sports
5
Q
What is a TBI?
A
Alteration in brain function or other evidence of brain disease caused by an external force
6
Q
What are the 2 types of TBIs?
A
Primary
Secondary
7
Q
What causes a primary TBI?
A
Direct impact
8
Q
Focal
A
Affecting one area of the brain
9
Q
Diffuse
A
Affecting more than one area of the brain
10
Q
Is a primary TBI focal or diffuse?
A
Can be focal or diffuse (diffuse axonal injury DAI)
Focal = 2/3 injuries
Diffuse= 1/3 injuries
11
Q
What causes a secondary TBI?
A
Indirect result of primary injury
12
Q
What happens when someone has a secondary TBI?
A
Systemic responses and cascade of cellular and molecular cerebral events
13
Q
How are TBIs diagnosed?
A
Glasgow Coma Scale (GCS)
14
Q
What is the Glasgow Coma Scale?
A
Scores 1-6 based on best eye response, best verbal response and best motor response. Totals are calculated and classified from mild-severe
15
Q
What is a score 2 on the GCS?
A
-Eye opening to pain
-Incomprehensible sounds
-Extension to pain
16
Q
What is a score 3 on the GCS?
A
-Eye opening to verbal command
-Inappropriate words
-Flexion to pain
17
Q
The lower the score the more ______________________?
A
Severe the damage
-Severe head injury = GCS score of 8 or less
18
Q
Are primary focal TBIs closed or open?
A
Can be closed or open
19
Q
What type of primary focal TBI is more common?
A
Closed
20
Q
What is the appearance of the brain of a closed primary focal TBI?
A
Dura mater remains intact, Brain tissue not exposed
21
Q
What causes a closed primary focal TBI?
A
Head striking a hard surface
Moving object striking head
Blast waves
22
Q
What is the appearance of the brain of an open primary focal TBI?
A
Break in dura mater
Brain tissue exposed
23
Q
What causes an open primary focal TBI?
A
Penetrating trauma
Skull fracture
24
Q
Examples of primary focal closed TBIs?
A
Coup/Contrecoup
Contusion
epidural (extradural) hematoma
Subdural hematoma
Intracerebral hematoma
25
Examples of primary focal open TBIs?
Compound skull fractures
Missile injuries
26
What is a Primary focal closed TBI?
Specific, observable brain injuries that occur in a precise location
27
What percent of primary focal closed TBIs are mild?
80%
28
What are some severe primary focal closed TBIs?
Contusions
Epidural
Subdural
Hematomas
29
Coup
Injury at the site of impact
30
Contrecoup
Injury from brain bouncing back and hitting opposite side of skull
31
What is a contusion?
Brain bruising caused by the compression of th eskull at the point of impact
32
What is the contusion the result of?
Blood leaking from injured vessel
33
What causes a more severe contusions?
Smaller contact area
34
What is the most common site of contusion injuries?
Frontal lobe
35
What forms after a contusion?
Edema because of increased ICP
36
When an edema forms in the brain after a contusion what happens?
Hemmorhages, edema, infarction and necrosis making the tissue become pulpy
37
When do the greatest injury effects peak after a contusion?
18-36 hours after injury
38
How is a contusion diagnosed?
Glasgow coma scale
CT scan
MRI
39
How is a contusion treated?
Surgical removal of large contusions and areas of haemorrhage may be required
40
What is an epidural hematoma (EH)?
Bleeding between dura mater and skull
-Artery bleeding and hematoma
41
What is the most common site of EH?
Temporal fossa
42
What are symptoms of EH?
Loss of consciousness
Hematoma grows= severe headache, confusion and seizure
Hemiparesis
Pupil dilation
43
What is hemiparesis?
Weakness or inability to move one side of the body
44
When is injury prognosis of a epidural hematomy good?
If treated before both pupils dilate
45
How is EH treated?
medical emergency
46
What does dural refer to?
Dura Mater
47
What is a subdural hematoma?
Bleeding between dura mater and brain
48
What are the two kinds of subdural hematoma?
Acute
Chronic
49
What is an acute subdural hematoma?
Develop quickly, within hours
-Hematomas grow, ICP rises, pressure is applied to bleeding veins (short-term limitation)
50
What are the symptoms of an acute subdural hematoma?
Headache to confusion
-Loss of consciousness
-Pupil dilation
-Hemianopia
-Anopia
51
What is hemianopia?
Blindness over half of the field of vision
52
What is anopia?
Blindness
53
What is a chronic subdural hematoma?
-Develop over weeks to months
Subdural mass bleeding causing the subdural space to fill with blood, and a vascular membrane forms around hematoma
54
Chronic subdural hepatomas are common in those who?
Abuse alcohol
55
What are symptoms of a chronic subdural hematoma?
Headaches
Tenderness over hematoma
Worsening dementia and paranoia (rigidity)
56
How are chronic subdural hepatomas treated?
Craniotomy to remove jelly-like blood
57
What is a intracerebral hematoma?
Bleeding within the brain
-Penetrating and shearing force injure small blood vessels causing a mass and edema
58
What percent of head injuries are intracerebral hematoma?
2-3%
59
What areas of the brain are the common sites of intracerebral hematomas?
Frontal and temporal lobes
60
What are symptoms of intracerebral hematomas?
Sudden rapid decrease in level of consciousness
Pupil dilation
Positive Babinski reflex
61
What is a positive Babinski reflex?
Big toe bends up and back to the top of the foot and the other toes fan out
62
What is a Compound Skull Fracture (CSF)?
Opens a path between cranial contents and the environment
-Open primary focal TBI
63
When should a CSF be considered?
Whenever cuts of the scalp, tympanic membrane, sinuses, eye or mucous membranes occur
64
What are the causes of Compound skull fractures (CSF)?
Crush or stretch injuries
65
What is a crush injury?
Cutting or crushing
-Whatever the missile touches
66
What is a stretch injury?
Blood vessel or nerve damaged without direct contact
67
What are symptoms of open brain injuries?
Unconscious
68
What is a basilar skull fracture?
Involves at least one of the bones that compose the base of the skull. Generate spinal fluid leaking from ear or nose and blackened eyes.
69
What causes basilar skull fractures?
Substantial blunt force trauma
70
What causes Primary diffuse injuries (diffuse axional)?
High levels of acceleration or deceleration (whiplash) or rotational forces
71
What is a primary diffuse injury?
Widespread injury caused by forces which lead to the shearing of axonal fibers and white matter tracts
72
The cognitive consequences of a primary diffuse injury are based on?
The degree of shearing
-Higher degree = extensive cognitive impairments
e.g Car crash survivors
73
How are primary diffuse TBIs diagnosed?
Electron microscope to detect axonal damage
74
What syndromes are included as secondary brain injuries?
Trauma and stoke syndromes
75
What systemic process are involved in secondary brain injuries?
Hypotension, hypoxia etc.
76
What cerebral processes are involved in secondary brain injuries?
Inflammation, edema, increased ICP
77
How do primary brain injuries lead to secondary brain injuries?
Effects of primary TBIs cause a disruption to the BBB which causes neuronal death
78
How are secondary brain injuries managed?
Prevention of hypoxia
Maintenance of cobra perfusion pressure
Removal of hematomas
Nutritional management
79
What are the categories of TBIs?
Mild
Moderate
Severe
80
What is a mild TBI?
aka Mild concussion
Characterised by immediate but transitory clinical manifestations
81
How long does loss of consciousness last for a mild TBI?
less than 30 minutes
82
What is the GCS score for a mild TBI?
13-15
83
What are symptoms of mild TBIs?
Headache, nausea, vomiting
84
How are mild TBIs diagnosed?
Blood test to determine need for CT scan
85
How long does loss of consciousness last for a moderate TBI?
30mins to 6 hours
86
What is the GCS score for a moderate TBI?
9-12
87
Moderate TBIs cause permanent defects in what?
Arousal and attention
88
What are symptoms of moderate TBIs?
Confusion and amnesia lasting more than 24v hours
Abnormal brain imaging
89
How long does loss of consciousness last for a severe TBI?
More than 6 hours
90
What is the GSC score for severe TBIs?
3-8
91
How does a severe TBI progress?
Permanent damage ---> vegatative state ----> Death
92
What are signs of a severe TBI?
Changes in pupillary reaction, cardiac and respiratory systems
Decerebrate or decorticate posturing
Abnormal brain imaging
Increased ICP 4-6 days after injury
93
Decorticate posturing
Person is stiff with bent arms, clenched fists, and legs held out straight
94
Decerebrate posturing
Arms and legs being held straight out, the toes being pointed downward, and the head and neck being arched backward
95
What are symptoms of Severe TBIs?
Compromised coordinated movements, verbal and written communication
96
What is the goal of treatment for someone with a severe TBI?
Maintain cerebral perfusion and promote neural protection
97
Whta determines probable complications of TBIs?
Severity and location of brain injured
98
What are 3 post-traumatic syndromes?
1. Post-concussion Syndrome
2. Post-traumatic Seizures (epilepsy)
3. Chronic Traumatic Encephalopathy (CTE)
99
How long does Post-concussion syndrome last?
Weeks-months after concussion
100
What symptoms of concussions require further evaluation?
Drowsiness, confusion, vomiting
Unequal pupils
CSF drainage from ears or nose
Double vision
101
When should a concussion be under close observation?
First 24 hours
102
What percentage of TBIs develop Post-traumatic seizures (epilepsy)?
10-20%
103
What kind of brain injuries are at the highest risk for developing Post-Traumatic Seizures?
Open brain injuries
104
What causes the increased seizures associated with Epilepsy?
Molecular changes cause the sprouting of new hyper excitable neural activity leading to increased seizures
105
What is Chronic Traumatic encephalopathy?
Progressive dementing disease that develops with repeated brain injury
106
What is Chronic traumatic encephalopathy associated with?
Contact sports (especially football)
blast injuries with soldiers
107
What occurs in the brain of someone with CTE?
Tau neurofibrillary tangles
108
What are the consequences of CTE?
VIolent behaviour
Change in cognitive and motor function
Depression
Suicide
109
Who is at risk for SPinal cord and vertebral injuries?
Male gender 20-39 yoa
Adult 79+ (bc of falls)
110
What causes a Primary Spinal cord injury?
Initial mechanical trauma causing immediate tissue damage
111
When does a primary spinal cord injury occur?
If the injured spine does not receive adequate immobilization following trauma
112
When can a primary spinal cord injury be life-threatening?
If C1-C4 is injured
-Loss of CV and respiratory function
113
What is a secondary spinal cord injury?
Disease causing process occuring within minutes and continues for weeks
114
Where does a hemorrhage appear in Secondary spinal cord injuries?
In grey matter
-death of all grey matter at the spinal level
115
Where do secondary spinal cord symptoms occur?
Two cord segments above and below injury
116
WHat happens when the spinal cord swells during secondary spinal cord injury?
Increases dysfunction and makes it difficult to distinguish permanent and temporary damage
117
What cells die during a secondary spinal cord injury?
Oligodendrocytes
-Caused by myelin degeneration
118
What are some vertebral injuries?
â–ª Vertebral fractures, dislocation, bone
fragments = shearing and compression
â–ª Vertebrae fracture easily due to torn
supporting ligaments
â–ª Vertebra misalignment and dislocation occurs
â–ª Vertebral injuries occur at most moveable
portions of column
â–ª Hyperextension, Flexion, and Rotations damage
119
What is spinal shock?
Develops immediately after injury, Complete loss of function at or below level of injury
120
What happens to the hypothalamus during spinal shock?
It cant regulate body heat
-person assumes temp of air aka Poikilothermic
121
How long does spinal shock last?
7-20 days
122
When does spinal shock return?
With reflex of emptying the bladder
123
What is neurogenic shock?
Occurs with injury above T6
Unopposed parasympathetic activity (due to absence of sympathetic activity)
➢ Result: Vasodilation, hypotension
124
