Neuro Mod 8 Flashcards
(131 cards)
1
Q
Primary injury to the spinal cord?
A
Direct physical impact immediately damages spinal cord cells (neurons/glial cells) and causes necrosis
2
Q
Secondary injury to the spinal cord occurs within ______
A
hours
3
Q
Secondary injury to the spinal cord?
A
Cellular necrosis from primary injury causes immune/inflammatory cascade, neuro excitatory responses to ischemia (further damage area adjacent to primary injury)
4
Q
Medical strategies for primary spinal cord injury?
A
Stabilize injury, address emergency life threatening concerns
5
Q
Medical strategies for secondary spinal cord injury?
A
Neuroprotective therapy to minimize: acute-phase procedural/surg intervention, systemic pharm agents, cell-based therapies
-high dose IV steroids used in past (unclear evidence, guidelines do not support)
6
Q
What is spinal shock?
A
Acute loss of motor, sensory, reflex functions below level of injury:
-areflexia (including bulbocavernosus reflex)
-flaccid paralysis (all muscles below injury, bowel/bladder dysfunction, resp. dysfunction if high cervical injury)
-Complete anesthesia
7
Q
When does spinal shock occur?
A
Immediately after acute spinal cord injury
*not usual w gradual injury (tumors, etc.)
8
Q
Phase 1 of spinal shock?
A
Areflexia/hyporeflexia: immediate
9
Q
Phase 2 of spinal shock?
A
Initial reflex return: first one to return is bulbocarvernosus (w/in 24-48 hr), usually a marker for end of spinal shock
*deep tendon reflexes remain absent
10
Q
How to check for bulbocarvernosus reflex?
A
compress glans penis or clitoris and observe for anal sphincter contraction
*another method: tug on foley catheter
11
Q
Phase 3 of spinal shock?
A
Early hyperreflexia: some DTRs return gradually (1-4wks) after injury and are hyper reflexic (transition phase from hyporeflexia to hyperreflexia)
12
Q
Phase 4 of spinal shock?
A
Final hyperreflexia/spasticity: all DTR below level of injury return/are hyperreflexic
*flaccid paralysis is replaced by hypertonicity/spasticity 1-12 months post injury
13
Q
What is neurogenic shock a result of?
A
acute spinal cord injury or sometimes non-traumatic causes of SCI (anesthesia, infection, toxins, etc)
14
Q
How does neurogenic shock manifest?
A
Hypotension, bradyarrhythmia, temp dysregulation
15
Q
Neurogenic shock occurs in what % of SCI?
A
</=10%
16
Q
Neurogenic shock is associated w/ what kind of SCI?
A
cervical high thoracic (SCI above T6)
17
Q
Neurogenic shock is ____ ____ if not managed immediately?
A
Potentially fatal
18
Q
Pathophys of neurogenic shock?
A
Disrupts sympathetic pathways in upper SC, leads to severe loss of sympathetic function while parasympathetic is intact
19
Q
Loss of sympathetic tone allows for ______ parasympathetic activity
A
Unopposed
20
Q
What does unopposed parasympathetic activity lead to?
A
Hypotension (systolic <100), Bradycardia, Hypothermia
21
Q
Management goal of neurogenic shock?
A
Restore hemodynamics
22
Q
How to manage hypotension w/ neurogenic shock?
A
(MAP 85-94), IV fluids, vasopressors, inotropes (inc strength of cardio contraction)
*too much fluid can cause overload/pulm edema
23
Q
How to manage bradycardia w/ neurogenic shock?
A
Anticholinergics (atropine, glycolpyrolate)
24
Q
What is autonomic dysreflexia?
A
Extreme HTN w/ bradycardia
*potentially life threatening
25
Autonomic dysreflexia is a complication of SCI above the T6 level and rare if it occurs below _____
T10
26
What % of SCI will develop autonomic dysreflexia?
20-70%
27
A hx of autonomic dysreflexia is a potential complication for what?
Med procedures, surgeries, labor
28
Pathophys of autonomic dysreflexia?
Cutaneous or visceral stimulation below level of injury --> stimulates sympathetic reflex activity
29
Cutaneous/visceral stimulation of autonomic dysreflexia pathophys?
Bladder/rectum: distend, foley catheter, impaction
Cutaneous: pain, cold, pressure ulcers, etc.
Injuries: fx, etc.
UTIs
30
Sympathetic reflex activity of autonomic dysreflexia pathophys?
Massive vasoconstriction in lower 2/3 of body and extreme HTN --> stimulates parasympathetics to inhibit sympathetics in brainstem via barorecptors to compensate
31
Parasympathetic signals in autonomic dysreflexia pathophys cannot descend past _______
level of injury (allows sympathetic reflexes to remain active below this point, massive vasoconstriction and HTN persist here)
32
Treatment for autonomic dysreflexia?
Immediately sit patient up to decrease BP, Do not lay pt down, remove irritating stimuli asap
*bladder distention is mc cause: evaluate catheter
*bowel: constipation/impaction
*skin: clothes, pressure sores
33
If unable to resolve irritating stimuli causing autonomic dysreflexia, what should be done?
Transfer to emergency medical system ASAP
34
If not treated promptly, autonomic dysreflexia can lead to what?
Seizures, cerebral hemorrhage/stroke, potential death
35
What two areas do descending motor tracts originate in the CNS?
Motor cortex (primary motor area) or Brainstem (red nucleus, tectum, vestibular nuclei, reticular nuclei)
36
What are the two major descending motor tract pathways?
Lateral and medial (anterior) motor tracts
37
Lateral motor tracts & their control?
Lateral corticospinal tract & rubrospinal tract
Control fine motor movements of distal extremities
38
Anterior/medial motor tracts & their control?
Tectospinal, anteriomedial corticospinal, reticulospinal, vestibulospional tracts
Control axial/trunk and reflexes
39
Lateral corticospinal and rubrospinal tracts travel ________ in the _______ of the spinal cord
Next to each other in the lateral column
40
Lateral corticospinal tract pathway?
Motor cortex output --> internal capsule --> ipsilateral anterior brainstem --> cross midline in lower medulla --> descend in lateral spinal column --> terminate in anterior horn motor neurons to supply UE/LE muscles
*controls fine motor movement
41
What is a result of a lesion in the lateral corticospinal tract above the medulla (stroke, tumor of motor cortex, internal capsule, anterior brain stem)?
Contralateral hemiparesis
42
What is a result of a lesion in the lateral corticospinal tract below the medulla (SCI or MS/ALS in lateral spinal cord)?
Ipsilateral hemiparesis below lesion
43
Function of rubrospinal tract?
Supports fine motor movement, promotes UE flexors/inhibits US extensors
*more involved in UE than LE
44
Pathway of rubrospinal tract?
Originates in red nucleus of midbrain --> descends lateral column of spinal tract just anterior to lateral corticospinal tract --> terminates at anterior horn motor neurons that supply UE/LE
45
An isolated rubrospinal tract lesion is rare and would not cause ________
hemiparesis
46
A lesion in the lateral column (that affects both rubrospinal and lateral corticospinal tracts would result in what?
Hemiparesis
47
What is decerebrate posturing?
UE and LE extended
48
What is decorticate posturing?
UE flexed, LE extended
49
Decorticate and decerebrate posturing are associated with ____ outcomes
poor
50
Brainstem damage involving the red nucleus and below would result in what?
Decerebrate posturing
*red nucleus decreases UE flexor tone/allows UE extensor tone to dominate at elbow
51
Which is more severe/has a worse outcome: decerebrate or decorticate posturing?
Decerebrate
52
Brainstem damage above the red nucleus would result in what?
Decorticate posturing
*loss of normal cortex inhibition to red nucleus, excessive flexor tone of UE to dominate
53
The medial (anterior) motor tracts are involved in what?
Axial (trunk)/proximal limb control/balance
54
The medial (anterior) corticospinal tract controls/maintains axial/proximal limb voluntary movement and works synergistically with what?
Lateral corticospinal tract's control of distal voluntary motor movement
55
Pathway of the medial (anterior) corticospinal tract?
Motor cortex to brain same as lateral *except does not cross midline at medulla --> descends in anterioromedial spinal cord --> terminates near medial ventral horn of most levels of the spinal cord (C1 to approx. L2/L3)
56
Function of the tectospinal tract?
Visual reflexes/coordination of head and eye movement
*reflexive reactions to visual input
57
Pathway of tectospinal tract?
Originates at superior colliculi of midbrain --> descends anteriomedial spinal cord --> terminates in cervical spine (supplies postural muscles of head/neck
*only found in cervical spine
58
Function of reticulospinal tract?
Modulates reflexive/automatic motor movement related to posture/gait (sensory input to reticular system modifies motor control, modulates flexor response to noxious pain input)
59
Pathway of reticulospinal tract?
Originates reticular nuclei in lower 2/3 of brainstem --> descends in anteriomedial spinal cord --> terminates in motor nuclei of anterior horn in all levels of spinal cord
60
Function of medial vestibulo spinal tract?
Controls head and neck movement/posture
61
Pathway of medial vestibulo spinal tract?
Begins medial vestibular nuclei of medulla --> descends in anteriomedial spinal cord --> terminates on motor nuclei of neck muscles located in anterior horn of cervical spinal cord
*only found in cervical spine
62
Function of lateral vestibulospinal tract?
Balance and extensor tone
63
Pathway of lateral vestibulospional tract?
Begins lateral vestibular nuclei of medulla --> descends anteriomedial spinal cord --> terminates on motor nuclei of antigravity (extensors) muscles located in anterior horn in all levels of spinal cord
64
The corticobulbar tract is a motor tract that originates in the ______ cortex and terminates on motor nuclei of cranial nerves ___, ____, ___, and ___
Primary. 5, 7, 10, 12
65
What does the corticobulbar tract innervate?
Muscles of the tongue, face, jaw, pharynx/larynx
66
The corticobulbar tract is the _____ version of corticospinal tracts
head
67
Function of corticobulbar tract?
Bilateral voluntary movement of upper face/mouth/pharynx/larynx muscles
&
Contralateral voluntary movement of lower facial muscles (lower CN7) and tongue (CN12)
68
Pathway of corticobulbar tract?
Primary motor cortex ---> descends through internal capsule & anterior brainstem ---> terminates in motor nuclei of CN 5, 7, 10, 12
69
CN 7 innervation?
Bilateral innervation of upper facial muscles, and contralateral innervation of lower facial muscles
70
CN12 innervation?
Contralateral innervation of tongue
71
Lesion of the cortex or corticobulbar tract has what kind of affect on upper facial muscles?
None
72
Lesion of the cortex or corticobulbar tract has what kind of affect on lower facial muscles?
Contralateral hemiparesis of lower facial muscles (CN7) and tongue (CN12)
73
Corticobulbar tract lesion vs bells palsy?
Bells palsy damages CN7 itself (hemiparesis ipsilateral upper & lower facial muscles)
Corticobulbar tract lesion damages tract that innervates CN7 (hemiparesis contralateral lower facial muscles)
74
What are upper motor neuron structures?
Cortex, IC, descending motor tracts in brainstem/SC, terminal end of descending neuron before synapse w motor nucleus in anterior horn
75
What are lower motor neuron structures?
Anterior horn (motor nucleus), motor root, motor portion of spinal nerve root & peripheral nerve
76
UMN lesion/damage to anything above anterior horn is caused by what pathologies?
Stroke, SCI, tumor, MS, ALS, etc
77
Which pathology causes both UMN and LMN sx?
ALS
78
Signs/sx of UMN lesion?
Hyperreflexia, hypertonicity/spasticity, spastic weakness/paresis, small amount of muscle atrophy d/t disuse
79
What are present w/ UMN lesion?
Pathological reflexes: Babinski's siogn, Hoffmans sign, etc (primitive signs normal in infants but normally disappear in adults)
*UMN lesions cause them to reappear/indicate loss of cortical inhibition
80
What is babinskis sign?
Plantar reflex test (reflex hammer dragged from heel to ball of feet along lateral plantar surface) will stimulate extension of great toe and fanning of other toes
*present in healthy infants or UMN lesion
*normal reflex in adults: toe flexion
81
What is hoffmans sign?
Flexion of thumb or index finger after performing hoffmans test (flick middle finger at DIP joint)
aka digital reflex
82
LMN lesion/damage to peripheral motor pathway can result from which pathologies?
Radiculopathy, peripheral nerve entrapment, Guillain-barre, ALS
83
Signs/sx of LMN lesion?
Hyporeflexia, hypo-tonicity, flaccid weakness, severe muscle atrophy (occurs quickly w/in 2 wks), pathological reflexes not present
84
What is present in LMN lesions?
Fasciculations (small visible muscle twitches d/t involuntary contraction/relaxation of small bundle muscle fibers)
85
Somatosensory refers to what sensations?
Touch, pain, temp, vibration, proprioception (joint-limb position sense)
86
3 spinal cord pathways of somatosensory info going to the brain/brainstem?
Dorsal column-medial lemniscus system, spinocerebellar tracts, spinothalamic tracts
87
Function of dorsal column-medial lemniscus system?
Transmits discriminating touch (well localized touch), pressure, vibration, proprioception from brain to body
88
Pathway of dorsal column-medial lemniscus system?
Sensory info enters posterior horn --> ascends in ipsilateral posterior column ---> medulla, crosses midline ---> thalamus ---> projects to primary somatosensory cortex (3,1,2)
89
Lesion of dorsal column-medial lemniscus system above the medulla results in what?
Contralateral loss of proprioception (discriminating touch/vibtaion)
90
Lesion of dorsal column-medial lemniscus system below the medulla results in what?
Ipsilateral loss of proprioception (discriminating touch/vibtaion) below the lesion
91
Vibration sense test for dorsal column-medial lemniscus system?
tuning fork (128 hz) over bony prominence
92
Joint position sense test for dorsal column-medial lemniscus system?
Contact side of finger/toe & move it up/down and assess if pt can determine direction
93
Discriminating touch tests for dorsal column-medial lemniscus system?
2 pt discrimination: moving vs static, monofilaments
94
Romberg's test for dorsal column-medial lemniscus system?
Stand feet close together, observe amount of trunk sway
*safely guard and ask pts to close eyes & observe for sway/loss of balance
95
Positive rombergs test (rombergs sign)?
Increased trunk sway or loss of balance w/ eyes closed when compared to eyes open
96
Function of spinocerebellar tracts?
Transmit unconscious proprioception to cerebellum
97
Pathway of spinocerebellar tracts?
proprioceptive info enters SC --> ascends in ipsilateral lateral column --> ascend to brainstem/cerebellum
98
Isolated lesion of the spinocerebellar tracts is _____
Rare
99
Lesion of spinocerebellar tracts may cause what?
Small amount of ataxia (uncoordination)
*but lateral column injury/lesion would probably involve lateral corticospinal tract resulting in hemiparesis that would overshadow ataxia
100
Spinothalamic tracts are also known as what?
Anterolateral tracts or anterolateral system
101
Function of spinothalamic system?
Transmit pain and temp
102
Which two pathways form the spinothalamic/anterolateral system?
Lateral spinothalamic tract & anterior spinothalamic tract
103
Function of lateral spinothalamic tract?
Fast pain away: immediate localized pain associated w/ tissue damage/injury
*detect/localize pain/temp of body & mediates discriminative pain/temp aspects from body
104
Lateral spinothalamic tract pathway?
Nociceptive info enters SC/cross midline immediately --> ascends contralateral lateral column ---> thalamus --> projects to primary somatosensory cortex (3, 1, 2)
105
Lesion of lateral spinothalamic tract would result in what?
Contralateral loss of pain/temp below level of lesion
106
Lateral spinothalamic tract tests?
Pinprick/pinwheel test: detect ability to sense sharp pain
Temp test: compare warm vs cold object
107
Function of anterior spinothalamic tract?
Slow pain away: delayed/unpleasant and diffuse sensation associated w/ tissue damage/injury
*mediaste visceral, consciousness, autonomic, and emotional/behavioral rxns to pain
*involved in central modulation of pain
108
Pathways of anterior spinothalamic tract?
Nociceptive info enters posterior horn/immediately crosses midline in SC --> ascends contralaterally in anterior column --> terminates at many diff structures (reticular nuclei, tectum, pretecal, thalamus/project to limbic)
109
Reticular termination of anterior spinothalamic tract controls what info?
Autonomic responses, arousal, alertness, pain modulation
110
Tectum termination of anterior spinothalamic tract controls what info?
Visual reflexes
111
Pretectal (periaqueductal gray) termination of anterior spinothalamic tract controls what info?
Pain modulation
112
Thalamus/projection into limbic system termination of anterior spinothalamic tract controls what info?
Emotional/behavioral aspects of pain (diffuse poorly localized pain)
113
Anterior spinothalamic tract clinical tests?
Pain response: such as glasgow coma scale
*require pathways of anterior spinothalamic tracts to be functioning along w other structures necessary (eye, verbal, motor)
114
Region of SC damaged in Brown sequard syndrome?
Incomplete lesion: 1/2 (R/L) of cord is damaged
115
Motor dysfunction of Brown sequard syndrome?
Ipsilateral motor loss below level of lesion
116
Sensory dysfunction of Brown sequard syndrome?
Ipsilateral loss of proprioception/touch/vibration below level of lesion
&
Contralateral loss of pain/temp below level
117
Prognosis of Brown sequard syndrome?
Better than other SC syndromes
118
Region of SC damaged w/ anterior cord lesion?
Incomplete lesion: anterior 2/3 of cord
119
Motor dysfunction of anterior cord lesion?
Bilateral loss below level
120
Sensory dysfunction of anterior cord lesion?
Bilateral loss of pain/temp below level
***No loss of proprioception, or discrimination between touch/vibration
121
Prognosis of anterior cord lesion?
Poor for ambulation and B/B function
122
Region of the SC damaged w/ posterior cord lesion?
Incomplete lesion: posterior columns damaged
123
Motor dysfunction of posterior cord lesion?
None
124
Sensory dysfunction of posterior cord lesion?
No loss of pain/temp
Bilateral loss of proprioception/discrimination between vibration/touch below level
125
What sign is positive with posterior cord lesion?
Romberg's
126
Region of SC damaged w/ central cord lesion?
Incomplete lesion: area around central canal of cord is damaged
*impair spinothalamic tracts as they cross midline
127
Motor dysfunction of central cord lesion?
None
128
Sensory dysfunction of central cord lesion?
Cervical level: loss of pain/temp in classic cape distribution of UE
*no loss of proprioception or discriminating between touch/vibration
129
Region of SC damaged w/ transverse cord lesion?
Complete lesion: all columns & grey matter damaged
130
Motor dysfunction with transverse cord lesion?
Bilateral loss below lesion
131
Sensory dysfunction with transverse cord lesion?
Bilateral loss of proprioception, discrimination between vibration/touch, & pain/temp below lesion
