Case 14 Flashcards
1
Q
What are the 3 different principles for spinal injury operations?
A
Decompress
Realign
Stabilise
2
Q
What are examples of conservative treatment of spinal injury?
A
Halo vest
Braces
Cervical colar
3
Q
When would conservative treatment of spinal injury be indicated?
A
Stable fracture
Some polytraumas
Unfit for surgery
Osteoporotic bones
4
Q
What can be used to immobilise the entire spine?
A
Semi-rigid collar
Sandbags either side of head
Spinal board - only used for transport to avoid pressure sores
5
Q
What is flaccid areflexia?
A
Loss of motor, sensory, reflex and autonomic function
6
Q
What is priapism?
A
Persistent often painful erection
7
Q
What could suggest a spinal cord injury in the unconscious patient?
A
Flaccid areflexia Diaphragmatic breathing Pain response above clavicle Bradycardia/ hypotension Priapism
8
Q
What is shock?
A
Cellular hypoxia from inadequate:
Organ perfusion
Tissue oxygenation
9
Q
When does spinal shock usually resolve by?
A
24 hours of cord injury
10
Q
What occurs in spinal shock?
A
Below the level of injury you get:
Flaccid paralysis
Areflexia
Lack of sensation
11
Q
What causes spinal shock?
A
Physiologic spinal cord shut down in response to injury
12
Q
What indicates end of spinal shock and how is this elicited in practise?
A
Return of reflexes - occurring in caudal to cranial direction
Test bulbocavernosus reflex (anal sphincter contraction in response to glans penis squeezing)
13
Q
What causes neurogenic shock?
A
Reduced sympathetic outflow T1-L2
= unopposed vagal tone
14
Q
What are the signs of neurogenic shock?
A
Flaccid paralysis
Hypotension
Bradycardia
15
Q
What causes the hypotension and bradycardia in neurogenic shock?
A
Reduced sympathetic stimulation causes:
Hypotension - loss of blood vessel tone
Bradycardia - reduced cardiac stimulation
16
Q
What is transient neurapraxia and what is it caused by?
A
Temporary loss of motor/ sensory function in the absence of structural changes
Caused by blunt injury, compression and ischaemia
17
Q
What is complete spinal cord injury and when can it be confirmed?
A
No sensation or voluntary motor function below the level of the injury
Only confirmed after resolution of spinal shock - when reflex activity has returned
18
Q
What is sacral sparing?
A
Presence of sacral sensation, voluntary rectal tone and great toe movement
Potential for recovery
19
Q
How are the different parts of the lateral spinothalamic and corticospinal tracts distributed?
A
Cervical (medial) - arms
Thoracic
Lumbar - legs
Sacral (lateral)
20
Q
What are the features of CENTRAL cord syndrome?
How common is it?
What’s the prognosis?
A
Motor and sensory
Most common cord syndrome
Fair prognosis
21
Q
What are the features of ANTERIOR cord syndrome?
How common is it?
What’s the prognosis?
A
Motor, some sensory
Common
Poor prognosis
22
Q
What are the features of POSTERIOR cord syndrome?
How common is it?
What’s the prognosis?
A
Posterior column tetraparesis
Uncommon
Poor prognosis
23
Q
What are the features of Brown-Sequard cord syndrome?
How common is it?
What’s the prognosis?
A
Ipsilateral motor, contralateral pain and temp
Uncommon
Good prognosis
24
Q
What are the features of COMPLETE cord syndrome?
How common is it?
What’s the prognosis?
A
Total loss below level
Uncommon
Poor prognosis
25
How would you manage a patient recovering from central cord injury?
Lie flat for 6 weeks
| Then tilt table to avoid postural hypotension that can cause further neurological deterioration
26
What radiological tests need to be carried out if spinal injury suspected?
Lateral cervical spine - detects 85% of cervical fractures
| Entire spine - 10% with 1 fracture have another non-contiguous injury
27
What does ABDCE stand for when assessing a lateral C spine X-ray?
```
Adequacy/ alignment
Bone
Cartilage
Dens
Extra-axial soft tissue
```
28
The ADI (atlas dens distance) should be less than 5mm, if it is greater what does it indicate?
Transverse and accessory ligament rupture
29
What is divided up into thirds according to steel's rule of thirds?
1/3 dens, 1/3 space, 1/3 spinal cord
30
If the space between the dens and spinal cord closes in and begins to compress the spinal cord, what's wrong?
Atlanto-axial instability
| Alar ligaments have failed
31
How is static instability inferred?
Imaging
32
What is dynamic instability?
Deformity that worsens under physiologic loads
33
What would be observed in posterior ligamentous complex injury on X-ray? and MRI?
>50% loss of vertebral height
>30 degree kyphosis
MRI - disrupted PLC
34
What can erect cervical X-rays show?
Load bearing deformity
| Ligament injury/ instability
35
What do dynamic X-rays show?
Physiological instability
36
Why are steroids not used in SCI?
They're osteoporotic
37
What is SCIWORA and what causes it?
Spinal cord injury without radiological abnormality
Oedema, haemorrhage, infarct, transection, concussion
Rare - no factor, ligament injury or extra neural compression
38
What are the possible complications of spinal cord injury?
```
Pneumonia
Postural hypotension
DVT/ PE
Autonomic dysreflexia = acute, uncontrolled hypertension
Renal failure
Pseudo-obstruction
Sexual dysfunction
Pressure sores
Psychological problems
Inadequate ventilation - C3,4,5 damage
```
39
What is ankylosis?
Abnormal stiffening and immobility of a joint due to fusion of the bones
40
What sort of SCI does partial preservation zone apply to?
Complete injuries
41
What is tetraplegia?
Paralysis resulting in partial/ total use of all limbs/ torso
42
What is paraplegia?
Paralysis similar to tetraplegia but arms are spared
43
What is spondylosis?
Degeneration of the intervertebral discs - painful
44
How common is cauda equina syndrome, what's the usual cause, what's important to remember in examination?
Rare
Canal filling disc compressing on entire cauda equina
Check sphincter disturbance, time important (diagnosis and treatment)
45
What does the spectrum of cauda equina syndrome consist of?
```
Low back pain
Uni/ bilateral sciatica
Saddle anaesthesia
Motor weakness in lower extremities
Variable rectal/ urinary symptoms
```
46
Which reflex is tested at the ankle?
S1
47
Which reflex is tested at the knee?
L4
48
Which reflex is tested at the wrist?
C6
49
What reflexes are tested for near the elbow?
Biceps - C5
| Triceps - C7
50
What myotome is tested by elbow flexion?
C5
51
What myotome is tested by wrist extension?
C6
52
What myotome is tested by elbow extension?
C7
53
What myotome is tested by finger flexion?
C8
54
What myotome is tested by finger abduction?
T1
55
What myotome is tested by hip flexion?
L2
56
What myotome is tested by knee extension?
L3
57
What myotome is tested by ankle dorsiflexion?
L4
58
What myotome is tested by big toe extension?
L5
59
What myotome is tested by ankle plantar flexion?
S1
60
What are the gradings of power?
0 - total paralysis
1 - palpable/visible contraction
2 - active movement gravity eliminated
3 - active movement against gravity
4 - active movement against some resistance
5 - active movement against full resistance
61
What's the difference between paraparesis and hemiparesis?
Paraparesis - partial paralysis of lower limbs (spinal injury)
Hemiparesis - weakness of entire body on 1 side (head injury)
62
What are the serious causes of back pain to exclude?
(ATIT)
AAA, pancreatitis, malignancy
spinal Trauma, Infection, Tumour
63
Which cranial nerves come off the cerebral hemispheres?
I Olfactory
| II Optic
64
Which cranial nerves come off the midbrain?
III Oculomotor
| IV Trochlear
65
Which cranial nerves come off the pons?
V Trigeminal
VI Abducens
VII Facial
66
Which cranial nerves come off the junction between pons and medulla?
VIII Vestibulocochlear
67
Which cranial nerves come off the medulla?
IX Glossopharyngeal
X Vagus
XI Accessory
XII Hypoglossal
68
Which connective tissue sheath encloses fascicles?
Epineurium
69
Which connective tissue sheath surrounds individual fascicles?
Perineurium
70
Which connective tissue sheath separates individual fibres?
Endoneurium
71
What do Pacinian corpuscles respond to?
Pressure
72
What do Meissener's corpuscles respond to?
Light touch
73
What's the difference between malunion and nonunion?
Malunion: when a fracture heals in a non optimal position
Nonunion: failure to heal, common in the tibia
74
What's an osteoclast?
Large cells that dissolve the bone
75
What's an osteoblast?
Form new bone
76
What's an osteocyte?
Cells inside the bone
Formed from osteoblasts
Their long branches connect them to the other osteocytes
Sense pressures/ cracks in the bone and help to direct where osteoclasts will dissolve the bone
77
Explain the difference in manifestations of injuries to different segments of the dorsal column
Gracile fascicles - Ipsilateral loss of proprioception and fine touch from the leg
Cuneate Fasciculus - Ipsilateral loss of proprioception and fine touch from the arm
78
At resting potential, where are K+ and Na+ greatest in concentration? Which pump maintains this gradient?
More Na+ outside
More K+ inside
Na+/K+ pump (Mr Nasty out, K+ in)
79
How do local anaesthetics work?
Bind to Na+ channels
| Stop sensory conduction
80
What does the toxicity of local anaesthetics mainly involve?
CNS
| Cardiovascular system
81
What are the CNS toxicity of local anaesthetics?
```
Feeling of inebriation
Lightheadedness
Drowsiness
Numbness of tongue and perioral region
Restlessness
Paraesthesia
Dizziness
Blurred vision
Tinnitus
Headache
Nausea
Vomiting
Muscle twitching
Tremors
Convulsion
```
82
What are the cardiovascular system toxicities of local anaesthetics?
Myocardial depression
| Peripheral vasodilation - hypotension and bradycardia
83
What does adrenaline do to blood vessels?
Vasoconstrictor
84
How does vasoconstriction desirable in local anaesthetic administration?
Diminishes local blood flow
| Slows rate of absorption - prolonging anaesthetic effect
85
Inhibition of which fibres cause a loss of cold sensation?
C fibres
86
Inhibition of which fibres cause a loss of pinprick sensation?
A delta fibres
87
Inhibition of which fibres cause a loss of touch sensation?
A beta fibres
88
What is the action of Botulinum?
Blocks ACh release
89
What is the action of Atracurium?
Non-depolarising
90
What is the action of Suxamethonium?
Depolarising
91
How do depolarising agents work and do they cause fasciculations?
Competitive agonists of ACh at postsynaptic nicotinic receptor (causing depolarisation)
Fasciculations
92
How do non-depolarising agents work and do they cause fasciculations?
Competitive antagonists of ACh at postsynaptic nicotinic receptor (preventing depolarisation)
No fasciculations
93
What is damaged in neurapraxia (seddon)/ I (sunderland)?
Myelin sheath
94
What is damaged in axonotmesis (seddon)/ II, III and IV (sunderland)?
II Axons
III Axons and endoneurium
IV Axons, endoneurium and perineurium
95
What is damaged in neurotmesis (seddon)/ V (sunderland)?
Complete severance of nerve
96
Out of neurapraxia, axonotmesis, neurotmesis, which results in no conduction?
Axonotmesis, neurotmesis
| neurapraxia is just slowed conduction
97
What does sunderland class VI nerve injury describe?
Mixed - injury varies fascicle to fascicle
98
What nerve is affected in carpal tunnel syndrome and which muscles does is supply?
```
Median nerve
LOAF (OAF - thenar eminence)
Lumbricals 1 and 2
Opponens pollicis
Abductor pollicis brevis
Flexor pollicis brevis
```
99
Which nerve injuries have a tinel's sign and advancing tinel's sign/ recover?
Tinel's sign - axonotmesis II, III, IV, neurotmesis V
| Advancing tinel's/ recover - axonotmesis II, III
100
Which nerve injuries require treatment?
Axonotmesis III - internal neurolysis
Axonotmesis IV - repair/ graft
Neurotmesis V - repair/ graft
101
```
Group the following words describing bone in terms of meaning:
Cortical
Spongy
Trabecular
Compact
Cancellous
```
Trabecular/ Spongy/ Cancellous - 20% of total skeleton
Cortical/ Compact - outer, dense, strength-providing for weight bearing, 80% of total skeleton
102
What is bone made up of?
Water
Hydroxyapatite (mineral form of calcium apatite)
Collagen type I
Non-collagenous proteins
103
Why does cartilage heal slower than bone?
Cartilage doesn't have blood vessels
104
What type of collagen does hyaline cartilage contain?
Type II collagen
105
What type of cartilage is articular cartilage?
Hyaline
106
What are the differences between the layers of hyaline/ articular cartilage?
Superficial zone - tangentially orientated collagen fibrils, flattened discoid shaped chondrocytes
Middle zone - highest proteoglycan content
Deep zone - radially orientated collagen fibrils
Calcified zone
107
What happens to the density of chondrocytes moving from superficial to deep zones of hyaline/ articular cartilage?
Decreases
108
What is the normal plasma calcium level?
2.2-2.6 mmol/L
Less than 2.2 = hypocalcaemia
Greater than 2.6 = hypercalcaemia
109
What are the possible consequences of hypercalcaemia?
Voltage gated ion channels don't open as easily
Depressed nervous system function
Deposition of excess calcium and phosphate
Kidney stones
Respiratory arrest
110
Calcium metabolism and exchange between ECF and intestine/ bone/ kidney are under the hormonal influence of?
Vitamin D
| PTH
111
How are calcium levels increased if they become too low?
Calcitriol (active form of vitamin D) promotes absorption of calcium from GI tract
PTH increases osteoclast no and activity, decreases calcium loss in urine, stimulates formation of calcitriol - increasing Ca2+ in blood
112
How are calcium levels decreased if they become too high?
Parafollicular cells in thyroid gland secrete calcitonin
| Calcitonin inhibits osteoclast activity, promotes bone formation decreasing blood Ca2+
113
Is D3 active?
No - inactive
114
How is D3 activated?
25-hydroxylation in liver
| Additional hydroxylation in kidney under regulation of calcium, phosphorus and PTH
115
What is the role of 1,25-dyhydrocyvitamin D?
Stimulates intestinal calcium and phosphate resorption - raising serum calcium and phosphate levels
Decreases PTH levels
116
What is the role of PTH?
Stimulates bone turnover
Renal phosphate excretion - decreasing serum phosphate levels
Renal calcium absorption - raising serum calcium levels
Raise 1,25-dyhydrocyvitamin D levels
117
What condition is the mnemonic moans, groans, stones and bones used for?
Hypercalcaemia e.g. from hyperparathyroidism
| Psychiatric moans, abdominal groans, stones, painful bones
118
What does primary hyperparathyroidism result in?
PTH hypersecretion leading to hypercalcaemia (moans, groans, stones and bones)
119
What are the possible consequences of hypocalcaemia?
Voltage gated ion channels open spontaneously
Tetany
Paraesthesia around mouth/ feet
Cardiac arrest
120
What's in the centre of an osteon?
Haversian canal
121
What surrounds the haversian canal in an osteon?
Osteocytes
122
Briefly explain the bone remodelling cycle
```
Resorption by osteoclasts
Osteoclasts apoptosed/ removed
Reversal by osteoblasts
Formation
Mineralization
```
123
What are the 3 stages of bone fracture healing?
Inflammation
Repair
Remodelling
124
What happens in the inflammation stage of fracture healing?
Blood vessel crossing fracture line broken - haematoma formation
Infiltration of inflammatory mediators (interleukins, growth factors, hormones)
Proliferation and differentiation of stem cells stimulated
Minutes to days
125
What happens in the repair stage of fracture healing?
Periosteal fibrocartilaginous callus formation - fibroblasts produce collagen and chondroblasts to make fibrocartilage which ossifies
Bony callus formation - osteoblasts produce spongy bone trabeculae
Lasts weeks
126
What happens in the remodelling stage of fracture healing?
Dead portions resorbed by osteoclasts
Compact bone replaces spongy around periphery of fracture
Lasts months
127
How does smoking inhibit bone healing?
Vasoconstriction - poor blood supply
| Directly inhibits osteoblasts
128
What is osteoporosis?
Low bone mass - less osteoblast activity than osteoclast
More so in trabecular rich sites e.g. skin and hip as remodelling rates higher in trabecular bone than cortical
Loss of connectivity between adjacent bone plates
Fragility and increased fracture risk
129
What effect do oestrogens and testosterone have on bone?
Stimulate osteoblast activity
130
What are the risk factors for osteoporosis?
```
Increases with age
Women
Family history
Smoking, alcohol, diet low in calcium and vit D
Low MBI
Physical inactivity
European/ Asian
Prednisolone (steroid) use
Reduced oestrogen in women (post menopause/ hysterectomy/ late menarche/ early menopause)
```
131
Does T or Z score relate more to fracture risk?
T score - SDs away from mean, relative to young normals
| Z relative to normal people of SAME age
132
Although there is no true fracture threshold, what would be classed as osteoporosis?
2.5 SDs from young normal mean or lower
133
For every drop in SD from young normal, what happens to the fracture risk?
Fracture risk doubles for every SD reduction
134
What's the 1st line treatment for osteoporosis?
```
Ca2+ and colecalciferol (vit D3)
and Bisphosphonate (alendronate/ risendronate/ ibandronate) - antireabsorptive drugs (inhibit osteoclast function, induce osteoclast apoptosis)
```
135
What is the adult form of rickets?
Osteomalacia
136
What causes osteomalacia/ rickets?
Inadequate calcification of extracellular bone matrix
Usually caused by vitamin D deficiency
Insufficient calcium and phosphate so new osteoid
137
Where does the spinal cord end?
Adult: L1/2
Child: L3/4
138
What are the symptoms of MS?
```
MS is an Upper Motor Neuron lesion
UMN lesions typically present with
-diffuse wasting
-no wasting
-increased reflexes
-increased tone
-no fasiculations
-babinski maybe present (absent in LMNL's)
```
139
What are the erector spinae muscles?
Iliocostalis
Longissimus
Spinalis
140
In sociology what are the 4 different coloured flags and what do they stand for?
Red - biomedical factors
Yellow - psychological/ behavioural factors
Blue - social/ economic factors
Black - occupational factors
141
What is Spondylolysis?
Congenital or acquired deficiency of the pars interarticularis of the neural arch of a particular vertebral body, usually affects L4/ L5
142
What is Spondylolisthesis?
Slippage of one vertebra on another
143
What is spondylosis?
Degenerative disc degeneration or facet joint degeneration
144
Which osteoporosis treatment is described as dual action and why?
Strontium ranelate - increases deposition of new bone by osteoblasts and reduces the resorption of bone by inhibiting osteoclasts
145
What does the trauma triad of death include?
Hypothermia, acidosis and coagulopathy
146
How is osteomalacia/ rickets treated?
Vitamin D
| Exposure to moderate sunlight
147
How is the amount of bone and ration of matrix to bone mineral altered in osteoporosis and osteomalacia?
Osteoporosis - decreased amount, ratio the same
| Osteomalacia - normal amount, ratio of matrix to bone mineral increased (more matrix, less mineral)
148
What effect does calcitriol have on calcium, phosphate and PTH levels?
Increases Ca2+
Increases phosphate
Decreases PTH
149
What effect does PTH have on calcium, phosphate and calcitriol levels?
Increases Ca2+
Decreases phosphate
Increases calcitriol
150
What is the urinary marker of bone turnover?
Hydroxyproline
151
What would the blood profile of someone with Paget's disease be like?
High ALP
| Normal Ca2+, phosphate, vit D and PTH
152
How may Paget's disease be diagnosed?
X ray
Blood test: high ALP (normal Ca2+, phosphate, vit D and PTH)
Increased urinary Hydroxyproline (urinary marker of bone turnover)
Increased uptake of isotope bone scan
153
What happens in Paget's disease?
Osteoclast overactivity
Compensatory osteoblast activity
Disordered, woven, mosaic bone
Weaker as higher proportion of spongy to compact bone
154
What are the symptoms of Paget's disease?
```
70-90% asymptomatic
Deep, constant, boring, worse on weight-bearing bone pain
Fracture
High CO
Possible compression
```
155
Which people with Paget's disease need to be treated and with what?
Symptomatic
In danger of nerve compression
Around weight-bearing joint
Bisphosphonates
156
What are the 2 different forms of bone mets?
Lytic: destructive
Sclerotic: increased abnormal bone formation
157
How may someone with bone mets present?
Pain
Fracture
Spinal cord compression
Elevated ALP and calcium
158
How is bone mets treated?
Bisphosphonates and radiotherapy for pain
Surgical
Chemo/ hormone therapy
159
What are the blood levels of Ca2+, phosphate, ALP and PTH in osteomalacia?
Ca2+: LOW
Phosphate: LOW
ALP: high/ normal
PTH: high/ normal
160
What are the blood levels of Ca2+, phosphate, ALP and PTH in osteoporosis?
All normal
161
What are the blood levels of Ca2+, phosphate, ALP and PTH in primary hyperparathyroidism?
Ca2+: high/ normal
Phosphate: low (PTH decreases it)/ normal
ALP: high/ normal
PTH: HIGH
162
What are the blood levels of Ca2+, phosphate, ALP and PTH in bone mets?
Ca2+: high
Phosphate: high
ALP: high
PTH: low
163
What does the posterior root carry?
Sensory afferents
164
What does the anterior root carry?
Motor efferents
165
What does the posterior and anterior rami supply?
Posterior: synovial joints of vertebral column, deep back muscles and overlying skin
Anterior: much larger remaining area
166
Which 3 muscle groups make up the transversospinales?
Semispinalis
Multifidus
Rotatores
167
What are the intervertebral discs made of?
Fibrous anulus fibrosus around periphery
| Gelatinous nucleus pulposus in centre
168
How can pain from a degenerative disc be differentiated from facet joint pain?
Degenerative disc - bending forward worsens pain
| Facet joint - bending forward relieves pain, bending backward worsens pain
169
What does the Babinski reflex test for?
Abnormal big toe extension - upper motor neurone lesion
170
What proves a complete spinal cord injury?
Absence of sacral sparing
- No voluntary anal contraction or deep anal pressure sensation
- All S4-5 sensory scores = 0
171
What is the ASIA impairment scale?
```
A = complete
B = sensory incomplete (sensory function preserved)
C = motor incomplete (motor function preserved, half or more key muscle function grade less than 3)
D = motor incomplete (motor function preserved, half or more key muscle function grade 3 or more)
E = normal
```
172
What does the denticulate ligaments attach to?
Attach pia mater to arachnoid and dura
173
What structure coming off the spinal cord does the sympathetic chain attach to?
Ventral/ anterior ramus
174
What does the pia continue as below the conus medullaris?
Filum terminale - descends all the way to the coccyx, anchoring the spinal cord
