Week 20 spinal cord Flashcards
What types of fibres innervate the bladder?
The external sphincter?
Bladder = visceral motor = sympathetic/parasympathetic
Sphincter = somatic motor = voluntary control
Discuss the functional anatomy of the spinal cord.
Motor divisions:
Somatic
Visceral which has sympathetic and parasympathetic
Sensory divisions:
Discriminative touch, conscious proprioception, and vibration,
Pain and temperature,
Unconscious proprioception to cerebellum.
Why would a T12 fracture affect lumbar segments of spinal nerves?
Because they travel inferiorly within the epidural space before exiting at their nerve root level. For example L1 and L2 roots exit the spinal cord close to T12 and travel downwards to the L1 and L2 vertebrae.
What is unique about the thoracic level of the spinal cord?
Lateral horn, small anterior horn.
In which portion of the spinal cord are ascending and descending tracts located?
White matter
In which portion of the spinal cord are posterior and anterior horns located and what is their function?
Gray matter.
Posterior = sensory.
Anterior = motor.
What types of fibres come from the lateral horn of the thoracic spinal cord?
Visceral motor/ sympathetic
Which arteries provide blood supply to the spinal cord?
Anterior spinal artery.
Posterior spinal arteries.
Segmental medullary arteries.
From which vessels does the anterior and posterior spinal arteries arise?
Vertebral arteries just proximal to basilar artery.
From which vessel do the segmental medullary arteries arise?
Aorta.
Fasciculus gracilis
Sensory tract (fine touch, conscious proprioception) from ipsilateral lower limb.
Fine touch, proprioception.
Fasciculus cuneatus
Sensory tract (fine touch, conscious proprioception) from ipsilateral upper limb.
Fine touch, proprioception.
Spinocerebellar tract
Nonconscious proprioception from limbs to cerebellum.
Does not decussate.
Lateral corticospinal tract
Motor to ipsilateral ventral horn - mostly limb musculature.
Skilled movement of the extremities.
Decussates in medulla.
Spinothalamic tract
Pain and temperature from contralateral side of body.
Only fibres projecting from the spinal cord to the thalamus.
Anterior corticospinal tract
Motor to ipsi and contralateral ventral horn - mostly axial musculature.
Postural adjustment.
Which CN provide parasympathetic fibres?
III, VII, IX, X
Where does sympathetic innervation arise?
T1-L2
What provides innervation to the detrusor mm of the bladder?
Parasympathetic: S2,3,4
What innervates the internal sphincter of the bladder in males?
Sympathetic: T12, L1
What innervates the external sphincter of the bladder?
Pudendal, somatic motor: S2,3,4
What area of the brain makes decisions about voiding the bladder?
Cortex.
What area of the brain does the cortex send voiding decisions to?
Pontine micturition centre in brain stem.
Pontine micturition centre
Coordinates voiding.
Activates the parasympathetics - detrusor contraction.
Inhibits sympathetics - relaxation of internal sphincter.
Inhibits somatics (pudendal nerve) - relaxation of external sphincter.
What types of neurons are the projections from the Pontine micturition centre?
UMN
Exteroceptive information
From the external world, eg: touch, pressure, temp, pain, vision, hearing
Conscious proprioception
From within the body: muscles, tendons, joints, position sense.
Conscious perception and appreciation of sensory information.
Enteroceptive information
From the viscera
Nonconscious proprioception
From within the body; muscles, tendons, joints, position sense.
Coordination and refinement.
Anterolateral system
All fibers carrying pain and temp from spinal cord to the brainstem and thalamus.
Some fibers will branch off throughout the brainstem to contact pain modulating and temperature systems.
Lissauer’s tract
Receives axons carrying pain/temp info and provides passage to these axons, up, down, or staying at the same levels before synapsing in the Substantia gelatinosa.
“Feathers” out the axons.
Substantia gelatinosa
Transfers pain/temp signal to anterior white commissure on contralateral side of spinal cord.
Posterior column medial lemniscus system
Carry discriminative touch, vibration, conscious proprioception.
Signal enters and travels up the tract on the same side (fasciculus cuneatus or gracilis).
Decussates at medulla.
Where do pain and temperature fibers decussate?
At the spinal cord level they enter on.
Where do discriminative touch, vibration, and proprioception fibres decussate?
Medulla.
Where is sensory raw data collected before being processed?
Primary somatosensory cortex.
Where does unconscious proprioception information end up?
Cerebellum.
Denticulate ligament
Thickening of pia and glial elements that form ribbons along lateral surface of spinal cord.
Separates anterior and posterior roots.
Posterolateral sulcus
Entry point for posterior rools carrying sensory information
Anterolateral sulcus
Exit point for anterior nerve roots carrying motor information
What structures provide blood supply to the anterior and posterior spinal roots at each level?
Radicular arteries formed from branches of segmental spinal arteries
What artery supplies the anterior 2/3 of the spinal cord?
Posterior 1/3?
Anterior 1/3 = anterior spinal artery.
Posterior 1/3 = Posterior spinal artery.
This system is supplied by both vertebral-basilar and spinal segmental arteries.
Sympathetic nervous system innervation
T1-L2
Lateral horns provide visceral efferent bodies.
Parasympathetic nervous system innervation
CNs
S2-S4 motor efferents form lateral horns.
What structure is present in the male bladder but not the female?
Internal urethral sphincter
How does the function of the female external urethral sphincter differ from males?
There are 2 additional muscles;
sphincter urethrovaginalis
compressor urethrae
Innervation of the internal urethral sphincter
Sympathetic T12 - L2.
Fibres travel with lumbar splanchnic nerves and synapse in inferior mesenteric ganglion.
Innervation of the detrusor muscle
Parasympathetic S1-S4.
Fibres travel with the pelvic nerve.
Innervation of external urethral sphincter
Somatic S2-S4 Pudendal nerve.
Mechanoreception from bladder to cortex
Contralateral spinothalamic tract
Function of frontal cortex in micturition
Central control of micturition.
Go/No go.
Conscious control over voiding.
Sends signals to pontine micturition center and periaqueductal grey.
Periaqueductal grey
Relay center for coordinating inputs from the cortex and spinal cord to the pons.
Pontine micturition center
Coordination center in the pons.
Key relay station for coordination of sympathetic, parasympathetic, and somatic activity required for voiding and urine storage.
Neurogenic bladder
Altered bladder function (spastic or flaccid) after a spinal cord injury.
Spastic (reflex) bladder
Lesion at or above T XII.
Involuntary bladder contractions.
Bladder contraction and sphincter relaxation are uncoordinated.
Symptoms: intermittent bladder contractions -> urine leakage, sphincter spasm during urinations -> incomplete emptying of bladder.
Flaccid (atonic/overflow) bladder)
Lesion below T XII,
Large dilated bladder -> damage due to overstretch.
Loss of sphincter coordination and detrusor contraction -> difficulty initiating voiding.
Symptoms: Overflow incontinence
Spinohypothalamic tract
Direct visceral response to pain (HR, nausea).
Spinomesencephalic tract
To periaquaductal gray in midbrain.
Integration centre with downstream influences on other brainstem systems that modulate pain.
Spinoreticular tract
To brainstem; reticular formation.
Modulation of pain.
Anterolateral system tracts
Spinothalmaic
Spinohypothalamic
Spinomesencephalic
Spinoreticular
Where, specifically, does the spinothalamic tract terminate?
Ventral posterolateral nucleus of the thalamus.
Lateral corticospinal tract carries information about what types of movements?
Skilled movement of the extremities.
Anterior corticospinal tract carries information about what types of movements?
Postural adjustment.
List losses other than physical associated with SCI
Altered self image.
Altered self identity.
Altered social roles.
Loss of control.
Loss of self esteem/confidence.
Discuss some possible immediate reactions post SCI
Pt often awake and aware of seriousness of injury.
Concurrent injuries are common.
Factors such as pain, meds, sensory deprivation, anxiety can influence reactions.
Acute care can be disorienting, frightening, or impersonal.
Initial focus is on survival.
List the 5 stages of grief
Denial.
Anger.
Bargaining.
Depression.
Accpetance.
Discuss patient reactions once in the rehab setting
Losses become more apparent to the pt.
Adjustment and coping has begun.
60% will adapt and cope appropriately.
40% will need psych intervention.
**Do not make assumption.
Discuss patient reactions after SCI rehab
Identity, competence, acceptance, and mastery.
What factors can positively influence adjustment post SCI?
Social support.
Sense of self-management.
Identification of risk factor for poor psychosocial outcomes.
What factors can negatively influence psychological response to SCI?
Multiple and severe co-morbidities.
Long hospital stay.
Probability of permanent, severe functional loss.
What are 4 types of coping strategies?
Problem-focused.
Emotional-focused.
Adaptive.
Maladaptive.
What is ableism?
A belief system that sees person with disabilities as being less worthy of respect and consideration, less able to contribute and participate, or of less inherent value than others.
List some predictors of vulnerability
Previous psychiatric disorder or substance use disorder.
Family hx of psychiatric disorder.
Chronic pain and fatigue.
HX of family fragmentation.
Recent loss of relationship.
Discuss the impact of loss d/t SCI on mental health
Adjustment disorder.
Depression.
Anxiety.
PTSD.
Substance use.
Family members can also experience these.
Discuss adjustment disorder
Develops w/in 3 months of stressful event.
Interferes with social functioning and performance of ADLs.
Symptoms:
Marked emotional distress, anxiety
Inability to cope with life or plan ahead
Insomnia and physical stress symptoms.
Discuss major depressive disorder
Marked and persistently depressed mood.
Loss of interest/enjoyment.
Feelings of guilt/worthlessness.
Feeling of hopelessness.
Disturbed sleep and/or appetite.
Reduced energy.
Reduced concentration.
Ideas of self harm/suicide.
Discuss PTSD
Witnessed or experienced a severe traumatic event.
Provided a response of intense fear, helplessness, or horror.
Emotional numbness, avoidance of triggers.
Flashbacks/dreams.
lrritability/depression.
Sleep disturbance.
Poor concentration/memory.
Social withdrawl.
Discuss substance use after SCI
Associated with poor coping skills.
More common in young, single men.
More common in those with poor social supports.
Associated with increased risk of pressure ulcers.
Discuss suicide after SCI
Extreme behavioural response to adversity.
5x more common in SCI than gen pop.
6-10% of all SCI deaths.
Most likely to occur 5-6 years after injury.
Passive suicidal ideation leads to self neglect and medical complications.
Some will consider and choose MAID.
Management of suicidal ideation
Ensure immediate safety - take to ER if necessary.
Get psych consult- urgent basis.
Manage triggers such as pain.
Involve family and other support systems if possible.
Regular observation.
Encourage emotional expression.
Which scales are available to measure emotional/physical challenges?
PHQ-9 for depression.
GAD-7 for anxiety.
FIM for functional independence.
SF-36 for quality of life.
Return to work.
Mortality and morbidity rates.
How to help facilitate adjustment post SCI?
Provide support and information in hopeful and compassionate way.
Maintain hope for the patient.
Be a good listener.
Provide routine and structure, sense of normality.
Help focus on short-term goals and the present.
List components to positive adjustment
Personal strength.
Life meaning.
Positive attitude.
Engagement with life.
Social supports.
Availability of resources.
Discuss the concept of personal strengths
Independence.
Mastery and self confidence.
High level of internal locus of control.
Discuss the concept of life meaning.
Attributed meaning to their injury.
Acceptance and moving forward.
Personal value change - relationships become more important.
Discuss the concept of positive attitude
Fighting spirit
Discuss the concept of engagement with life
Keeping active.
Returned to work or community activities.
Discuss the concept of support of significant others
Positive social and family relationships.
Feeling emotionally connected.
Discuss the concept of availability of resources
Sufficient financial and health support.
Adequate and accessible housing.
Less need for care.
What is the largest cause of traumatic SCI each year?
Motor vehicle accidents (48%)
Falls (16%)
Violence (12%)
Sports accidents (10%)
other (14%)
What sex is more likely to suffer traumatic SCI
Males:Females 4:1
Median age for traumatic SCI
37
How often is alcohol involved in traumatic SCI?
25%
What increases the risk of traumatic SCI?
Spinal disease:
Spondylosis
Atlantoaxial instability
Osteoporosis
Spinal arthropathies
Congenital spinal abnormalities
Pathophysiology of traumatic SCI
Forces result in trauma to spinal column.
Contusion, compression, shear, transection injury to cord.
Secondary injury in minutes/hours after primary injury d/t:
ischemia
hypoxia
inflammation
edema
excitotoxicity
apoptosis.
Edema worsens over 3-6 days and then decreases around day 9.
In the field management of traumatic SCI
- ABCD, keep in mind there may be other traumas.
Assume spinal precautions if head injury, decreased LOC, neck pain, or neuro defects. - Log-roll techniques & use of back boards/spinal immobilizer.
- Placement of rigid C-spine collar.
- Tranport to higher level of care.
Initial hospital management of traumatic SCI
- ABCD
- Monitor vitals, maintain bp.
- Keep in mind lesions above C5 may impact phrenic nerve, require intubation.
- Maintain spinal precautions, immobilization.
- Examine for life threatening trauma.
- Neuro exam.
Classification of traumatic SCI
Complete spinal cord injury.
Incomplete spinal cord injury.
Discuss complete SCI
Involvement of the entire x-sectional spinal cord.
Includes all ascending and descending tracts.
Loss of all function below level of lesion.
Discuss incomplete SCI
Involvement in only some of the cord, varying degrees/tracts.
Preservation of some types of function below the level of lesion.
Categorized as:
Anterior cord
Central cord
Hemi-cord/Brown-Sequard
What is the standard exam for spinal cord injury
ASIA exam
Consists of myos, derms, ano-rectal exams.
List the ASIA Impairment Scale Categories
A - COMPLETE: Loss of motor and sensory below lesion, absent VAC, absent DAP.
B - SENSORY INCOMPLETE: Loss of motor below lesion, sensation preserved.
C - MOTOR INCOMPLETE: Preserved motor w/>grade 3 in <50% of key mm functions and sensory below lesion.
D - MOTOR INCOMPLETE: Preserved motor w/>grade 3 in >50% of key mm function and sensory below lesion.
E - NORMAL: Patient had prior defects but now has normal function.
Discuss spinal shock
Loss of all spinal cord function below level of injury.
May have flaccid areflexia and absensce of UMN signs.
Can lead to diagnosis confusion.
May last hours, days, weeks, but typically 24 hours.
Discuss neurogenic shock
Loss of sympathetic innervation => hypotension, bradycardia.
Can occur in SCI above T6:
Parasympathetic (cranial outflow) becomes unopposed by sympathetic (thoracic/lumbar outflow).
Once patient is stabilized, what are the next steps?
1.Imaging;
X-rays universal and quick, but can’t see spinal cord injury.
CT but normal does not exclude SCI.
MRI modality of choice for SCI.
- Decompression and stabilization.
Surgery.
Halo.
Post surgery need admission to hospital, then transfer to rehab centre.
Physio, OT, music therapy, recreation therapy, dietician, pharmacists, psychology, etc.Discus
Discuss autonomic dysreflexia
Lesion above T6 can result in hyper-reflexive sympathetic nervous system.
Painful stimulus below level of lesion triggers symp. response: vaso ctx, elevated bp.
Carotid baroreceptors sense rising bp, trigger inhibitory signals but these can’t get through the injured cord and SNS is unregulated.
PNS becomes triggered above lesion: bradycardia, pupillary ctx, sweating, flushing.
SNS triggered below lesion: pale, cool extremities, piloerection.
Develops after 1 month following SCI.
Can be medical emergency.
Treatment of autonomic dysreflexia
ABCs
Sit patient up: orthostatic reduction of bp.
Remove tight fitting clothes.
Find and remove offending stimulus.
Meds to reduce bp: nifedipine, hydralazine, nitrates, labetalol.
Discuss CV complications in SCI
CAD, PVD, stroke.
Impaired fasting glucose, low HDL, high LDL more prevalent.
Decreased mm mass, increased body fat, decreased activity levels.
HTN less common: Lesions above T6 have lower bp and HR d/t decreased sympathetic tone.
Discuss respiratory complications in SCI
High C-spine lesions may need chronic ventilator.
Weak respiratory mm => dyspnea, exercise intolerance.
Weak cough reflex => risk for pulmonary infection.
Higher DVT and PE risk in initial months, then settles. Prophylaxis only needed in first few months post injury.
Discuss spasticity complications in SCI
Velocity dependent increase in mm tone.
Loss of descending inhibition => spasticity, clonus, hyperreflexia.
Worsened by cold, stress, infection.
Can have painful spasms, decreased mobility, contractures.
Need balance to maintain/facilitate functional abilities.
Treatment of spasticity in SCI
Stretching.
PT.
Bracing/orthotics.
Baclofen (GABA-B agonist, can cause sedation, seizures if rapidly stopped).
Tizanidine.
Diazepam.
Dantrolene.
Discuss urinary complications in SCI
Detrusor hyperactivity - bladder spasms, frequency/urgency, incontinence.
Sphincter hyperactivity - incomplete emptying.
Detrusor-sphincter dyssynergia - lack of coordinated emptying.
Atonic bladder - urinary retention and overflow incontinence in pts with conus medularis lesions and LMN bladder dysfunction.
Increased risk for UTI.
Impaired kidney function.
Renal/bladder stones.
Treatment for urinary dysfunction in SCI
Oxybutynin, Tolterodine - reduce bladder tone and spasticity.
Prazosin, Terazosin, Tamsulosin - reduce sphincer tone.
Botulinum
Catheterization
Discuss bowel dysfunction in SCI
Hyperactive anal sphincter => chronic constipation/overflow incontinence.
Needs consistent bowel routine.
Discuss sexual dysfunction in SCI
ED common in males.
Male infertility d/t Ed, low sperm quality, ejaculatory dysfunction.
Anorgasmia in females.
Ovulation and fertility generally unaffected but pregnancy considered HIGH RISK.
Discuss pressure ulcers in SCI
Constant pressure on bony prominences.
Requires ongoing monitoring, creams, pressure reducing cushions.
Wound care for ulcers.
Discuss MSK issues in SCI
Osteoporosis.
Heterotopic bone formation.
Contractures.
Rotator cuff injuries in manual wheelchair users.
Discuss pain in SCI
Can be considerable following SCI.
Neuropathic or MSK/nociceptive.
Difficult to treat.
Discuss syringomyelia in SCI
Can lead to central cord syndrome.
SCI is a potential cause for development of syrinx.
Could be asymptomatic, but could lead to new neuro symptoms.
Discuss life expectance in SCI
Mortality is higher in first year.
Reduction of overall life expectancy of 10%.
What are the components of an effective healthcare team?
Share a common purpose.
Role clarity of own and roles of others.
Recognize role of leadership.
Utilize effective processes.
Experience trustworthy relationships.
Give and receive feedback.
Excel in communication.
ISBAR
Identify
Situation
Background
Assessment
Repsonse
CUSPP
Concerned
Uncomfortable
Safety
Plan
Proceed
Types of compounded harm experiences
Powerless: need involvement as equal partner.
Inconsequential: Need to see learning and improvement.
Manipulated: Need honesty, openness, and candour.
Abandoned: Need acknowledgement of responsibility and offer of repair.
De-humanised: Need to feel seen, heard, and that they matter.
Disoriented: Need flexible, timely support to restore feeling of safety.
Alternate approach to experiences of harm
Restorative justice.
Relational harm
Damage to trust and relationships between patients, families, and providers.
Compounded harm
Responses that are adversarial or defensive deepen relational harm.
LEADS framework
Leads self
Engages others
Achieves results
Develops coalitions
Systems transformation
Brachial plexus nerve roots
C5-T1
Musculocutaneous nerve roots
C5,6,7
Axillary nerve roots
C5,6
Radial nerve roots
C5-T1
Median nerve roots
C6-T1
Ulnar nerve roots
C8, T1
Axillary artery
From subclavian.
Becomes axillary once it crosses the 1st rib.
Becomes brachial after crossing lats.
Walls of axilla
Anterior: Pecs, subclav, clavpectoral fascia.
Lateral: Intertubercular groove.
Posterior: subscap, teres major, lats, long head of triceps.
Medial: upper thoracic wall, SA.
Floor: Skin of armpit.
Axillary sheath
Surrounds arteries, veins, nerves, and lymphatics.
Innervation of SA
Long thoracic nerve C5,6,7
What does paralysis of SA or long thoracic nerve cause?
Winged scapula.
Innervation of Brachialis
Musculocutaneous C5,6,7
Innervation of Coracobrachialis
Musculocutaneous C5,6,7
Axillary, Basalic vein
Axillary through axilla, becomes basalic at biceps.
Cephalic vein
Lateral to short head of biceps, crosses on top of pec minor/coracoid.
Median cubital vein
Anastomosis between basalic and cephalic veins in cubital fossa.
What is the result of whippet (inhaled NO) use?
Functional B12 deficiency.
B12 needed as cofactor for conversion of homocysteine to methionine which is needed for myelin production.
Subacute combined degeneration
Combined degeneration of dorsal columns and corticospinal (& spinocerebellar) tracts.
Usually caused by B12 deficiency d/t Zn or NO toxicity.
Can also be d/t infection (HIV, Syphilis).
TX: discontinue NO/Zn, B12 injections.
Hemi-cord or Brown-Sequard syndrome
D/t penetrating trauma, compression by spinal tumour, MS.
Weakness on one side, loss of sensation on the other.
TX: IV steroids (methylprednisone). If MS, treat w/monoclonal abs.
Conus medullaris syndrome
Involvement of most distal end of spinal cord.
Combination of UMN and LMN findings.
What do we need to be concerned about with longitudinally extensive lesions?
Neuromyelitis Optica.
MOGAD Myeline Oligodendrocyte Glycoprotein Antibody-associated Disease.
Sarcoid.
Tumours
Central Cord Syndrome
Caused by falls/hyperextension.
Weakness and loss of sensation in upper extremities, but lower fine.
Most common incomplete SCI.
Syringomyelia
Dilation of the central canal.
Congenital or acquired.
Capelike distribution.
Congenital: Chiari 1 malformation.
Acquired: trauma, inflammation, tumours.
Syringomyelia treatment
Neurosurgical shunt.
Anterior Cord Syndrome
Usually d/t decreased blood flow from anterior spinal artery.
Damage is bilateral (1 anterior spinal artery).
Area most susceptible to damage is below T8 (anastomosis above this level).
Bilateral LMN signs at level of lesion.
Progresses to UMN signs below level of lesion.
Loss of STT below level of lesion.
NO DORSAL COLUMN
Somatosensory evoked potentials
Stimulation to hands/feet.
Proximal electrodes capture propagation of signal along sensory pathway.
Sees if signal is slowed/blocked.
Can detect a functional problem in the spinal cord.
Major support cell of PNS
Schwann cell
Major support cell of CNS
Oligodendrocyte
Components of PNS
Anterior horn cells.
Nerve roots.
Dorsal root ganglion.
Peripheral nerves.
NMJ.
Muscles.
What type of cells are found in the dorsal root ganglion?
Bipolar cells.
How many pairs of spinal nerves are there?
31
Acetylcholine quanta
Packaged ACh molecules in vesicles at the presynaptic terminal level.
What happens at the NMJ?
AP depolarizes presynaptic junction.
Voltage-gated Ca channels activated.
Ca into presynaptic terminal.
ACh released via exocytosis.
ACh bind to ACh receptors at postsynaptic membrane.
Na channels open - local depolarization (endplate potential).
What type of motor neuron innervates extrafusal fibres?
A-alpha
What type of motor neuron innervates intrafusal fibres?
A-gamma.
Keeps spindle taught so it can remain sensitive to stretch.
Alpha-gamma coactivation
When a signal is sent to the alpha motor neuron, the same signal is sent to the gamma motor neuron to contract the spindle.
What information do Ia afferents carry?
Length and velocity.
What information do II afferents carry?
Length only.
Pontine micturition centre
Coordinates voiding.
Activates parasympathetics for ctx of detrusor.
Inhibits sympathetics for relaxation of internal sphincter.
Inhibits somaticts (pudendal nerve) for relaxation of external sphincter.
What tool can help decide if imaging is needed in a suspected c-spine trauma?
Canadian C-spine Rules
What can help decide if imaging is needed in adults with low back px?
Red flag symptoms.
What is the imaging modality of choice in trauma?
CT
What are low back px red flags?
Hx of cancer.
Urinary dysfunction.
Fever, chills.
Unexplained wt loss.
Nocturnal px.
Saddle anesthesia.
Progressive or severe neuro deficits.
Refractory px w/proper medication.
Trauma hx in elderly.
Systematic approach for evaluating imaging
Alignment.
Bones.
Discs.
Soft tissues.
Spinal cord.
What must be included on a lateral view of c-spine to be diagnostically acceptable?
C7/T1 junction.
What are the two standard views of the t-spine & l-spine?
Frontal.
Lateral.
What are the 2 CT windows?
Bone.
Soft tissue.
What should the width of prevertebral soft tissues be in the upper c-spine?
No more than 1/2 the width of adjacent vertebral body.
What are the two sequences in MRI?
T1 weighted - CSF is black
T2 weighted - CSF is white (T2=H2O)
How do we describe images on MRI?
Intensity.
Black = hypointense
Gray = isointense
White - hyperintense
What is it called when there is more than one signal present on an MRI?
Mixed signal intensity.
What is spinal stability dependent on?
At least two intact columns.
