Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries...

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Spinal cord injuries

Transcript of Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries...

Page 1: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.

Spinal cord injuries

Page 2: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.

Overview:

• Anatomy of the spinal cord• Case presentation• Spinal cord injuries – Classification– Complete and incomplete syndromes

• Respiratory complications of spinal cord injuries

• ICU management of spinal cord injuries• Pharmacological management

Page 3: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.

Gross anatomy

• Begins at the foramen magnum of the skull, where it is continuous with the medulla oblongata

• Cervical enlargement gives rise to the brachial plexus• Lumbar enlargement gives rise to the lumbosacral

plexus• Tapers inferiorly to the conus medullaris – from here

the filum terminale attaches to the coccyx• Lower end of the spinal cord lies at the lower border

of L1• Vertebral column is much longer than the spinal

column, so the cord segments do not correspond numerically to the vertebral bodies

Page 4: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.

Columns of the spinal cord

• Spinal column stabilised by three major ligaments;– Anterior longitudinal ligament– Posterior longitudinal ligament– Ligamentum flavum

• Anterior column: Anterior 2/3 vertebral bodies and the anterior ligament

• Middle column: Posterior 1/3 vertebral bodies and the posterior ligament

• Posterior column: Ligamentum flavum and everything else

• Injury involving > one column is considered unstable

Page 5: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.
Page 6: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.

Spinal cord structure

• Inner core of grey matter, surrounded by an outer covering of white matter

• Grey matter is arranged in an ‘H- shape’, with anterior and posterior horns, joined by a thin grey commissure which contains the central canal

• The T1-L3 segments also contain a lateral grey horn

Page 7: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.
Page 8: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.

Grey matter of the spinal cord

• The anterior horn is divided into medial, central and lateral columns– Medial group is present in most segments innervating the

skeletal muscles of the neck and trunk – Central group is the smallest and is present in some cervical

and lumbosacral segments– Lateral group is present in the cervical and lumbosacral

segments innervates the skeletal muscles of the limbs

• Posterior horn has four different groups of nerve cells– Substantia gelatinosa group– Nucleus propius – Nucleus dorsalis – Visceral afferent nucleus

• Lateral grey horns contain pre-ganglionic sympathetic fibres

Page 9: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.

Tracts of the spinal cord• Ascending (sensory):– Dorsal (posterior) columns: deep touch,

proprioception, vibration– Lateral spinothalamic: pain and temperature– Anterior spinothalamic: light touch

• Descending (motor):– Lateral corticospinal: voluntary motor– Anterior corticospinal: voluntary skilled motor– Rubrospinal: control of movement– Vestibulospinal: posture and balance– Tectospinal: reflex postural movements in response

to visual stimuli

Page 10: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.
Page 11: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.

Spinal cord injuries

• Causes:–Majority caused by MVAs; falls; iatrogenic

• Mostly young males, but the other demographic includes older people with concurrent degenerative spinal canal narrowing

• Frequently associated with other conditions:– Shock syndromes– Other injuries

Page 12: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.

A likely story…

Page 13: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.

Say hello to Jim.• 85 year old male who slipped backwards

and hit head on towbar behind car• Presented to Tenterfield Hospital, then

T/F to Armidale, where CT showed unstable C4/5 #

• Transferred to JHH for NSx R/V• Conscious and spontaneously breathing• Hard collar in situ, but poorly fitting• GCS 13: E3V4M6, PEARL• B/G: metastatic prostate ca, HTN, T2DM

Page 14: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.

Jim’s imaging

• Unstable C4/5 fracture

Page 15: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.

Further examination…

• Normal cranial nerve examination • Decreased strength (2/5) and absent

reflexes bilaterally in upper limbs• Decreased pain and temperature

sensation bilateral hands• Normal strength (5/5), reflexes and

sensation in bilateral lower limbs• Developed urinary retention

Page 16: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.

American Spinal Injury Association Neurological impairment scale

Page 17: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.

Classifications

• Quadriplegia– Injury to the cervical spine, leading to impairment in

the arms, trunk, pelvis and legs

• Paraplegia– Injury to the thoracic, lumbar or sacral segments,

leading to impairment in the trunk, legs and pelvic organs

• Complete– No motor or sensory function below the affect level

• Incomplete– Some preserved motor or sensory function below the

affected level

Page 18: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.

Complete injury

• No voluntary anal contraction• 0/5 distal motor score• 0/2 sensory score• Bulbocavernous reflex present

Page 19: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.

Incomplete spinal cord injuries

• Anterior cord syndrome• Central cord syndrome• Brown-Sequard syndrome• Posterior cord syndrome

Page 20: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.

Anterior spinal cord syndrome

• Injury to the anterior spinal cord caused by either direct compression of the spinal cord, or damage to the anterior spinal artery

• Usually from a flexion/compression injury• Bilateral loss of pain, temperature and light touch

below the lesion due to disruption of the anterior and lateral spinothalamic tracts

• Motor dysfunction due to the disruption of the anterior corticospinal tracts, and damage to the anterior grey horn neurons

• Worst prognosis of incomplete SCI– 10-20% chance motor recovery

Anterior

Page 21: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.

Central spinal cord syndrome

• Most common incomplete spinal cord injury• Often in the elderly with extension injury

mechanisms, due to anterior osteophytes and posterior infolded ligaments

• Motor dysfunction due to disruption of the lateral corticospinal tracts and damage to the anterior grey horn neurons

• Bladder and bowel involvement• Bilateral loss of pain, temperature and light touch

due to disruption of the spinothalamic tracts• Sacral sparing• Good prognosis, but

unlikely to regain full functionAnterior

Page 22: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.

Brown-Sequard syndrome• Caused by complete cord

hemitransection• Ipsilateral motor dysfunction, with

LMN weakness at the level of the injury, and UMN signs below the injury

• Ipsilateral proprioception and vibration loss due to posterior column damage

• Contralateral pain and temperature loss 2-3 segments below the lesion due to disruption of the spinothalamic tracts

• Good prognosis

Page 23: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.

Posterior cord syndrome

• Rare syndrome• Most commonly caused by vascular

compromise, with occlusion to the posterior spinal artery

• Sensory dysfunction with ipsilateral loss of proprioception and vibration, and preservation of pain and temperature

Anterior

Page 24: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.

Cauda equina syndrome• Caused by damage to the cauda equina, a

collection of S1-L5 nerves• Technically a peripheral nerve lesion, so will

cause lower motor neuron signs• Presentation:– Saddle anaesthesia, bilateral lower limb sensorimotor

loss and pain, bowel and bladder symptoms (especially urinary retention)

– Absent or reduced lower limb reflexes, decreased rectal tone

• MRI best to evaluate nerve compression• Needs urgent surgical decompression within 48

hours

Page 25: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.

Jim’s progress notes…• Admitted under NSx• Few episodes of vomiting on ward, during

which he likely aspirated• RRT on ward for respiratory arrest –

intubated and T/F to ICU• Some more stuff happened….• Improved and ready to trial extubation….• Unfortunately, he failed extubation due to

hypoxia• Why?

Page 26: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.

Respiratory complications with SCI

Spinal cord level

Muscle involvement

Effect on respiration

Clinical consequence

C1-3 Complete paralysis of all respiratory muscles

Vital capacity only 5-10% of normal; absent cough

Apnoea and immediate death

C3-6 Varied impairment of diaphragmatic contraction

Vital capacity 20% of normal; weak and ineffective cough

Ventilation necessary in acute stages; majority will be weaned from mechanical ventilation

C6-8 Diaphragm and accessory cervical inspiratory muscles intact. Intercostals and abdominal muscles intact

Expiration entirely passive. Secretion retention. No respiratory failure unless coexisting lung/chest injury/illness

T2-4 Vital capacity 30-50% normal, and weak cough

Page 27: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.

SCI effects on breathing• Loss of intercostal function:

– Failure of AP expansion of the ribcage– Chest wall sucked in during diaphragmatic contraction

• Loss of lower thoracic segment innervation:– Diaphragm starts in a flatter position, which decreases contraction

pressure

• Loss of abdominal muscle tone:– As the diaphragm flattens, abdominal contents are pushed outwards

and the lower ribcage is pulled inwards, causing paradoxical see-saw breathing

– Diaphragm is pulled down by the weight of the abdomen

• Inefficient, rapid, shallow breathing results, with more dead space ventilation

• Abdominal muscle weakness results in decreased ability to cough and clear secretions

Page 28: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.

ICU management of SCI patients

Page 29: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.

Respiratory management

• Airway management• Physiotherapy• Posture• Mucolytics• Abdominal binding• Monitor for infection• Bronchoscopy

Page 30: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.

Longer term respiratory care

• Tracheostomy–More comfortable; minimise laryngeal

damage; less dead space compared to ETT; associated with fewer respiratory infections

• Weaning from ventilation– Portex sprints are as effective or better

than PS weaning, with both superior to SIMV weaning

Page 31: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.

Cardiovascular complications after SCI

• Neurogenic shock– Occurs with lesions above T6 due to loss of

sympathetic tone and unopposed parasympathetic tone

– Vasodilation and hypotension; bradycardia

• Thromboembolism– Due to immobility and venous stasis

• Sympathetic hyperreflexia– Unopposed sympathetic tone below the level

of injury, triggered by sensory stimuli

Page 32: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.

Gastrointestinal complications after SCI

• Delayed gastric emptying and ileus– Common and may last 2-3 weeks– Aperients, early feeding, NGT, prokinetic

agents

• Gastric stress ulceration– PPI prophylaxis

• Constipation

Page 33: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.

Metabolic system considerations

• Temperature regulation– Hypothermic due to vasodilation– Hyperthermic due to inability to sweat

below level of injury

• Hyperglycaemia – Common due to stress response–Worsens ischaemic neurological injury

Page 34: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.

Pharmacological treatment of SCI

• Steroids– Previously, high dose methylprednisone was

standard of care for SCI– Since shown to significantly increase mortality

in patients, compared to placebo

• NOGO-A antibody– NOGO-A is an inhibitory molecule that

prevents neuronal plasticity and axonal regeneration

– Current clinical trial to determine effects of an intrathecal infusion of NOGO-A antibody

Page 35: Spinal cord injuries. Overview: Anatomy of the spinal cord Case presentation Spinal cord injuries – Classification – Complete and incomplete syndromes.

References • Snell. Clinical neuroanatomy. 7th Ed. (2010). Lippincott Williams and Williams:

Philadelphia• J Patten. Neurological differential diagnosis. 2nd Ed. (1996). Springer: London• M Denton, J McKinlay. Cervical cord injury and critical care. Continuing education

in Anaesthesia and Critical Care. (2009). Vol 9: No. 3• Stahel et al. Management strategies for acute spinal cord injury: current options

and future perspectives. Current Opinion Critical Care. (2012). 18:651-660• A Neill. Basic neuroanatomy for the critically ill. SMACC. http://

smacc.net.au/2013/02/basic-neuroanatomy-for-the-critically-ill/ • C Wheeless. Anterior cord syndrome. Wheeless’ textbook of orthopaedics..Last

updated: 25/4/12. http://www.wheelessonline.com/ortho/anterior_cord_syndrome Date accessed: 30/6/13

• S Hishmeh. Posterior cord syndrome. Orthopaedics:one. Last updated: 22/6/09. http://www.orthopaedicsone.com/display/Main/Posterior+cord+syndrome Date accessed: 30/6/13

• D Moore. Spinal cord injuries. Ortho bullets. Last updated: 20/5/13. http://www.orthobullets.com/spine/2006/spinal-cord-injuries Date accessed: 30/6/13