Cord Injury

Cauda Equina

Definition

 

Compression of some or all of the nerve roots in the cauda equina

- bladder dysfunction

- bowel dysfunction

- saddle anaesthesia

- variable motor and sensory loss

 

Aetiology

 

HNP

- most common

 

Epidural haematoma

- post surgical

- spinals and anticoagulation

 

Epidural abscess

 

Tumours

- metastatic prostate / lung / breats

 

Trauma

 

Chronic stenosis / spondylithesis

 

Post surgical

- seen post stenosis decompression

- cause unknown

 

Anatomy

 

Spinal cord ends at L1 / conus medullaris

- L3 in children

- spinal cord appears to migrate proximally with growth

- relative greater growth of the spinal column

 

Conus medullaris

- attached to coccyx

- filum terminale

 

Dural sac containing L2 - S5

 

Neurology

 

Lower motor neurone symptoms in leg

- weakness

- sensory loss

- decreased / absent reflexes

 

Bladder dysfunction

 

S2-4 disruption

- parasympathetic nerves

- promote bladder emptying

- contract detrusor & relax internal sphincter

 

Unable to feel bladder filling

 

Unable to void

- retention

- eventual overflow

 

Pathology

 

Nerve roots

- very susceptible to compression

- don't have 3 layers like peripheral nerve roots

- endoneurium only

- then CSF and dura

 

May develop ischaemia

- radicular arteries

- form of compartment syndrome

 

Issue

 

Injury to the sacral nerve roots can be permanent

- need early decompression < 24 hours

- otherwise permanent bladder and bowel dysfunction

 

Symptoms

 

Two groups

- acute presentation - severe pain

- insidious presentation - stenosis / spondylolithesis

 

Bladder dysfunction

- difficulty initiating / stopping stream

- progresses to retention

- progresses to overflow incontinence

 

Bowel

- unable to feel or control / incontinence

 

Other symptoms

- severe back pain

- severe sciatica

- lower leg weakness and parasthesia 

- saddle anaesthesia / can't feel toilet paper

 

Signs

 

Perianal sensation

- may have preserved light touch

- may need pin prick

- S 3,4,5

 

Rectal tone

- decreased

 

Bladder

- full

- increased volume on bladder scan

- cannot feel tug on catheter

 

MRI

 

Usually a disc will take up > 1/3 of canal diameter

 

Management

 

Urgent Decompression

 

Timing

- evidence of improved outcomes for decompression within 48 hours versus > 48 hours

- no evidence for < 24 hours

- reasonable to do so as soon as able

 

Outcomes

 

Buchner and Schiltenwolf Orthopedics 2002

- 17 / 22 regained full urinary function

 

Outcome likely related to

- duration of symptoms / timing of decompression

- severity of initial symptoms / signs / bladder dysfunction

 

 

 

Central Cord Syndrome

Epidemiology

 

Most common pattern cord injury

 

Hyper-extension injury in middle aged man with osteoarthritic spine

 

Usually C3/4 and C4/5

 

Mechanism

 

Most common type / in older patient with pre-existing spondylosis / OPLL

- hyperextension injury

- compression of the cord

- anteriorly by osteophytes

- posteriorly by infolded ligamentum flavum

 

Pathology

 

Injury of central gray matter

- weaker in arms than legs

- LMN in arms 

- UMN in legs

- sacral sparing common

 

Examination

 

Flaccid paralysis in upper limbs

 

Spastic paralysis in lower limbs

- more likely to be preserved

 

Xray

 

Typically normal / no fractures

 

MRI

 

Demonstrates stenosis

 

Cord

- high signal intensity on T2

- localise level of injury

 

Management

 

NHx

 

Usually regain walking and bladder function

Hands have the worst prognosis

 

Prognosis

 

Aarabi et al J Neurosurg Spine 2011

- 42 patients, 82% men, average age 58

- admission ASIA scores and midsagittal diameter of cord most related to prognosis

 

Issue

 

Decompression v non operative management

 

Surgical Timing

 

Chen et al J Neurosurg Spine 2009

- review of surgical decompression in 49 patients

- no difference between decompression < 4 days or > 4 days

- younger patients did significantly better

- 1/3 patients dissatisfied with outcome

 

Algorithm

 

Observe initially

- maximise medical treatment / HTN / oxygenation

 

If improving

- non operative

 

No improvement

- operative management

 

 

 

Spinal Cord Injury

Definition

 

Complete Lesion 

- bulbocavernosus reflex present 

- no cord function below lesion

- very poor prognosis for recovery

 

Incomplete Lesion

- bulbocavernosus reflex present

- some cord function below lesion

- good prognosis for recovery

 

Anatomy

 

Vertebral Canal narrowest at T8/9

- Also area of vascular watershed

 

Dorsal Columns 

- light touch, vibration & proprioception

- CTLS (cervical fibres central, sacral fibres lateral)

- decussate in medulla

- Cuneate Nucleus = Cervical & Thoracic

- Gracile Nucleus = Sacral & Lumbar

 

Lateral Corticospinal Tract

- motor tract

- CTLS (cervical central, sacral fibres peripheral)

- decussate in medulla

 

Anterolateral Spinothalamic Tract

- pain & temperature

- decussate immediately after cord entry

 

Incomplete Patterns

 

1.  Central Cord Syndrome

- most common

- hyperextension injury

- UL > LL due to arrangement of fibres in dorsal column and anterior corticospinal

- CTLS

- distal > proximal

- sacral sparing

 

2.  Anterior Cord Syndrome

- complete paralysis with dorsal column sparing

- anterior spinothalamic & lateral corticospinal tracts lost

- secondary to ischaemic event

- maintain BP and oxygenate patient

- very poor prognosis

 

3.  Brown Sequard

- cord hemisection

- usually secondary to laceration

- ipsilateral dorsal columns & motor

- contralateral loss pain & temperature

 

4.  Posterior Cord Syndrome

- rare

- dorsal column loss only

- due to tumour / iatrogenic (sublaminar wires etc)

 

5.  Cauda Equina Syndrome

- injury below L1

- only nerve roots at this level

- LMN injury to lumbar and sacral nerve roots

- large L5/S1 disc commonest cause in narrow canal < 100 mm2

- faecal incontinence + urinary incontinence

- nil anal tone or sensation

 

6.  Conus medullaris injury

- cord ends at L1

- injury at this level results in LMN LL weakness and UMN sacral lesions

- may have a spastic bladder which enables urination without catheterisation

- T12 / L1 burst fracture most common cause

 

Sacral Sparing

 

Triad of

- anal voluntary contraction

- perianal sensation

- FHL function

 

Indicates

- incomplete injury

- potential for recovery

- due to pial arteries on cord surface supplying small amount of tissue 

 

Blood Supply

 

Anterior Spinal Artery

- arises from vertebral arteries at foramen magnum

- supplies entire cord except for dorsal columns

- narrows and may become absent in thoracic region

 

Posterior Spinal Arteries

- paired

- smaller

 

Segmental Arteries

- average of 8 paired arteries

- may be single segmental supply between T4 and T8

- Artery of Adamkiewicz from left between T9-11 in 80% cases

 

Micturition control

 

Stretch receptors in bladder wall

 

As distension occurs

- afferent signal travels up pelvic splanchnic nerves (S2/3/4)

- sacral cell bodies send signal back via efferent in same nerves

- produce contraction of detrusor

 

Parasympathetic control

- this is a lower motor neuron reflex arc

- override by higher cortical centres with development

 

Cauda Equina

- LMN to S2-4

- flaccid bladder / overflow incontinence

 

Conus medullaris injury

- results in UNM changes at that level

- detrusor mm spastically contracts

- higher cortical control disrupted

- result is spastic bladder - incontinence

 

Surgical division sacral nerve roots 

- produces LMN effect

- if leave at least 1 S3 - 100% continent

- if leave at least 1 S2 - 50% continent

- if above S2 incontinent because pelvic splanchnics removed

 

Assessment

 

Spinal shock

 

Refers to flaccid paralysis due to physiologic disruption of all spinal cord function

- all motor, sensory and reflexes absent below level of injury

 

An accurate assessment can only be made when spinal shock has resolved

- 48 hrs in 99%

 

Absence of SS confirmed by the return of cord mediated reflexes below the anatomic level of the injury

- bulbocavernosus reflex is the lowest and thus the first to return

 

Frankel Grading

 

A Complete

- no motor or sensory function in the sacral region

 

B Incomplete

- sensory intact

- no motor function below the neurological level and includes sacral segments S4-S5

 

C Incomplete

- motor function is preserved below the neurological level 

- at least half the muscles have power < grade 3

 

D Incomplete

- motor function is preserved below the neurological level 

- at least half the muscles have power > grade 3

 

E Normal motor and sensory function

 

MRC Power Grading (Medical Research Council)

 

0 - no visible movement

1 - palpable or visible contraction

2 - active movement with gravity eliminated

3 - active movement against gravity

4 - active movement against some resistance

5 - active movement against full resistance

 

ASIA Dermatomes (American Spinal Injury Association)

 

C5 Elbow Flexor / Lateral Arm Sensation

C6 Wrist Extension / Dorsal thumb

C7 Elbow Extension / Dorsum MF

C8 Finger Flexion (MF DP) / Dorsum LF

T1 Interossei / Medial Arm sensation

T2 Armpit sensation

 

L1 Inguinal ligament sensation

L2 Hip Flexors / Middle Medial Thigh

L3 Knee extension / Knee sensation

L4 Ankle DF / Medial malleolus

L5 Long toe extension / First web space

S1 Ankle PF / Heel 

S2 Back of knee sensation

 

Each muscle rated 0 - 5 for power

- score out of 50 for R and L

- total score out of 100

 

Sensory Levels

 

T4 - nipple

T7 - xiphisternum

T10 - umbilicus

T12 - groin

 

Reflexes

 

Cremasteric Reflex T12-L1

- stroke thigh & scrotal contraction

 

Anal Wink S2-4

- stroke cleft for anal contract

 

Babinski

- upgoing = UMN

 

Oppenheimer

- stroke tibial crest & toes go up

 

Bulbocavernosus Reflex

 

Technique

- squeeze glans / clitoris or pull on catheter

- anal contracture

 

If present with complete cord lesion

- indicates S2-S4 region firing

- spinal shock resolved

- can prognosticate about level of neurological injury

 

Timing

- returns in 99% in 24 hours

- indicates end of spinal shock

 

TL fracture may permanently damage BCR

 

Medical Treatment

 

Steroids

 

Bracken N Engl J Med 1990

- randomised multi-centre trial

- methylprednisone v naloxone or placebo

- suggested benefits of corticosteroids within 8/24 but not after

- based on oedema reduction

- GIT haemorrhage may result or be exacerbated

 

Bracken Cochrance Database Syst Review 2012

- review of 8 randomised control trials

- shown that methylprednisolone, if given within 8 hours, improves motor recovery

 

Canadian Spine Society

- some of the efficacy seen in trials is only in post-hoc analysis

- evidence is actually very weak, level II and III

- side effects include sepsis, pneumonia and GI complications

- is not standard of care, but only a treatment option

 

Dosing

 

Methylpred

- 30 mg/kg bolus

- 5.4 mg/kg/hr for 23/24

 

Contra-indications

- > 8 hours after presentation

- penetrating spinal injury

- infection

- diabetes

- < 13 years old

- pregnancy

 

Surgical Decompression

 

Timing

 

Progressive neurology 

- urgent decompression

 

Non Progressive Neurology

- decompress as soon as stable

- timing uncertain

 

Results from decompression

 

Cervical

- improvement in both incomplete & complete cord injury

- 1 or 2 extra levels in cervical spine improves function significantly

 

Thoracolumbar

- improvement in incomplete cord injury

- no improvement with complete cord injury

- extra level in thoracic spine doesn't improve fuxnion

- prevents late degeneration / deformity / pain

 

 

 

 

Spinal Cord Injury Management

Epidemiology

 

RTA 50%

Falls 20%

Sport 20%

 

Unconscious after MVA or fall

- 10% chance cervical spine injury

- Cervical > Thoracic > Lumbar

- cervical spine is mobile & not protected

- quadriplegia more common than paraplegics

- assume cervical spine injury till cleared 

 

Permanent paralysis 10%

- incomplete > complete deficit

 

Natural History

 

Death in first year secondary to CRF and Infection

- 20% of Quadriplegics

- 10% of Paraplegics

 

Useful recovery

- complete lesions < 10% chance

- incomplete ~ 75% chance

 

Quadriplegics

- inpatient stay ~ 9/12

- OT doesn't decrease this

- life expectancy decreased by 10 years

 

Paraplegics

- inpatient stay ~ 4/12

- OT does decrease this 

- life expectancy normal

 

Mechanism of injury

 

Primary response / Mechanical

- Contusion (No.1) / Compression / Stretch / Laceration

 

Secondary response

- Ischaemia / Vascular Injury / Vasoactive Substance / Inflammation

 

Definition

 

Neurological level

- lowest level at which motor and sensory function is normal

 

Complete lesion / no sacral sparing

- absence of sensory and motor function in the lowest sacral segment

- no sacral sparing

 

Incomplete lesion / sacral sparing

- presence of sacral and motor function in the lowest sacral segment

- indicates preserved function below the defined neurological level

 

Complete Cord lesion

 

NHx

 

90% recovery of one & 20% recovery two root levels

- if motor grade at level is 2/5 at one week, will gain functional recovery

- if pinprick spared in dermatome, will likely recovery functional > 3/5 strength

- this may be significant i.e. diaphragm, elbow extension C7

- may be increased with surgical decompression

- majority recovery in first 6 - 9 months

 

Function

 

C1-3

- portable ventilation

 

C4

- need CPAP at night

- mouth controlled wheelchairs

 

C5

- active elbow flexion

- dependant for transfer and bed position

 

C6

- shoulder stability (RC)

- wrist extension

- can give them tenodesis grip

 

C7

- triceps

- can roll over and transfer

- eat independently

 

C8-T1

- independent

 

Walking

- > grade 3 hip flexion on one side

- > grade 3 knee extension on other side

 

Neurogenic Shock

 

Cause

 

2° unopposed parasympathetic vagal tone

- sympathetic tone lost

- loss of vasomotor tone with marked vasodilatation

- result is hypotension + bradycardia

 

Diagnosis

- hypotensive + bradycardia + warm periphery 

 

Management

 

Response to fluids moderate (CVP)

- trendelenburg position

- Atropine (0.6 mg push)

- may require inotropic support / Dopamine

 

Pharyngeal suction & intubation stimulate vagus

- may produce bradycardia & cardiac arrest

 

Respiration

 

Midcervical lesion

- C3/4/5

- phrenic nerve defunctioned

- paralysis of diaphragm

 

Low cervical / high thoracic lesion

- paralysis of intercostal muscles

 

Accessory muscles & abdominal respiration used in both circumstances

 

At The Scene

 

Unconscious  Patient

 

Assume spinal fracture secondary to force that caused unconsciousness

- place neck in neutral

- stabilise with gentle longitudinal traction

- hard collar + sandbags

 

Conscious Patient

 

Spinal injury assumed if

- complaining of sensory abnormality / weakness / paralysis

- back or neck pain

 

Immobilisation

- as above

 

Transportation

 

Spinal care / log roll

- monitor airway & O2 saturations

- beware overhydration

- keep patient warm

 

Initial Hospital Management

 

History

- Mechanism of injury

- any neurological deterioration / improvement since injury

 

ATLS

- paraesthesia masks abdominal & leg injuries

 

Vertebral assessment

- log-roll to allow visualisation

- palpate for tenderness / step

- perform PR (saddle anaesthesia / anal tone)

 

Features cord injury

- flaccid areflexia

- lax anal tone

- diaphragmatic breathing

- pain > clavicle only

- hypotensive & bradycardic

- priapism

 

Neurological Assessment / SMART

 

Sensation

- spinothalamic tracts (Pin prick)

- posterior column (Fine touch, Proprioception)

Motor - Corticospinal Tracts

Autonomic ~ Priapism

Reflexes - DTR / Abdominal / Anal / BCR

Tone

 

X-ray

 

Lateral film  

- must see C7/T1

- swimmer's view may be necessary

- pick up 85-90%

 

Cervical trauma series

- AP + Peg / Ondontoid View + Lateral

- up to 95%

 

CT / MRI

 

Early Management

 

1.  Stabilise Spine

 

Cervical

- unstable - Gardner Wells Tongs 4 kg initially

- stable - bed rest, hard collar

 

Thoracolumbar

- patient lies supine

- no flexion

 

2.  Respiratory

 

Worse if chest trauma 

- monitor ABG's

- physiotherapy

- incentive spirometry / triflow

- if respiratory function deteriorates may require intubation

 

3.  CVS

 

Avoid hypotension

- maintain SBP > 90 mmHg

- CVP monitor

- IDC monitor urine output

 

4.  Urinary

 

Bladder usually acontractile

- initial retention

- stretching of Detrusor muscle may delay return of function

- initial IDC followed by intermittent catheterisation

- high incidence UTI & calculi 

 

5. GIT

 

Paralytic Ileus 

 

Usually occurs

- NBM 48/24

- NGT 

 

Abdominal distension splints diaphragm

- vomit & aspiration may occur

- monitor electrolytes & supplement K+

 

Constipation 

- problem after a few days

- microlax & laxatives

 

Gastric ulceration

- can be masked

- ranitidine

 

6.  Skin & Position

 

Turn every 2 hours & inspect skin

- 4 Person lifts

- Edgerton Tilt bed

- Stryker frame

 

7.  Joints & Limbs

 

Daily Passive ROM

- foot drop splints

- hand splints 

 

Spasm 

- Baclofen, Dantrolene

 

HO common

- especially with head injury

- presents as hot red swelling

 

8.  Medication

 

Anticoagulants

- high risk of DVT & PE 

- anticoagulation indicated if no contra-indications i.e. surgical stabilisation

- subcutaneous Heparin & TEDS

 

Steroids

- controversial

- main reason why spinal injuries progress is lipid peroxidation

- bolus dose of Methylprednisolone could inhibit peroxidation

 

Antibiotics

- prophylaxis not indicated

- treat infection only

 

9.  Autonomic Dysreflexia

 

Occurs > T5

- usually with cervical spine injuries

- splanchnic nerves / sympathetic exit at T8 and are interrupted

 

Distended viscus / bladder or bowel

- efferent sympathetic outflow from cord

- vasoconstriction causes HTN

- HTN stimulates carotid body

- centrally mediated vagal response

- bradycardia & vasodilation

 

Presentation

- 80% within the first year

 

Signs

- severe HTN / systolic BP > 200

- headache / facial flushing / bradycardia

 

May result in

- cerebral hemorrhage

- seizures

- pulmonary oedema

 

Managment

- decompress organ - IDC / fecal disimpaction

- sublingual nifedipine

- IV Hydralazine

 

 

Tendon Transfer

Epidemiology

 

Nearly 2/3 cervical level injury survivors have C6 root level function

- biceps and wrist extension function

 

Requirements

 

1. Transfer / Triceps

 

2. Object manipulation

- grip 

- key grip / self catheterisation 

 

Timing

 

Consider > 18/12

 

Allows

- serial evaluation

- psychological adjustment

 

Delayed if evidence of neurological recovery

 

Principles

 

1. Start on side with most function / or dominant limb

 

2. If 2 point discrimination > 10mm

- operate on only one limb, as patient uses visual cues

 

3. Keep treatment simple

 

4. Restore elbow extension first if C6

- Moberg Deltoid - Triceps

- aids transfer

 

5. Perform only one operation at time

 

6. Don't transfer spastic muscles

-  ? dynamic EMG

 

7. Remember principles of tendon transfer

 

Classification

 

Neurologic level 

- lowest level with normal motor & sensory function bilaterally

- level of bony fracture doesn't exactly correspond with level of cord injury

 

Frankel Grade

 

A Complete neurological deficit

B Sensory only below injury level

C Motor < 3 below level

D Motor < 5 below level

E Normal

 

Transfer summary

 

C5

- Moberg deltoid to triceps transfer

 

C6

- Moberg deltoid to triceps transfer

- FPL tenodesis

 

C7

- BR to EDC / EPL for finger extension

- ECRL to FDP for finger flexion

 

C8

- Zancolli FDS tendodesis to prevent intrinsic plus

 

C5 Quadriplegia

 

Intact

- deltoid / supraspinatus / biceps

 

Require

- elbow extension / Moberg deltoid to triceps

- forearm pronation / Zancolli Biceps tendon re-routing

 

A.  Deltoid to Triceps transfer  - Moberg

 

Indications

- Triceps < Grade 3

 

Benefits

- helps stabilisation in wheelchair

- helps transfers

- improves control of self-help devices

 

Procedure

- posterior 1/3 of deltoid isolated

- dissect up till see AXN entering posterior deltoid & stop

- preserve as much of its tendinous insertion

- tendon grafts obtained / EDL or T anterior

- tendon grafts interlaced between distal deltoid belly & triceps aponeurosis

 

Post op

- elbow immobilised in extension for 6/52 with GHJ adducted

- then slowly flex 10° per week

- avoid transfer for 3/12 

 

B.  Zancolli Biceps Tendon Rerouting 

 

C5 level patients lack ability to place hand in working position

 

Procedure

 

1.  Obtain passive pronation first

- removal of interosseous membrane + DRUJ

 

2. Biceps tendon exposed

- Z Plasty

- distal 1/2 rerouted around neck of radius

- sutured to at tension to obtain full pronation & yet allow extension

 

C6 Quadriplegia

 

Intact

- wrist extension - BR, ECRL, ECRB 

- pronation

 

Require

- elbow extension / Moberg biceps to triceps transfer

- stronger wrist extension / BR to ECRB

- Key pinch / BR to FPL / Moberg FPL tenodesis 

 

A.  Moberg FPL Tenodesis

 

Indication

- strong wrist extensors with no finger flexors i.e. C6 lesion

- creates key pinch

 

Mechanism

- tenodesis of FPL to provide flexion with wrist extension

 

Procedure

 

Release of A1 pulley of thumb

- permits bowstringing

- increases mechanical advantage

 

FPL tenodesis to volar radius

- exposed in forearm

- divided 6 cm proximal to wrist

- tenodesed to volar radius by passing through hole in radius & sutured to itself 

 

Dorsal tenodesis of extensor hood of thumb MCPJ 

- stops MCPJ hyperflexion

- hood sutured to dorsum of MC through drillholes

 

Fusion of IPJ of Thumb

- at zero degrees

- via longitundinal K wire

 

Post op

- thumb spica for 4/52

 

B.  BR to FPL 

 

Indications

- strong ECRL or ECRB

 

C.  BR to ECRB

 

Indications

- strong BR with weak ECRB/ ERCL

 

Advantage

- allows wrist extension for tenodesis effect of finger flexors

- gives grasp

 

C7 Quadriplegia

 

Intact

- triceps

- EDC

 

Require

- finger & thumb flexion

 

Criteria

 

Many SCI patients can be helped with hand surgery - 75%

 

Suitable criteria

- 2 point discrimination < 10mm

- plateau of neurology 12-18/12

- grade 4 MRC power of transfer (lose minimum 1 grade)

- no uncontrolled spasticity

- no excessive pain in hand

- psychologically stable

 

Zancolli 2 Stage procedure

 

Stage I / Finger & thumb extensors

- BR to EPL / EDC

- use CMCJ thumb 

- thumb MCPJ volar plate capsuloplasty / suture plate to MC neck / stop hyperextension

- transfer BR to EPL & ED via long radial incision

- immobilize for 4/42

 

Stage II / Grasp

- 6/12 later

- ECRL to FDP

 

Options to power FPL

1. TT to ECR Tertius if present

2. Side to side suture to ECRB

3. Passive tenodesis (Moberg)

 

C8 Quadriplegia

 

Intact

- FDP/FDS

 

Require

- prevent MCPJ hyperextension

 

Zancolli FDS Lasso tenodesis

 

Technique

- divide FDS slips at A2 level

- pass proximal slips under A1 

- suture slips to FDS above A1 

- effectively suture FDS to A1