W4: spinal cord injury and pathology

Question 1

What are some likley causes of spinal pathology for acute, sub-acute and chronic conditions?

Answer 1

Acute - vascular
Sub-acute: inflammatory
Longer: malignancy, degenerative

Question 2

What are the key features of an upper motor neuron lesion?

Answer 2

Pyramidal weaknesses (preferentially spares the antigravity muscles)
Spasticity
brisk reflexes
Upgoing extensor plantar reflex (babinski sign)
Clonus

Question 3

What are the features of a lower motor neuron lesion?

Answer 3

Flaccid muscle weakness
Normal or reduced tone
Reduced or absent reflexes
Wasting
Fasiculations (sign muscle de-afferented i.e no nerve supply)

Question 4

Where are the spinal cord enlargements?

Answer 4

The cervical and lumbar spine.

Question 5

What is the anatomy of the distal end of the spinal cord?

Answer 5

The end of spinal cord is called the conus medullalris
The spinal nerves that come from this is called the cauda equina
The filum terminale is a fibrous (non neural) band that extends from the conus medullaris to the periosteum of the coccyx, it stabilises the spinal cord and is made from the remenants of the meninges.

Question 6

What type of symptoms to lesions in the cervical and thoracic spine present as?

Answer 6

Upper motor neuron signs

Question 7

What type of symptoms do lesions in the lumbar spine present as?

Answer 7

Lower motor neuron signs

Question 8

What type of symptoms do lesions in the conus medullaris present as?

Answer 8

Upper and lower motor neuron lesions

Question 9

What lesions result in bladder and bowel symptoms?

Answer 9

Lesions anywhere in the spinal cord.

Question 10

What are the different functions of the spinal cord?

Answer 10

Sensory information from the body to the brain (afferent)
Motor control from brain to the body (efferent)
Autonomic function from brain to body
Spinal reflexes.

Question 11

Identify the tract in the blue part of the spinal cord

Answer 11

lateral corticospinal tract

Question 12

Identify the tract in the red part of the spinal cord

Answer 12

Spinothalamic tract

Question 13

Identify the tract in the gree part of the spinal cord

Answer 13

The posterior columns
Contains the dorsal column medial lemniscus pathway

Question 14

What is the function of the lateral corticospinal tract?

Answer 14

Motor control

Question 15

What is the function of the spinothalamic tract?

Answer 15

Sensory, pain and temperature

Question 16

What is the function of the dorsal column medial lemniscus pathway?

Answer 16

Light touch sensation, vibration, proprioception and joint position sense

Question 17

What is the pattern of topographic representation of the human body on the motor complex called?

Answer 17

Homonculus

Question 18

What are the key anatomical features in term of the location of the motor tracts?

Answer 18

Crosses over in the medulla
Descends in the lateral spinal cord.

Question 19

What are the key anatomical features in terms of the two main sensory inputs to the brain?

Answer 19

DCML - ascends in dorsal part of spinal cord, crosses over in the medulla

STT - crosses over immediately in the spinal cord, ascends in the lateral part of the spinal cord.

Question 20

What is the key spinal anatomy relating to the autonomic tracts?

Answer 20

Arise from the intermediolateral column or lateral column of the spinal cord.
At level T1-L2

Question 21

How do autonomic spinal cord lesions often present?

Answer 21

Autonomic dysfunction
Blood pressure dysregulation
Horner syndrome
Bladder and defecation control problems

Question 22

What is Horner syndrome?

Answer 22

Distinct signs of one side of face - ptosis, miosis, anhydrosis of face
Caused by lesion along sympathetic pathway to head, neck and eye.

Question 23

What is the common clinical presentation of lesion in the cauda equina?

Answer 23

Flaccid weakness
Normal or reduce tone (LL)
Reduced or absent reflexes (LL)
Patchy leg sensory reduction
Sphnicter involvement - reduced anal tone

Question 24

What are the common clinical signs of pyramidal weakness in a patient?

Answer 24

Spasticity
Arm - overly flexes
Legs - stronger extensors - leads to circumduction of hips in gait

Question 25

What are the clinical presenting features of a spinal tumour?

Answer 25

Progressive and chronic presentation
Often has a early presentation of lower back pain

Question 26

What are the common presenting features of a prolapsed disk causing compressive spinal cord injury.

Answer 26

Often presents after a work injury - such as pulling, pushing, heavy lifting etc
Risk factors include: obesity, occupation, older age, smoking,
OFten worse symptoms when driving

Question 27

How does transverse myelitis or inflammation of the spinal cord present?

Answer 27

Potential causes: injections, autoimmune disease
Normaly has an acute or subacute presentation.
Most common between ages 10-19yrs then 30-39yrs.
More common in females.

Question 28

What is the treatment for transverse myelitis?

Answer 28

High dose steroids +/-nother immunosuppression medication

Question 29

What are the feature of a spinal stroke?

Answer 29

Acute onset - due to disruption fo the blood supply to the spinal cord
Can affect the anterior spinal artery
Can affect the posterior spinal arteries
Symptoms start as intiali spinal shock, later develop spasticity
Treatment aism to by suppportive and treat any underlying cause.

Question 30

What is cauda equina syndrome?

Answer 30

LMN signs
Neurosurgical emergency
Compression of the lumbar and sacral spinal nerves in the cauda equina
key signs include: severe/progressive bilateral lower limb neurological deficit, recent onset urinary retention/incontinence, fael incontinence, saddle anaesthetia

Question 31

What are the typical urinary symptoms when a lower or perihperal nerve have lesions, or he nerve root has a lesion?

Answer 31

Hesitancy, poorr stream ,retention, overflow incontinence.
Bladder emptying syndromes

Question 32

What are the changes in urinary symptoms when there is a cord lesion?

Answer 32

Urgency
Frequency
Urge incontinence
Overactive bladder, may also get urinary retention is bladder sphincter dysynergia.

Question 33

How can the spinal cord be split up by its blood supply?
Think in terms of cross sectional anatomy and a spinal cord stroke.

Answer 33

Question 34

What are the normal presenting features of Brown-Sequard syndrome?

Answer 34

Multi possible causes: spinal tumor, truma, transverse myelitis so onset is different by patient
Key siymptoms
One side: UMN weakness (CS), loss of position, fine touch and virbation (DCML)
Opposite side: loss of pain and temp (ST)

Question 35

What is Rombergs test?

Answer 35

Assesses a persons sense of balance, specifically the dorsal column of the spinal cord.
Used to diagnose ataxia.
Person standing with eyes open: balance is better as able to use visual, proprioceptive and vestibular information
However when eyes closed is reliant and proprioception and vestibular function.
Remove shoes, stand with feet together and eyes open/closed for thirty seconds, if unable to keep balance when closed the test is positive.

Question 36

What is meant by subacute combined degeneration of the spinal cord?

Answer 36

Myelopathy due to VB12 deficiency (very poor or restricted diet, pernicious anemia, NO abuse etc).
Specifically affects the Dorsal column so presents with loss of sensation, distal parasthetsis and sensory ataxia causing gait disturbances.
Often has co-existing peripheral neuropathy
Treatment is B12 replacement

Question 37

What is tabes dorsalis?

Answer 37

A form of neurosyphilis seen as a complication of late stage syphylis infection.
Tends to peak 10yrs after initial infection and is more common in males.
Preferentially causes degeneration of the dorsal column. may also effect the peripheral nervous tissue.

Question 38

What is syringomyelia?

Answer 38

Central lesion affects crossing spinothalamic tract, normally found in the cervical spine.
Can in some cases extend to involve the anterior horn and sympathetic and eventually corticospinal. Cavity causing lesion grows as accumulats CSF and puts pressure on edges of cavity and compresses adjacent nerve fibres.
Treatment is conservative or neurosurgical.
Cause: congenital (Chiaria malformation), trauma or malignancy.

Question 39

What is chiari malformation?

Answer 39

Is most often congenital but can be acquired.
Problems in the brain and skull structure cause the lower brain such as the cerebellu to press on and through the foramen magnum into the spinal canal.
This leads to erve compression and build up of CSF pressure.
Often causes syringomyelia as affects CSF pulsation through the central canal.

Question 40

What is autonomic dysreflexia?

Answer 40

Medical emergency can affect people with spinal cord injuries above T6.
Noxious stimuli below the level of the lesion elicit sympathetic overactivity that constricts blood vessels below the lesion causing hypertension.
The sympathetic neurons are not balanced by inhibitory descending signals from the brain.
sympathetic activation below lesion, parasympathetic above lesion as consequence of baroreceptor activation. - causes inappropriabte cerebrovascular response.
Normally triggered by an issue in the bladder or the bowel.
Key signs: hypertension, bradycardia, facial flushing, headache, sweating.

Question 41

What is the treatment for autonomic dysreflexia?

Answer 41

Catheter in bladder
PR with lidocaine gel and remove faeces from rectum
IV treatment - hydralazine, labetolol
Sit patient upright.