Diseases of the Spinal Cord and Nerve Roots Flashcards
Does damage to the spinal cord damage upper or lower motor neurons?
Upper
RECAP- where is the motor cortex?
Precentral gyrus
Myelopathy?
Anything that causes damage to the spinal cord
Myelitis?
Inflammation causing damage of spinal cord
What are some of the motor signs seen in spinal cord damage?
->remember, upper motor signs as UMN affected
No muscle wasting
Increased muscle tone
Increased reflexes
Extensor plantar response
In an upper motor neuron weakness, which muscles of the upper limb are stronger, the extensors or flexors?
Flexors
In an upper motor neuron weakness, which muscles of the lower limb are stronger, the extensors or flexors?
Extensors
Where do you find upper motor neuron signs?
Below the level of the lesion
Is damage to spinal cord usually unilateral or bilateral?
Bilateral as quite thin
If there is spastic tetraparesis, which part of the spinal cord is damaged?
Cervical
->tetra=four, if lesion is here, all four limbs affected
If there is spastic paraparesis, which part of the spinal cord is damaged?
Thoracic
If the lesion was in the thoracic cord, which limbs would be affected?
Lower limbs
If the lesion was in the cervical section of the spinal cord, which limbs would be affected?
Upper and lower limbs
If you damaged the spine at the level of T9/10, where would there be abnormal sensation?
Below the level of the damage, in this case, below the umbilicus
Sometimes lesions only affect half of the spinal cord. This gives rise to what?
Brown-Sequard syndrome
When a lesion only damages half of the spinal cord, pain and temperature are lost on the same side as the lesion in body parts below that level.
True or false?
False
When a lesion only affects half of the spinal cord, joint position and vibration are abnormal on the same side as the lesion below that level.
True or false?
True
When a lesion only affects half of the spinal cord, any weakness would usually be on the same side as the loss of joint position and vibration sensation.
True or false?
True
Therefore, in Brown-Seqaurd, what happens on the ipsilateral side to the lesion?
Loss of vibration and sense of joint sense.
Weakness
Therefore, in Brown-Seqaurd, what happens on the contralateral side to the lesion?
Loss of pain or temperature sensation
What is a syrinx?
Fluid filled cavity within the spinal cord, usually the grey matter
What do syrinx’s (a type of lesion) result in?
Loss of pain and temperature on same side.
Often joint position and vibration sense are not affected.
->this is because they come into the spinal cord more posteriorly
Syringomyelia?
Syrinxes in the cervical cord in which people lose pain and temperature sensation on same side.
Multiple sclerosis affects the dorsal columns. Therefore, which sensations will be lost?
Joint position and vibration.
Pain and temperature remain unchanged.
What would happen if there was a lesion of the anterior spinal cord?
Loss of pain and temperature as damaged spinothalamic trunk where they cross over.
If there is damage of the spinal cord, as well as motor and sensory damage, what other function can be altered?
Bladder and bowel function
->there are autonomic tracts going down to these
Describe the potential changes in bladder function if the spinal cord is damaged.
Retention of urine without pain
Irritable bladder with frequency and incontinency.
Describe the potential changes in bowel function if the spinal cord is damaged.
Bowel disturbance- constipation or incontinence
Causes of myelopathy (damage to spinal cord) are usually described as being intrinsic or extrinsic.
What is meant by these terms?
Intrinsic cause is one which affects the spinal cord directly.
Extrinsic cause is one which damages the spinal cord from outside the spinal cord.
Give an example of an extrinsic cause of myelopathy.
Prolapsed IV disc
Tumour of meninges pressing on spinal cord.
Are extrinsic causes usually treated by surgery or medicine?
Surgery
In general, if someone is presenting with spinal cord symptoms, which investigations would be carried out?
Localise using MRI
Investigate cause using bloods. CSF
What is one thing you would need to look at in bloods of someone presenting with spinal cord symptoms?
Vitamin B12 levels
Spinal strokes or infarction are due to damage of what?
Damage to vascular supply
Which arteries supply the anterior and posterior spinal cord?
Anterior spinal artery
Posterior spinal artery
What is the anterior spinal cord a branch of?
Vertebral artery
Which thromboembolic diseases could cause spinal cord infarction?
Endocarditis
Atrial fibrillation
How would a spinal cord stroke present?
-Could be sudden or over several hours, but fairly sudden
-Back pain/ radicular pain
-Weakness
-Numbness and paraesthesia
-Urinary symptoms
What is meant by radicular pain?
Pain which started in posterior spine and radiates to anterior abdomen or thorax
Which part of the spinal cord are usually affected in someone with a spinal cord stroke?
Most damage or infarction occurs in anterior spinal artery- this damages spinothalamic but spares dorsal column.
What happens in initial spinal shock?
Rapid shutdown of spinal cord.
Low tone, absent reflexes.
What is the acute treatment for spinal cord strokes?
No acute treatment- cannot thrombolyse spinal cord strokes.
Manage risk factors e.g. maintain adequate BP, antiplatelet therapy, reverse hypovolaemia/arrhythmia
What is the management for a spinal cord stroke?
OT and physio
Continue to manage vascular risk factors
Which vitamin deficiency can lead to spinal cord degeneration?
Vitamin B12
How do we get vitamin B12?
In the diet, in animal products
:))
How is vitamin B12 absorbed?
Gut absorbs but requires intrinsic factor in order to do so.
What can cause a vitamin B12 deficiency
-Diet, especially in vegans
-Pernicious anaemia
-Total gastrectomy
-Crohn’s
-Tapeworms
->in terms of gastrectomy, stomach removed so cannot produce intrinsic factor
How does pernicious anaemia lead to B12 deficiency?
Antibody produced to intrinsic factor which prevents vitamin B12 absorption
Vitamin B12 deficiency does not just affect the spinal cord, which other parts of the nervous system may it affect?
Brain
Eyes
Brainstem
Cerebellum
Peripheral nerves
Which parts of the nervous system are affected more quickly by a vitamin B12 deficiency?
Spinal cord
Peripheral nerves
->spreads to brain if long-term deficiency
What are the symptoms of vitamin B12 deficient myelopathy?
Paraesthesia of hands and feet
Painless retention of urine
Degeneration of corticospinal tracts and dorsal column
May have extensor plantar
Which investigations are used in the diagnosis of B12 deficient myelopathy?
FBC/blood film
Vitamin B12 measured
What is the treatment for B12 deficient myelopathy?
Intramuscular B12
