Diseases of the spinal cord and nerve roots Flashcards
Which neurons does myelopathy/myelitis affect?
UMN’s - disease of the spinal cord
Which neurons does radiculopathy/radiculitis affect?
LMN’s - disease of the nerve roots
Name a tick-borne infection that can cause radiculitis?
Lyme.
What is myeloradiculitis?
Compression of the cord which causes both UMN and LMN signs.
What are the medical causes of myelopathy/radiculopathy?
- inflammation
- infarction
- infection
- infiltration
- degenerative (neurons)
What are the surgical causes of myelopathy/radiculopathy?
- tumour
- vascular abnormalities
- degenerative (spine)
- trauma
What are the signs of an UMN lesion?
- no muscle wasting
- increased tone
- increased reflexes
- pyramidal pattern of weakness (weakness in extensors of upper limbs and flexors of lower limbs)
What are the signs of an UMN lesion?
- wasting (only the muscle innervated by the affected nerve will be wasted)
- decreased tone
- decreased reflexes
- weakness
Which nerve roots supply reflexes?
Biceps: C5/C6
Triceps: C7
Knee jerk: L3/L4
Ankle jerk: S1
What would be caused by a left-sided hemisection of the cord?
Brown-Sequard syndrome:
- left sided paralysis
- left sided loss of proprioception and vibration sense
- right sided loss of pain and temperature
What would the signs of a C5 cord lesion be?
UMN lesion:
- wasting of C5 innervated muscles
- increased tone
- reflexes decreased in biceps and increased in all other reflexes
- power decreased in all C5 innervated muscles and pyramidal pattern below
- sensory level - all dermatomes below C5 are impaired
What are the medical causes of myelopathy?
- demyelination (MS)
- ischaemic (due to occlusion of blood vessels eg dissection of an aortic aneurysm)
- transverse myelitis
- metabolic (B12 deficiency)
What can cause ischaemic myelopathy?
Spinal stroke.
Which parts of the spinal cord are most at risk of a spinal stroke?
- Most likely to get a stroke in thoracic cord or lower down
- Anterior spinal artery most commonly affected
Give a few examples of causes of spinal cord ischaemia.
- atheromatous disease
- thromboembolic disease
- arterial dissection (aortic)
- decompression sickness (common in Aberdeen divers due to air emboli)
- venous occlusion
What is the presentation of a spinal cord stroke?
- back pain
- visceral referred pain (diffuse)
- paraparesis (usually in legs as thoracic cord is most vulnerable)
- urinary retention followed by bladder and bowel incontinence
Which investigation is used for a spinal cord stroke?
MRI
How is a spinal cord stroke treated?
- reduce risk of recurrence (maintain BP, reverse hypovolemia etc)
- manage vascular risk factors
What is the prognosis for a spinal cord stroke?
- return on function depends on degree of damage
- only 25-40% have more than a minimal recovery
Which features characterise demyelinating myelitis?
Lesions of inflammation and demyelination which leads to temporary neuronal dysfunction.
Commonly part of MS disease presentation.
Only affects 1 half of the cord eg 1/2 of C5 - partial myelitis.
How is demyelinating myelitis investigated and treated?
LP - looking for CSF-specific inflammation (ie inflammation that is in the CSF but not in the blood).
Supportive or methylprednisolone.
What is MS?
Patchy myelitis.
What are the causes of transverse myelitis?
- idiopathic
- Lyme
- autoimmune
- viral
- post-vaccination
What is pernicious anaemia?
Autoimmune condition in which autoantibodies against intrinsic factor in the gut prevent vitamin B12 absorption.
