Diseases of the Spinal Cord and Nerve Roots (Medical) Flashcards
What is a myelopathy?
spinal cord
an injury to the spinal cord due to severe compression that may result from trauma, congenital stenosis, degenerative disease or disc herniation
Myelopathy describes any neurologic deficit related to the spinal cord
What is a radiculopathy?
spinal roots/nerve roots
refers to a set of conditions in which one or more nerves are affected and do not work properly (a neuropathy)
image showing corticospinal tracts and where myelopathy and a rediculopathy would affect
What makes up the CNS and PNS
Everything in CNS is brain, brain stem and spinal cord and your PNS is anterior horn cells and nerve root and beyond
What are some signs of UMN cord pathology?
- No wasting
- ↑tone - spasticity, UMN normally cause inhabition of reflex arc
- ↑reflexes, extensor plantar, clonus
- Pyramidal pattern of weakness - decreased control of active movement, particularly slowness
What are some signs of LMN cord pathology?
- wasting
- ↓tone
- ↓reflexes, flexor plantar
- weakness
What are expected sensory signs of cord pathology?
Myelopathy → sensory level
Hemicord lesion → Brown- Sequard syndrome (an incomplete spinal cord lesion characterized by findings on clinical examination which reflect hemisection of the spinal cord (cutting the spinal cord in half on one or the other side))
IMage explaining Brown-Sequard syndrome
What sensory signs would you see in rediculopathy?
dermatomal sensory loss
What signs would you see if there was a pathology of the autonomic fibres?
bladder and bowel problems
What would you see in a C5 cord lesion
Wasting of C5 innervated muscles
↑ tone in legs > arms
Power ↓C5 innervated muscles, pyramidal pattern below
Reflexes ↓biceps, ↑all lower reflexes
Sensory level
Anything above the lesion has weaker tone and reflexes - UMN symptoms present below the level of the lesion
What are surgical causes of myelopathy or radiculopathy?
Tumour - Extradural, intradural/extramedullary, intramedullary
Vascular abnormalities - Haemorrhage, AVM, dural fistula
Degenerative (spine)
Trauma
What are congenital/genetic medical causes of myelopathy
Friedrich’s ataxia, spinocerebellar ataxias, hereditary paraparesis
What are aquired medical causes of myelopathy
• Inflammation
Demyelination (Multiple Sclerosis)
Autoimmune (antibody mediated eg aquaporin 4, lupus)
Sarcoid
- Vascular: ischaemic vs haemorrhage
- Infective
Viral: herpes simplex/zoster, EBV, CMV, measles, HIV etc
Bacterial: TB, borrelia (Lyme), syphilis, brucella
Other: schistosomiasis
- Metabolic: B12 deficiency
- Malignant: infiltrative/paraneoplastic
- Idiopathic
Iatrogenic
What does ischaemic myelopathy cause?
spinal stroke/infarction
Where do the posterior and anterior spinal arteries arise?
posterior - comes from little small vessels form the aorta
anterior - branch of the vertebral arteries
What is it called when arteries perfusing an area meet and why is this important?
watershed areas
this area is most vulnerable to ischemia as pressure here is lowest
What are causes of spinal cord ischaemia?
- Atheromatous disease (aortic aneurysm)
- Thromboembolic disease (endocarditis, AF)
- Arterial dissection (aortic)
- Systemic hypotension
- Hyperviscosity syndromes/prothombotic disease
- Vasculitis
- Arteriovenous abnormalities
- Endovascular procedures
- Meningovascular syphilis
- Decompression sickness - happens when diving, air bubbles block arteries
What is the clinical presentation of a spinal cord stroke?
- May have vascular risk factors
- Onset may be sudden or over several hours
- Pain - Back pain/radicular, Visceral referred pain
- Weakness - Usually paraparesis rather than quadraparesis given vulnerability of thoracic cord to flow related ischaemia - if cervical tehn will attack armds aswell but often just legs
- Numbness and paraesthesia
- Urinary symptoms - Retention followed by bladder and bowel incontinence as spinal shock settles
What are some general examination points for a spinal cord stroke?
- Usually anterior spinal artery => dorsal columns spared
- Occlusion of a central sulcal artery can present as a partial Brown-Séquard syndrome
- Usually mid thoracic
- May be spinal shock
How may imaging appear in a spinal stroke
imaging during a spinal stroke may look normal even though one is present
What is the treatment of a spinal cord stroke
• Reduce risk of recurrence
Maintain adequate BP
Reverse hypovolaemia/arrhythmia
Antiplatelet therapy
- OT and physiotherapy
- Manage vascular risk factors
What is the prognosis of a spinal cord stroke?
unless significant motor recovery in the first 24 hours, chance of major recovery is low
pain may be persistent and significantly contribute to disability
20% mortality, only 35-40% have more than minimal recovery
Variable but often poor prognosis
What is demyelinating myelitis?
usually part of MS
common cause of medical spinal cord disease
can affect the young
spinal cord stroke is vascular but this is inflammation
What is demyelinating myelitis in MS characterised by?
Characterised by pathological lesions of inflammation and demyelination leading to temporary neuronal dysfunction
one or more lesions
Where does demyelinating myelitis in MS effect?
white matter of the CNS
Does MS affect the PNS
no only the CNS
What may be the intial presentation of MS?
demyelinating myelitis
What is the onset of demyelinating myelitis like?
Subacute onset (slower than ischaemia)
What is the recovery of demyelinating myelitis like?
Spontaneous recovery
What is important to ask and remeber whena patient presents with demyelinating myelitis?
There may be a history of previous neurological or ophthalmological episodes so always ask
When investigation myelitis in MS what is important to look at during investigations?
the brain as will show if the patient has had any previous episodes
When a MRI cord lesion is present what is important to consider
MS as well as non MS causes such as vascular causes
What is the CSF like in MS?
few white cells (<50)
What is the treatment of MS myelitis?
supportive
methylprednisolone - a corticostreioid used to supress the immune system and decrease inflammation
What deficiency is a metabolic cause of myeelopathy?
B12 deficiency
Where can you get B12 from?
Abundant in meat, fish, animal by-products
What is absorption of B12 done by?
Absorption from the gut requires intrinsic factor (IF), a binding protein secreted by gastric parietal cells
What is a B12 deficiency due to?
- Diet (vegans)
- Pernicious anaemia: autoimmune condition in which antibodies to IF prevent B12 absorption
- Total gastrectomy, Crohn’s, tape worms
Where does B12 deficiency have an affect on?
Effect most of the nervous system:
- Myelopathy
- Peripheral neuropathy
- Brain
- Eye/optic nerves
- Brainstem
- cerebellum
What symtpoms does B12 deficiency myelopathy cause?
- Paraesthesia hands and feet, areflexia - abnormaly sensation, pins and needles
- First UMN sign extensor plantars
- Degeneration of:
Corticospinal tracts → paraplegia
Dorsal columns → sensory ataxia
• Painless retention of urine
(mix of UMN and LMN signs)
What are the investigations that may be used for B12 deficiency myelopathy
FBC/blood film (can be N)
B12 levels
What is th treatment of B12 deficiency myelopathy?
Intramuscular B12 (quicker the better)
