Define Myelopathy vs Radiculopathy?
Myelopathy is a category of spinal cord disease affecting fibres above the Ventral Horn cells, also called Cord lesions
(Can affect any types of nerve fibre depending on the location and extent of the lesion, so what tracts it hits)
Radiculopathy is a category of spinal cord diseases affecting fibres below the ventral horn cell, also called Root lesions because they effect the nerve roots
How could a myelopathy affecting UMNs appear?
- Hyperreflexia & Plantar Extension
- Pyramidal pattern of weakness
Weakness in lower limb flexors and upper limb extensors
How could a myelopathy affecting LMNs appear?
- Decreased Tone
- Weakness & Wasting
How could a myelopathy affect sensation?
Can trigger a sensory level:
- If theres a lesion at T4 cutting off the sensory fibres youll get abnormal sensation below T4
A hemicord lesion causes Brown-Sequard Syndrome
What is Brown-Sequard Syndrome?
Tell tale sensory sign of a hemicord lesion
- Lose Contralateral pain & temp (Spinothalamic)
- Lose Ipisilateral muscle strength, vibration, proprioception & mechanoreception (CST/Dorsal Column)
How would a radiculopathy (root lesion) present?
With sensory and motor features isolated to that spinal nerve
Hence its important to know your dermatomes/myotomes
What kind of ANS symptoms can come from spinal cord disease?
Bowel & Bladder problems
How would a lesion at C5 pressing on the cord & nerve root present?
- UMN signs below C5
- Possible Sensory level at C5
- Numbness in C5 dermatome
- Weakness in C5 muscles (Deltoids/biceps)
- Hyporeflexia in Biceps reflex (C5 LMN is compressed)
How do we categorise the causes of spinal cord lesions>?
Into intrinsic causes which are non-compressive and largely medical
Into Extrinsic causes which are compressive and largely surgical
List the categories of Spinal cord tumours? (Type of extrinsic spinal cord lesion)
Intradural & Extramedullary
Intramedullary (These are intrinisic spinal cord lesions)
What are the causes of intrinsic (Non-compressive) spinal cord lesiosn?
- Inflammatory e.g. Demyelinating Myelitis such as MS
- Vascular (mostly Ischaemic vs haemorrhagic)
- Viral e.g. HIV, EBV, CMV, Herpes simplex
- Bacterial e.g. TB
- Metabolic e.g. B12 Deficiency
- Malingnant e.g. intramedullary tumour or paraneoplastic
- Congenital & Genetic
Whats another name for Ischaemic Myelopathies?
And what causes Ischaemic Myelopathies?
Literally anything that can damage your arteries incl:
- Atheromatous disease
- Thromboemboli from Endocarditis or AF
- Venous Occlusion
- Air emboli (A possible presentation of decompression sickness)
How would ischaemic myelopathy present?
- First they will probably have vascular risk factors
- The onset will be sudden or over several hours
- Radicular Back Pain and/or visceral referred pain
- Urinary retention in spinal shock and incontinence after
What does radicular pain mean?
Pain radiating down a dermatome due to irritation of the nerve root, a radiculopathy
What kind of weakness is more common in ischaemic myelopathy?
Paraparesis (partial paralysis of lower limbs) rather than quadraparesis because the thoracic cord is the mostly likely area to be damaged
How would you investigate a suspected Spinal Stroke?
- Most often Ant spinal art (so dorsal columns spared) and mid thoracic
- May be spinal shock present
How would we treat Ischaemic Myelopathy and whats the prognosis?
- OT & physio
- Manage vascular risk factors
- Reduce recurrence risk by maintaining adequate BP, antiplatelets and reversing any hypovolaemia or arrythmia. All as relevant
20% die and only 30/40% have more than a minimal recovery
Describe the presentation of an MS myelopathy?
- More likely partial than transverse
- May well be their first presentation, look for history of neuro or opthalmological episodes
- Slower onset than ischaemic, subacute i.e. ~1week
How do we treat MS?
- Disease Modifying to reduce attack incidence
- Methylprednisalone to reduce attack severity
How does a B12 deficiency trigger a spinal cord lesion?
It causes the spinal cord to slowly degenerate over time
What care the common causes for a B12 deficiency?
- Dietary Failure e.g. Vegan
- Loss of ileum to surgery or disease (e.g. Crohn’s)
- Loss of intrinsic factor such as pernicious anaemia where antibodies attack intrinsic factor
How does a B12 deficiency present?
- Brain, brainstem and cerebellar issues
- Eye/optic nerve issues
- Peripheral neurpathy
# L’hermitte’s sign, a sudden electric shock down the spine when you flex you neck forward (indicates C cord pathology)
# Paraesthesia & Areflexia
# UMN signs
# Progessive degeneration of the CST (Paraplegia) and Dorsal Column (Sensory Ataxia)
# Painless urine retention (ANS neurons lost)
How do we investigate and treat for a B12 deficiency?
- Blood Film
- B12 blood test