Diseases of the Spinal Cord & Nerve Roots (Medical) Flashcards
What is the difference between a myelopathy and radiculopathy?
Myelopathy is a disorder of the spinal cord - UMN; from pressure on the cord
Radiculopathy is a disorder of the spinal roots - LMN; compression of nerve root
What are the motor signs of an upper motor neuron lesion - myelopathy?
Increased tone
Increased reflexes, extensor plantar
Pyramidal pattern of weakness
What are the motor signs of a lower motor neuron lesion - radiculopathy?
Decreased tone
Decreased reflexes, flexor plantar
Weakness
Why is the plantar reflex significant?
The abnormal extensor plantar response reliably indicates metabolic or structural abnormality in the corticospinal system upstream from the segmental reflex (has been observed in structural lesions e.g. haemorrhage, brain and spinal cord tumors, and multiple sclerosis, and in abnormal metabolic states e.g. hypoglycemia, hypoxia, and anesthesia)
What are the sensory signs for a spinal cord pathology?
Myelopathy - sensory level
Hemicord lesion - Brown-Sequard syndrome
What is Brown-Sequard syndrome?
A rare neurological condition characterized by a lesion in the spinal cord which results in weakness or paralysis (hemiparaplegia) on one side of the body and a loss of sensation (hemianesthesia) on the opposite side (results from hemisection of spinal cord due to injury or pathology)
Describe the sensory loss in (complete) Brown-Sequard?
On ipsilateral side: Reduced vibration Reduced joint position sense +WEAKNESS [Dorsal Column] On contralateral side: Reduced pain Reduced temperature [Spinothalamic]
What are the sensory signs of a root pathology?
Radiculopathy - dermatomal sensory loss
What are the autonomic signs of a cord/root pathology?
Bladder/bowel problems
What are some congenital causes of myelopathy?
Friedrich’s ataxia
Spinocerebellar ataxias
Hereditary paraparesis
What are the categories of acquired medical causes of myelopathy?
Inflammation (demyelination, autoimmune, sarcoid) Vascular Infective (viral bacterial, other) Metabolic Malignant/infiltrative Idiopathic
What are the inflammatory causes of myelopathy?
Demyelination - MS
Autoimmune - antibody mediated e.g. aquaporin 4, lupus
Sarcoid (inflammatory cells forming granulomas)
(treated via immunosuppression)
What are the vascular causes for myelopathy?
Ischaemic v haemhorrage
What are viral infective causes of myelopathy?
Herpes simplex/zoster, EBV, CMV, measles, HIV etc
What are bacterial infective causes of myelopathy?
TB, borrelia (Lyme), syphilis, brucella
What is another infective cause of myelopathy?
Schistomiasis
What is a metabolic cause of myelopathy?
B12 deficiency
What are causes of spinal cord ischaemia?
A, A, T, T, V, V, S, H, E, D, M
Atheromatous disease (aortic aneurysm) Arterial dissection (aortic) Thromboembolic disease (endocarditis, AF) Thrombotic haematological disease Vaculitis Venous occlusion Systemic hypotension Hyperviscosity syndromes Endovascular procedures Decompression sickness Meningovascular syphillis
What are some of the features of the clinical presentation of spinal cord stroke?
- may have vascular risk factors
- onset sudden or over few hours
- pain
- weakness
- numbness + parasthesia
- urinary symptoms
What type of pain is found in spinal cord stroke?
Back pain/radicular
Visceral referred pain
What type of weakness is found in spinal cord stroke?
Usually paraparesis rather than quadraparesis given vulnerability of thoracic cord to flow related ischaemia
What urinary symptoms are found in spinal cord stroke?
Retention followed by bladder and bowel incontinence as spinal shock settles
What artery is usually affected in spinal cord stroke?
Anterior spinal artery
Occlusion of which artery can present as a partial Brown-Sequard syndrome?
Central sulcal artery
What investigation should be used for suspected spinal cord stroke?
MRI
What is the treatment for spinal cord stroke?
- Reduce risk of recurrence (maintain adequate BP, reverse hypovolaemia/arrhythmia, antiplatelet therapy)
- OT and physio
- Manage vascular risk factors
What is the prognosis for spinal cord stroke?
- return of function depends on degree of parenchymal damage
- unless sig recovery in first 24 hrs, chance of major recovery is low
- pain may be persistent + contribute to disability
- 20% mortality, 35-40% have more than min recovery
What is demyelinating myelitis?
Inflammation causing damage to myelin sheath of nerve fibres
What condition is DM usually a part of?
Multiple sclerosis
What is demyelinating myelitis in MS characterised by?
Pathological lesions of inflammation and demyelination leading to temp neuronal dysfunction; affects white matter of CNS; one or more lesions anywhere
Demyelination myelitis of MS
- partial or complete transverse myelitis
- may be initial presentation of MS (60-70% have MRI brain typical of MS)
- subacute onset (slower than ischaemia)
- may be history of neuro/opthalmo episodes
What is the treatment for MS myelitis?
- supportive
- Methylpredisnolone
What is vitamin B12 found in?
Meat, fish and most animal byproducts
What does absorption of B12 from the gut require?
Intrinsic factor, a binding protein secreted by gastric parietal cells
What is pernicious anaemia?
An autoimmune condition in which antibodies to intrinsic factor prevent B12 absorption
What are the commonest causes of pernicious anaemia?
Inability to absorb B12 at the terminal ileum
Failure to produce intrinsic factor in the stomach
What does B12 deficiency cause complications in?
Total gastrectomy
Crohns
Tape worms
How much of the nervous system does B12 deficiency affect?
Most of it
What parts of the nervous system does B12 def affect?
- Myelopathy (L’Hermitte’s sign - sudden sensation resembling electric shock that passes down back of neck and into spine; may radiate out into arms and legs)
- Peripheral neuropathy
- Brain
- Eye/optic nerves
- Brainstem
- Cerebellum
How does B12 def present?
- Paraesthesia hands + feet, areflexia
- First UMN sign extensor plantars
- Degeneration of: corticospinal tracts -> paraplegia; dorsal columns -> sensory ataxia
- Painless retention of urine
How is B12 def investigated?
FBC/blood film, B12
How is B12 def treated?
Intramuscular B12 injections
Given daily, then once every 3 months
Why does treatment for B12 def need to be given quickly?
Untreated it can become permanent
