Neurology - Multiple Sclerosis Flashcards
What is multiple sclerosis (MS)?
A chronic and progressive autoimmune condition involving demyelination in the central nervous system
Immune system attacks the myelin sheath of myelinated neurones
What age group is most commonly affected by multiple sclerosis?
Young adults (under 50 years)
More common in women
What cells produce myelin?
Oligodendrocytes in the central nervous system
Schwann cells in the peripheral nervous system
When can re-myelination occur?
Early disease
Symptoms can resolve
What is a characteristic feature of MS lesions?
Lesions vary in location, described as ‘disseminated in time and space’
What are potential causes of multiple sclerosis?
Influenced by:
* Multiple genes
* Epstein–Barr virus (EBV)
* Low vitamin D
* Smoking
* Obesity
What is the onset like in MS?
Sumptoms usualyl progress over more than 24 hours
Symptoms last days to week at first then improve
How does optic neuritis present in MS?
Unilateral reduced vision, developing over hours to days
Caused by demyelination of the optic nerve, develops over hours to days
What are key features of optic neuritis?
Key features include:
* Central scotoma
* Pain with eye movement
* Impaired colour vision
* Relative afferent pupillary defect
What is a relative afferent pupillary defect?
Affected eye constricts more when shining light in other eye
Reduced response on direct reflex
What are other causes of optic neuritis?
Other causes include:
* Sarcoidosis
* Systemic lupus erythematosus
* Syphilis
* Measles or mumps
* Neuromyelitis optica
* Lyme disease
What is the treatment for optic neuritis?
High-dose steroids
What is an MRI used for in optic neuritis?
Predicts which patients will develop MS
What eye movement abnormalities can occur due to lesions in cranial nerves III, IV, or VI?
Can cause double vision (diplopia) and nystagmus
What is Oscillopsia?
Visual sensation of the environment moving
Unable to create a stable image
What is internuclear ophthalmoplegia?
Caused by a lesion in the medial longitudinal fasciculus, nerve fibres connect cranial nerve nuclei that control eye movements- ensures nerves cooardinate eye movements
Impairing adduction on the same side as the lesion and nystagmus in the contralateral abducting eye
What does a CNVI lesion cause?
CNVI (abducens) controls the lateral rectus muscle
Affect eye cannot abduct
Causes diplopia when abducting with non-affected eye
What focal neurological symptoms can MS present with?
Focal weakness
- Incontinence
- Horner syndrome
- Facial nerve palsy
- Limb paralysis
Focal sensory
- Trigeminal neuralgia
- Numbness
- Paraesthesia
- Lhermitte’s sign
What is Lhermitte’s sign?
An electric shock sensation that travels down the spine and into the limbs when flexing the neck
Indicates disease in cervical spinal cord in dorsal column
Caused by stretched demyelinated dorsal column
What is transverse myelitis?
A site of inflammation in the spinal cord causing sensory and motor symptoms depending on the lesion’s location
What is ataxia?
A problem with coordinated movement, which can be sensory or cerebellar
What causes sensory ataxia?
Loss of proprioception due to lesion in dorsal columns
Positive Romberg’s test
What causes cerebellar ataxia?
Cerebellar lesion
What are the classifications of multiple sclerosis disease patterns?
Classifications include:
* Clinically isolated syndrome
* Relapsing-remitting MS
* Secondary progressive MS
* Primary progressive MS
