Multiple Sclerosis Flashcards
what is MS
Multiple sclerosis (MS) is a chronic and progressive condition that involves demyelination of the myelinated neurones in the central nervous system.
MS is caused by an _________ process involving the activation of immune cells against the ______.
is caused by an inflammatory process involving the activation of immune cells against the myelin.
MS typically presents in ….
symptoms tend to improve in….
MS typically presents in young adults (under 50 years) and is more common in women. Symptoms tend to improve in pregnancy and in the postpartum period.
Myelin is provided by cells that wrap themselves around the axons. These are __________ in the peripheral nervous system and _________ in the central nervous system.
Myelin is provided by cells that wrap themselves around the axons. These are Schwann cells in the peripheral nervous system and oligodendrocytes in the central nervous system.
Multiple sclerosis typically only affects ……. which NS?
Multiple sclerosis typically only affects the central nervous system (the oligodendrocytes).
in MS: There is inflammation around myelin and infiltration of immune cells that cause damage to the _____.
There is inflammation around myelin and infiltration of immune cells that cause damage to the myelin.
describe how people initially present with MS?
When a patient presents with symptoms of a clinical “attack” of MS, for example, an episode of optic neuritis, there are usually other lesions of demyelination at the same time throughout the central nervous system, most of which are not causing symptoms.
In early disease, _________ can occur and symptoms can resolve
In early disease, re-myelination can occur and symptoms can resolve
is MS reversible?
In early disease, re-myelination can occur and symptoms can resolve. In the later stages of the disease, re-myelination is incomplete and symptoms gradually become more permanent.
A characteristic feature of MS is that
The key expression to remember to describe the way MS lesions change is…..
A characteristic feature of MS is that lesions vary in their location over time, meaning that different nerves are affected and symptoms change over time. The key expression to remember to describe the way MS lesions change location over time is that they are “disseminated in time and space”.
what are the causes* of MS?
The cause of the demyelination is unclear, but there is growing evidence that it is influenced by a combination of:
Multiple genes
Epstein–Barr virus (EBV)
Low vitamin D
Smoking
Obesity
describe how MS presents (time wise)
Symptoms usually progress over more than 24 hours. At the first presentation, symptoms tend to last days to weeks and then improve. There are a number of ways MS can present.
describe optic neuritis (MS presentation)
Optic neuritis is the most common presentation of multiple sclerosis. It involves demyelination of the optic nerve and loss of vision in one eye. This is discussed in more detail below.
describe the eye movement abnormalities MS might present with?
Patients may present with double vision due to lesions with the sixth cranial nerve (abducens nerve).
There are two key phrases to remember to describe a sixth cranial nerve palsy:
There are two key phrases to remember to describe a sixth cranial nerve palsy: internuclear ophthalmoplegia and conjugate lateral gaze disorder.
describe internuclear ophthalmoplegia?
Unilateral lesions in the sixth nerve causes a condition called internuclear ophthalmoplegia. Internuclear refers to the nerve fibres that connect between the cranial nerve nuclei that control eye movements (3rd, 4th and 6th cranial nerve nuclei). The internuclear nerve fibres are responsible for coordinating the eye movements to ensure the eyes move together. Ophthalmoplegia means a problem with the muscles around the eye.
describe conjugate lateral gaze disorder
Lesions in the sixth cranial nerve cause a conjugate lateral gaze disorder. Conjugate means connected. Lateral gaze is where both eyes move together to look laterally to the left or right. It is disordered in a sixth cranial nerve palsy. When looking laterally in the direction of the affected eye, the affected eye will not be able to abduct. For example, in a lesion affecting the left eye, when looking to the left, the right eye will adduct (move towards the nose) and the left eye will remain in the middle as the muscle responsible for making it move laterally is not functioning.
give some focal weakness that MS can present with
Bells palsy
Horners syndrome
Limb paralysis
Incontinence
give some focal sensory symptoms Ms might present with
Trigeminal neuralgia
Numbness
Paraesthesia (pins and needles)
Lhermitte’s sign
what is Lhermitte’s sign?
Lhermitte’s sign is an electric shock sensation that travels down the spine and into the limbs when flexing the neck. It indicates disease in the cervical spinal cord in the dorsal column. It is caused by stretching the demyelinated dorsal column.
describe the ataxia MS might present with
Ataxia is a problem with coordinated movement. It can be sensory or cerebellar:
Sensory ataxia is the result of loss of the proprioceptive sense, which is the ability to sense the position of the joint (e.g. is the joint flexed or extended). This results in a positive Romberg’s test and can cause pseudoathetosis.
Cerebellar ataxia is the result of problems with the cerebellum coordinating movement. This suggestions cerebellar lesions.
describe the disease course for MS patients
The disease course is highly variable between individuals. Some patients may have mild relapsing-remitting episodes for life whereas others have primary progressive MS that progresses without any improvement in symptoms. There are certain classifications used to describe the pattern of MS in an individual. These patterns are not separate conditions but part of a spectrum of disease activity.
what is clinically isolated syndrome?
This describes the first episode of demyelination and neurological signs and symptoms. MS cannot be diagnosed on one episode as the lesions have not been “disseminated in time and space”. Patients with clinically isolated syndrome may never have another episode or develop MS. If lesions are seen on MRI scan then they are more likely to progress to MS.
describe the relapsing-remitting pattern of MS?
Relapsing-remitting MS is the most common pattern at initial diagnosis. It is characterised by episodes of disease and neurological symptoms followed by recovery. In MS the symptoms occur in different areas with different episodes. This can be further classified based on whether the disease is active and/or worsening:
Active: new symptoms are developing or new lesions are appearing on MRI
Not active: no new symptoms or MRI lesions are developing
Worsening: there is an overall worsening of disability over time
Not worsening: there is no worsening of disability over time
