A23. Multiple sclerosis Flashcards
Multiple sclerosis Definition
Chronic, progressive, multifocal, autoimmune inflammatory disease of the CNS.
Multiple sclerosis is more common in which gender
Women:men = 2:1
age onset of Multiple sclerosis
Disease of young adult, starts in 30-40s
in n which region is Multiple sclerosis more frequent
More frequent in the northern hemisphere
etiology of Multiple sclerosis
A. Genetic susceptibility: HLA, some increased risk in relatives
B. Environmental factors: Viruses, geographic latitude (more towards the poles), vitamin D
Environmental factors that could cause Multiple sclerosis
- Viruses,
- geographic latitude (more towards the poles),
- vitamin D
pathology Multiple sclerosis
- T-cells are activated in the periphery, then cross-react with parts of myelin in the CNS →
Demyelination and secondary axon degeneration.
The demyelinated regions are called plaques.
● Active plaques are characterized by blood-brain barrier dysfunction, perivascular infiltration of
lymphocytes and plasma cells and segmental demyelination.
● In chronic plaques, scar tissue is formed (sclerosis) due to astrocyte proliferation
Active plaques in multiple sclerosis are characterized by
- blood-brain barrier dysfunction,
- perivascular infiltration of lymphocytes and plasma cells
- and segmental demyelination.
what happens In chronic plaques that occur in multiple sclerosis
scar tissue is formed (sclerosis) due to astrocyte proliferation
what is meant by plaques in multiple sclerosis
The demyelinated regions are called plaques
(T-cells are activated in the periphery, then cross-react with parts of myelin in the CNS →
Demyelination and secondary axon degeneration)
Pathological types of multiple sclerosis
a. T-cell and macrophage mediated inflammation
b. B-cell and complement mediated inflammation
c. Oligodendrocyte destruction, axonal lesion
d. Primary oligodendrocyte dystrophy
Main points about Multiple sclerosis
- Demyelination
- Inflammation
- Secondary axonal damage
- Inflammatory processes → Relapses
- Secondary axonal damage → Brain atrophy → Deficits (delayed manifestation)
Secondary axonal damage in multiple sclerosis leads to
→ Brain atrophy → Deficits (delayed manifestation)
Possible symptoms of Multiple sclerosis
- Optic neuritis - Blurry vision, pain on movement, often first sign
- Sensory - Paresthesias, numbness, tingling, always distribution specific for central cause
- Motor symptoms - Paraparesis, hemiparesis, monoparesis, tetraparesis
- Brainstem symptoms - Gaze palsy, internuclear ophthalmoplegia (INO), trigeminal pain
-
Cerebellar symptoms - Limb/trunk ataxia, dysarthria, nystagmus, tremor, coordination/balance
problem - Autonomic symptoms - Urge incontinence (detrusor hyperactivity), detrusor-sphincter dyssynergia
- Cognitive symptoms, subcortical dementia
-
Paroxysmal symptoms (may occur several hundred times a day, short duration) - Lhermitte’s
sign, trigeminal neuralgia, dystonia, hemiataxia - Aspecific symptoms - Fatigue, depression
which tracts are involved in multiple sclerosis?
which are more affected?
May involve all tracts of CNS, but longer tracts are more affected.
which symptom often manifests first in multiple sclerosis
Optic neuritis -
* Blurry vision
* pain on movement
often first sign
Sensory symptoms in multiple sclerosis
- Paresthesias,
- numbness,
- tingling,
- always distribution specific for central cause
Motor symptoms in multiple sclerosis
- Paraparesis,
- hemiparesis,
- monoparesis,
- tetraparesis
Brainstem symptoms -in multiple sclerosis
- Gaze palsy,
- internuclear ophthalmoplegia (INO),
- trigeminal pain
Cerebellar symptoms -in multiple sclerosis
- Limb/trunk ataxia,
- dysarthria,
- nystagmus,
- tremor,
- coordination/balance problem
Autonomic symptoms - in multiple sclerosis
- Urge incontinence (detrusor hyperactivity),
- detrusor-sphincter dyssynergia
Paroxysmal symptoms in multiple sclerosis
(may occur several hundred times a day, short duration) -
* Lhermitte’s sign,
* trigeminal neuralgia,
* dystonia,
* hemiataxia
Lhermitte’s sign
(Barber chair phenomenon)
* is a transient sensation of an electric shock that extends down the spine and extremities
* upon flexion and/or movement of the neck.
Diagnostic criteria of multiple sclerosis
McDonald criteria (2017) →
* Prove that inflammation is chronic (dissemination in time) and
* widespread (dissemination in space)
McDonald criteria (2017)
- for multiple sclerosis
In case of zero attacks and lesions what additional criteria is needed for diagnosis of MS based on McDonald criteria
- One year of disease progression (retrospective/prospective)
- and at least 2 out of 3 criteria:
*dissemination in space in the brain
*dissemination in space in the spinal cord based on 2 or more T2 lesions
*Positive CSF
In case of 1 attack, 1 lesion what additional criteria is need for diagnosis of MS
disseminatiton in space and time
or
await for further clinical attack implicating a different CNS site
In case of 1 attack, 2 lesions what additional criteria is needed for diagnosis of MS
Dissemination in time on MRI
or
await for further clinical attack implicating a different CNS site
In case of 2 or more attacks, and 1 lesion what additional criteria is needed for diagnosis of MS
Dissemination in space on MRI
OR
await for further clinical attack implicating a different CNS site
In case of 2 or more attacks, and 2 or more lesions what additional criteria is needed for diagnosis of MS
None
Clinical evidence alone will suffice
First choice of diagnostic tool in Multiple sclerosis
MRI
Diagnostic tools in Multiple sclerosis
- MRI (first choice)
- CSF examination
- Evoked potentials
- Serology (differential)
what is seen on MRI in multiple sclerosis
- typical distribution of demyelinated plaques around:
*ventricles
*juxtacortically
*corpus callosum
*brain,
*spinal cord
what is MRI used for in multiple sclerosis
- diagnosis
- follow up
CSF examinations in multiple sclerosis
- normal routine values,
- OCBs (oligoclonal bands)
- Not needed for diagnosis, but may support it. Characteristic to see elevated IgG index or presence of oligoclonal gammopathy (OGP).
Evoked potentials use in diagnosis of MS
- VEP(Visual Evoked Potential) to investigate visual tract,
- MEP(Motor evoked potentials )
- SEP( somatosensory evoked potention test)
SEP Somatosensory evoked potential
- The electrical response of the brain, as measured by electroencephalography, in response to electrical stimulation of superficial nerves (e.g., tibial nerve).
- studies the relay of body sensations to your brain and how the brain receives those sensations.
Motor evoked potentials (MEPs)
- are electrical signals recorded from muscle tissue in response to stimulation of the motor cortex.
- The stimulation may be magnetic or electrical
- applied directly to the motor cortex or
- applied transcranially through the skull
Stimulus of Visual evoked potential (VEP) and in which disorders is it indicated
Light impulse
Checkered patterns
* Demyelinating disorders (e.g., optic neuritis in the case of multiple sclerosis)
Somatosensory evoked potential (SEP) is indicated in
Demyelinating disorders (e.g., multiple sclerosis) and axonal damage
Motor evoked potential (MEP) is indicated in
- Damage to the motor cortex and other motor neurons (e.g., amyotrophic lateral sclerosis)
- Demyelinating disorders (e.g., multiple sclerosis) and axonal damage
Serology in MS
(differential) -
* Borreliosis,
* Treponema,
* anti-AQP4 (very specific for Devic’s disease)
Devic disease or neuromyelitis optica) is also knows as
- Neuromyelitis optica spectrum disorders (NMOSD)
- previously known as Devic disease or neuromyelitis optica) is also knows as
definition of Devic disease
immune-mediated, chronic inflammatory disorders of the CNS that primarily affect the optic nerve and spinal cord
Closely resembles the clinical appearance of MS
