Flashcards in 9.7 Autoimmune of NS Deck (30)
What is MS?
EPisodes of demyelination affecting areas of the CNS separated by space and time
What is an environment factor of MS?
Vitamind D levels
- Further away from the equator has higher levels of MS
What occurs in MS?
Unregulated imune system dysfunction causes inflammatory lesions in the CNS. These lesions cause demyleination, followed by a period of remyelination . With time this will lead to a permanent loss of myelin with secondary axonal loss
What is the immune activation in MS?
1. Autoreactive myelin specific T helper cells (Th1 and 17)
2. Failure of regulation when stimulated by antigens
3. Th1 secretes IFN gamma and Th17 secretes IL-17 which can adhere and cross the BBB
4. These activated T cells encounter myelin and activate migroglia
5. Microglia express class II molecules which further promotes T cells, microglia and PMN
What is affected in MS?
White matter tracts
What are the presenting complaints of MS?
Sensory symptoms in unusual pattern
Motor deficit (10%)
Cerebellar: ataxia, dysarthria
What is the clinical course of MS?
Attacks and recovery with an increasing likelihood after each attack that they are left with some kind of impairment
Secondary progressive: no attacks but symptoms are getting worse
What are the unfavourable prognosis factors of MS?
Older age at onset
Motor/cerebellar signs at onset
Short interval between initial and second attack
High relapse rate in early years
Incomplete remission after first relapse
High lesion load early by MRI
What is the diagnosis of MS?
One clinical episode
Clinical episodes separated by time and space
MRI to look for plaques
What are the MS treatment aims?
Prevent permanent disability
Reduce disability from acute attacks
What is acute disseminated encephalitis?
T cell attacking the myelin after a viral illness or vaccination and is most common in children
Lesions will appear like MS but all of the same age
What are the investigations and treatment in ADEM?
CSF: raised WCC and protein
Evidence of infection
Exclude other causes
Follow risk MS
Treat: high dose methylprednisolone
What is Neuromyelitis optica?
inflammation and demyelination of the optic nerve and the spinal cord
Caused by antibodies against aquaporin-4
What is the diagnosis of Neuromyelitis optica
2 of: brain MRI at onset not meeting MS criteria, Continuous lesion over >3 veretebral segments, NMO-IgG seropositive
What will you see in Neuromyelitis optica?
Long cervical lesions (>3 segments)
Symmetrical cerebral lesions
Brainstem with extension to thalami
Acute attacks that respond to plasmapharesis but not steroids
Long term Rx with immunosuppression (prednisolone, azathioprine and rituximab)
What is primary cerebral vasculitis and who dos it affect and what is the presentation?
inflammation of the blood vessels of the brain and sometimes spinal cord
Affects middle aged males
Present with headache, stroke events, cognitive impairment and seizures
What is Guillian Barre?
Acute post infectious peripheral nauropathy which progresses for no more than 4 weeks - ascending paralysis the most common
What is the pathogenesis of Guillan Barre?
Antigen presentation, inflammatory actiation targeting myelin or axonal components, inflammatory response causing secondary axonal loss in primary demyelinating disease followed by remyelination and axonal regeneration
What are the triggers for Guillan Barre?
Viral infection: campylobacter jejuni, cytomegalovirus, EBV, mycoplasma pneum
Presenting symptoms of Guillan Barre?
Pain, numbness, parasthesia
Weakness LL > UL > face > respiratory
Areflexia (may have reflexes early)
Investigations for Guillan-Barre
CSF: cytoalbuminaemic dissociation, raised WCC, oligoclonal bands, protein
Nerve conduction studies
ESR, CRP, ANA, HIV, drugs and toxins, MRI spinal cord, CXR, pulmonary function testing
What do you need to be wary of in Guillan-Barre?
Lung function - can lose respiratory muscles so ventilate at 15ml/kg of FVC
DVT management, cardaic monitoring, postural hypo/hypertension, pressure sore management
What is the treatment for Guillan-Barre?
Treat complications: DVT prophylaxia, respiratory management, ICU support, Presure care, pain management
What is chronic inflammatory demyelinating polyradiculoneuropathy?
Infalmmatory neuropathy for at least 2 months. Sensory signs present in most cases and associated with paraproteins
When will you have Anti-Hu?
Encephalitis and neuropathy
When will you have affected voltage gated K channels?
When will you have Anti-Yo (purkinje cells)
When will you have Anti-Ri
Opsoclonus and myoclonus
When will you have Anti-GAD?
Stiff man syndrome