Neurology 2(A) - MS Flashcards
What is transverse myelitis, and its symptoms?
inflammatory, demyelinating disease of the spinal cord
subacute non-compressive myelopathy
What are causes of transverse myelitis?
Parainfectious (40%) CMV, EBV, Mycoplasma, HTLV, HIV etc Cord ischaemia (12%) MS associated 20-30% Idiopathic 21-60%
Sx evolve over hours to 1-2 weeks
Improve over weeks to months
What is the primary pathology of MS?
demyelination and axonal loss
What proportion of MS patients develop visual involvement?
80% will have at some stage.
20-50% will have optic neuritis as their presenting Sx
What are the Sx of optic neuritis?
acute or subacute unilateral eye pain - on eye movement 90%
central scotoma/red vision loss
RAPD or marcus Gunn pupil
Disc oedema - fundus usually normal as retrobulbar defect
Overt bilateral and simultaneous is rare - but subclinical involvement is noted in 70%
rarely progressive after 2 weeks - if >1/12, other pathology likely
What is the prognosis of optic neuritis?
90% regain vision over 2-6/12 15yr risk of permanent vision loss = 1% Risk of progression to MS - 0 lesions 25% risk at 15y 1 lesion 50% 15yr risk >=3 lesions 78% risk at 15y
In patients w optic neuritis, who are at lowest risk of MS?
No MRI lesions
Male
atypical features (papilloedema, severe visual loss, no pain)
Risk 4% over 15y
what proportion of patients have abnormal visual evoked responses?
unilateral conduction delay - abnormal in 85 of patients with CDMS (2 or more relapses)
can be used to detect subclinical disease or silent previous attack
What is the classical finding on CSF in MS?
oligoclonal bands (evidence of intrathecal IgG) - NOT in serum
>95% are positive in CDMS
adds prognostic value - 25% risk of 2nd attack (CDMS) at 3 years, only 5% if MRI, OGB negative
8% of general pop has OCB - vasculitis (1mary, 2ndary), CNS infections, paraneoplastic disorders, CIDP etc.
What are features of CIS or FDE?
40% optic neuritis (85% have single symptom) 30% Transverse myelitis 20% Brainstem, cerebellum 10% - paroxysmal stiffness/limb spasm - bladder - cognitive - pseudo-radiculopathy/trigeminal neuralgia - episodic fatigue L'Hermitte's Uhtoff's phenomenin sexual dysfunction
What are features of relapsing remitting MS?
90% initially F:M 2-3:1 Benign disease in 25% Extremely aggressive in 5% (relapsing progressive) Relapses reduce after 1st 5 years
What are features of secondary progressive MS?
50-75% wtihin median of 15y
with relapses 1/3
w/o 2/3
What are features of primary progressive MS?
10% overall, 20% males
on average behaves exactly like SPMS
gradual but continous neruological decline
Progressive relapsing MS?
What progresses from CIS to CDMS?
Presence of OCB 1.7 RR for recurrent attack
In general - MRI normal 10-30% risk over 3-5y
If MRI abnormal 60-90% risk over 3-5 years.
In Radiologically isolated syndromes - 33% will develop Sx over 1-10y (med 5.4)
high risk of clinical Sx if spinal cord lesions are present
What are features of benign MS?
Dx can only be made in retrospect! Treat all pts the same
only 50% remain benign, 21% needed walking stick, 23% had SPMS.
Defn is weighted towards motor deficits - cognitive, psychological and social challenges still significant.
80% of untreated patients go on to further attacks, and 50% go on to SPMS and increased disability
What effect does interferons or glatiramer and teriflunomide have on CIS?
delays onset of CDMS by 45% at 2-3y
Reduced MRI activity
No effect on disability at 5 years
Reduced cerebral atrophy
What are the 4 principles of Dx MS?
1) Typical Sx and signs
2) Dissemination in space and time
3) MRI criteria can be used as substitute for clinical eps
4) Exclusion of alternative causes with paraclinical tests if needed
What is the dissemination in space criteria in McDonald 2010?
Clinical: symptoms/signs in >=2 functional systems of CNS
Radiological: lesions in >=2 regions of the CNS
- periventricular
- juxtacortical
- infratentorial
- spinal cord
- all lesions in symptomatic region excluded in brainstem and spinal cord lesions
What is the dissemination in time criteria in McDonald 2010?
Clinical: >=2 relapses at least 1 month apart
Radiological: a new lesion on follow-up MRI brain (irrespective of timing) OR simultaneous non-enhancing AND contrast enhancing lesion
What are the Dx criteria for primary progressive MS?
- 1y of disease progression (retro/prosp determined)
- plus 2/3 of the following criteria:
a) evidence of DIS in the brain based on >=1 T2 lesions in at least one area characteristic of MS (periventricular, juxtacortical or infratentorial)
b) evidence of DIS in the spinal cord based on >=2 T2 lesions in the cord
c) positive CSF for oligoclonal bands/Inc IgG index)
What conditions must be excluded pre Dx of MS?
- other 1mary demyelinating diseases of the CNS - Devic’s disease or NMO, ADEM or acute disseminated encephalomyelitis
- secondary demyelinating conditions - SLE, Sjogren’s PAN, Bechet’s, sarcoid
- infections - mycoplasma, EBV, CMV, HIV, HTLV, Rickettsia, Lyme disease
- Tumours
- Psychiatric disorders - conversion disorder, somatisation
What are features of Devic’s Disease?
1% of all MS, 50% in eastern asia Relapsing remitting involvement of optic nerves and or spinal cord Long cord lesions >3 segments without brain lesions on MRI without OCB usually sequential (can be simult) Monophasic in 1/3, relapsin in 2/4 Sp and Sn Ab in anti-Aquaporin 4 Intractable vomiting, hicoughs and narcolepsy can be presenting features
What are features of Anti-Aquaporin antibodies?
aka anti-NMO IgG
Sn and Sp 88 and 83% for Devics vs MS
less Sn with Devics from partial devic’s
12-15% have seronegative NMO - can be +ve for anti-MOG Ab
Directed against AQP4 - spinal cord grey matter, periaqueductal and periventricular regions, astrocytic foot processes, renal medulla, gastric parietal cells, area postrema - vomiting centre
What are features of Acute Disseminated Encephalomyelitis?
AKA post infectious encephalomyelitis
infectious prodrome 1-4 weeks pre
- EBV, mycoplasma pneumonia, strep pyogenes, CMV, Rickettsia, HIV, varicella, corona virus
- encephalopathy with behavioural changes, irritability, confusion, lethargy, drowsiness
- multifocal polysymptomatic neuro deficit
- low grade fevers, seizures, headache common
- most recover completely
What are other MRI features of MS?
Cerebral atrophy - large ventricles, loss of cortex, visible sulci
T1 hypointense lesions or Blackholes - permanent axonal loss, correlates with disability in MS
Loss of GM and WM in MS, GM loss correlates with EDSS
What is PML?
caused by JC virus - polyoma virus
assoc with AIDS in the past, or lymphoproliferative dz
now assoc with natalizumab, rituximab, alemtuzumab and MMF, MTX, AZA