Multiple sclerosis Flashcards
Definition of multiple sclerosis
A chronic inflammatory condition of the CNS characterised by multiple plaques of demyelination disseminated in time and space.
Epidemiology of multiple sclerosis
Lifetime risk: 1/1000.
Mean age of onset = 30 years.
Sex F>M = 3:1.
Race: more common in caucasians.
Associations of multiple sclerosis
Genetic: HLA-DRB1
Viral (EBV). Minor viral infections often precede relapses.
Pathophysiology of multiple sclerosis
CD4 cell-mediated destruction of oligodendrocytes leading to demyelination and eventual neuronal death. Initial viral inflammation primes humeral antibody responses versus myelin basic protein (MBP). Hallmark plaques of demyelination.
Classification of multiple sclerosis
- Relapsing-remitting: 80%. Symptoms come and go with periods of good health.
- Secondary progressive: follows relapsing-remitting (gradually more or worse symptoms with fewer remissions)
- Primary progressive (10%) - symptoms gradually worsen with no remission.
Rate of progression of multiple sclerosis
About 50% of those with relapsing-remitting MS develop secondary progressive MS during the first ten years of their illness
Presentation of multiple sclerosis
TEAM Tingling Eye: optic neuritis (reduced central vision + pain on eye movement) Ataxia & other cerebellar signs Motor: usually spastic paraparesis
Clinical features of multiple sclerosis
Sensory: dys/paraesthesia, reduced vibration sense, trigeminal neuralgia
Motor: spastic weakness, tranverse myelitis
Eye: dyplopia, visual phenomena, bilateral INO, optic neuritis then atrophy.
Cerebellum: trunk and limb ataxia, scanning dysarthria, falls.
GI: swallowing disorders, constipation.
Sexual/GU: Erectile dysfunction + anorgasmia, retention, incontinence.
Lhermitte’s sign.
What is Lhermitte’s sign
Neck flexion causes electric shock sensation in trunk/limbs. Sign suggests lesion or compression of upper cervical cord or brainstem, classically MS.
Describe optic neuritis
Presenting complaint is pain on eye movement, and rapid decrease in central vision.
Uhthoff’s phenomenon: vision worse with heat e.g. hot bath.
On examination: reduced acuity, reduced colour vision, white disc, central scotoma, RAPD.
What is Uhthoff’s phenomenon
The worsening of neurological symptoms in MS and other demyelinating conditions.
Describe internuclear ophthalmoplegia
Disruption of MLF (medial longitudinal fasciculus) connecting CN6 to CN3.
Weak adduction of ipsilateral eye + nystagmus of contralateral eye. Convergence preserved.
Investigations for multiple sclerosis
MRI: Gadolinium-enhancing or T2 hyper-intense plaques. Gd-enhancement = active inflammation. Typically located in periventricular white matter.
Lumbar puncture: IgG oligoclonal bands (not present in serum).
Antibodies: anti-MBP, NMO-IgG (highly specific for Devic’s syndrome).
Evoked potentials: delayed auditory, visual and sensory.
Diagnostic criteria for multiple sclerosis
Diagnosis is clinical, by demonstration of lesions disseminated in time and space
May use McDonald criteria
Differential Dx for multiple sclerosis
Inflammatory conditions that may mimic multiple sclerosis plaques:
CNS sarcoidosis
SLE
Devic’s (neuromyelitis optica NMO): MS variant with transverse myelitis and optic atrophy, distinguished by presence of NMO-IgG antibodies
General features of management for multiple sclerosis
Good communication + providing written information
Inform the patient of their legal obligation to inform the DVLA
Encourage autonomy
Support family/carers
Close communication between members of MDT
Medical management of multiple sclerosis relapses
Any episode of sudden increase (=12-24h) of distressing symptoms or activity limitation.
Exclude UTI before starting steroids.
Methylprednisolone IV or PO 500mg/day for 5 days (warn of SE of metallic taste).
Avoid giving steroids >3 times a year or >3 weeks in one go, no tapering needed. Gastric protection with omeprazole 20mg QD or ranitidine 150mg QD.
Disease-modifying therapy in multiple sclerosis
Interferon beta licensed for relapsing-remitting MS in patients who can walk 100m. Most common SE is flu-like episode 24h after dose, but easy to control with ibuprofen.
Glatiramer: daily subcutaneous injection.
Injection site reactions for IFN beta and glatiramer, but decrease with longer use.
Also: Dimethyl fumarate (oral, daily), teriflunomide, alemtuzumab.
Natalizumab (but 1 in 600 PML), fingolimod, mitoxantrone (risk of systolic dysfunction and leukaemias).
Precautions in women taking disease-modyfing therapy for multiple sclerosis
Avoid any disease-modifying drugs for 12 months before conception
Medical treatment of pain in multiple sclerosis
Can be neuropathic or muskuloskeletal in origin (d/t reduced mobility).
Analgesia, then TENS if analgesia not sufficient.
CBT may help.
Neuropathic pain - anticonvulsants e.g. carbamazepine or gabapentin, or antidepressants e.g. amitriptyline.
Treatment of spasticity in multiple sclerosis
Passive stretching.
First line: gabapentin, baclofen
Second line: dantrolene, botulinum injections
Treatment of urological complications in multiple sclerosis
Offer condom catheter for men or pad for women, or intermittent self-catheterisation if high residual volume.
Anticholinergics (oxybutinin, tolterodine).
Desmopressin for night problems or daytime frequency but never more than once in 24h.
Factors for poor prognosis in multiple sclerosis
Older female
Motor signs at onset
Many relapses early on
Many lesions on MRI
