Neurology Flashcards
What proportion of the patients achieve seizure free remission with treatment at 5 years?
Around 75%
What is the chance of second seizure within 2 years of the first seizure?
50%
Generally recurrence occurs in first 6 months
What 3 symptoms are most likely to improve with deep brain stimulation in parkinsons disease?
- Levodopa responsive symptoms 2. On off fluctuations 3. Dyskinesia
Does normal lower limb reflexes exclude the differential diagnosis being Guillain Barre syndrome?
No. Normal reflexes can occur upto 10%
What is MELAS syndrome?
Progressive neurodegenerative disorder characterized by mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke syndrome. Patients present with myopathy with weakness, easy fatigability and exercise intolerance. Other features include seizures, DM, hearing loss, cardiac disease, short stature, endocrinopathies and neuropsychiatric dysfunction. Lactic acidosis is an important feature with high lactate:pyruvate ratio. Skeletal biopsy is required to confirm the diagnosis of MELAS.
Why is intravenous pyridostigmine in a patient with myasthenic crisis controversial?
Can cause coronary vasospasm leading to MI Also large doses of anti-cholinesterase can promote excessive salivary and gastric secretion leading to risk of aspiration pneumonia
Management of myasthenic crisis?
Either urgent plasmapheresis or IVIG (equivalent) Respiratory support Methylprednisone or therapeutic doses of prednisone at 1mg/kg
Pharmacological and non-pharmacological treatment for restless leg syndrome?
Dopamine agonist (pramipexole, ropinirole) Avoidance of alcohol, caffeine, smoking, good sleep hyegiene, moderate regular exercise, hot baths, or leg massage before bedtime.
Match the following genes to diseases: C9ORF72 FXN NOTCH3 PMP22 ATXN1
C9ORF72 - Motor neuron disease FXN - Friedrich’s ataxia NOTCH3 - CADASIL PMP22 - CMT1A ATXN1 - Spinocerebellar ataxia 1
Difference between oligodendrocytes and schwann cells
Oligodendrocytes are peripherally located, wraps around multiple axons Schwann cells are located in CNS, wraps around single axon only
Causes of transverse myelitis
Most commonly infectious (40%) - CMV, EBV, mycoplasma, HTLV, HIV. Infectious not often found. 20-30% MS associated Upto 60% can be idiopathic
Describe symptoms and signs of optic neuritis
Acute/subacute unilateral eye pain on movement followed by variable degree of visual loss, especially central scotoma. May have colour desaturation. Rarely progressive after 2 weeks. Signs may include RAPD (Marcus Gunn pupil), usually normal fundi on exam.
What is the significance of optic neuritis?
Predicts progression to MS. Predicted by baseline MRI findings: If no lesions - risk 25% at 15 years if >3 lesions - 78% risk at 15 years. Hence MRI is the most useful diagnostic tool.
What is the role of CSF examination in MS?
Adds prognostic value.
In CIS, risk of CDMS is 25% at 3 years if OCB positive
If normal MRI and OCB negative, risk of MS 5% only.
90% of CDMS have positive OCB.
Define Uhtoff’s phenomenon
Reversible, stereotypic decremenet in physical and cognitive speed due to increased ambient body temperature and exercise. Nerve conduction slowing with conduction block due to small increases in core temperature.
4 types of CDMS subtypes
- Relapse remitting MS - 90%
- Secondary progressive MS - Progresses from RRMS to SPMS 50-75% within 15 years. With relapses in 1/3, without relapses in 2/3.
- Primary progressive MS - affects 20% of males, gradual but continuous slow neurological deterioration
- Progressive relapsing MS - <5%, gradual but continuous neuro deterioration with superimposed relpases
Common areas for MS lesions to occur in MRI brain
- Periventricular
- Juxtacortical
- Infratentorial
- Spinal cord
Describe Neuromyelitis optica (Devic’s disease)
Relapsing and remitting involvement of optic nerves and/or spinal cord.
May present with intractable vomiting, hiccups due to involvement of area postrema and narcolepsy.
Long cord lesions on MRI (>3 vertebral segments) without brain lesions on MRI (50-80% will be normal) and also without OCB on CSF.
Anti-Aquaporin 4 (anti-NMO IgG) or anti-MOG antibodies are specific and sensitive
Describe appearance of MRI lesions of MS
Well circumscribed
Rounded or ovoid in appearance
Typically few mm in size to 1cm
Appears hypointense on T1 and hyperintense T2 weighted MRI
How do you treat PML?
Stop immunosuppressants immediately.
Plasma exchange - however may cause severe IRIS with cerebral oeema and clinical deterioration. Therefore need to give IV methylpred high dose at the end of PLEX.
Environmental causes of MS
- Smoking - first modifiable risk factor which can delay the onset of SPMS
- EBV
- Insufficient Vit D intake
5 poor prognostic factors for MS
- Male
- Older age of onset - less brain plasticity
- Higher attack rates in first 5 years
- Poor relapse recovery
- Short inter-relapse interval.
What are the favourable factors in MS?
- Younger age at onset (more brain plasticity)
- Optic neuritis as the presenting symptom
How does glatiramer work?
Synthetic polypeptide containing myelin basic protein (MBP) - may promote proliferation of Th2 cytokines.
Used as an injection daily - associated with injection site reaction.
Safest in pregnancy




