Neuro Flashcards
Multiple sclerosis, myasthenia, TIA, guillain barre, epilepsy, stroke, charcot marie tooth, parkinsons,, myopathies, peripheral neuopathies
What is multiple sclerosis, dx. and how does it usually present
autoimmune disease causing demyelination of nerves - often has relapsing and remitting disease leading to progressive MS caused by incomplete healing of demyelination
- needs two discrete time and space attacks to diagnose (or 1 acute episode + MRI evidence of other one)
Presents
Neurological deficit >1 hour, more than 30 day between attacks. Usually one deficit
eg. weakness or paresthesia in limbs
- optic neuritis (pain on movement + reduced acuity)
- ataxia, dysarthria/ tremor
- urinary urgency/faecal incontinence
- CN symptoms, vertigo, dementia, seizures
+ depression,
Risk factors for MS + flare. Exam features
Family hx, caucasian, F>M, 20-40 yo, HLA DRB1, living far from equator
Risk for flare
- heat, infection/fever, exercise, post partum relapse
Exam - unilateral signs
- UMN weakness - spastic
- sensory loss of fine touch/vibration/proprioception (posterior column)
- cerebellar signs- nystagmus/ slurred speech/impaired coordination/dysmetria/dysdiadochokinesia
-cranial nerves: decreased VA, central scotoma, inter-nuclear opthalmoplegia
DDx for MS + investigations
DDx
- sarcoidosis
- small vessel ischaemia/multiple emboli/stroke/
- spinal cord compression in trauma/RA,
- spinal tumour,
- optic neuritis could be neuromyelitis optica
Ix
Renal function for drugs
-MRI head + spine +/- gadolinium, T1 T2 looking for demyelinated sites
- -high signal T2 lesions
periventricular plaques, dawson fingers
- evoked response testing - visual delayed because of demyelination but well preserved waveform
- somatosensory, auditory
- LP for CSF
- oligoclonal IgG bands = CNS inflammation - worse prognosis
- myelin basic protein - acute demylinaton
- WCC>100ml/L severe demyelination
- increased intrathecal synthesis of IgG (serum vs CSF IgG and albumin ratio
-ANA
Treatment of MS - pharm and non pharm - acute relapse, bladder spasticity, bladder dysfunction, facial spasm, tremor
- MDT (OT, physio), support groups
- Bed rest with nursing during relapses
- Splint if foot drop
- Bowel and bladder self catheterization
Regular exercise, stopping smoking and avoiding stress
Pharm
- Acute relapse/Flare treated with high dose prednisone or IV methyprednisolone if severe - doesn’t alter progress
- Iv interferons and monoclonal antibodies eg. Natalizumab, ocralizumab - reduce relapse frequency
- Or plasma exchange to get rid of other antibodies
- Other immunosuppressives - dimethyl fumarate (modulator), methotrexate, azathioprine
Symptomatic
Severe spasticity - baclofen (muscle relaxant)
Bladder dysfunction/spasm - oxybutynin (antciholin) + amitriptyline
Facial spasm - carbamazepine
Tremor - clonazepam or propanolol
what are the symptoms & past medical history to ask on history for myasthenia gravis
Symptoms
o Ocular – diplopia, drooping eyelids
o Bulbar – difficulty chewing and
swallowing, choking, dysarthria
o Limb girdle – proximal muscle
weakness, fatigue on exertion
- Weakness worsened by pregnancy, exercise, infection, change in climate, emotion, over treatment, drugs such as gentamicin, tetracycline, beta blockers.
- Past medical history
o Difficult anaesthesia (prolonged
muscle weakness after anaesthesia)
o Pneumonia
o Thymectomy
o Other auto-immune diseases – SLE,
rheumatoid arthritis - How much anticholinesterase required?
- Any admissions to hospital with myasthenic crisis? (resp distress)
what are the specific signs and investigations of myasthenia gravis on exam / ix
EXAMINATION
- Observation
o Ptosis
o Peek sign
o Smile – snarling expression
- Muscle fatigue
o Sustained upward gaze
o Counting aloud
o Hold arms above head - Weakness of neck flexion
- Thymectomy scar
- Reflexes intact, no sensory loss, muscle atrophy minimal
- diplopia
INVESTIGATIONS
- Antibodies
o Acetylcholine receptor antibodies
(anti-AChR) in 90%
o If seronegative, look for muscle specific kinase antibodies (MuSK)
- Neurophysiology
o Electromyogram – repetitive
stimulation at low frequencies with
decremental muscle response
o Single fibre EMG – increased jitter
and blocking - Thymoma investigation
o Chest X-ray
o Thoracic CT or MRI - Respiratory function tests
- Look for associated conditions
o TFT’s, RF, ANA
what is the symptomatic,relapse and disease suppression treatment of myasthenia gravis + SE of those treatments
Symptomatic
- Anticholinesterase
o E.g. Pyridostigmine 60-120mg PO
up to 6x daily
o SE: increased salivation, lacrimation,
vomiting, diarrhea
- Avoid drugs that impair NM transmission like gentamicin, procainamide
- Sudden worsening of respiratory symptoms can be life threatening and treated with mechanical ventilation and plasmapheresis.
Often precipitated by infection, so treat aggressively (not with aminoglycosides)
Disease Suppression
- Relapses treated with prednisolone. Often needed long term once anticholinesterases are inadequate.
- steroid SE- Give osteoporosis prophylaxis.
If failed steroids - immunosuppression
o Azathioprine
Methotrexate
o Rituximab in desperate cases
Thymectomy (because MG associated with
thymomas)
o If symptoms < 50 yrs, and ACH-antibody positive
What are the differential dx (proximal muscle weakness) and epidemiological features of myasthenia gravis
DDX
- Lambert-Eaton syndrome.Pre-synaptic
failure of release of acetylcholine caused by
Small CC of lung. Muscle weakness improves
on use.
- Polymyositis
- Acquired myopathy (hyperthyroid, SLE,
Cushing’s)
Epidemiological features of M Gravis
- LMN by autoabs to nicotinic aCH receptors - muscular weakness which worsens with use
- F (30s) > M70s
- extra ocular, bulbar, face, neck, limb girdle, trunk
TIA (deficit <24 hrs) causes - differentials -history
CAUSES
- Atherothromboembolism
o Most common
- Cardioembolism
o Mural thrombus post MI, AF, valve disease, prosthetic valves
- Hyperviscosity
o Polycythemia, elevated WCC, myeloma
DDx
- Hypoglycaemia
- Migraine aura
- Focal epileptic seizure
- Syncope and hypotension
- Hyperventilation
- Vertigo +/- secondary nausea and ataxia
- MS
- Somatization
HISTORY + EXAM FINDINGS
- As per stroke territories
- Global events such as syncope and dizziness
are not typical of TIA
- Amaurosis fugax (progressive loss of vision
in one eye “like a curtain descending”
-
exam and ix for TIA + stroke risk after TIA score
Exam: cardio / resp
Listen for carotid bruit, measure BP, listen
for murmurs, AF
Ix
Bloods
- FBC, ESR, U+E’s glucose, lipids
Imaging
- CXR
- Carotid USS +/- angiography
- CT or diffusion weighted MRI head
- Echo – foramen ovale or other holes?
- ECG - AF
STROKE risk after TIA (score 6-7 - observation in stroke clinic)
A – Age ≥ 60 (1)
B – Blood pressure ≥ 140/90 (1)
C – Clinical Features
Unilateral weakness (2)
Speech disturbance w/o weakness (1)
D – Duration of Symptoms
Lasting ≥ 1 hour (2)
Lasting 10 – 59 minutes (1)
D – Diabetes (1)
Management - non pharm, pharm and invasive for TIA
MANAGEMENT
Non-Pharmacological
- Diet, exercise
- Smoking cessation
- Avoid driving for 1/12
Pharmacological
- Control CV risk factors
o Cautiously lower blood pressure – target 140/85mmhg
o Statins
o Control DM
o Smoking cessation
- Antiplatelet
o Aspirin 300mg daily or Clopidogrel 75mg daily - Anticoagulation
o If cardiac emboli (e.g. from AF or mitral stenosis)
Invasive
- Consider carotid endarterectomy if > 70%
stenosed and operative risk is good.
Operating on 50 – 70% stenosis has some
value if operative risk very low.
- Should be performed within 2 weeks of first
presentation.
- Do not use antiplatelets beforehand.
- Carotid stenting is a good alternative if not good for surgery
Guillain Barre
- presentation - neuro- pain/motor/sensory, resp, speech, face findings
acute inflam demyelinating polyneuropathy triggered by antecedent infection
Motor - progressive muscle weakness over days - lower before upper, proximal before distal.
Areflexia – absent knee/ankle, +/- plantars
- Paraesthesia in feet/hands (mild, before
weakness) - Autonomic dysfunction (sweating,
tachycardia, BP changes, arrhythmias - Pain: legs, back
- Resp: SOB-OE, resp muscle weakness
- Speech: facial & oropharyngeal weakness –
slurring - Face: facial droop, dysphagia
- Eyes: diplopia, extra-occular weakness, ptosis
Ix for guillain barre
INVESTIGATIONS
Nerve conduction studies:
- Slowing of velocities
LP:
- Raised CSF protein (>5.5g/L)
Bloods:
- Raised AST & ALT, slight bili rise
- Anti-ganglioside Ab; helps differentiate subtype (unknown in AIDP)
- Serology Campylobactor, CMV, EBV, Mycoplasma
Spirometry:
- 6hr intervals at bedside
- may show decreased Vc, maximal inspiratory P or expiratory P.
Imaging:
- MRI to rule out spinal cord pathology
diagnostic criteria for guillain barre and management - treatment and supportive
CRITERIA
1. Progressive muscle weakness in limbs
2. Areflexia (hypo-)
3. +/- Progressive over 2-4wks, symmetry,
mild sensory change, CN involved.
Recovery begins 2-4wks after plateau. Autonomic
changes, no fevers, CSF/EMG findings.
MANAGEMENT
Treatment:
- IV Ig 0.4g/kg/24hrs for 5 days (CI: IgA def, renal failure)
- Plasma exchange
Supportive:
- Ventilate (bulbar/bilateral CNVII palsy, dysautonomia) if resp involvement
- DVT prophylaxis
- Monitor vitals
- Analgesia: neuropathic type
- Physio input
guillian barre Monitoring, prognosis and complications
MONITORING
Progression over 2wks, plateau 2-4wks, then
recovery
F/U within 2/52 of acute phase, then 4-6wks for
6months, then at 6 months, then 1yr.
PROGNOSIS
85% good recovery. 20% mortality if ventilated.
Poorer outcomes if older age, severe Sx, rapid onset,
atrophy, need for ventilation, high antibody titre
COMPLICATIONS
Fatigue
Resp Failure (30%)
Bladder areflexia
Adynamic ileus
Paralysis 15% - strengthening exercises in acute rehab
DVT risk – 2 to immobilization
epilepsy - different types of seizures
Focal onset
- With or without awareness
- Motor or non-motor
- Focal to bilateral tonic-clonic
Generalized onset
- Always impaired awareness
- Motor
o Tonic-Clonic Seizures (LOC, limbs stiffen (tonic) then jerk (clonic). )
o Myoclonic Seizures (Sudden jerk of limb, face or trunk)
o Atonic Seizures (Sudden loss of muscle tone, no LOC)
- Non-motor
o Absence Seizures (Brief pauses ≤10s, carries on where left off) - Unknown onset
What are the 4 categories of differentials causes for epilepsy with examples
- Idiopathic (2/3 is familial)
- Structural : Cortical scarring (post head injury)
- Space occupying lesion
- Stroke - Systemic : SLE, Sarcoidosis, Poly arteritis nodosa
- Non-epileptic causes
- Trauma, haemorrhage, increased ICP
- alcohol, benzo
- metabolic disturbance + fever
-liver disease
-infection of brain
-drugs (TCA , cocaine, tramadol)
-pseudo seizures
history and exam of epilepsy
HX
- Details of seizure (ideally from eyewitness)
o Length of time, what it looked like, LOC, tongue biting, incontinence
- Ask about prodrome (change to mood or
behavior hours to days before seizure)
and aura (a partial focal seizure) - Post ictal period (headache, confusion,
myalgia, lethargy),
Todd’s paresis= focal
weakness after seizure - Triggers such as flickering lights, alcohol, TV
- Provocation (as per non epileptic causes)
- First episode? Previous funny turns or odd
behavior? - Family history
- Recent drug or alcohol use, lack of sleep=triggers
Exam focus/ findings for epilepsy and diagnosis of epilepsy
EXAMINATION
- Seek any clinical evidence of a focal brain lesion
- Exclude non-neurological causes
- Pay attention to signs of traumatic injury
- Check tongue
DIAGNOSIS
- Clinical diagnosis
- Positive findings on EEG (spikes) can help but cannot refute
- Make sure is truly a seizure
- Highly likely if:
o no provocation
o absence of syncopal prodrome
o Post-ictal drowsiness +/- confusion
Ix for seizure and Differentials for transient LOC
DIFFERENTIAL DIAGNOSIS FOR TRANSIENT LOC
- Syncope
o Reflex – vasovagal (stress, temp, pain) or carotid sinus. Reflex vasodilation or
bradycardia.
o Orthostatic – failure of homeostatic maintenance of BP on postural change,
dehydration, antihypertensives,
autonomic failure e.g. Parkinson’s
o Arrhythmia – transient compromise of cardiac output “Stokes-Adams attack”
o Cardiac - structural heart disease especially LV outflow obstruction, MI,
PE, AS
- Hypoglycaemia
INVESTIGATIONS
- FBC, glucose, electrolytes, Ca, Mg, Creatinine, LFTs
- Urine toxicology screen
- CXR
- Consider LP
- CT head esp. if fever, focal neuro signs, slow recovery
- EEG/MRI in selected patients, usually as an OP
Non pharm + pharm management of seizures - generalised - atonic/myoclonic/tonic vs partial
MANAGEMENT
Non-Pharmacological
- Avoid triggers
- Avoid driving until seizure free for 1 year
(this can be reduced if a clear and nonrecurring cause is found)
- Counselling regarding swimming, heights,
heavy machinery
- Enlist help of epilepsy nurse specialist
- If first seizure, refer to first seizure clinic
Pharmacological
- Do not start treatment after 1st seizure unless
structural brain lesion, focal neurological deficit, or unequivocal epileptiform EEG
- Neurologist to commence drug therapy after 2nd seizure
- If only 1-2 seizures a year and no need of driving, then they may want to take no meds
- (start low, go slow)
- Generalised (tonic clonic, myoclonic, absence, atonic)
1.Sodium Valproate (first line)
o Lamotrigine (second line)
o Can also consider levetiracetam,
carbamazepine, topiramate,
oxycarbazepine
o AVOID carbamazepine and
oxycarbazepine in tonic, atonic and
myoclonic seizures
- Partial +/- secondary generalization
o Carbamazepine (first line) - If pregnant or breastfeeding:
o Lamotrigine
Invasive
- Neurosurgical resection if clear
epileptogenic focus and refractory to
medication
monitoring/ side effects with anticonvulsants - sodium valproate, lamotrigine, carbamazepine, phenytoin, levetiracetam, topiramate
- SV - highest teratogenecity, pancreatitis, hepatic failure,
- interact with other anticonvulsants, tca, warfarin, aspirin - carbamazepine - worsen absence, myoclonic seizures - allergic rash, hyponatremia (<125 bad), hepatotoxicity . Ok in pregnancy
- toxicity risk w azoles, macrolide, ssri,
- reduces e2, warfarin, Ca2+ blockers, statins - lamotrigine - safe in pregnancy <200mg. SE - allergic rash with increased dose - affected by other anticonvulsant (increased
- phenytoin - worsen absence, myoclonic allergic rash, hirsuitism, hepatotoxicity - induces enzyme - E2, P2 ,warfarin, TCA, CCB, -
- therapeutic drug monitoring - Topiramate - adjunctive therapy ataxia, weight loss, acute angle glaucoma, kidney stone, cognitive impairment
- affect digoxin and cocp increase -
What are the presentation and risk factors for stroke - ischaemic and haemorrhagic
Presentation
Ischaemic 85%
- Large artery atherosclerosis + thrombosis
- Cardioembolic
- Lacunar thrombus in situ
Haemorrhagic
-Hypertension
-Coagulopathy APLS
-AV malformation
-Berry aneurysm
Risk factors
- For Ischaemic: carotid bruit, AF , past TIA, IHD
- For Haemorrhagic: meningism, severe headache and coma within hours
- General risk factors – smoking, HTN, T2DM, lipids
What are the investigations and when do you do them/ what is acute management of stroke - timing aims, inclusion/ exclusion criteria
Acute event
1. Protect airway ABCD
2. Call code stroke
3. Stroke symptoms <24 hours ago - Order CT head non contrast
- parenchymal or subarachnoid haemorrhage ?- yes then CTA circle of willis,
- No - CTA carotids + circle of willis + perfusion
4. Bloods – FBC, U&E, glucose, coags, trops.
Thrombophilia screen in <50yo
5. ECG + obs / neuro monitoring
Acute ischaemic
- aim thrombolysis within 45 minutes of arrival (max 4.5 hrs post event)
– if previously independent.’
- Exclusion – if bleeding on CT, BP >185/110, recent stroke, MI, surgery or trauma within 30 days
—Alteplase 0.9mg/kg max 90 mg. 10% over 1 minute, 90% in 60minute infusion
- Manage SBP 150-170 during infusion/ for first 24hrs –eg. Labetalol, GTN, hydralazine
OR transfer for thrombectomy within 90 min of hospital arrival (max 6 hrs post event for AC, 24hrs PC)
- If independent mobility ADLS prior to stroke, no haemorrhage evidence of clot
- Discuss with OCNeuroSMO
Acute Haemorrhagic
- Stop antithrombotic
Reverse anticoagulation –call haem
Neurosurgical referral
