Corrections - Neurology Flashcards
Where do the pontine arteries radiate from?
What do they supply?
From the basilar artery on the brainstem.
They supply the pons.
Presentation of a pontine haemorrhage?
1) Pinpoint pupils: thought to be caused by irritation and stimulation of parasympathetic pathways in the pons
2) Paralysis: due to motor tracts in the pons that descend to supply the limbs
3) Low GCS
What structures are within the lateral medulla?
How does this explain features of a posterior inferior cerebellar artery lesion (i.e. lateral medullary syndrome)?
1) sympathetic tract: hence ipsilateral Horner’s syndrome
2) inferior cerebellar peduncle (connects medulla to cerebrum): ipsilateral ataxia
3) part of the trigeminal nerve nucleus: ipsilateral facial numbness
4) spinothalamic tract: contralateral body numbness
5) nucleus ambiguus (which gives rise to some vagus nerve and glossopharyngeal motor fibres): dysphonia and dysphagia
What should all TIA patients have?
an urgent carotid doppler unless they are not a candidate for carotid endarterectomy
What can be taken for 2ary prevention of stroke if clopidogrel is contraindicated?
Aspirin + dipyridamole
Role of dipyridamole in 2ary prevention of stroke?
Dipyridamole works synergistically with aspirin by inhibiting platelet activation and adhesion, as well as having vasodilatory effects.
How long should aspirin + dipyridamole be continued in 2ary prevention of ischaemic stroke?
lifelong
Causes of a brain abscess?
1) ascending infection from middle ear or from facial sinuses
2) trauma or surgery to the scalp
3) penetrating head injuries
4) embolic events from endocarditis
Presentation of brain abscess?
1) headache: often dull, persistent
2) fever: may be absent and usually NOT the swinging pyrexia seen with abscesses at other sites
3) focus neurology e.g. oculomotor nerve palsy or abducens nerve palsy 2ary to raised intracranial pressure
4) other features consistent with raised intracranial pressure e.g. nause, papilloedema, seizures
Management of brain abscess?
1) surgery: craniotomy
2) IV antibiotics: IV 3rd-generation cephalosporin + metronidazole
3) intracranial pressure management: e.g. dexamethasone
What can rapid correction of hyponatraemia cause?
Osmotic demyelination syndrome (central pontine myelinolysis)
Symptoms of osmotic demyelination syndrome?
How soon after correction of hyponatraemia do they occur?
Typically after 2 days.
Symptoms: dysarthria, dysphagia, paraparesis or quadriparesis, seizures, locked in syndrome, confusion, and coma.
These are usually IRREVERSIBLE.
Acute vs chronic management of migraine?
Acute: triptan + NSAID/paracetamol
Chronic: propanolol or topiramate
Features of a medication overuse headache?
- present for 15 days or more per month
- developed or worsened whilst taking regular symptomatic medication
- patients using opioids and triptans are at most risk
- may be psychiatric co-morbidity
Management of medication overuse headache?
simple analgesics and triptans should be withdrawn abruptly (may initially worsen headaches)
opioid analgesics should be gradually withdrawn
What 2 classes of drugs are at most risk of causing medication overuse headache?
triptans & opioids
What class of drug is metoclopramide?
Dopamine antagonist: blocking dopamine receptors in the chemoreceptor trigger zone of the CNS.
This can decrease N&V but increase EPSEs.
What is a Valsalva maneuver?
Performed by a forceful attempt of exhalation against a closed airway, usually done by closing one’s mouth and pinching one’s nose shut while expelling air out as if blowing up a balloon.
What do headaches that are worsened by alsalva manoeuvres associated with?
Raised ICP until proven otherwise
Most common side effect of lumbar puncture?
Post-lumbar puncture headache (1/3 patients)
UKMEC 4 conditions for COCP?
1) more than 35 years old and smoking more than 15 cigarettes/day
2) migraine with aura
3) history of stroke or ischaemic heart disease
4) history of thromboembolic disease or thrombogenic mutation e.g. Factor V Leiden
5) breastfeeding <6 weeks postpartum
6) uncontrolled HTN
7) active breast cancer
8) major surgery with prolonged immobilisation
9) positive antiphospholipid antibodies (e.g. in SLE)
Most common side effects of sildenafil?
1) headache
2) visual disturbances: blue discolouration (The blue pill (viagra) causes blue discolouration of vision)
3) nasal congestion
4) flushing
5) GI side effects
6) priapsim
What is a prolactinoma?
Prolactinomas are a type of pituitary adenoma, a benign tumour of the pituitary gland.
Features of a prolactinoma?
- amenorrhoea
- galactorrhoea
- infertility
- osteoporosis
- loss of libido
- headache
- visual changes: bitemporal hemianopia (‘tunnel vision’)
What condition can give a falsely low HbA1c reading?
Sickle cell anaemia (and other haemoglobinopathies) due to decreased lifespan of RBCs.
Acute management of cluster headache?
High flow O2 and subcutaneous triptan
How should triptans be given in acute cluster headache?
SC
What is paroxysmal hemicrania (PH)?
Defined by attacks of severe, unilateral headache, usually in the orbital, supraorbital or temporal region.
Features:
- Often associated with autonomic features e.g. tearing, nasal congestion
- Usually last less than 30 minutes and can occur multiple times a day.
What is paroxysmal hemicrania (PH) completely responsive to?
indomethacin (NSAID)
Presenation of acute closed angle glaucoma?
1) Severe pain: may be ocular or headache
2) decreased visual acuity
3) symptoms worse with mydriasis (e.g. watching TV in a dark room)
4) hard, red-eye
5) haloes around lights
6) semi-dilated non-reacting pupil
What is acute closed angle glaucoma?
There is a rise in IOP secondary to an impairment of aqueous outflow.
Who are triptans contraindicated in?
Patients with coronary artery disease as they can cause coronary vasospasm.
What are the 3 options for migraine prophylaxis?
1) propanolol
2) topiramate
3) amitriptlyine
What is preferred for prophylaxis of migraines in women of childbearing age?
Propanolol
Can topiramate be used for the prophylaxis of migraines in women of reproductive age?
Why?
No
1) it may be teratogenic
2) it can reduce the effectiveness of hormonal contraceptives
Causes of Horner’s syndrome can be differentiated according to the LOCATION of anhidrosis.
Give some causes of Horner’s with anhidrosis of the face only
Caused by pre-ganglionic lesions:
1) Pancoast’s tumours
2) Thyroidectomy
3) Trauma
4) Cervical rib
Give some causes of Horner’s with anhidrosis of the face, arm and leg
Caused by central lesions:
1) Stroke
2) MS
3) Tumour
4) Encephalitis
5) Syringomyelia
Give some causes of Horner’s where there is NO anhidrosis
Caused by post-ganglionic lesions:
1) Carotid artery dissection
2) Carotid aneurysm
3) Cavernous sinus thrombosis
4) Cluster headache
Presentation of a carotid artery dissection?
1) Headache (60-75%): usually severe, unilateral, gradual onset
2) Partial Horner’s syndrome (58%): ptosis & miosis if a haematoma of the artery compresses sympathetic nerve fibres to the eye that run along the carotid sheath
3) Pulsatile tinnitus (27%)
4) Unilateral neck pain (25%)
5) Transient monocular blindness (25%)
6) Cranial nerve palsy (12%): most commonly cranial nerves IX to XII
If there is the present of sweating in Horner’s syndrome, where is the lesion?
Post-ganglionic
Give some differentials for facial pain
1) Trigeminal neuralgia: Severe lancinating facial pain along one or more branches of the trigeminal nerve.
2) Sinusitis: Facial pain accompanied by symptoms such as nasal discharge or congestion suggests sinusitis.
3) Dental problems: Dental caries or abscesses can cause localised facial pain.
4) Tension type headache: Band-like pressure around the forehead that can extend into facial regions.
5) Migraine: Unilateral throbbing head and face pain associated with nausea, vomiting or photophobia.
6) Giant cell arteritis: In older patients, new onset facial pain may be a sign of this condition, which can threaten vision.
What is chronic cough 2ary to in sinusitis?
Post-nasal drip
How is pain of cluster headaches often described?
Intense, sharp, stabbing pain around eye
Describe eye in cluster headache
- Redness, lacrimation & lid swelling
- Miosis and ptosis in a minority
Features of temporal arteritis?
- typically >60y
- usually rapid onset (e.g. < 1 month)
- headache (found in 85%)
- jaw claudication (65%)
- tender, palpable temporal artery
- around 50% have features of PMR: aching, morning stiffness in proximal limb muscles (not weakness)
- lethargy, depression, low-grade fever, anorexia, night sweats
What condition does temporal arteritis have an overlap with?
Polymyalgia rheumatica (50%)
Management of trigeminal neuralgia?
High-dose prednisolone as well as urgent referral for assessment by a specialist.
How can smoking affect carboxyhaemoglobin levels?
Smokers may normally have carboxyhaemoglobin levels of up to 10% (normal 0.5-2.5)
What is the most common complication following bacterial meningitis?
Sensorineural hearing loss
What is benign rolandic epilepsy?
a form of childhood epilepsy that typically occurs between the age of 4 and 12 years.
Features of benign rolandic epilepsy?
1) seizures characteristically occur at night
2) seizures are typically partial (e.g. paraesthesia affecting the face) but secondary generalisation may occur (i.e. parents may only report tonic-clonic movements)
3) the child is otherwise normal
When do seizures typically occur in benign rolandic epilepsy?
At night
What does an EEG characteristically show in benign rolandic epilepsy?
Centrotemporal spikes
Prognosis of benign rolandic epilepsy?
Excellent - seizures stopping by adolescence
Can cocaine toxicity cause seizures?
Yes
CVS effects of cocaine?
1) coronary artery spasm –> myocardial ischaemia/infarction
2) both tachycardia and bradycardia may occur
3) hypertension
4) QRS widening and QT prolongation
5) aortic dissection
When should parents call an ambulance in febrile convulsions?
Lasting >5 minutes
Person suddenly falls to the ground then lays motionless - what type of seizure?
Atonic
What are 2 important causes to rule out in status epilepticus?
1) hypoxia
2) hypoglycaemia
When is is juvenile myoclonic epilepsy (Janz syndrome) typically seen?
typical onset is in the teenage years, more common in girls
Features of juvenile myoclonic epilepsy?
1) infrequent generalized seizures, often in morning//following sleep deprivation
2) daytime absences
3) sudden, shock-like myoclonic seizure (these may develop before seizures)
When are genralised seizures often seen in juvenile myoclonic epilepsy?
often in morning//following sleep deprivation
Management of juvenile myoclonic epilepsy?
usually good response to sodium valproate
What is Chagas’ disease?
caused by the protozoan Trypanosoma cruzi.
What is the most frequent and most severe manifestation of chronic Chagas’ disease?
Cardiomyopathy
What is used to prevent seizures in patients with severe pre-eclampsia and treat seizures once they develop?
Magnesium sulphate
What do psychogenic non-epileptic seizures tend to mimic?
Generalised tonic-clonic seizures and generally last longer.
Patient has episodes of olfactory hallucinations while retaining consciousness throughout - what is most likely diagnosis?
Focal aware seizure
The following 2 groups of patients are at an increased risk of developing hepatotoxicity following a paracetamol overdose:
1) patients taking liver enzyme-inducing drugs (rifampicin, phenytoin, carbamazepine, chronic alcohol excess, St John’s Wort)
2) malnourished patients (e.g. anorexia nervosa) or patients who have not eaten for a few days
Describe effect of alcohol on liver in paracetamol overdose
Interestingly, acute alcohol intake, as opposed to chronic alcohol excess, is not associated with an increased risk of developing hepatotoxicity and may actually be protective.