Neuro stuff you forget Flashcards
Describe the visual field defect you get in ischaemic stroke
Contralateral homonymous hemianopia with macula sparing
The damage would be on same side but area of vision lost is flipped. It more points to PCA but can happen w/ MCA or ACA.
Describe S/S of posterior inferior cerebellar artery stroke
Lateral medullary syndrome because the PICA supplies the lateral medulla. It presents with:
- Ipsilateral Horner’s, Cerebellar signs, loss of facial spinothalamic sensation (pain, temperature)
- Contralateral - loss of spinothalamic sensation (ipsilateral on face)
What is presentation of upper brainstem and lower brainstem infarction
Upper - locked-in syndrome
Lower - pseudobulbar palsy
Describe Weber’s syndrome
A midbrain stroke in branches of the posterior cerebral artery (PCA) that supply the midbrain. Presents with:
- Ipsilateral palsy of CN3 (dilated pupil - mydriasis, as loss of CN3 PSNS) and down/out
- Contralateral hemiparesis - decussation of UMNs occurs below the lesion (midbrain > pons > medulla where they decussate)
When is endarterectomy indicated?
> 70% stenosed (ECST) or NASCET trial said >50%.
NB this is done via MRA/CTA after carotid doppler done.
Describe acute Mx of ischaemic stroke and the windows
Emergency CT and other Ix.
- Aspirin 300mg after CT if cannot do thrombolysis. Given daily (In AF anticoagulants/warfarin should not be started until 14 days after stroke)
- Thrombolysis if can be given <4.5hrs of symptom onset but lots of CI (cannot be bleeding anywhere). Hold off aspirin and give 24hrs later
- Endovascular/mechanical thrombectomy, criteria are:
- Large clots in large anterior vessels (widespread sx)
- <6hrs of Sx onset (if <4.5 can do this + thrombolysis)
- Pt reasonably functioning/not too frail
Supportive care for stroke
Admit to stroke unit
Assess swallow to prevent aspiration pneumonia (NG PEG?)
Prevent DVT via IPCDs (not stockings or heparin - haemorrhage)
Cannot drive for 1m after stroke
Describe stroke primary and secondary prevention
Primary - lifestyle: exercise, reduce alcohol/smoking weight loss, control conditions (DM, HTN, cholesterol)
Secondary:
- Dual antiplatelet therapy, usually aspirin 300mg for 2 weeks then switch to clopidogrel or aspirin + dipyridamole
- Statins for high cholesterol
- Control HTN 2 weeks later (not in acute phase), same with anticoagulants if CHADS-VASc AF indicates
What is malignant MCA syndrome and how is it treated?
Space occupying cerebral oedema following MCA stroke causing rapid neurological deterioration.
Requires mannitol and surgical decompression
What is definition of TIA? Mx?
Transient episode of neurological dysfunction caused by ischaemia without acute infarction
Same as stroke - aspirin 300mg. Control HTN long term
Bamford classification criteria for total anterior circulation stroke (TACS)
All 3 of following:
- Unilateral weakness (face, arm and leg)
- Homonymous hemianopia (remember, contralateral with macular sparing)
- High cerebral dysfunction (e.g. dysphasia, visuospatial disorder
Bamford classification criteria for partial anterior circulation stroke (PACS)
2/3 of following (opposed to all 3 for TACS)
- Unilateral weakness (face, arm and leg)
- Homonymous hemianopia (remember, contralateral with macular sparing)
- High cerebral dysfunction (e.g. dysphasia, visuospatial disorder
However, higher cerebral dysfunction alone is also classified as PACS
Bamford classification criteria for posterior circulation stroke (POCS)
Effects cerebellum and brainstem, only need 1 of the following:
- CN palsy and a contralateral motor/sensory defect
- Bilateral motor/sensory deficit
- Conjugate eye movement disorder (e.g. horizontal gaze palsy)
- Cerebellar dysfunction (e.g. vertigo, nystagmus, ataxia)
- Isolate homonymous hemianopia
Bamford classification criteria for lacunar syndrome (LAS)
A subcortical stroke only effecting a 1 small vessel hence no loss of higher cerebral function. One of following needs to be present:
- Pure sensory stroke
- Pure motor stroke
- Ataxic hemiparesis
Describe what Cushing reflex is and the quadrad
Late sign indicating impending brain herniation. The quadrad is:
- HTN (increases to increase CPP = MAP - ICP)
- Bradycardia
- Irregular breathing
- Wide pulse pressure
What is CPP equation and its significance?
Cerebral perfusion pressure = MAP - ICP
If ICP rises in stroke, CPP will fall. Body causes HTN to increase MAP to try to prevent this.
<60 CPP start getting LOC
<30 starts becoming fatal
General Mx of haemorrhagic stroke (and correction of coagulation)
ABCDE
Priority is surgical drainage - clot evacuation/ligation of bleeding vessel
IV mannitol (osmotic causes water excretion at kidney)
Airway care - intubation/ventilation
Reverse anticoagulants:
- Warfarin corrected with Beriplex (prothrombin complex) + vit K to replace clotting factors.
- DOACs reversed with idarucizumab or andexanet alfa
- Heparin reversed with protamine
How to tell apart chronic and acute haematoma on MRI (T2)
Acute - whiter than brain tissue as hyperdense (think T2 makes water white and blood is like water)
Chronic - darker than brain tissue
Tx of SAH
Nimodipine
Some of the neurosurgeons conservative Mx to rising ICP
Sit up in bed (gravity)
Good ventilation - high CO2 causes vasodilation, not good in haemorrhage
Keep patient cold (heat also causes vasodilation)
In severe cases, can sedate/paralyse pts to reduce metabolic demand
Name Parkinson plus syndromes
Progressive supranuclear palsy - axial rigidity, signs of dementia (frontal disinhibition) and parkinson’s with faailure of downward gaze (gaze paresis)
MSA - prominent autonomic features (orthostatic hypotension, incontinence, difficulty regulating temperature)
Shy-Drager syndrome
Lewy body dementia - hallucinosis, flutating Level of conscious
More have symmetrical onset and poor response to L Dopa
Parkinson’s drugs - name and describe MoA:
Peripheral dopa-decarboxylase inhibitor used w/ L-Dopa
Dopamine agonists
Monoamine oxidase B inhibitors
COMT inhibitor
Peripheral dopa-decarboxylase inhibitor = carbidopa, giving co-careldopa to prevent SE (nausea/hypotension)
Dopamine agonist = ropinirole/Pramimpexole. Remember have an O in suffix like dOpamine
MoABi - Selegilin/Rasagiline. End in ilin so Inhibit. Must not start SSRI due to risk of serotonin syndrome
COMT inhibitors = entacapone, prevent peripheral degradation of L-dopa. -pone kinda sounds like COMT
Can you give metoclopramide, domperidone or anticholinergics to PD patients?
Metoclopramide no as dopamine antagonist that cross BBB
Domperidone yes, same MoA but cannot cross BBB
Do not give anticholingerics for drooling etc. as induce confusion in elderly
What is kernig’s and Brudzinski’s signs?
Kernig’s = inability to allow full extension of the knee when the hip is flexed to 90 degrees
Brudzinski’s = forced flexion of the neck elicits a reflex flexion of the hips
Both signs of meningsm.
When are you vaccinated against meningitis B, C and ACWY?
B - looks like an 8 so 8weeks and 16weeks
C - 12 weeks and 1 year
ACWY - 14years
What is the defect seen in internuclear ophthalmoplegia?
Ipsilateral failure of adduction of the ipsilateral eye
It is due to lesion at medial longitudinal fasciculus in paramedian area of midbrain/pons, it interconnects CN 3, 4 6 so needed for conjugate eye movements.
Convergence maintained as Edinger-Westphal nucleus
Can be due to strokes or MS.
Migraine headache prophylaxis
1st - topiramate / sodium valproate (teratogenic)
2nd - propranolol or atenolol (ci in asthma)
3rd - amitriptyline
Cluster headache prophylaxis
Verapamil
Propranolol, valproate or prednisolone
How long does tension, migraine and cluster headache typically last?
Tension - 30mins to 7 days
Migraine - 4 to 72hrs
Cluster - 15 to 180minutes
Why do you need to be careful with AEDs and COCP?
AEDs are hepatic enzyme inducers so may reduce efficacy of OCP.
What are 2 drug classes used in AD?
ACh inhibitors - Donepezil, Rivastigmine, galantamine. Give mild symptomatic benefit in mild/moderate.
Memantine (NMDA receptor antagonist) only used in moderate/severe AD.
What is MMSE cut-offs for mild, moderate, severe AD?
Mild - 20-24
Moderate - 13-20
Severe - 0-12
How do you distinguish between sensory ataxia and cerebellar ataxia?
Sensory ataxia gets worse when eyes closed/in dark, while cerebellar no change (bad in both)
This is because to maintain balance, we need 2/3 of proprioception, vestibular apparatus and vision. Only vestibular if in dark and sensory ataxia.
Nerve roots of median and ulnar nerves and what they supply
Median - C6 to T1. Mainly does anterior compartment of forearm muscles. Also LLOAF (thenar). Sensation to palm.
Ulnar - C8 to T1. Mainly intrinsic muscles of hand apart from LLOAF and FCU and medial part of FDP.
How do you distingusih between common peroneal nerve palsy and L5 radiculopathy
Peroneal nerve palsy generally causes an isolated foot drop, eversion also affected.
L5 radiculopathy is similar and inversion. Not complete paralysis, pain on straight leg raise and hip abductors more likely to be weak (L5 superior gluteal nerve)
How do you treat essential tremor?
Propranolol or primidone
How does Bell’s palsy present, Ix, DDx (from stroke), Tx.
Ipsilateral paralysis of facial muscles, hyperacusis, lost of taste in ant 1/3 of tongue, dry mouth (chorda tympani), decreased lacrimation.
Ix - clinical, but rule out Lyme disease.
Stroke has forehead sparing (Upper spares upper), Bell’s is lower so has no forehead sparing. Ramsay hunt syndrome
Most get better over 3 weeks. Steroids given within 72hrs of symptom onset and eye protection. Limited evidence of aciclovir but used if severe.
What is Ramsay Hunt syndrome?
Reactivation of VZV in geniculate ganglion, a nerve bundle of the facial nerve. Causes similar Sx but with a vesicular rash.
Describe normal pressure hydrocephalus MoA, Px, Ix, Mx
A reversible cause of dementia thought to be 2o to reduce CSF absorption at arachnoid vili. Can be secondary to injury, SAH, meningitis.
Classic triad = wee (incontinence), whacky (dementia), wobbly (gait abnormality similar to PD). Sx develop over a few months
CT shows hydrocephalus
Mx - ventriculoperitoneal shunting
Describe idiopathic intracranial hypertension (pseudotumour cerebri) MoA, Px, Ix, Mx
Cause unknown
Sx of raised ICP in otherwise well obese women. These are pressure-like/throbbing headaches (worse in morning and on straining w/ vomiting), transient visual loss (<30s), neck and back pain, diplopia due to CN6 palsy. Papilloedema
Imaging, visual vield testing. Diagnosis via Dandy criteria.
Tx - low salt, weight reduction. Acetazolamide when indicated.
What do you do with GCS of <13 or 8
Head injury and GCS <13 means CT scan within an hour
GCS of 8 = intubate (rhymes)
