Neurology Flashcards
List risk factors for stroke
Hypertension
Diabetes
Atrial fibrillation
Smoking
Hyperlipidaemia
Sleep apnoea
Describe the different types of stroke
Ischaemic – blockage of blood vessels (85%)
Haemorrhagic – burst blood vessels (15%)
Describe the clinical presentation of large vessel stroke
- Cortical signs
> Right brain: right gaze preference, neglect
> Left brain: left gaze preference, aphasia - MCA
> Arm > leg weakness
> LMCA: aphasia
> RMCA
> Neglect
> Topographical difficulty
> Apraxia
> Constructional impairment
> Anosognosia (lack of insight - doesnt uderstand or perceive illness)
- ACA
> Leg > arm weakness, grasp
> Muteness, perseveration (stay on same thought), abulia (lack of willpower)
> Personality change - PCA
> Contralateral hemianopia
> Memory loss/confusion
> Ataxia
Describe the clinical presentation of a small vessel stroke
Lenticulostriate perforating arteries supplying deep white matter
No cortical signs
Cause sensory or motor loss, or both
Equally distributed - lacunar syndromes
Describe the clinical presentation of a posterior circulation stroke
Crossed signs
Cranial nerve findings
Headache
Describe brainstem stroke syndromes
Combination of cranial nerve abnormalities and crossed motor/sensory findings e.g.
> Double vision - diplopia
> Facial numbness or weakness (CN V)
> Slurred speech
> Difficulty swallowing
> Ataxia
> Vertigo
> Nausea and vomiting
> Hoarseness
Describe the causes of haemorrhagic strokes
- Uncontrolled hypertension
> Spontaneous rupture of a small artery deep in the brain
Typically in the basal ganglia
- Aneurysm
- Arteriovenous malformation (AVM)
Describe the acute treatment of ischaemic stroke
tPa – tissue plasminogen activator (alteplase)
> Must be used within 4.5 hours of onset
>Reduces disability risk by 30% but an ICH risk
Mechanical clot retrieval - thrombectomy
Aspirin
Double statin dose
What are the contraindications for the use of tPa
Haemorrhage
SBP > 185 or DBP > 110
Recent surgery, trauma or stroke
Coagulopathy
Seizure at onset of symptoms
NIHSS > 21
Age > 80
Glucose < 2.2
Describe the pathophysiology of MS
Idiopathic inflammatory demyelinating disease of the CNS
Acute episodes of inflammation are associated with focal neurological deficits
Demyelination results in loss of neurological function
> Weak leg
Visual loss
Urinary incontinence
Deficits usually develop gradually, last more than 24h and may gradually improve over days to weeks
MS is diagnosed when there is evidence of 2 or more episodes of demyelination disseminated in space and time
Describe the subtypes of MS
- Relapsing remitting Multiple Sclerosis (RRMS)
> Unpredictable attacks which may or may not leave permanent deficits followed by periods of remission - Primary progressive multiple sclerosis (PPMS)
> At least 1 year of disease progression
> Steady increase in disability without attacks - Secondary progressive multiple sclerosis (SPMS)
> Initial relapsing-remitting multiple sclerosis
> Suddenly begins to decline without periods of remission - Benign multiple sclerosis (BMS)
Describe the causes of MS
Genetics
Sunlight / vitamin D exposure
Viral trigger – EBV
Multifactorial – smoking
Which syndromes may develop into MS?
- Optic neuritis
> Painful visual loss that comes on after a few days
> Can resolve after a few weeks
> 30% will develop MS within 5 years, 15% within 15 year - Clinically isolated syndromes
> Single episode of neurological disability due to focal inflammation of brain or spinal cord
> Can be a first attack of MS or be due to infection
> Can include optic neuritis and transverse myelitis - Transverse myelitis
> Inflammation of the spinal cord
> Leg weakness, sensory loss, incontinence, sexual dysfunction
> Causes: MS, viral infections - Radiologically isolated syndromes
> Incidental findings that look like MS; may or may not develop MS
Describe the investigations used in MS
- MRI brain + cervical spine with gadolinium contrast
> Dawson’s finger: radiographic feature of demyelination, reflects perivenular inflammation
> Evidence of demyelination in 2 regions e.g. periventricular and spinal cord - dissemination in space
> If enhancing and non-enhancing areas of demyelination – dissemination in time
- Lumbar puncture
> Oligoclonal bands in CSF - Bloods (exclude other conditions)
> B12/folate
> Serum ACE (sarcoidosis)
> HIV, Lyme and syphilis serology
> ESR/CRP
> ANA/ANCA/RF
> Aquaporin-4 antibodies: if transverse myelitis / optic neuritis
> Calcium (sarcoidosis) - Visual evoked potentials
> Measure conduction of nerve signals in optic nerve to identify subclinical optic neuritis
What is the definition of a relapse and a pseudorelapse in MS?
Relapse
> New neurological deficit lasting >24h in the absence of pyrexia or infection
Pseudo-relapse
> Reemergence of previous neurological symptoms or signs related to an old area of demyelination in the context of heat or infection
What is the steroid regime for an MS relapse?
1g of IV methylprednisolone for 3 days OR
500mg of oral methylprednisolone for 5 days and
PPI for gastroprotection
Describe treatments for MS
RRMS
> Alemtuzumab
> Natalizumab
> Anti-CD20: ocrelizumab, ofatumumab, rituximab
> Fingolimod
> Dimethyl fumarate
> Cladribine
> Stem cell transplants
Progressive MS
> PPMS - ocrelizumab
> SPMS - siponimod
Describe a relative afferent pupillary defect (RAPD) and its causes
Aka Marcus Gunn Pupil
Pupil remains dilated in one eye despite exposure to bright light – swinging light test
Shows unilateral optic nerve or retinal dysfunction
Causes
- Disease of retina
> Retinal detachment
> > Floaters
Flashes of light
Shadow in vision field
> Retinal ischaemia
- Optic nerve disease
> Optic neuritis
> > Pain with eye movement
Loss of vision
> Inflammation from multiple sclerosis
- Severe glaucoma
> Headaches
Nausea/vomiting
Eye redness
Blurred vision
- Trauma
List the different types of primary and secondary headaches
Primary
- Migraine
- Tension headaches
- Trigeminal autonomic cephalgias
Secondary
- Thunderclap headaches
- High pressure headaches
- Low pressure headaches
- Neuralgias
Describe tension type headaches
At least 10 episodes of headache occuring on <1 day/month on average
Lasting from 30 minutes to 7 days
Characteristics
> Bilateral location
> Pressing or tightening (non-pulsating) quality
> Mild or moderate intensity
> Not aggravated by routine physical activity
> No nausea or vomiting
> No more than one of photophobia or phonophobia
Describe the pathophysiology of migraine
Interaction between primary afferent nociceptive neurons / trigeminovascular system / brainstem / thalamus / hypothalamus / cortex
Calcitonin gene related peptide (CGRP)
Not a primary vascular problem
Describe the diagnostic criteria for migraine
At least 5 attacks
Headache attacks lasting 4-72h when untreated
Characteristics
- Unilateral location
- Pulsating quality
- Moderate or severe pain intensity
- Aggravated by routine physical activity
At least one of the following
- Nausea and/or vomiting
- Photophobia and phonophobia
Describe the phases of migraine
Prodrome: hours-days
- Yawning
- Polyuria
- Depression
- Irritability
- Food cravings
- Poor concentration
- Sensitivity to light and sound
- Poor sleep
Aura: 5-60m
- Visual
- Sensory
- Language
- Motor
Headache: 4-72h
- Throbbing headache
- Nausea
- Vomiting
- Photophonophobia
- Worse with activity
Postdrome: 24-48h
- Depression
- Euphoria
- Poor concentration
- Fatigue
Describe the acute treatment of migraine
Avoid opiates
Simple analgesics – aspirin 900mg or ibuprofen 400-600mg
Triptans
> Sumatriptan 50-100mg
> All oral triptans are gastrically absorbed – may not work if patient is vomiting
> Only work once headache starts
Early or persistent vomiting
> Add antiemetic – metoclopramide 10mg or prochlorperazine 10mg
> Consider nasal zolmitriptan or subcutaneous sumatriptan
No response
> Try other triptans OR triptan + NSAID
Describe migraine prophylaxis
Lifestyle advice, triggers
Prophylaxis if >4-5 disabling headaches per month
Use headache diaries
For each medication, determine efficacy at 3 months
> If ineffective, wean medication and try another one
> If effective, continue 6-12 months
Agents
> Propranolol
> Topiramate
> Amitriptyline
> Candesartan
> Flunarazine
Describe the treatment of refractory or chronic migraine
Onabotulinumtoxin A
> Chronic migraine
>15 headache days per month
MOH previously addressed
Failed on at least 3 prophylactics
CGRP inhibitors – monoclonal antibodies
> Erenumab
Describe cluster headaches
At least 5 attacks
Severe or very severe unilateral orbital, supraorbital and/or temporal pain lasting 15-180 minutes when untreated
Signs ipsilateral to the headache
> Conjunctival injection or lacrimation
> Nasal congestion or rhinorrhoea
> Eyelid oedema
> Forehead and facial sweating
> Forehead and facial flushing
> Sensation of fullness in the ear
> Miosis or ptosis
Sense of restlessness or agitation
Occurring with a frequency between one every other day and 8 per day
Describe trigeminal neuralgia including its treatment
One-sided intense, stabbing paroxysmal facial pain
Triggered by wind, chewing, touch
Other symptoms
- Facial muscle spasms
- Autonomic symptoms
> Lacrimation
> Diffuse conjunctival injection
> Rhinorrhoea
Investigations
> MRI
> Trigeminal nerve distorted and compressed by superior cerebellar artery
Treatment
> Carbamazepine
> Surgical microvascular decompression
Describe raised pressure headaches
Characteristics
> Worse on lying flat
> Improve on sitting up
> Worse in the morning
> Persistent nausea/vomiting
> Worse on valsalva e.g. coughing, laughing, straining
> Worse with physical exertion
> Transient visual obscurations with change in posture
Examination findings
> Optic disc swelling – papilloedema
> Impaired visual acuity / colour vision
> Restricted visual fields / enlarged blind spot
> IIIrd nerve palsy
> VIth nerve palsy – false localising sign
> Focal neurological signs
Describe thunderclap headache including causes
First and worst headache – subarachnoid haemorrhage
Severe sudden onset headache
Typically maximum onset within 1 minute, typical duration >1h
Medical emergency, same day specialist assessment
Non-contrast CT scan (NCCT) within 12h onset
> If CT normal, lumbar puncture
> For blood products – oxybilirubin
If CT/LP normal consider other investigations
> MRI
> MR/CT venogram
> MR/CT angiogram
Causes
- Subarachnoid haemorrhage
- Intracerebral haemorrhage
- Aortic dissection – vertebral or carotid
- Cerebral venous sinus thrombosis
- Ischaemic stroke
- Bacterial meningitis
- Spontaneous intracranial hypotension
- Pituitary apoplexy
Describe the course, tract and pathology associated with the olfactory nerve
Smell
Course
> Travels through the ethmoid bone and lays upon the cribriform plate
> Arises from the cerebrum
Tract
> Olfactory cells of nasal mucosa
> Olfactory bulbs
> Pyriform cortex – temporal lobe, near hippocampus
Pathology
> Hyposmia
> Normal ageing
> Viral URTI
> Chronic rhinitis or sinusitis
> Head trauma
> Neurodegenerative disorders – Parkinson’s, Alzheimer’s
Describe the function and tract associated with the optic nerve
Vision
Enter: optic canal
Arises from the cerebrum
Tract
> Retinal ganglion cells
> Optic chiasm
> Thalamus
> Primary visual cortex – occipital lobe
Describe the examination of the optic nerve
Optic discs with ophthalmoscope
> Papilloedema: raised ICP
> Optic atrophy: previous optic neuritis
Pupillary reflexes
> Direct and consensual light reflexes
> Swinging light test for RAPD
> Accommodation reflex
Visual acuity - Snellen chart
Visual fields and blind spot: confrontation
Colour vision: Ishihara colour plates
Describe the physiology of the pupillary light reflex
Light is shone into the the left eye and the travels via the optic tract and synapses at the pretectal nucleus
Interneurones then synapse with both Edinger-Westphal nuclei
Post-ganglionic fibres run with ciliary nerves and terminate on sphincter pupillae
Pupillary constriction in both eyes (direct and indirect) when a light is shone in one
Describe different types of visual field defects
Optic - ipsilateral monocular visual loss
Optic chiasm - bitemporal hemianopia
Optic tract - contralateral homonymous (affecting both visual fields) hemianopia
Parietal upper optic radiation - contralateral homonymous inferior quadrantanopia
Temporal lower optic radiation - contralateral homonymous superior quadrantanopia
Occipital visual cortex - contralateral homonymous hemianopia (macular sparing)
Most common tumours impacting anterior visual pathways
> Pituitary adenoma
> Meningioma
> Craniopharyngioma
Describe eye muscles and movements associated with them, as well as their assessment
Assessment – smooth pursuit – draw H shape in the air
Oculomotor nerve
> Superior rectus
> Elevation of eyeball
> Also adduction and medial rotation
> Inferior rectus
> Depression of eyeball
> Abduction and lateral rotation
> Medial rectus
> Adducts the eyeball
> Lateral rectus
> Abducts the eyeball
> Inferior oblique
> Elevation of the eyeball
> Abduction and lateral rotation
Trochlear nerve
> Superior oblique
> Depression of eyeball
> Abduction and medial rotation
> Abducens nerve
> Lateral rectus
Describe the function and tract of the oculomotor nerve
Eye movements
> Inferior oblique
> Superior, medial and inferior rectus
Levator palpebrae superioris – keeps upper eyelid open
Lens accommodation: ciliary muscles
Pupil constriction - parasympathetic
> Ciliary muscles and sphincter pupillae
Arises from the midbrain-pontine junction
Nucleus
> Motor
> Located in the midbrain at the level of the superior colliculus
> Parasympathetic
> Dorsal midbrain – Edinger Westphal nucleus
Exit: superior orbital fissure
> Exits brainstem from the interpeduncular fossa of the midbrain
> Passes through cavernous sinus
> Enters orbit through superior orbital fissure
Describe complete 3rd nerve palsy
Ptosis
Pupillary dilatation
Eye in a “down and out” position
Due to unopposed actions of lateral rectus and superior oblique
Describe the function and location of the trochlear nerve
Eye movements - superior oblique
Arises from the midbrain
> Level of inferior colliculus
Exit: superior orbital fissure
Describe the function of the trigeminal nerve and its location
Arises from pons
3 branches
- V1 - ophthalmic nerve
> Branches
> Supraorbital nerve
> Nasociliary nerve
> Ciliary branches supply the cornea
> Exit: superior orbital fissure
> Enter: supraorbital foramen
- V2 - maxillary nerve
> Exit: foramen rotundum
Enter: infraorbital foramen
- V3 - mandibular nerve
> Exit: foramen ovale
> V3 meningeal branch exits through foramen spinosum
> Enter: mental foramen
> Muscles of mastication:
> Temporalis
> Masseter
> Pterygoids
> Motor to muscles of mastication and general sensory to face
Describe the function and location of the abducens nerve
Eye movement (abduction - lateral rectus)
Arises from the pontine-medulla junction
Exit: superior orbital fissure
Describe the function and location of the facial nerve
Muscles of facial expression
> Frontalis
> Orbicularis occuli
> Orbicularis oris
Supplies secretory glands
> Sublingual & submandibular glands
> Lacrimal glands
Supplies taste of anterior 2/3 of the tongue
Corneal reflex
> Lightly touch cornea with cotton wool
> Afferent – CN V
> Efferent – CN VII
> Normal response is blinking
> May be lost in pontine lesions
Arises from the pontine-medulla junction
Enter: internal acoustic meatus
Exit: stylomastoid foramen
Describe the location and function of the vestibulocochlear nerve
Arises from the pontine-medulla junction
2 nerves
> Vestibular nerve - balance
> Nerve endings within semicircular canals
> Reach cerebellum and spinal cord
> Cochlear nerve - hearing
Reaches auditory cortex in the temporal lobes
Enter: internal acoustic meatus
Describe the testing of the vestibulocochlear nerve
Rinne’s test
> Tuning fork is held at the mastoid process and then at the external auditory meatus
> Patient is asked which is louder
BC > AC – conductive deafness
AC > BC – normal or sensorineural deafness
Weber’s test
> Tuning fork is held at the vertex
Patient is asked which ear they hear the vibration loudest in
Normal – same in both ears
Conductive hearing loss – deaf ear
Sensorineural hearing loss – good ear
Describe the function and location of the glossopharyngeal nerve
Sensory
> Taste – posterior 1/3 of tongue
> Proprioception for swallowing – pharyngeal wall
> Blood pressure receptors – carotid sinuses
Motor
> Swallow and gag reflex – pharyngeal muscles
> Lacrimation – lacrimal glands
Parasympathetic
> Saliva production – parotid glands
Originates from the medulla, posterior to the olive
Exit: jugular foramen
How is the glossopharyngeal nerve tested?
Motor
Ask patient to open mouth and say “ahh”
Watch for elevation of the soft palate
Unilateral weakness of CN IX – deviation of uvula away from the lesion – glossopharyngeal palsy
Describe the function and location of the vagus nerve
Sensory
> Chemoreceptors
> Blood oxygen concentration
> Carotid bodies
> Pain receptors (dura)
> Respiratory and digestive tracts
> Sensation
> External ear, larynx and pharynx
Motor
> Heart rate and stroke volume
> Pacemaker and ventricular muscles
> Peristalsis
> Smooth muscles of the digestive tract
> Air flow
> Smooth muscles in bronchial tubes
> Speech and swallowing
> Muscles of larynx and pharynx – recurrent laryngeal nerve
Parasympathetic
> Smooth muscles and glands of the same area innervated by the motor component, as well as thoracic and abdominal areas
Exit: jugular foramen
Describe the function and location of the spinal accessory nerve
Exit: jugular foramen
Neck muscles
- Sternocleidomastoid
- Trapezius
Head rotation and shoulder shrugging
Originates from medulla, posterior to the olive
Describe the location and function of the hypoglossal nerve
Motor – speech and swallowing
> Muscles of the tongue
Originates from medulla, anterior to the olive
Exit: hypoglossal canal
Describe a hypoglossal nerve palsy
Observe the tongue at rest and ask patient to stick out their tongue & move it from side to side
Unilateral/bilateral wasting or fasciculations (at rest)
Unilateral XIIth weakness causes the tongue to deviate towards the side of the lesion
Slow and spastic tongue movements suggest pseudobulbar palsy
Describe internuclear ophthalmoplegia
Disorder of conjugate gaze
Failure of adduction of affected eye with nystagmus on lateral gaze in contralateral eye
Can be unilateral or bilateral
Results from lesion of medial longitudinal fasciculus – connects IIIrd and VIth nerve nuclei
Commonly seen in multiple sclerosis (MS)
Describe Horner’s syndrome and its causes
Ipsilateral disruption of cervical / thoracic sympathetic chain
Causes
> Congenital
> Brainstem stroke
> Cluster headache
> Apical lung tumour
> Multiple sclerosis
> Carotid artery dissection
> Cervical rib
> Syringomyelia
Consists of
> Miosis
> Ptosis
> Apparent enophthalmos
> Anhydrosis
Describe herpes zoster ophthalmicus
Pain may precede vesicles
Shingles affects ophthalmic division of trigeminal nerve
> V2/V3 rarely affected
Elderly and immunocompromised at risk
Treated with oral aciclovir