Neuro Flashcards
Causes of vertigo
Benign paroxysmal positional vertigo (BPPV)
Vestibular neuronitis
Labyrinthitis
Meniere disease
Central causes: TIA/brainstem infarct Tumour MS Chiari formation
Conductive hearing loss causes
Otitis media (with effusion)
wax
perforated eardrum
cholesteaoma
Sensioneural hearing loss causes
Presbycusis - old age degeneration (noise trauma)
Menieres disease
infection (meningitis, labyrinthitis)
acoustic neuroma (neoplasm)
Rinnes test interpretation
NORMAL = Air conduction better than bone Conductive = bone conduction better than air Sensioneural = Air better than bone
Webers test interpretation
NORMAL = heard in midline Conductive = heard in bad ear Sensioneural = heard in good ear
What is BPPV
vertigo provoked by certain changes in head position.
movements = turning in bed, bending over, looking upward
Causes of BPPV
Idiopathic
head trauma
mastoid surgery
Symptoms of BPPV
vertigo on positional changes
DOES NOT cause hearing loss, fainting or any other neurological signs
BPPV pathophysiology
Utricle contains otoconia (calcium carbonate crystals), these become dislodged and migrate into the semicircular canals.
[Fluid in semicircular canals should not move but the crystals activate nerve endings as if the fluid is moving.
Diagnostic/treatment for BPPV
Epley manoeuvre
What is vestibular neuronitis
Inflammation of vestibular nerve commonly associated with acute illness
Causes of vestibular neuronitis
Sinusitis, URTI, vascular disease in the elderly
Commonly affects younger adults
What is labyrinthitis
infection of the inner ear, usually a viral cause and associated with vestibular neuritis.
Distinction between labyrinths and vestibular neuronitis
labyrinthitis results in hearing changes in addition to vertigo. May produce tinnitus
What is Menieres disease
chronic, incurable inner ear disorder as a result of large collections of fluid (endolymph) in the inner ear.
Unknown cause.
Develops in 40s-60s
Symptoms of Menieres disease
Fluctuating hearing loss and vertigo, tinnitus.
What are the two subtypes of haemorrhage stroke
intracerebral haemorrhage
subarachnoid haemorrhage
Where can an intracerebral haemorrhage occur
Intraparenchymal (within brain tissue)
Intraventricular (within the ventricles)
Classification system for ischaemic stroke
Bamford classification (based on clinical findings)
Signs of a total anterior circulation stroke TCAS
Need all three:
Unilateral weakness of face, arm and leg
Homonymous hemianopia
Higher cerebral dysfunction (dysphasia)
Signs of a partial anterior circulation stroke PCAS
Two of the following:
Unilateral weakness of face, arm and leg
Homonymous hemianopia
Higher cerebral dysfunction (dysphasia)
Signs of posterior circulation syndrome PCOS
One of the following:
Cranial nerve palsy and a contralateral motor/sensory deficit
Bilateral motor/sensory deficit
Conjugate eye movements (horizontal gaze palsy)
Cerebellar dysfunction (vertigo, nystagmus, gaze palsy)
Isolated homonymous hemianopia.
Lacunar stroke signs
No loss of higher cerebral functions (dysphasia) ONE of the following for diagnosis: pure sensory stroke pure motor strike ataxic hemiparesis
Where do lacunar infarcts occur
cerebral white matter, basal ganglia, pons
Lesion of CN IV will cause what eye symptoms
Downward gaze and vertical diplopia
What eye muscles is CN III (oculomotor) responsible for
Medial rectus
Inferior oblique
Superior rectus
Inferior rectus
What functions does CN III have
Eye movement
pupil constriction
accommodation
eyelid opening
What would a palsy of CN III cause
ptosis
down and out eye
dilated fixed pupil
Which eye muscles is CN IV (trochlear) responsible for
Superior oblique
What would a palsy of CN IV cause
downward gaze
vertical diplopia
What are the functions of the trigeminal nerve CN V
Facial sensation
Mastication
What would a lesion of the trigeminal nerve cause
Trigeminal neuralgia loss of corneal reflex loss of facial sensation paralysis of mastication muscles deviation of jaw to weak side
what are the branches of the trigeminal nerve
opthalmic - sensory
mandibular - mixed
maxillary - sensory
Where do the branches of the trigeminal exit the skulls
v1 - superior orbital fissue
v2 - foramen rotundum
v3 - foramen ovale
what eye muscles does the abducens nerve control
Lateral rectus
What would palsy of the abducens nerve cause
inability to abduct the eye - horizontal diplopia
where does the abducens nerve exit skull
superior orbital fissue
what does the facial nerve do
facial movement
taste anterior 2/3 of tongue
lacrimation
salivation
what would lesion of the facial nerve cause
paralysis of upper AND lower face
loss of corneal reflex
loss of taste
hyperacusis (louder sounds)
where does the facial nerve arise
internal auditory meatus
functions of VIII vestibulocochlear
hearing
balance
what does lesion of VIII cause
hearing loss
vertigo
nystagmus
acoustic neuroma (Schwann cell tumour of the cochlear nerve)
Where does CN VIII arise
internal auditory meatus
functions of IX glossopharyngeal
taste (posterior 1/3 of tongue)
salivation
swallowing
lesions of IX
hypersensitive carotid sinus reflex
loss of gag reflex
where does IX arise
jugular foramen
Functions of vagus X nerve
phonation
swallowing
innervation of viscera
lesions of vagus nerve
uvula deviation away from lesion
loss of gag reflex
where does the vagus nerve arise
jugular foramen
functions of XI accessory
head and shoulder movement
lesion of accessory nerve
weakness turning head to contralateral side
weakness of should adduction
hypoglossal nerve fucntion
tongue movement
lesion of hypoglossal
tongue deviate toward side of lesion
where does the accessory nerve arise
jugular foramen
where does hypoglossal nerve arise
hypoglossal canal
where does olfactory nerve arise
cribriform plate
where does optic nerve arise
optic canal
where does trochlear nerve arise
superior orbital fissue
where does oculomotor nerve arise
superior orbital fissure
what is the number one cause of viral encephalitis
HSV
Does HSV encephalitis occur in primary or secondary infection
BOTH!
What happens after primary infection with HSV
migrates to sensory ganglion where it stay until a secondary infection occurs
What happens when HSV reaches the brain
causes encephalitis
or meningoencephalitis
presentation of HSV encephalitis
fever
headache
focal neuro signs
Differentiation of HSV encephalitis from other causes
uncommon
SEVERE - 70% die without treatment
Early treatment important
treatment for HSV encephalitis
IV acyclovir
Where does HSV encephalitis target
temporal lobe
neurological effects of HSV encephalitis
aphasia
seizures
CSF changes HSV encephalitis
lymphocytosis
elevated protein
RBCs
Class of drugs used for migraine prophylaxis/treatment
prophylaxis - 5-HT receptor Antagonists
treatment - 5-HT receptor agonists
What is firstling treatment for migraine prophylaxis
propranolol
or topiramate
When should topiramate be avoided
women of child bearing age
teratogenic
reduces effectiveness of contraceptives
First line drug treatment of migraine
oral triptan + paracetamol/NSAID
Second line treatment of migraine
metoclopramide (can cause acute dystonia in young)
prochlorperazine
complimentary therapy for migraine
riboflavin supplements
acupuncture
What is the first-line treatment drug of generalised seizures
sodium valproate (UNLESS WOMEN OF CHILDBEARING AGE)
second line treatment for generalised seizures
lamotrigine
carbamazepine
[first-line for women of childbearing age]
treatment of absence seizures
sodium valproate or ethosuximide
first-line treatment of myoclonic seizures
sodium valproate
second-line treatment of myoclonic siezures
clonazepam
lamotrigine
Which seizures can carbamazepine exacerbate
absence or myoclonic
Bamford classification criteria to be assessed
Unilateral hemiparesis and/or hemisensory loss of the face, arm and leg
homonymous hemianopia
higher cognitive dysfunction e.g. dysphasia
Involvement of TACI
middle and anterior cerebral arteries
all 3 of Bamford criteria
PACI involvement
smaller arteries of anterior circulation e.g. upper and lower division of middle cerebral artery
two of the Bamford criteria present
Lacunar infarct involvement
Perforating arteries around the internal capsule, thalamus and basal ganglia
- unilateral weakness
- pure sensory stroke
- ataxic hemiparesis
involvement of posterior circulation infarcts
vertrebrobasilar arteries one of the following: 1. cerebellar of brainstem syndromes 2. LOC 3. isolated homonymous hemianopia
Management of TIA
ABCDE2 score
immediate 300mg aspirin (unless on anticoagulant or bleeding disorder)
Refer urgently to TIA assessment
Management of haemorrhagic stroke
Stop anticoagulation
consider referral for neurosurgery
blood pressure management
typical anterior cerebral stroke presentation
contralateral hemiparesis and sensory loss with weaker lower extremity (see cortical homunculus)
MCA stroke presentation
contralateral hemiparesis and sensory loss with more upper extremity involvement
+hemianopia
+aphasia
PCA stroke presenation
Contralateral homonymous hemianopia with macular sparing visual agnosia (can't visually understand objects i.e. recognise people)
Weber’s syndrome (branches of the PCA that supply midbrain) presentation
Ipsilateral CN III palsy
contralateral weakness of upper and lower extremity
posterior inferior cerebellar artery lateral medullary syndrome, Wallenberg syndrome presentation
Ipsilateral: face pain and temp loss
Contralateral: limb/torso pain and temp loss
Ataxia, nystagmus
Anterior inferior cerebellar artery (lateral pontine syndrome) presentation
Wallenbergs + facial paralysis and deafness
Retinal/opthalmic artery occlusion presentation
amaurosis fugax
Basilar artery stroke
‘Locked-in’ syndrome (complete paralysis apart from eye movements)
What do lacunar strokes have a high association with
hypertension
Where is Wernicke’s area
temporal lobe
where is Broca’s area
frontal lobe
Signs of parietal lobe lesions
sensory inattention
praxis
tactile agnosia
inferior homonymous quadrantanopia (lesion of superior optic radiation on contralateral side)
Signs of occipital lobe lesion
Homonymous hemianopia (with macular sparing) Cortical blindess (loss of vision) visual agnosia
Signs of temporal lobe lesion
Wernicke’s aphasia (word substitution)
superior homonymous quadrantanopia (pie in the sky, inferior optic radiation lesion)
auditory agnosia (impairment in sound perception)
prosopagnosia (difficulty recognising faces)
Signs of frontal lobe lesions
Broca's aphasia disinhibition perseveration (stuck on topic) anosmia inability to generate a list
Signs of cerebellar midline lesions
gait and truncal ataxia
signs of cerebellar hemisphere lesions
IPSILATERAL:
intention tremor, past pointing, dysdiadokinesis, nystagmus
Features of MND
UPPER AND LOWER MN SIGNS fasciculations vague sensory symptoms e.g. pain wasting of small hand muscles DOES NOT AFFECT OCCULAR MUSCLES
UMN signs
Spastic paralysis (twitch or spasm muscles) hyperreflexia hypertonia (rigid) No fasciculations positive Babinski sign
LMN signs
Flaccid paralysis (no movement) hyporeflexia hypotonia fasciculations negative Babinski sign
Types of MND
amyotrophic lateral sclerosis
progressive muscular strophy
bulbar palsy
Features of MS
optic neuritis Uhthoff's phenomenon (worsening of vision from heat) paraesthesia numbness trigeminal neuralgia spastic weakness ataxia tremor
Which tracts does Brown-Sequard syndrome (spinal cord hemisection) affect
lateral corticospinal tract
dorsal columns
lateral spinothalamic tract
Symptoms of Brown-Sequard syndrome
Ipsilateral spastic paresis below lesion
Ipsilateral loss of proprioception and vibration
Contralateral loss of pan and temperature
What causes subacute combined degeneration of the cord
vitamin B12 and E deficiency
Which tracts are affected by subacute degeneration of the cord
Lateral corticospinal tract
Dorsal column
Spinocerebellar tract
Symptoms of subacute degeneration of the cord
bilateral spastic paresis
bilateral loss of proprioception and vibration sensation
bilateral limb ataxia
Dermatome of thumb and index finger
C6
Dermatome of middle finger and palm
C7
Dermatome of ring and little finger
C
Dermatome of nipples
T4
Umbilicus dermatome
T10
Knee caps dermatome
L4
Big toe dermatome
L5
Lateral foot, small toe dermatome
S1
What visual defect is a pituitary tumour likely to cause
Bitemporal hemianopia (lesion of optic chiasm)
Cause of superior homonymous quadrantanopia
lesion of inferior optic radiation (Meyer’s loop) - temporal lobe
Cause of inferior homonymous quadrantanopia
Lesion of superior optic radiation (Baum’s loop) - parietal lobe
Mnemonic for inferior/superior quadrantanopia
PITS
Pariteal = Inferior
Temporal = Superior
