Neurological Conditions Flashcards
how is congenital nystagmus different to infantile nystagmus?
congenital nystagmus suggests the nystagmus has been since birth (but that is very rarely the case) whereas infantile nystagmus describes nystagmus from childhood
what are the two sub types of nystagmus?
-early onset: may have developed due to visual abnormality or can be idiopathic
-acquired: neuropathological like stroke or trauma or MS
name and describe what are the three types of early onset nystagmus
-Infantile
-Latent = where you cover the eye and the nystagmus is triggered or gets worse
-Spasmus nutans = comes on with head nystagmus and usually disappears within first year of life. Its high frequency low amplitude, and is accompanied by head oscillations (as is sometimes infantile nystagmus)
when does infant nystagmus seem to occur?
when theres another pathology in the visual system that causes a moderate moderate reduction in VA (severe vision loss can make you less likely to have visual nystagmus)
what is the null zone in nystagmus?
the position of the eyes where the nystagmus is at its best. Usually is achieved by the patient having an AHP.
how can you represent movements of nystagmus?
using a wave form graph (check ss)
on a waveform graph for nystagmus, what is the frequency?
frequency = 1/ cycle duration
on a waveform graph of nystagmus what is the intensity?
intensity = amplitude x frequency
ln a waveform graph for nystagmus, what does foveation mean?
the period of time when the eyes are moving most slowly, usually occurs when the eyes have just jerked back to fixation
in a waveform graph of nystagmus where is pathology most likely to occur?
in the slow phase
in a waveform graph for nystagmus, what is jerk form?
where the eyes drift to the left and then jerk back to the right and carry on in a cycle. This can be used to record and characterise the nsytagmus
what are the 3 types of waveform for nystagmus?
-Jerk = this tends to suggest a better functioning visual system as the patient is able to re-orient their gaze to the fixation target
-Pendular
-Dual jerk
what is oscillopsia?
where the world seems to oscillate back and forth but this is rare in infantile nystagmus. Could be due to efference copy.
in an eye trace graph what are the movements for infantile nystagmus?
horizontal are like zig zag lines and theres one straight line in the middle which is vertical movements because theres basically no vertical movements
what do people with infantile nystagmus see?
usually see images blurry as blurry or coming in and out of focus and people and oscillopsia may occur when the patient is very tired
for someone with oscillopsia, what nystagmus are they most likley to have?
acquired nystagmus
what is latent nystagmus also known as?
fusion maldevelopment nystagmus syndrome
what makes latent nystagmus manifest?
when nystagmus worsens when one eye is covered
what are the signs of latent nystagmus?
*only present when one one eye is covered
* Quick phases directed towards fixating eye
* Higher intensity in abduction (follows alexanders law)
* Slow phases do not accelerate
* (Almost) always accompanied by strabismus
for spasmus nutans, what are the signs?
High frequency, low amplitude
* Accompanied by head oscillations
* Spontaneous regression within first few years of life
if you see vertical nystagmus, what nystagmus is it most likely?
probably acquired as infantile nystagmus is usually horizontal but should still be checked
what are opsoclonus and ocular flutter?
eye movements that are not nystagmus because there’s no slow phase however these are suspicious of neurological damage
what are the main signs of acquired nystagmus and what are the most common causes?
-asymmetric nystagmus
-vertical nystagmus
most commonly MS or stroke
what is the difference between opsoclonus and ocular flutter
opsoclonus is involuntary rapid eye movements in all directions while ocular flutter is also rapid eye movements they are only in the horizontal so less severe and some people can do this voluntarily
what do you need to record when recording nystagmus?
- Does it worsen with occlusion?
- Does it dampen with convergence?
- Record nystagmus in each gaze position using arrows to categorise whether its pendular, jerk or rotary
what are important questions to ask in history and symptoms for nystagmus?
-whether there’s oscillopsia as even in infantile it can occur occasionally
-whether the nystagmus has changed as that could mean it’s neurological because infantile is non-progressive and changes are not expected with age
why not use a phoropter when refracting someone with nystagmus?
as you need to let the patient be in the null zone to obtain best vision
what kind of refractive error (high or low) can you expect for someone with nystagmus?
high refractive error is common probably due to poor emmetropisation
what is typical astigmatism in someone with idiopathic nystagmus?
1.85DC - mostly corneal astigmatism thought to be due to interaction between the cornea and the lids
whats the best type of perimetry and pressure test to do on someone with nystagmus?
-microperimetry
-NCT
what tip can you encourage for children with nsytagmus?
encourage them to use their null zone as much as possible even if that means an abnormal head posture. This is to give their vision the best opportunity to develop.
(remember some individuals may have 2 null zones and the null zone may be different for distance and near)
what conditions are associated with infantile nystagmus?
- Albinism
- Achromatopsia
- Congenital cataract
- Corneal opacity
- Optic disc atrophy
- Leber’s congenital amaurosis
- Aniridia
- Retinopathy of Prematurity
- Corectopia
- Congenital stationary night blindness
- Joubert syndrome
what are associated conditions with latent nystagmus?
strabismus
what are associated conditions with acquired nystagmus?
– Stroke / multiple sclerosis most common
– Vestibular disorders
– (Various form of brain damage)
NEEDS INVESTIGATION FROM NEUROLOGY
what are the optical treatments for nystagmus?
- Contact lenses
- Base out prism
- Botox
- Biofeedback
- Acupuncture
- Intermittent photic stimulation
what are the surgical treatments for nystagmus?
- Tenotomy and reattachment
- Artificial divergence
- Anderson-Kestenbaum surgery
how can a patient benefit from infantile nystagmus treatment?
-gives the child more time to see
-improves AHP
what are the steps for treating nystagmus?
- teat the underlying condition
- correct the underlying ammetropia
what may be the best solution for visual correction for nystagmus?
contact lenses because:
-youre always looking through optical centre, unlike glasses (allows use of null zone)
-VA is often better in CLs compared to glasses
what type of nystagmus can BO prism help and how?
infantile and latent
-convergence can make nystagmus better so BO prism can be used to place the eyes in a convergent position
(always check for convergence null though as some patients require divergence so BI prism)
what are all the ways you can manage nystagmus?
-contact lenses
-base out prism (in most cases)
-botulinum toxin
-relaxation/ biofeedback/ meditation (nystagmus is worsen by stress)
-acupuncture
-pharmacological treatments
-surgery
what are the two types of surgery for nystagmus?
-null zone realignment surgery - Moving the null zone can improve posture, cosmesis, and
patient confidence
-surgery to reduce intensity - tenotomy and reattachment and artificial divergence (replaces the need for prism)
what is botulinum toxin used for in nystagmus management?
-reduces oscillopsia in acquired nystagmus
-can reduce nystagmus
what are 6 causes of headaches?
- Ametropia
- Binocular vision abnormality
- Environmental – poor lighting, glare
- Pathological
- Toxic & hypoxic
- Stress, anxiety - one of the most common types (tension headaches and these do not affect vision)
what are the symptoms of a HA caused by papillooedema?
*Diffuse or unilateral throbbing, often severe
headache (HA)
* Often pain worse when waking in the morning
* HA worse with coughing or change of posture
* Nausea and vomiting
* Vision, pupils, fields not usually affected until late
stages
*may have amaurosis fugax (temporary loss of vision in one eye)
what are the headaches that affect the eyes?
- Papilloedema
- Shingles
- Giant cell arteritis
- Migraine
- Closed angle glaucoma
what is the age of onset for migraines?
18-30 years
what are the risk factors of migraines?
- Female : male 3:1
- Up to 90% have family history
what are the two types of migraines?
common migraines - without aura
classic migraine - with aura
what is the most common headache that does not cause vision?
tension headache. bilateral, steady and does not throb
what are the worrying features of headaches?
- Short history
- Continuous
- Worsening
- General malaise (being generally unwell)
- Other symptoms
what are the less worrying features of headaches?
- Long history
- Intermittent
- Good GH
- No other problems
what is the parasympathetic pupil innervation pathway?
pupil constriction
1.preganglionic cells in nucleus of edigner westphal
2. axons exit through CN III
3. these synapse in the ipsilateral ciliary ganglion
4. iris constrictor stimulated via short ciliary nerves
what is the sympathetic pupil innervation pathway?
pupil dilation
1. light stimulates luminance detecting RGCs
2. axons of optic nerve and tract exit before the LGN
3. these axons synapse in olivary pretectal nucleus
4. bilateral projection to synapse in both EWs
what are the symptoms of papilladema?
- Diffuse or unilateral throbbing, often severe
headache (HA) - Often pain worse when waking in the morning
- HA worse with coughing or change of posture
- Nausea and vomiting
- Vision, pupils, fields not usually affected until late
stages - May be amaurosis fugax (few secs up to 30×/day)
what causes shingles?
Reactivation of the varicella-zoster virus later in life (same virus
that causes chickenpox)
what are the symptoms of shingles?
a skin lesion that comes with headache and tingling (usually) on the side of the lesion
what are the symptoms of a common migraine?
-no visual aura
- Unilateral dull ache, progresses to throbbing pain of increasing intensity
-Frequency, duration and severity vary
-can last anywhere between 4-48hrs
-attacks can be 1-4x per month
how is common migraine different to classic migraine
-common migraine headaches last longer than classic migraine
-common migraine attacks are more frequent than classic
what are the symptoms of classic migrain
-visual aura
-neurological disturbance like speech, hemiparesis
-pain lasts less than an hr
-preceded by visual distubrances like zig zag scotomas, tunnel vision and homonymous hemianopia
-pain similar to common migrainw
what are the visual, neurological, abdominal, dermatological and phycological phenomena associated with migraine?
- Visual: commonly scotoma, +ve or-ve scintillating
- Neurological: pareses, dysphasia
- Abdominal: nausea*, vomiting
- Dermatological: skin pallor*, flushing
- Psychological*: memory, aggression, depression`
what are the types of aura in classic migraines?
- Teichopsia (80% of auras)
- Chevaux de fries
- Scotoma (central or peripheral loss)
- Pure hemianopia
- ‘Heat haze’
what is an acephalgic migraine?
If a visual migraine aura appears without a headache, it is still a migraine, but is called an acephalgic migraine
what is teichopsia?
an aura where you have the perception of zig zag lines surrounding a scotoma
Usually start in the centre of the visual field and move
outwards during the course of the migraine, but can start in the periphery and move inwards.
how does teichopsia happen?
due to planar waves of neural activity passing through V1 and when closer to the fovea, teichopsia moves more slowly due to cortical magnification
what does chevaux de frise aura look like?
jumbles lines at various orientations with a crazed glass appearance
what are some precipitating factors of migraines?
- Diet e.g. lactose, chocolate, nuts, red wine
- Contraceptive pill
- Excessive sleep
how can you manage migraines?
-Avoiding precipitating factors
-controlling the pain with ergotamine (not for pregnant women), aspirin and codeine
-using beta blockers as prophylactics
what headaches do not usually affect vision?
- Tension headache
- Cluster headache
- Acute meningitis
- Subarachnoid haemorrhage
- Trigeminal neuralgia
- Ankylosing spondylitis (of cervical spine)
- Rheumatoid arthritis
what 7 headaches do not usually affect vision?
- Tension headache
- Cluster headache
- Acute meningitis
- Subarachnoid haemorrhage
- Trigeminal neuralgia
- Ankylosing spondylitis (of cervical spine)
- Rheumatoid arthritis
what are the associated factors of tension headaches?
stress, anxiety and lack of sleep
what are the symptoms of tension headaches?
- Steady bilateral (non-throbbing pain) often
starts occipitally or frontal – pain over eyes - Does not get worse with activity unlike migraine and no other symptoms (nausea etc.)
- Recurrent, begin towards end of day
who is more predisposed to cluster headaches?
males more than females, 4:1, usually 30-50 years old
how long do cluster headaches usually take to resolve?
weeks to months
what are the symptoms of cluster headaches?
- Sudden onset, severe burning sharp pain,
- Unilateral: oculotemporal region
- HAs occur at night – brief & intense, recurrent
- Last 2-4 hrs (may recur several times in 24 hrs)
- May be accompanied by: lacrimation, conjunctival
injection, sweating, Horner’s syndrome
what are the symptoms of acute meningitis headache ?
- Non specific, throbbing and very severe HA
- Neck stiffness
- Rapid or gradual onset
what is a subarachnoid haemorrhage and what are the symtoms? what can it lead to?
(Haemorrhagic stroke between the meninges)
* Initial sudden HA due to altered ICP
* Followed by persistent HA
* Pain present on waking, worse with coughing
* (Rarely) can lead to CNIII palsy
what age group is more likely to be affected by trigeminal neuralgia? what type of pain is it?
elderly patients
-intermittent ‘red hot poker’ pain
what kind of headache pain can rheumatoid arthiritis cause?
pain around eyes or unilateral temple or occipital zone
what are some single acute causes of headaches?
- Raised ICP
- Subarachnoid
haemorrhage - Referred pain from
sinuses, teeth, eye - Herpes zoster
what are some subacute causes of headaches>
temporal arteritis and raised icp
what are acute recurrent headache causes?
-migraine
-cluster headaches
-trigeminal neuralagia
what are the two types of stroke?
- Ischaemic (blockage/lack of blood flow)
~ 87% - Haemorrhagic (bleed in the brain)
~ 13%
what is a tia?
a mini stroke so you have symptoms for a while but then they resolve by themselves: most commonly it’s when symptoms last less than an hour e.g. facial palsy that only lasts 40 minutes.
what can cause an ischaemic storke?
-thrombosis
-embolism
-expanding tumour
whats the difference between a thrombosis and an embolism?
a thrombosis is when a blood clot grows in a blood vessel whereas an embolus is any foreign material that travels within the body that can become stuck
a thrombus can become an embolism if it breaks away from the vein
where in the brain can bleeds from a haemorrhagic stoke be?
-intracerebral
-subarachnoid (between the meninges)
usually due to a burst aneurysm
what is haemorrhagic transformation?
where an ischaemic stroke becomes a haemorrhagic stroke as the ischaemia results in bleeding
what are the non modifiable risk factors of stroke?
- Increasing age
- More common in men
- History of stroke or TIAs
what are the non modifiable risk factors of stroke?
- Hypertension
- Diabetes
- High cholesterol
- Heart disease
- Smoking, excessive alcohol, obesity
- Atherosclerosis
what are the opthalmic consequences of a stroke?
– Homonymous hemianopia (optic radiations / V1)
– Unilateral visual neglect (parietal [usually])
– Diplopia (brainstem / cranial nerves III, IV & VI)
– Oculomotor dysfunction (brainstem): Including impaired pursuit, acquired nystagmus, supranuclear gaze palsies
– Perceptual disorders like simultanagnosia and agnosia
what does the circle of wilis allow for?
if any of the arteries within it in the brain become damaged, it does not lead to the whole blood supply being compromised
what is anton syndrome?
where a patient cannot see anything but the patient claims they can see.
this can be caused by stroke
what visual problems does a stroke originating in the middle cerebral artery cause?
- homonymous hemianopia
- hemiplegia (total paralysis) / hemiparesis (partial paralysis)
- hemiparaesthesia (loss of
sensation) of hand, arm, face
what visual problems does a stroke originating in the posterior cerebral artery cause?
- homonymous hemianopia
- visual recognition disorders
(agnosia etc)
what problems does a stroke originating in the basilar artery cause?
- diplopia
- vertigo (vection, causing
dizziness) - acquired nystagmus
- ‘drop attack’ (sudden fall
without loss of consciousness)
what problems does a stroke originating in the anterior cerebral artery cause?
*hemiplegia
* hemiparaesthesia of
lower limbs
* relatively uncommon
what visual problems does a stroke originating in the ophthalmic artery cause?
unilateral loss of vision
what are the main symptoms of optic nerve disease?
-complaining of poor vision
-transient loss of vision (visual obscurations)
-rarely pain
signs of optic nerve dysfunction
-reduced VA
-RAPD
-Dyschromatopsia
-reduced sensitivity to bright light
-visual field defects
-reduced contrast sensitivity
what visual field defects do you get in optic neuropathies?
– Central scotoma
– Centrocaecal
scotoma
– Altitudinal defect
– Nerve fibre bundle
defect
what is optic atrophy?
late stage changes that occur in the optic nerve due to axonal degeneration between the LGN and retina
how does papilloedema come about?
due to intracranial hypertension that causes
name 3 optic disk abnormalities
disk swelling
optico-ciliary shunts
optic atrophyw
what diseases can cause optic disk swelling?
– Papilloedema
– Optic Neuritis
– Anterior ischaemic optic neuropathy
(NAION)
– Compressive Lesions
what is papilloedema? what does long standing papilloedema lead to?
swelling of the optic nerve head secondary to raised intracranial pressure and is usually bilateral
long standing leads to optic atrophy
what are some causes of raised intracranial pressure?
- Space-occupying lesion
- Blocked ventricular system-
hydrocephalus - Blocked CSF absorption
- idiopathic intracranial hypertension
- Diffuse cerebral oedema
- Hypersecretion of CSF
what are the two types of hydrocephalous?
-communicating hydrocephalus: Obstruction to CSF flow in basilar cisterns or cerebral
subarachnoid space
-non-communicating hydrocephalus: obstruction to CSF flow in the ventricular system or at exit of the foramina of the fourth ventricle
what are the signs of mild papilloedema?
- VA normal
- Mild disc hyperaemia
- Indistinct disc margins- initially nasally
- Mild venous engorgement
- Normal optic cup
what is secondary optic atrophy?
optic atrophy preceded by swelling of the optic nerve head
what are the signs of secondary optic atrophy?
- VA-severely decreased
- Mild disc elevation
- Indistinct disc margins
- Disc pallor with few crossing vessels
- Absent optic cup
what are the signs of established papilloedema?
- VA- usually normal
- Severe disc elevation
*hyperaemia - Very indistinct margins
- Obscuration of small vessels on disc
- Marked venous engorgement
- Reduced or absent optic cup
- Haemorrhages and cotton wool spots
- Macular star
what are the signs of chronic papilloedema?
-variable VA due to visual obscurations and macular star
-marked disk elevation
-indistinct disk margins
-variable venous engorgement
-absent optic cup
what is pesudopapilloedema?
when the optic disk is swollen due to causes other than raised icp
what are the acquired causes of pseudopapilloedma?
-papillitis
-ischaemic papillopathy
-juxtapapillary choroiditis
-optic disk infiltration
what diseases can cause optico ciliary shunts?
– Optic nerve sheath
meningioma
– Optic nerve glioma
what diseases can cause optic atrophy?
– Post-optic neuritis
– Compressive- due to
tumours etc.
– Hereditary optic
atrophies e.g. leber’s hereditary optic neuropathy and dominant optic atrophy
how can you clinically test the optic nerve?
- VA
- Colour
- Saturation
- Pupils
- Ophthalmoscopy
- Fields (usually 4-20 for optic nerve)
*imaging the visual pathways via CT and MRI scans
*electrophysiology (VEP) - good to help detect if there is a problem
list 7 causes of optic atrophy
- Long-standing papilloedema
- Post optic neuritis
- Compressive Optic atrophy- e.g., due to
tumours - Hereditary Optic Atrophies
- Nutritional Optic Neuropathies
- Central Retinal Artery Occlusion
- Glaucoma
give 4 congenital optic nerve anomalies without systemic association
– Tilted disc
– Disc drusen
– Optic disc pit
– Myelinated nerve fibres
what are the signs of a tilted disk?
- VA normal
- Common, bilateral
- Frequent myopia, high astigmatism
- Small disc, oval, most commonly nasal
defect - May have a superotemporal field defect
not observing the vertical midline
what are the signs of disk drusen?
- Absent cup
- Pink/ yellow or
waxy, pearl-like - Indistinct lumpy
margin
*may be under surface or penetrating
why does disc drusen show up on CT scans?
because it contains calcium
what are the signs of optic disk pit (uncommon)
-unilateral
-normal VA
-large disk with oval/ round pit and pit is usually temporal
what are the complications of an optic disk pit?
Macular detachment, especially if the pit is centred on the maculo-papillar bundle
name 5 congenital optic nerve anomalies with systemic associations
-optic disk coloboma (morning glory anomaly)
- Optic nerve hypoplasia
– Megalopapilla
– Peripapillary staphyloma
– Optic disc dysplasia
what is optic nerve hypoplasia? signs?
can be unilateral or bilateral diminished number of nerve fibres
-va to be variably reduced
-small disk often pink
what are optic disk drusen?
hyaline-calcified deposits which are often bilateral and can be above or below the surface of the disk
what is optic neuritis caused by?
inflammation, infection or demyelination (most common)
what is the most common type of optic neuritis?
retrobulbar neuritis where the optic disk appears normal
what diseases can cause infectious optic neuritis?
-syphilis
-lyme
-herpes
-tb
-mumps
what diseases can cause inflammatory optic neuritis?
-sarcoidosis (Optic nerve head may have a lumpy appearance
-SLE
-behcets
what are the signs of neuroretinitis?
-va impairment is variable
-disk swelling
-disk hyperaemia
-nerve fibre layer involvement
-macular star
what are the two types of anterior ischaemic optic neuropathy (AION)?
-non arteritic: vascular insufficiency causes short posterior ciliary arteries to be occluded
-arteritic (GCA)
what are the signs of acute non arteritic AION?
– Diffuse oedema of disc
or oedema of just one sector
– Few small splinter haemorrhages over
disc
– Other disc is usually crowded
how does non arteritic aion present?
-affects people aged 45 and on
-has no systemic features but often underlying cardiovascular risk factors
-presents with sudden, painless monocular vision loss
what are the signs of late non-arteritic AION?
– Resolution of oedema
and haemorrhages
– Optic atrophy
– Variable eventual loss
of vision
how can you treat non arteritic AION?
address systemic predispositions like underlying cardiovascular risk factors
what disease causes arteritic AION?
GCA which is a type of vasculitis
how do you treat Arteritic Anterior Ischaemic
Optic Neuropathy?
rapid referral to HES for high dose steroids as it presents with severe acute visual loss and can become bilateral if left untreated
what are the signs of arteritic AION?
– Chalky disc
– Disc oedema diffuse
– Few small splinter chaped haemorrhages
– Optic atrophy if long- standing
How is lebers heriditary optic neurpathy (LHON) inherited?
from maternally inherited mitochondrial DNA mutations
what are the presenting features of LHON?
– Male
– 15-25 years
– Rarely female
– Characteristic history of consecutive visual
loss- ie first one eye then the other
– Fellow eye involved within 2 months
what are the signs of LHON?
acute:
– Disc hyperaemia/ swelling
– Dilated capillaries
– ‘telangiectatic microangiopathy’ (small dilated and tortuous blood vessels that do not leak on FFA)
– Large vessels- tortuous
– Swollen peripapillary nerve fibre layer
late:
-bilateral generally featurless optic disk atrophy
why is LHON not papilloedema?
as even though in LHON the disk is swollen, papilloedema is when the disk is swollen specifically due to raised ICP
how are cells in a normal retina different in LHON?
the RGC density in LHON is reduced
how can you manage LHON (same as ADOA)?
refer for:
– Diagnosis- genetic testing
– Genetic counselling
– Visual rehabilitation- LVAs, advice on
schooling, statementing,
– Register as severely sight impaired
there is no cure or proven treatment - poor prognosis
what is dominant optic atrophy (ADOA)?
rare autosomal dominant inherited disease that causes bilateral optic atrophy - affects males and females equally and can be passed on by both
what are the presenting features of ADOA?
– Onset congenital or juvenile
– Clinical diagnosis typically between ages 6-12 years
– Visual loss highly variable- anything from very near normal to 6/60 or rarely less
– Gradual onset- no sudden loss vision
what are the signs of ADOA?
– Optic atrophy
– Temporal pallor
- centroceacal or paracentral visual field defect
name 3 optic nerve tumours
– Optic nerve glioma
– Optic nerve sheath meningioma
– Sphenoidal ridge meningioma
what is an optic nerve glioma?
a tumour of the optic nerve glial tissue and typically affects younger patients, teens and children mainly girls
what disease is optic nerve glioma associated with?
neurofibromatosis type I
what does optic nerve glioma present with?
slow presentation:
-gradual visual loss
-proptosis
-optic atrophy (eventually)
how is optic nerve glioma treated?
-observed if slow growth and vision is goof
-removed if vision is reducing and cosmetic appearance is poor
-radiotherapy is it has spread into intracranial cavity
what is an optic nerve sheath meningioma and what does it present with?
-tumour of meninges as it wraps around optic nerve
-presents with gradual vision loss due to optic nerve compression and proptosis
what are the clinical signs of optic nerve sheath meningioma?
-optociliary shunts
-meninges appear calcified and thick in CT scan
what is a sphenoidal ridge meningioma and what does it present with?
tumour of meninges across the sphenoid ridge
presents with proptosis and gradual vision loss as tumour is slow growing
