Peads : Neuro-Opthalmology - Alistair Flashcards
What are some tips when approaching exams?
do ur brainscapes bitchs
How can we diffrentiate between retina and optic nerve signs?
- Elctrophysciology is invalable!! OCT, ERG,EOG and VEP
There are limitaions to each tests tho
What is a neurofibromas?
firm swelling
What can upperlid neurofibromas suggest?
Px has glaucoma
What can the face and head abnormalities show you?
Some developmental issues which can lead to shallow orbits ect
What can ptosis imply?
MG
What are five characteristics of MG?
- Varibility, linked to fatiguness
- 50% will affect the eyes
- 12% cause restriction in the eyes, eyelids and eye muscles
- Affects facial and oropharyngeal (throat) muscles
- Women > men
What is the cause of myasthenia?
Abnormalilties of the ACH receptors
How can we test for MG?
- Endrophonium (tensilon)
- ACH receptor antibody (blood test)
How does edrophonium testing work for MG?
It is a reversible inhibitor which will increase ACH effect ; this will tell us if muscle weakness is due to MG fatgiue or not
problem is that it can be dangerous
What can be the cause of proptosis?
- Sinus disease
- Tumours
- Thyroid eye disease
What should we first ask ourselves when presented with proptosis?
WHat direction is it?
What diseases would manifest a on axial, straight proptosis?
- Thyroid disease
What diseases would manifest a off axial, not straight proptosis?
- Tumours in the orbit can push the eye out in any direction
- Sinus disease, this can also push out the eye in any direction
What are two indirection signs of reduced vision?
- Nystagmus
- Strabismus
How many types of nystagmus is there?
45 and they can be pendular or jerk
What is the definition of nystagmus?
This si the rhymic oscillation of the eyes.
What is the aetiology of nystagmus in child?
- Infantile nystagmus
- Reduced Vision in childhood
- tumours
What is the aetiology of nystagmus in adults?
- Brainstem issues : MS, vascular
- Cerebellar disease
- Vestibular disease
- CNS
EXTRA NOTE just for understadning nystagmus : what is cerebellar and vestibular disease?
- Cerebellar : coordination issues
- Vestibular : vertigo / dizziness
If a child has congential catarcts will the child have nystagmus?
No! Nystagmus is not present at birth
What are some types of nystagmus?
- Physiological
- Pathological
- Sensory defecit
- Neurological
- special types
- Idiopathic
- Infantile
what should we think about when presented with someone with nystagmus?
- What age did it come
- what other symptoms is this asscioated too?
How do we evaluate nystagmus?
- Uni or bilateral
- manifest or latent
- Type and degree. Jerk or pendular
- Direction, waveform, amplitude freq and intensity.
- CHP
How can we find out the amplitude, freq, waveform and intensity?
Nystagmus electropgrpahy
How does sensory nystagmus develop?
It will in the eye that has the poor vision due to lesions in the anterior Visual pathway.
what age does sensory nystagmus develop?
Only 6 and under
What is cortical visual impairment?
Abnormal visual response that is not caused by the eyes
Can sensory nystagmus be seen in px with cortial VI?
No.
WHat can the speed of direction tell us?
SLow = shit vision
faster = better va
What is Asymmetric Nystagmus?
The nystagmus is diffrent in each eye.
Why may asymmetric nystagmus present?
- Blind in one eye
- OM apraxia
- Spasmus nutans
What is spasmus nutans?
This is idiopathic and will present as the child head nodding ; this is in the nystagmus lecture
Watch this video to see it:
https://www.youtube.com/watch?v=J77RgASz3yk
What is oculomotor apraxia?
This is when the child finds it hard to move their eyes ; abnromal saccades. The casue is complex
I got this from this link:
https://aapos.org/glossary/oculomotor-apraxia
What is the onset of infantile nystagmus?
between 6-12 months.
How can we diagnose infantile nystagmus?
They have no ocular or neurological disease.
… if they did it would be a diffrent type of nystagmus
what are the signs of infantile nystagmus?
- Uniplanar and normal Horizontal
- FH
Are the signs pathognomic?
Pathognomic means the signs are specific to one condition
Answer is NO it is not specific
How can we manage Nystagmus?
- Prisms
- CL
- Surgery
BUt they are not effective (they are shit)
If a child has dipliopa how can we diffrentiate between the palsies?
ask where the diplopia is
dip changing in diff directions ect
what can cause cranial nerve palsies?
- Raisied ICP
- Vascular
- Compresion
- Infections
- Trauma
Why are certain nerves damaged?
- thin
- compressions
- kinking
Why is the 6th nerve prone to insult?
Due to its pathyway, casuing it to do a right angle entering the cavernous sinous. This makes it vunerable to trauma and Raised ICP
Why is the 4th nerve easily damaged?
It is long and thin and comes from the back of the brain. Vunerable to minor head injuries
Is 3rd nerve easily damaged?
No, this one is the solider out of the three. It is the absolute role model of how things should be. Though and strong minded.
Takes brutal, catastrophic shannaniganic trauma to hurt this one. Or by aneurysm / tumour
How can orbital diseases effect the eyes?
Trapped muscles in the orbit floor
EXTRA: During the intial orbtial floor does the eye come forward or backwards?
Backwards, as there is space for the eye now the muscle is on the floor
How can we assess the dipliopia?
- Mono or binocular
- direction of dip
- near, dist
- left or right
what can causes unequal pupils - anisocoria ?
Eye diseases : such as uvietis (extra note: synechiae, we give cycloplegics to help this)
what other pupil defects can we get?
- Efferent : parasympathetic (horners) or sympathetic (3rd nerve)
- Afferent
- Light-Near dissosciation
- Adies Tonic pupil
WHat is light- near disscioation?
This is when the pupils react to ACC but not light
what causes light - Near dissociation?
Common cause is diabetes. Can be due to tumour also
How do we assess pupils?
- Get the child to look far ; so they are not accomodating
- Use a good light
