Systemic disease- neurology Flashcards
How does neuro-opthalmic disease usually present?
Loss of visual acuity or field
Eye movement defects (may present as squint or diplopia)
Which muscles are supplied by the 3rd, 4th and 6th cranial nerves?
Oculomotor- inferior oblique, medial, inferior and superior rectus
Trochlear- superior oblique
Abducens- lateral rectus
How would 6th nerve palsy present?
Weakness of eye abduction on the affected side- eye may point medially/inwards when relaxed
What condition might be considered with 6th nerve palsy and papilloedema?
Raised intracranial pressure compressing the abducens nerve
What is the most common aetiology of 6th nerve palsy?
Microvascular pathology e.g. diabetes, hypertension
What movements is the superior oblique muscle responsible for?
Intorsion
Depression from an adducted position
Weak abduction
What clinical sign may indicate a 4th nerve palsy in a child?
Characteristic head tilt
How does 4th nerve palsy present?
Diplopia
What are the common causes of a 4th nerve palsy?
Congential (may present decompensated)
Microvascular
Tumour
Bilateral (closed head trauma)
Other than the extra-ocular muscles, which muscles does the 3rd nerve supply?
Levator palpebrae superioris
Sphincter pupillae
How does a 3rd nerve palsy present?
Ptosis, dilated pupil, eye “down and out”
What might cause a painful 3rd nerve palsy?
Aneurysm
What causes internuclear opthalmoplegia?
Disruption to the medial longitudinal fasciculus.
Causes- multiple sclerosis and other demyelinating diseases, vascular causes
Which pathologies affect the optic nerve?
Ischaemic optic neuropathy
Optic neuritis (commonly MS)
Tumours (rarely)
How do optic nerve defects affect visual field?
Are either complete, or abide the horizontal
How does optic neuritis usually present?
Progressive visual loss Pain "behind" eye especially on movement Colour desaturation Central scotoma Gradual recovery
How does optic chiasm pathology affect the visual field?
Bi-temporal field defects
What kinds of diseases affect the optic chiasm?
Pituitary tumour
Craniopharyngioma
Meningioma
How is the visual field affected in optic tract/radiation pathology?
Often homonomous defects
Macula isn’t spared
Sometimes see quadrantanopia
Incongruous patches of visual loss
Which pathologies tend to affect the occipital cortex?
CVAs, demyelinating disease
How do occipital cortex pathologies affect the visual field?
Homonomous defects
Spare the macula
Congruous
