Neuro 1.1 Flashcards
1
Q
Possible symptoms of Neuro problems
A
- decreased vision
- pain
- headaches
- diplopia
- ocular motility problems
- nystagmus (spontaneous eye movements)
- pupillary abnormalities
- lid/facial abnormalities
- transient visual loss
- illusions/hallucinations
- micropsia (objects appear smaller)
- macropsia (objects appear bigger)
- dyschromatopsia (loss of colour perc)
- metamorphopsia (straight line grid appears wavy)
- visual agnosia (difficult to recognise visually presented objects)
- ataxia (loss of bodily movements)
- hemiparesis (weakness of one side of body)
- hemisensory weakness (loss of sensation on one side of body)
2
Q
H&S of Reduced Vision
A
- associated symptoms (pain, headache etc)
- unilateral/bilateral
- time course
3
Q
Reduced vision - unilateral or bilateral
A
- unilateral - lesion anterior to chiasm
- bilateral - either bilateral ON’s or retina/chiasmal/retrochiasmal disease
- homonymous hemianopia - often regarded by px’s as affecting one eye instead of one side of vision
4
Q
Reduced vision - time course
A
- minutes - ischaemic retinal cause
- hrs - most commonly ischaemic, more likely ON
- days/weeks - more commonly inflammation
- months/years - compressive
- can be overlap
- px’s can become suddenly aware of chronic problem when fellow eye is covered
5
Q
Examination of Neuro cases
A
- VA
- pupils
- fundus examination
- VF
- CV
- contrast sensitivity
6
Q
Pupillary testing - sympathetic branch
A
- sympathetic innervation - innervates dilator pupillae muscle
- causes pupil dilation
- has much longer course than parasympathetic branch
7
Q
Pupillary testing - parasympathetic branch
A
- parasympathetic innervation - innervates pupil sphincter muscle
- causes pupil constriction
8
Q
Pupillary testing method
A
- Observe size, shape and asymmetry of pupils
- Check for D+C responses
- Swinging flashlight test (check for RAPD)
- Check for near reflex
9
Q
Pupillary testing - Step 1 (size, shape)
A
- use a distant non-accommodative target of light in dim light
- check for Anisocoria
- Difference of >0.4mm is anisocoria
- 25% of normal px’s have this in dim light, 10% in room light
- If anisocoria present, measure pupil sizes in dim and bright light and check difference (RE-LE)
- difference constant - normal
- difference largest in dim light - possible problem with dilation of smaller pupil
- difference largest in bright light - possibly problem with constriction of larger pupil
10
Q
Pupillary testing - Step 2 (D+C responses)
A
- can get no response or sluggish response
- magnitude of responses correlated to degree of damage (sluggish - minor, no response - severe)
- direct reflex affected - problem anywhere in nerve pathway
- direct reflex reduced but not absent - problem anywhere in nerve pathway
- No direct reflex in one eye and no consensual reflex in the other eye - likely to be problem inside eye/affecting nerve of eye in which the direct response affected
11
Q
Pupillary testing - Step 3 (swinging flashlight)
A
- check for RAPD!
- Pupil stays constricted (normal) = no RAPD
- Pupils dilate fully = total RAPD
- Pupils dilate a little bit and slowly; sluggish response = partial RAPD
- Magnitude of responses correlated to degree of damage (sluggish - minor, full dilation - severe)
12
Q
RAPD
A
- Gross retinal abnormality (VA of 6/60 or worse) in one eye or asymmetric
- Impaired ON function
- Asymmetric chiasmal compression (location affects one eye more than the other)
- May be detected even if pupillary response in 1 eye can’t be evaluated – trauma, pharmacologic
- RAPD does not result in anisocoria, are two separate things
13
Q
Pupillary testing - Step 4 (near reflex)
A
- usually only needed if abnormality in above steps
- look at distant, non-accommodative target
- look at near, accommodative target
14
Q
VF testing
A
- supplements acuity in assessing visual loss
- helps localise lesion along afferent visual pathway
- quantifies defect and assesses change over time
- choice of field testing, will depend on:
- degree of detail required
- px’s ability to co-operate
- Confrontational, Amsler, Perimetry
15
Q
VF Lesions
A
- RNFL
- respect horizontal midline
- one eye only or difference between eyes
- ON
- one eye only
- Optic Chiasm
- bitemporal hemianopia (central chiasm)
- binasal hemianopia (lateral chiasm)
- LGN
- inferior and superior fibres 1st meet
- Optic Radiations
- fan out, sweeping around lateral ventricle to occipital lobe
- inferior fibres -> temporal lobe
- superior fibres -> parietal lobe
- R field L retina, L brain
- L field R retina, R brian
- Primary Visual Cortex
- Disproportionately large area is macular function
- Post Chiasmal Lesions
- Affects BE
- Respect vertical midline
- More posterior produces:
- Congruous (same between eyes)
- Homonymous (same part of field in BE)
- Macular sparing
