7.1 Cranial Nerve III (Oculomotor) Palsy
7.2 Cranial Nerve IV (Trochlear) Palsy
7.3 Cranial Nerve VI (Abducens) Palsy
7.4 Cranial Nerve VII (Facial) Palsy
7.5 Optic Nerve Function
7.6 Visual Fields to Confrontation
7.7 Pupils
7.8 Horner’s Syndrome
7.9 Nystagmus
7.10 Neuro-Ophthalmic Differential Diagnoses and Aetiologies
Visual fields to confrontation are often tested in examinations. If performed systematically and the patient’s fixation is controlled, the location of the defect can usually be determined rapidly. Candidates can then proceed to look for additional signs consistent with that lesion. Common field defects in examinations include homonymous hemianopias, quadrantanopias and bitemporal hemianopias.
Remember:
Summary
Figure 7.6.1
Testing Visual Fields to Confrontation in the Inferotemporal Quadrant
The examiner is at the same level as the patient and has his fingers equidistant between the patient and himself. The patient is fixing on the examiner’s left eye with his right eye and has his left eye fully covered by his palm.
Figure 7.6.2
Documenting Visual Field Defects
Visual field defects should be documented from the patient’s perspective, but it is advisable to label the eyes. If extra clarification is required, the sides of the visual field (nasal / temporal) can be documented to avoid confusion. Alternatively one can describe the type of visual field defect (e.g. “left homonymous hemianopia”).
Does the patient have a craniotomy scar or look acromegalic?
For patients who are right-handed, the dominant hemisphere is the left 90% of the time. For patients who are left-handed, dominance of hemispheres is 50% either side.
Features
Clinical Tests
Dominant
(Usually Left)
Gerstmann’s syndrome:
Acalculia
Impaired serial 7’s
Agraphia
Impaired writing
Left-right disorientation
Can’t show you L and R hand or touch L ear with R hand
Finger agnosia
Can’t name their fingers
Non-dominant
Contralateral spatial neglect (L in 90%)
Only draws 1 side of clock
Doesn’t recognise 1 side of body
Constructional apraxia
Can’t copy picture (e.g. flower)
Dressing apraxia
Take shirt, turn inside-out: can it be put back on?
Either Side
Post-central Gyrus
Contralateral sensory disturbance:
Astereognosis
Can’t recognise object by feel
Graphaesthesia
Can’t read number drawn on hand
Perceptual rivalry
2-point discrimination
Touch both hands simultaneously, only perceive on normal side
Features
Clinical Tests
Wernicke’s area
Wernicke’s “sensory” / receptive dysphasia
Limbic
1. Memory
Short-term: Name three objects (“rose, orange, tree") - test again at end.
Long-term: When did WWII end?
2. Confabulation (Korsakoff’s psychosis)
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7.5 Optic Nerve Function
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7.7 Pupils
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