Course 3 - Cranial Nerves (I,II,III,IV & VI)

3. Cranial Nerves: I, II, III, IV & VI
Course-specific learning outcomes + references

After this course, you should make sure that you can:

• Describe the clinically relevant structure of cranial nerves I, II and III-VI
• Outline the principal properties, relations and functional interactions of these structures
• Assess their status via case history observation and appropriate testing
• Demonstrate key psychomotor skills relevant to your examination of the above
• Apply the above to a novel theoretical clinical situation, testing hypotheses generated

• Explicitly analyse your diagnostic process, reflecting on its strengths and weaknesses
• Evaluate the bearing of these processes on your subsequent healthcare

NB the above may be the subject of formative or summative assessment, in line with your prevailing professional body's guideliness

References

Visit as many of the references shown below as possible prior to your course. These are drawn from a variety of texts and take a range of forms (pictorial, textual and tabular). Our intention is to provide you with an assortment of information sources that you can choose from - and that you can match to your own learning style.

General introduction and orientation of anatomical relationships: Ref 8 pp 45-48
Cranial nerve I interpretation: Ref 8 p 45

Cranial nerve II visual field testing / scotoma interpretation: Ref 8 tables 7.1 and 7.7; fig 7.6; pp 51-64

Interpreting pupillary signs: Ref 8 pp 54-56

Cranial nerve III weakness: Ref 4 pp 194-195)

III Nerve paresis: Ref 4 pp 194-195

Visual pursuit - plan view of muscles involved in eye movement: Ref 8 p79, fig 9.2

Interpreting double vision: Ref 8 p 82 and fig 9.4

Procedure for nerves I-VI: Ref 1 pp 309-34, Ref 8 pp 41-84

3. Cranial Nerves: I, II, III, IV & VI
Indicative content – related theory and skills

You'll need to bring your own:

Bright pen torch
Red-headed and a white-headed neurological pins or their equivalent
Snellen chart / printed text of various sizes (e.g. newsprint)

Indications: Change in special senses of vision, smell or taste
Unexplained or unusual headaches
Head injury - especially if recent; but even if not...
Changes in personality or higher cognitive function

• The structures involved - and their properties/functions
Key considerations regarding PNS and CNS

Sensory and motor functions

Cranial nerves’ nuclei, origins and destinations

Relation to cranial foramina, meninges and other clinically important structures

• Cranial nerve I
Reduction and exaggeration of function. How do you perform your examination accurately?

What can this tell us about the nervous system?

• Cranial nerve II
Visual fields; visual acuity; colour perception; relevant reflexes
(NB Ophthalmoscopy is covered in a separate Crawford and Cook course)

• Cranial nerves III, IV and VI
Innervation of the eyes - current accepted layout

How to remember the action of the extra-ocular muscles
Observation (status of the eyes) and visual pursuit
Double vision: incriminating muscle and / or nerve dysfunction

• Altered cranial nerve function - terminology
Record and communicate your findings accurately and succinctly using accepted terms

• Interpretation of change in cranial nerves I, II, III, IV and VI function
Problem solving: - making sense of your examination findings
For example – observable signs, visual field changes; diplopia in a particular direction of gaze