Functional Neuroanatomy

Functional #neuroanatomy is a core skill for all neurology trainees. #TeachNeuro

I remain flabbergasted by the response I recently received from a trainee neurologist when I asked him how he would localise the anatomical site of a IIIrd nerve palsy. His response: “I would order an MRI scan to localise the lesion”. What is happening to our basic neurological skills? It has become clear to me that basic neuroanatomy knowledge amongst most neurology trainees is rudimentary, and is simply not detailed enough, to assist in the anatomical localisation of lesions.  I am therefore proposing that all trainees relearn functional neuroanatomy in a way that is designed to augment their skills in undertaking and interpreting the neurological examination. The following is a list of questions all neurology trainees should be able to answer: 

1. What does a IIIrd palsy look like?
2. What are the clinical features of a lesion involving the nucleus of the IIIrd nerve?
3. How do you localise a brainstem, or fasicular, IIIrd nerve palsy?
4. How do you localise a third palsy to the subarachnoid space?
5. How do you assess a the function of the trochlear nerve (IVth) in the presence of a IIIrd nerve palsy?
6. What features helps localise the IIIrd palsy to the cavernous sinus?
7. What is the significance of a pupil sparing IIIrd palsy? 
8. What is the significance of fixed mid-sized pupil in association with a IIIrd palsy?
9. What are the features of a palsy of the superior division of the IIIrd nerve?
10. What are the features of a palsy of the inferior division of the IIIrd nerve?
11. How do you localise a IIIrd nerve palsy to the superior orbital fissure? 
12. Is diplopia and invariable clinical feature of a IIIrd nerve palsy?
13. Can you describe the anatomy of the the IIIrd nerve?
14. Can you describe the paths of the parasympathetic and sympathetic innervation of the eye?

When I get the time I will produce a simple one-page infographic to answer all these questions. Does anyone want to help? I feel so strongly about this that I will be writing a commentary for Practical Neurology on this issue.