Motor cranial nerves


First thing to say is that there is no such thing as the cranial nerve examination. What you are examining is cranio-cervical function.

You might think this is neuro-buffoonery, but it is NOT!

If someone comes into hospital with acute onset left arm paralysis, you do examine the upper limbs with the view that the problem is either in the median, ulnar or radial nerve – do you?

You think to yourself, what part of the nervous pathway could the problem lie in – cortex, white matter, brainstem, spinal cord, nerve root, plexus etc.

Same deal applies to cranial nerves.

I would recommend you just split them into

  1. visual assessment – acuity, fields, movements, pupils, fundi
  2. motor assessment
  3. sensory assessment

Once you have done this, describe the nature of any problem and don’t leap to a “VIIth nerve palsy” if there is a left facial weakness. I’d rather you just told me there was a left facial weakness, to be perfectly honest.

For the motor nerves, just split the head and neck into 5 bits, and do some stuff in each bit. Spend more time in and around the mouth and, believe it or not, by the time you reach the shoulders, about 23 seconds later, you have tested them all.

cranial nerves.005
1 = forehead; 2 = eyes; 3 = in and around mouth; 4 = neck; 5 = shoulders


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