CPC: Brainstem

Question 1

What is Hoffman’s sign and what does it indicate?

Answer 1

The “Babinski of the upper extremity” –adduction of the thumb in response to stroking; a positive result indicates UMN damage

Question 2

When one of the vestibular nuclei is damaged, you get nystagmus that beats ___________.

Answer 2

to the damaged side

Question 3

In the upper-mid medulla, describe the relationships of the dorsal vagal nucleus, nucleus ambiguus, spinal trigeminal nucleus, solitary nucleus, vestibular nucleus, and the hypoglossal nucleus.

Answer 3

The spinal trigeminal nucleus is most lateral and anterior (anterior even to the ICP).
The nucleus ambiguus is just medial to that.
The solitary nucleus is posterior to the spinal trigeminal nucleus and the nucleus ambiguus.
The vestibular nucleus is just posterior to the solitary nucleus (and medial to the ICP).
The hypoglossal nucleus is most medial and posterior.
The dorsal vagal nucleus is between the vestibular nucleus and the hypoglossal nucleus.

Question 4

Occlusion of what vessel leads to lateral medullary syndrome?

Answer 4

The PICA

This leads to the patient’s symptoms: difficulty speaking and swallowing (CN X); ipsilateral deficit in facial pain sensation (spinal trigeminal nucleus); contralateral loss of pain and temperature sensation in both limbs (spinothalamic tract); uvular deviation to the contralateral side (CN X); nystagmus that beats to the ipsilateral side (CN IX); positive Romberg sign and ipsilateral ataxia (ICP); and ipsilateral Horner syndrome (due to occlusion of sympathetic tract which is in the lateral medulla but which we haven’t had to learn).

Question 5

True or false: vibration and fine-touch passes caudally before crossing and ascending.

Answer 5

False. It crosses immediately and ascends contralaterally.