Horner's syndrome

Question 1

What is Horner’s syndrome

Answer 1

Condition that results from damaged sympathetic neural pathway to the face (in particular the oculosympathetic pathway)

Question 2

What is the sympathetic innervation to the eye called?

Question 3

What is the first-order neurone for the oculosympathetic pathway?

Answer 3

From the posterolateral hypothalamus to the spinal cord

Question 4

What are 2nd order neurones?

Question 5

What is the 3rd order neurone?

Answer 5

Axon extends from the superior cervical ganglion and hitch-hikes along nerves that travel along the common carotid artery. Branches of these nerves innervate:

• Pupillary dilator muscle
• Müller’s muscle
• Sweat glands

Question 6

What is the cause for Horner’s syndrome?

Question 7

What sort of damage can happen to the 1st order neurone

Answer 7

seen in stroke, tumours and damage at the spinal cord (syringomyelia)

Question 8

What damage can happen to 2nd order neurones?

Answer 8

Pancoast’s tumour, cervical rib trauma, neuroblastoma

Question 9

What damage can happen to 3rd order neurones?

Answer 9

Dissection of the internal carotid artery, herpes zoster, cluster headache will affect sympathetic nerves’

Question 10

What sign is seen in congenital Horner’s

Question 11

What are the symptoms of Horner’s

Answer 11

• Loss of sweating on one side
• Loss of sweating on affected side
• Facial flushing
• Orbital pain/ headache

Question 12

What are the signs of Horner’s (triad + one other)?

Answer 12

1. Ptosis (drooping of the upper eyelid)
2. Anhidrosis (loss of sweating)
3. Miosis (pupil constriction)

+ apparent enophthalmos (sunken eye)

Question 13

What investigations would you do for horner’s?

Answer 13

• CXR
• MRI
• Eye drop test

Question 14

Why do a CXR?

Answer 14

to identify Pancoast tumour or any trauma (rib fractures)

Question 15

Why would you do an MRI?

Answer 15

to detect aneurysm and dissection

Question 16

What are the eye drop tests?

Answer 16

1. Cocaine- prevents noradrenaline reuptake so should make the pupil dilate (in normal physiology). If there is a block to the sympathetic innervation, there will be no noradrenaline release in the first place so pupil dilation is not seen. Absent mydriasis.
2. Apraclonidine- a weaker form of noradrenaline. Should cause the pupil to dilate in Horner’s syndrome as the pupillary dilator are so starved for sympathetic innervation, there is an upregulation of alpha 1 receptors (i.e. increased apraclonidine sensitivity). Mydriasis occurs.

Question 17

What is the treatment for Horner’s syndrome?

Answer 17

Treat the underlying cause.

May need surgical innervation for syringomyelia, tumours and carotid artery dissection.