Horner's Syndrome

Question 1

What are the causes of Horner’s syndrome?

Answer 1

1. Carcinoma of the lung apex (usually squamous cell carcinoma)
2. Neck - thyroid malignancy, trauma
3. Carotid arterial lesion (cartoid aneursym or dissection, pericarotid tumour, cluster headache)
4. Brain stem lesions - vascular disease (esp lateral medullary syndrome), syringobulbia, tumour
5. Retroorbital lesions
6. Syringomyelia (rare)

Question 2

Outline the Horner’s exam.

Answer 2

1. Sweating
2. CNs to exclude lateral medullary syndrome)
3. Ask patient to speak
4. Hands: clubbing, finger abduction
5. If hoarseness or lower trunk brachial plexus lesion –> respiratory exam for lung carcinoma.
6. Examine neck.
7. Sensory (for syringomyelia causign dissociated sensory loss).

Question 3

Does absence of brow sweating differences exclude Horner’s?

Answer 3

NO. Only occurs when lesion is proximal to carotid bifurcation.

Question 4

What are the signs of lateral medullary syndrome?

Answer 4

1. Nystagmus (to the side of the lesion)
2. Ipsilateral 5th (pain and temp), 9th and 10th CN lesions
3. Ipsilateral cerebellar signs
4. Contralateral pain and temp loss over the trunk and limbs.

Question 5

Why is speech examined when assessing Horner’s syndrome?

Answer 5

Looking for hoarseness associated with recurrent laryngeal nerve palsy from a chest or CN lesion.

Question 6

What is examined in the hands?

Answer 6

Look for clubbing.

Test finger abduction to screen for a lower trunk brachial plexus (C8, T1) lesion.

Question 7

What is examined in the neck?

Answer 7

Lymphadenopathy
Thyroid carcinoma
Carotid aneurysm or bruit (e.g. fibromuscular dysplasia –> dissection)

Question 8

What can syringomyelia cause?

Answer 8

Bilateral Horner’s syndrome

Question 9

What are the causes of constricted pupils?

Answer 9

1. Horner’s syndrome
2. Argyll Robertson pupil
3. Pontine lesion (often bilateral but reactive to light)
4. Narcotics
5. Pilocarpine drops
6. Old age

Question 10

What are the causes of dilated pupils?

Answer 10

1. Mydriatics, atropine poisoning or cocaine
2. Third nerve lesion
3. Adie’s pupil
4. Iridectomy, lens implant, iriditis
5. Post-trauma, deep coma, cerebral death
6. Congenital

Question 11

What is the underlying cause of Horner’s syndrome?

Answer 11

Interruption of the sympathetic innervation to the eye at any point.