Horner's Syndrome

Question 1

Horner’s Syndrome - Features

Answer 1

Features

• miosis (small pupil)
• ptosis
• enophthalmos* (sunken eye)
• anhidrosis (loss of sweating one side)

*in reality the appearance is due to a narrow palpebral aperture rather than true enophthalmos

Question 2

Horner’s Syndrome - Distinguishing between Causes

Answer 2

Distinguishing between causes
heterochromia (difference in iris colour) is seen in congenital Horner’s
anhidrosis: see below

CENTRAL Lesions = Anhydrosis of Face, Arm and Trunk

PRE-GANGLIONIC Lesions = Anhidrosis of the Face

POST-GANGLIONIC Lesions = No anhidrosis

Question 3

Horner’s Syndrome - CENTRAL Lesions

Answer 3

ANHYDROSIS OF FACE, ARM and TRUNK

The Ss

Stroke
Syringomyelia
Multiple sclerosis
Tumour
Encephalitis

Question 4

Horner’s Syndrome - PRE-GANGLIONIC Lesions

Answer 4

ANYDROSIS OF FACE

The Ts

Pancoast’s tumour
Thyroidectomy
Trauma
Cervical rib

Question 5

Horner’s Syndrome - POST-GANGLIONIC Lesions

Answer 5

NO ANHYDROSIS

The Cs

Carotid artery dissection
Carotid aneurysm
Cavernous sinus thrombosis
Cluster headache

Question 6

Internal Carotid Artery Dissection

Answer 6

Internal carotid artery dissection on the left side culminating in a partial left-sided Horner’s syndrome. The term ‘partial’ Horner’s is used because anhidrosis is absent. The sympathetic fibres innervating the facial sweat glands are anatomically located on the external rather than the internal carotid artery; thus, anhidrosis is not a finding in the setting of internal carotid dissection.

In terms of management, there is little role for surgery in spontaneous carotid artery dissections. All dissections put people at risk of thromboembolic complications because of turbulent flow at the sight, therefore we normally initiate antiplatelet or anticoagulation therapy. There is little evidence for which is better over the other in this area although pragmatically speaking antiplatelets are safer. Candidates for angioplasty and stent placement include patients with persistent ischaemic symptoms despite adequate anticoagulation, patients with a contraindication to anticoagulant/antiplatelet therapy, and patients with significantly compromised cerebral blood flow

Example Question:
A 48-year-old lady develops a sudden-onset left-sided headache in the face and neck areas 36 hours ago whilst at rest. It is of 10/10 severity and reached this maximum intensity within seconds. It has not subsided since and is throbbing in nature. She also developed a transient period of loss of vision in the left eye lasting 2 hours before resolving. She also says that ‘food tastes funny’ since these problems developed. On examination, she has small, sluggishly light-responsive left pupil compared to the right and partial left ptosis. The face is otherwise unremarkable to examine as is the remaining neurological examination. Routine blood investigations are unremarkable. Plain computerised tomography (CT) of the head is unremarkable. Lumbar puncture is negative for xanthochromia. CT angiogram of the head and neck vessels demonstrates a pseudo-lumen of the carotid artery. Which of the following treatments would you initiate?

	High flow 100% oxygen
	Prednisolone
	Indomethacin
	> Aspirin
	Acetazolamide

She has an internal carotid artery dissection on the left side culminating in a partial left-sided Horner’s syndrome. In this particular case, the loss of vision points towards possible amaurosis fugax, backing up the need for anti-thromboembolic agents.

Question 7

Partial Horner’s Syndrome - Diagnosis: Example Question

Answer 7

A 42-year-old man presented with a partial left Horner’s syndrome (ptosis with miosis, no anhidrosis), ipsilateral neck pain and reduced visual acuity on the same side.

He reported that the first symptom was neck pain and that his vision worsened over the next two hours. On admission, his blood pressure was 145/80 mmHg and heart rate was 80 beats per minute in sinus rhythm. His chest was clear.

His initial non-contrast enhanced CT brain scan showed a very small area of gliosis in the left frontal area possibly related to a distant injury, but no acute pathology.

Which of the following tests is likely to give you a diagnosis?

	MRI of the brain
	> CT carotid angiogram
	Chest X-Ray
	Erythrocyte sedimentation rate (ESR) and temporal artery biopsy
	CT venogram of the neck and brain

The oculosympathetic pathway leads a course from the posterior hypothalamus, through the brainstem followed by the spinal cord, over the apex of the lung to the superior cervical ganglion, and then finally ascends along with the internal carotid artery to ultimately reach the pupillary dilator muscle and Mueller’s muscle of the lid. These post ganglionic fibres within the carotid sheath are vulnerable to the compressive effects of a mural haematoma or pseudoaneurysm resulting from a carotid artery dissection. Such compression can result in a partial Horner’s syndrome.

In addition to this, patients with both carotid and vertebral artery dissections often present with neck pain.

Finally, in patients with a carotid dissection retinal ischaemia is often as a result of thrombi produced within the dissected portion of the vessel that then embolize distally towards the brain or in this case, the ophthalmic artery, a branch of the internal carotid artery.

The investigation of choice to diagnose a carotid dissection is a CT carotid angiogram, however, other such as MR angiograms of the neck are also adequate.

Question 8

Heterochromia

Answer 8

Difference in IRIS colour

Seen in Congenital Horner’s