INSTRUCTION

Examine this patient's face.

SALIENT FEATURES

History

· Ask the patient whether or not there is absence of sweating on one side of the face.

· History of lung cancer.

· History of cervical sympathectomy.

· Migraine.

Examination

If you notice ptosis during the examination, then you must answer the fo!lowing questions:

· Is ptosis complete or incomplete?

· Is it unilateral or bilateral?

· Is the pupil constricted (Homer's syndrome) or dilated (third nerve palsy)'?

· Are extraocular movements involved (third nerve palsy or myasthenia gravis)'? · Is the eyeball sunken or not (enophthalmos)?

· Is the light reflex intact (intact light reflex in Homer's syndrome)?

If the patient has Homer's syndrome then quickly proceed as fo!lows:

· Examine the supraclavicular area:

Percuss the supraclavicular area, looking for dullness of Pancoast's tumour. -Look for scar of cervical sympathectomy (be

prepared with indications for

cervical sympathectomy).

-Look for enlarged lymph nodes.

· Examine the neck:

- For carotid and aortic aneurysms.

- For tracheal deviation (Pancoast's tumour).

· Examine the hands:

- For small muscle wasting.

For pain sensation with a pin.

- For clubbing.

(These should help in making a diagnosis of syringomyelia or Pancoast's tumour.)

· If there is no clue so far about the cause, tell the examiner that you would like to examine for nystagmus, cerebellar signs,

cranial nerves and pale optic discs, and pyramidal signs to ascertain brainstem vascular disease or demyelination.

DIAGNOSIS

This patient has Homer's syndrome (lesion) associated with dullness in the supra-clavicular area indicating a Pancoast's tumour

(aetiology).

QUESTIONS

What causes Horner's syndrome?

The syndrome results from the involvement of the sympathetic pathway which starts in the sympathetic nucleus and travels through

the brainstem and spinal cord to the level of C8/TI/T2 to the sympathetic chain, stellate ganglion and carotid sympathetic plexus (Am

J Ophtha/mol 1958; 46: 289-96: Homer's syndrome: an analysis of 216 cases).

What are the features of Horner's syndrome?

It is characterized by:

· Miosis (resulting from paralysis of the dilator of the pupil).

· Partial ptosis or pseudoptosis (due to paralysis of the upper tarsal muscle).

· Enophthalmos (due to paralysis of the muscle of Mtiller).

· Often, slight elevation of the lower lid (because of paralysis of lower tarsal muscles).

What additional feature would you see in congenital Horner's syndrome?

There would be heterochromia of the iris, i.e. the iris remains grey-blue.

How would you determine the level of the lesion using only the history?

The level of the lesion is determined by the distribution of the loss of sweating:

· Central lesion - sweating over the entire half of the head, arm and upper trunk is lost.

· Lesions of the neck:

- Proximal to the superior cervical ganglion - diminished sweating on the face. - Distal to the superior cervical ganglion - sweating is

not affected.

ADVANCED-LEVEL QUESTIONS

How would you differentiate whether the lesion is above the superior ganglion (peripheral) or below the superior cervical

ganglion (central)?

Note. In peripheral lesions there is depletion of amine oxidase due to postganglionic denervation. As a result this sensitizes the pupil

to 1:1000 adrenaline, whereas it has no effect on the normal pupil or in central lesions (where the presence of the enzyme rapidly

destroys the adrenaline).

Mention one cause of intermittent Horner's syndrome.

Migraine.

What are the causes of ptosis?

Unilateral:

· Third nerve palsy.

· Homer's syndrome.

· Myasthenia gravis.

· Congenital or idiopathic.

Bilateral:

· Myasthenia gravis.

· Dystrophia myotonica.

· Ocular myopathy or oculopharyngeal dystrophy.

· Mitochondrial dystrophy.

· Tabes dorsalis.

· Congenital.

· Bilateral Homer's syndrome (as in syringomyelia).

If the patient has Pancoast's tumour, what is the most likely underlying pathology?

Squamous cell carcinoma.

J.F. Horner (1831-1886), Professor of OphthalmoLogy in Zurich, conceded that Claude Bernard had recognized the syndrome

before him.

Henry K. Pancoast (1875-1939) was the first Professor of Radiology in the USA at the University of Pennsylvania.