2. Introduction
The term Horner syndrome is commonly used in English-
speaking countries, whereas the term Bernard-Horner
syndrome is common in France
Horner syndrome (Horner’s syndrome) results from an
interruption of the sympathetic nerve supply to the eye
3. Horner’s
Characterized by the
classic triad of
Miosis (constricted pupil)
Partial ptosis
Loss of hemifacial sweating
( anhidrosis).
4. Neuroanatomy
Sympathetic innervation to the eye consists of a 3-neuron arc.
First-order central sympathetic fibers
Second-order preganglionic pupillomotor fibers
The third-order post ganglionic pupillomotor fibers
5. First-order central sympathetic fibers
Arise from the
posterolateral
hypothalamus
Descend uncrossed
through the midbrain
and pons
Terminate in the cell column
of the spinal cord at the
level of C8-T2 (ciliospinal
center of Budge).
10. Second-order preganglionic pupillomotor fibers
Exit spinal cord at
the level of T1 and
enter the cervical
sympathetic chain
They are in close
proximity to the
pulmonary apex and
the subclavian artery.
The fibers ascend through
the sympathetic chain and
synapse in the superior
cervical ganglion at the
level of the bifurcation of
the common carotid artery
(C3-C4).
11. Applied Anatomy
Pancoast tumor
tumor in the apex of the
lung, most commonly
squamous cell carcinoma
Birth trauma with injury to
lower brachial plexus
Cervical rib
12. Applied Anatomy
Aneurysm or dissection of
the aorta
Lesions of the subclavian or
common carotid artery
Neuroblastoma
Lymphadenopathy
eg, Hodgkin disease,
leukemia, tuberculosis, or
mediastinal tumors
13.
14.
15.
16. Second-order neuron lesions
Prior trauma
facial, neck, axillary, shoulder or arm pain
Cough
Hemoptysis
Previous thoracic or neck surgery
Previous chest tube or central venous catheter placement; or
neck swelling
17. The third-order pupillomotor fibers
Postganglionic
pupillomotor fibers exit
the superior cervical
ganglion and ascend
along the internal carotid
artery
Shortly after the
postganglionic fibers leave
the superior cervical
ganglion, vasomotor
branch off
It Travels along the
external carotid artery
to innervate the blood
vessels and sweat
glands of the face.
18. The third-order pupillomotor fibers
Ascending along the internal
carotid artery enter the
cavernous sinus
The fibers then leave the carotid
plexus briefly to join the
abducens nerve in the cavernous
sinus
It enter the orbit through the
superior orbital fissure along
with the ophthalmic branch of
the trigeminal nerve via the long
ciliary nerves.
The long ciliary nerves then
innervate the iris dilator and the
Müller muscle
19. Third-order neuron lesions
Internal carotid artery
dissection
associated with sudden
ipsilateral face or neck pain
Raeder syndrome
(paratrigeminal syndrome)
Carotid cavernous fistula
Cluster or migraine headache
Herpes zoster
20. Raeder’s syndrome
Horner’s with pain in the
distribution area of V1.
Caused by a neoplasm
compressing the trigeminal
nerve.
Differential for cluster
headaches.
21.
22.
23.
24.
25. Third-order neuron lesions
Diplopia from sixth nerve palsy
Numbness in the distribution of the first or second
division of the trigeminal nerve and pain
28. The interruption of the sympathetic fibers may
occur
Centrally
between the hypothalamus and the
fibers’ point of exit from the spinal
cord C8 to T2
Peripherally
in cervical sympathetic chain, at
the superior cervical ganglion, or
along the carotid artery
29. Drugs that may cause symptoms similar to Horner syndrome
include the following:
Acetophenazine
Bupivacaine
Butaperazine
Chloroprocaine
Chlorpromazine
Fluphenazine
Guanethidine
Influenza virus vaccine
Levodopa
30. Clinical Presentation
Patient history
Obtaining a careful history is very helpful in the localization of
lesions causing Horner syndrome.
The symptoms reported by the patient will depend on the site
of lesion
31.
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35.
36.
37.
38.
39.
40. differential diagnosis
Anisocoria
Adie pupil
Argyll Robertson pupil
Holmes-Adie pupil (contralateral)
Iris sphincter muscle damage
Senile miosis
Third nerve palsy
Unilateral use of miotic drugs
Unilateral use of mydriatic drugs
41. Anisocoria
Pupillary inequality greatest
In bright light
(large pupil)
In dim light
(small pupil)
3rd nerve palsy
Trauma
Tumor
Temporal lobe herniation
Aneurysm
No 3rd nerve palsy
Drug induced
Adie’s pupil
Iris damage (trauma/surgery/laser)
Basal meningitis
Ptosis
Horner syndrome
Physiological
42. Testing
Which is the abnormal pupil
Compare in light and dark.
Direct and consensual
response
Is accomodation affected?
49. Pharmacologic Testing
The pharmacologic tests document the presence or absence of
an ocular sympathetic lesion and identify the level of
involvement (ie, preganglionic or postganglionic)
Localizing the lesion is important because preganglionic
lesions are associated with a higher incidence of malignancy
that necessitates extensive investigations.
50. Topical cocaine test
The basis for the topical cocaine test is the ability of cocaine to
act as an indirect sympathomimetic agent by inhibiting the
reuptake of norepinephrine from the synaptic cleft at the nerve
ending
51. Procedure
The test is performed by instilling cocaine solution (2-4% ) into
each eye.
Cocaine instilled in an eye with intact sympathetic innervation
causes the pupil to dilate.
A sympathetically denervated pupil ( in Horner syndrome)
dilates poorly to cocaine, regardless of the level of the
sympathetic interruption, because of the absence of
endogenous norepinephrine in the synapse.
52. For optimal accuracy, test results should be evaluated 30
minutes or longer after cocaine is administered.
The maximal response is seen 40-60 minutes after instillation
of the drops.
Postcocaine anisocoria greater than 0.8 mm is sufficient to
diagnose Horner syndrome.
53. Disadvantages
The drops are difficult to obtain because they must be made at
a compounding pharmacy
The drops are relatively expensive
The test can yield equivocal results
Cocaine metabolites may be detected in urine
54. Topical apraclonidine test
The topical apraclonidine test is a practical and reliable
alternative to the topical cocaine test
It is readily available and adequately sensitive (87%) and is
currently the test of choice.
55. Apraclonidine
It is
an ocular hypotensive agent
weak alpha1-agonist
strong alpha2-agonist
Typically given in a 0.5% or 1% solution
It has little to no effect on a normal pupil but has a
mydriatic effect on an abnormal pupil
56. In Horner syndrome, upregulation of alpha1-receptors
increases apraclonidine sensitivity and causes denervation
supersensitivity of the iris dilator muscle.
The denervation supersensitivity results in pupillary dilatation
and lid elevation on the abnormal side but no response or mild
miosis on the normal side from alpha2-activity after
apraclonidine administration.
Reversal of anisocoria occurs after bilateral instillation of
apraclonidine.
57. In acute cases, false-negative test results may occur because the
alpha1-receptor upregulation on which the effect of
apraclonidine depends may take 5-8 days.
A negative apraclonidine test result especially in acute
settings does not exclude Horner syndrome.
In such cases, a cocaine test should be performed to exclude
Horner syndrome.
58.
59. Side Effects
Apraclonidine 0.5% or 1% may cause
Lethargy
Bradycardia
respiratory depression in infants , younger than 6 months
Because of the immaturity of the blood-brain barrier.
62. Topical hydroxyamphetamine test
The localization of a lesion causing Horner syndrome may be
aided by the use of the topical hydroxyamphetamine test.
Hydroxyamphetamine stimulates the release of stored
endogenous norepinephrine from the postganglionic axon
terminals into the neuromuscular junction at the iris dilator
muscles.
63. This test may distinguish a postganglionic third-order neuron
lesion from a presynaptic second-order or first-order neuron
lesion.
To perform the test, 2 drops of 1% hydroxyamphetamine
solution are instilled into each eye.
A period of 24-48 hours must be allowed to elapse between
the cocaine test and the hydroxyamphetamine test because
cocaine has the ability to inhibit the uptake of
hydroxyamphetamine into the presynaptic vesicles,
64. Hydroxyamphetamine drops instilled into an eye with Horner
syndrome with intact postganglionic fibers (ie, first- or second-
order neuron lesions) dilate the affected pupil to an equal or
greater extent than they do the normal pupil.
However, hydroxyamphetamine drops instilled into an eye with
Horner syndrome with damaged postganglionic fibers (ie,
third-order neuron lesions) do not dilate the affected pupil as
well as they do the normal pupil.
65. Treatment & Management
In general, appropriate treatment of Horner
syndrome depends on the underlying cause.
The goal of treatment is to eradicate the underlying
disease process.
In many cases, however, no effective treatment is
known.
Prompt recognition of the syndrome and expedient
referral to appropriate specialists are vital.