Horner's syndrome

Presenter : Dr Rahul AchlerkarModerator : Dr Atul Seth

IntroductionThe 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

Horner’s

Characterized by the classic triad of Miosis (constricted pupil) Partial ptosis Loss of hemifacial sweating

( anhidrosis).

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

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).

Applied Anatomy

First-order neuron lesionsCerebral vascular accident

(CVA)/Wallenberg syndrome Demyelinating disease

(eg, multiple sclerosis)Arnold-Chiari malformationBasal meningitis

(eg, syphilis)Basal skull tumors

First-order neuron lesions

Hemisensory lossDysarthriaDysphagia AtaxiaVertigoNystagmus

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).

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

Applied Anatomy

Aneurysm or dissection of the aorta

Lesions of the subclavian or common carotid artery

NeuroblastomaLymphadenopathy

eg, Hodgkin disease, leukemia, tuberculosis, or mediastinal tumors

Second-order neuron lesions

Prior trauma facial, neck, axillary, shoulder or arm pain

CoughHemoptysisPrevious thoracic or neck surgeryPrevious chest tube or central venous catheter placement; or

neck swelling

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.

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

Third-order neuron lesions

Internal carotid artery dissectionassociated with sudden

ipsilateral face or neck pain Raeder syndrome

(paratrigeminal syndrome)Carotid cavernous fistulaCluster or migraine

headacheHerpes zoster

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.

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

Studies

EtiologyHorner syndrome can be congenital, acquired, or purely

hereditary (autosomal dominant)

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

Drugs that may cause symptoms similar to Horner syndrome include the following:

AcetophenazineBupivacaineButaperazineChloroprocaineChlorpromazineFluphenazineGuanethidineInfluenza virus vaccineLevodopa

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

differential diagnosis

AnisocoriaAdie pupilArgyll Robertson pupilHolmes-Adie pupil (contralateral)Iris sphincter muscle damageSenile miosisThird nerve palsyUnilateral use of miotic drugsUnilateral use of mydriatic drugs

AnisocoriaPupillary inequality greatest

In bright light(large pupil)

In dim light(small pupil)

3rd nerve palsyTraumaTumorTemporal lobe herniationAneurysm

No 3rd nerve palsyDrug inducedAdie’s pupilIris damage (trauma/surgery/laser)Basal meningitis

PtosisHorner syndrome

Physiological

TestingWhich is the abnormal pupil Compare in light and dark.Direct and consensual

responseIs accomodation affected?

Light Reflex

Normal pupil reactionvideo

Argyll-Robertson pupilSmall, irregDoes not react to

light Reacts to

accommodationCauses

syphilis diabetes

Miotonic pupil (Adie’s syndrome)DilatedPoor response to light

and convergence. Constricts with weak

Pilocarpine Holmes-Adie

syndrome Reduced tendon

reflexes (Knee, ankle)- Orthostatic

hypotension

Afferent & efferent defects

Adie’s tonic pupil (OD)

Argyll-Robertson pupil

Horner’s pupil (OS)

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.

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

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.

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.

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

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.

ApraclonidineIt 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

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.

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.

Side EffectsApraclonidine 0.5% or 1% may cause LethargyBradycardiarespiratory depression in infants , younger than 6 months Because of the immaturity of the blood-brain barrier.

VIDEO

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.

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,

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.

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.

Thank You