Horner Syndrome: Anatomy of the - PowerPoint Presentation

Slide1

Horner Syndrome: Anatomy of the Oculosympathetic Pathway with Case RevieweEdE-149ASNR 2016

Jeffrey Sachs, MDMichael Zapadka, DOTimothy Martin, MDChristopher Lack, MD, PhDSlide2

DisclosuresThe authors have nothing to disclose.Slide3

ObjectivesTo review the anatomy of the oculosympathetic

pathway which if disrupted results in a clinical diagnosis of Horner syndrome. Identify the pathologic states that result in Horner syndrome.

Learn a straightforward imaging algorithm for the imaging work-up of Horner

s

yndrome which can be applied at your home institution.Slide4

IntroductionIn 1869 Swiss Ophthalmologist Friedrich Horner described a clinical triad of ptosis, miosis, and facial anhidrosis and correctly ascribed it to dysfunction of the oculosympathetic pathway.The oculosympathetic pathway takes a circuitous route in the head and neck between the hypothalamus and the end organs; the relevant anatomy here will be reviewed in the context of imaging pathology.

With so many varied clinical presentations, it may not be clear which imaging study is most appropriate at the initial evaluation. We will attempt to provide a cost-effective, efficient imaging algorithm that incorporates clinical data.Slide5

Clinical SymptomsPtosis: Drooping of the upper eyelid by 1-2 mm due to weakness of Mueller’s muscle, an accessory eyelid retractor. A rudimentary lower-lid retractor may also be affected, resulting in an “upside-down” ptosis.Miosis: Loss of the sympathetic innervation of iris dilator muscles results in unopposed parasympathetic iris constrictor muscle activation. This results in a small pupil on the affected side. Anisocoria, or a difference in pupil size, may be the sign that results in presentation to a physician.

Anhidrosis: Disruption of the vasomotor innervation to the face may result in lack of sweating on the affected side, although this is often not apparent in a room temperature office. Lack of flushing on the affected side may be also be present.Patient’s presenting with anisocoria can undergo pharmacologic testing to assess whether an anisocoria is due to Horner syndrome. Historically cocaine has been used to confirm a Horner syndrome, with

hydroxyamphetamine

then used to localize the lesion.

Apraclonidine

(

Iopidine

) is quickly becoming the new gold standard for pharmacologic testing of Horner syndrome, and is the test of choice at our home institution.Slide6

Apraclonidine Testing

Apraclonidine (light green a in the illustration) is primarily an α2 agonist that acts on the presynaptic bulb to decrease norepinephrine (NE) production, weakening dilation of a normal pupil. Its weak postsynaptic α1

action (which tends to dilate the pupil) is negligible in the normal state

(A)

.

In Horner syndrome, the lack of sympathetic tone results in an

upregulation

of postsynaptic adrenergic receptors, resulting in a

supersensitivity

to

apraclonidine

for dilation of the pupil in both preganglionic

(B)

and postganglionic (C) Horner syndrome. Therefore, the affected pupil dilates and the normal pupil does not appreciably change—reversing the anisocoria.

Reproduced with permission from Martin TJ, Corbett JJ.

Practical

Neuroophthalology

. McGraw Hill,  2013.Slide7

Apraclonidine Testing

A 57 year old man with a left Horner syndrome has a ptosis of the upper and lower eyelids with a smaller left pupil and resultant anisocoria.Apraclonidine 0.5% was instilled in each eye, and after 45 minutes the anisocoria

is reversed—the Horner pupil has dilated, and the normal pupil is little changed (appears smaller in this patient). Also note reversal of the left ptosis.

Reproduced with permission from Martin TJ, Corbett JJ.

Practical

Neuroophthalology

. McGraw Hill,  2013.Slide8

Overview of the Oculosympathetic PathwayThree neuron “chain”. Two synaptic connections.

The origin and course of the oculosympathetic pathway is illustrated (blue lines).

Reproduced with permission from Martin TJ, Corbett JJ.

Practical

Neuroophthalology

. McGraw Hill,  2013.Slide9

Overview of the Oculosympathetic Pathway1st order neurons originate in posterolateral hypothalamus, descend in the brainstem and intermediolateral cell column of the spinal cord, and synapse at the

ciliospinal center of Budge-Waller located at C8-T2 level.

The origin and course of the

oculosympathetic

pathway is illustrated (blue lines).

Reproduced with permission from Martin TJ, Corbett JJ.

Practical

Neuroophthalology

. McGraw Hill,  2013.Slide10

Overview of the Oculosympathetic Pathway2nd order neurons exit the spinal column primarily at the T1 level, enter the chest, ascend over the apex, under the subclavian artery, and ascend through the stellate and middle cervical ganglia before synapsing at the superior cervical ganglion which is located at the level of the carotid bifurcation anterior to the longus

colli muscle.

The origin and course of the

oculosympathetic

pathway is illustrated (blue lines).

Reproduced with permission from Martin TJ, Corbett JJ.

Practical

Neuroophthalology

. McGraw Hill,  2013.Slide11

Overview of the Oculosympathetic Pathway3rd order neurons travel in a plexus in the adventitia of the ICA. For a short segment they run with the 6th CN. Some fibers join the ophthalmic branch of CN 5 and enter the orbit via the superior orbital fissure to innervate Mueller’s muscle. Others join the long ciliary nerve (a branch of V1), which penetrate the sclera and innervate the radially oriented iris dilator muscle.

Sudomotor and vasomotor innervation to the face is supplied by sympathetic fibers travelling with the external carotid artery and its branches.The origin and course of the oculosympathetic pathway is illustrated (blue lines).

Reproduced with permission from Martin TJ, Corbett JJ.

Practical

Neuroophthalology

. McGraw Hill,  2013.Slide12

Overview of the Oculosympathetic PathwayDisruption anywhere along the chain can result in Horner syndrome.

The origin and course of the oculosympathetic pathway is illustrated (blue lines).

Reproduced with permission from Martin TJ, Corbett JJ.

Practical

Neuroophthalology

. McGraw Hill,  2013.Slide13

Case ExamplesSlide14

Case 165 year old male with seizure disorder and Horner syndrome

Sagittal T1WI without contrast demonstrates a hypointense mass centered within the hypothalamus.Slide15

FLAIR (above) and T2WI (below) demonstrate the bi-lobed nature of the mass which extends into the third ventricle.

T1WI +C demonstrates no appreciable enhancement.

Pathology: Hypothalamic

Hamartoma

First Order Neuron Lesion.Slide16

First Order Neuron Lesion

Anatomic LocationsHypothalamus

Mesencephalon

Pons

Medulla

Spinal

cordSlide17

First Order Neuron Lesion

PathologyNeoplasmHemorrhage

Infarction

Demyelinating disease

Syringomyelia

TraumaSlide18

Case 238 y/o woman with history of treated breast cancer and new finding of right sided miosis and ptosis. She also has a questionable soft tissue nodule in the treated right breast, which may have been present previously. What study to order?

CECT of the neck was performed. A soft tissue mass is present (arrows) in the right supraclavicular region between the right vertebral artery and common carotid artery adjacent to the right thyroid lobe.Slide19

PET/CT was also performed which confirmed the

hypermetabolic

nature of the abnormality.

Pathology: Metastatic Breast Carcinoma

2

nd

Order Neuron Lesion.Slide20

2nd Order Neuron Lesion

Anatomic LocationThoraxNeckSlide21

2nd Order Neuron Lesion

Pathology

Pancoast

tumor

Metastases, including lymphadenopathy

Chest surgery

Thoracic aortic aneurysms

Central venous access

Trauma

Infection (abscess)

Thyroid enlargement/mass

Thyroidectomy/other neck surgerySlide22

Case 3After Iopidine

administration the patient’s right eye dilates, confirming sympathetic denervation of the right eye.53 year old male referred to Neuro-Ophthalmology for Horner syndrome of 3 months duration. This was discovered after paranasal sinus surgery. As part of work-up, CT Chest, CTA Neck, and MRI Brain was performed.Slide23

A series of axial CTA images through the skull base demonstrate the focal sac-like outpouching arising from the medial aspect of the distal cervical right ICA consistent with a pseudoaneurysm arising in the setting of dissection (arrows). Dissection is by far the most common cause of a third order neuron lesion in the setting of Horner syndrome.Slide24

3rd Order Neuron Lesion

Anatomic LocationCarotid artery plexus, superior cervical ganglionCavernous sinus, superior orbital fissure, orbitIdiopathic/unknownSlide25

3rd Order Neuron Lesion

PathologyDissection/thrombosisCarotid-cavernous fistulaTumor such as nasopharyngeal carcinoma or extension of H&N cancers into carotid spaceCluster headache syndromeMicrovascular ischemiaGiant cell arteritisAutonomic neuropathiesSlide26

Additional Cases

DWI (left) and ADC Map (middle) demonstrate restricted diffusion in the left PICA territory.

CTA image demonstrates occlusion of the left vertebral artery.

Diagnosis: Wallenberg Syndrome

. First order neuron lesion.

As part of the lateral medullary syndrome (most commonly related to a PICA or Vertebral artery occlusion), patients may present with

ipsilateral

Horner syndrome in addition to dysphagia, ipsilateral facial anesthesia, anesthesia of the contralateral trunk and extremities, and ataxia.

F

ibers of the first order neuron are located in the

restiform

body of the inferior cerebellar peduncle.Slide27

61 year old female with complaint of eyelid droop for 18 months, first noticed after hernia surgery. CT of Neck and Chest ordered to further evaluate etiology of right Horner syndrome which was confirmed by

Iopidine testing.

Next CaseSlide28

Axial CECT of the neck demonstrates a markedly enlarged, heterogeneous thyroid gland with mediastinal extension.

Coronal reformatted image demonstrates the extent of thyroidal enlargement.

More

cephalad

in the neck the enlarged thyroid gland can be seen abutting and compressing the right

longus

colli

muscle (blue arrow). The sympathetic chain courses between the

longus

colli

and carotid sheath in the neck and is likely compressed in this case.

Diagnosis: Thyroid goiter.

2

nd

order neuron lesion.Slide29

Next CaseSlide30

CECT image (left) and T1WI + C (middle) demonstrate

nonopacifcation

of the cavernous sinuses, particularly on the right, with outward bulging of the right cavernous sinus wall.

Additional imaging demonstrates thrombus within the right inferior petrosal sinus (blue arrow, above image) and right internal jugular vein (yellow arrow, below image).

Diagnosis: Cavernous Sinus Thrombosis.

3rd order neuron lesion

12 year old male presenting with headache.Slide31

Next CaseSlide32

CECT images demonstrate massive heterogeneous, partially calcified lymphadenopathy in the left neck. There is significant compression of the left internal carotid artery (far right image, yellow arrows), and very likely along with the sympathetic chain.

16 month old female presenting with a left neck mass.

Diagnosis:

Neuroblastoma

.

3rd order neuron lesion.Slide33

Next CaseSlide34

34 year old with cervical radiculopathy.

Sag T2WI (left) and axial T2WI (right) demonstrate a small syrinx within the lower cervical/upper thoracic cord (red arrows). Although this patient did not have Horner syndrome, this is a representative example and location of a syrinx which could contribute to this entity.

Diagnosis: Syrinx.

1

st

order neuron lesion.Slide35

Next CaseSlide36

45 year old with left neck mass,

anisocoria

.

Axial CECT demonstrates a large, centrally necrotic mass centered within the left parotid gland.

Axial T2WI demonstrates the extent of disease with tumor extending into the adjacent

paraspinous

muscles as well as into the left

parapharyngeal

space. Tumor infiltrates throughout the left carotid space where the sympathetic chain resides.

Diagnosis: Metastatic squamous cell carcinoma.

3

rd

order neuron lesion.Slide37

Next CaseSlide38

53 year old female with headache, facial droop, and Horner syndrome.

CTA images demonstrate a contour deformity of the distal cervical left ICA (arrows), of uncertain chronicity. MRA was suggested to evaluate for dissection.

Noncontrast

T1WI with fat sat demonstrates a peripheral rim of T1 hyperintensity involving the distal cervical left ICA consistent with an intramural hematoma due to a focal dissection.

Diagnosis: Internal carotid artery dissection.

3

rd

order neuron lesion.Slide39

Next CaseSlide40

Iopidine drops confirm a right Horner syndrome.

76 year old female presenting with 3 week history of anisocoria and ptosis of the right eye.Slide41

Axial CECT of the neck demonstrates a low density circumscribed mass in the right T1-T2 neural foramen. Differential includes a nerve sheath tumor,

meningocele

, or

perineural

root sleeve cyst. MRI was recommended.

Axial T2WI demonstrates a circumscribed CSF intensity mass extending through the right neural foramen which is expanded.

The lesion is visible on the localizer sequence

at the level of T1.

Diagnosis:

Perineural

Root Sleeve (

Tarlov

) Cyst.

2

nd

order neuron lesion.

20% of

perineural

root sleeve cysts may be symptomatic, typically causing back or radicular pain. The authors postulate this as the etiology of the patient’s right Horner syndrome, likely related to mass effect on the exiting 2

nd

order neuron fibers travelling with the right T1 nerve root.Slide42

Next CaseSlide43

78 year old woman with

anisocoria

, history of breast cancer, multiple “lumps” in skin of right neck.

MRI of the right brachial plexus demonstrates a soft tissue mass (red arrow) which invades the right anterior scale muscle (blue arrow).

Series of sagittal images demonstrates the relationship of the subcutaneous mass to the anterior scalene muscle. Although this patient’s brachial plexus is not grossly invaded, invasion of the nerve roots of the brachial plexus by carcinoma is a potential etiology of Horner syndrome. The etiology of this patient’s

anisocoria

was not clearly established.

Diagnosis: Carcinoma

en

curiasse

.

Potential

2

nd

order neuron lesion.

Carcinoma

en

curiasse

is a rare form of cutaneous metastasis most often occurring in the setting of breast cancer. Slide44

Next CaseSlide45

11 year old female with Horner syndrome, 4

th

CN palsy, and treated orbital hemangioma.

Axial T2WI (left) and coronal FLAIR (middle) images demonstrate a right orbital hemangioma. Compression of the 3

rd

order neuron in the orbit is the likely etiology of this patient’s Horner syndrome.

Abnormal contour of the 4

th

ventricle noted. The

vermis

was fully formed.

Dolichoectasia

of the right intracranial ICA present.

Diagnosis: PHACE Syndrome.

3

rd

order neuron lesion.

PHACE

Syndrome includes

P

osterior fossa malformations,

H

emangiomas,

A

rterial/Aortic anomalies,

C

ardiac anomalies, and

E

ye anomalies. Slide46

Next CaseSlide47

43 year old male presenting with upper back pain, fever, and anisocoria.Upon presentation to the ED, beads

of sweat are visible on the left side of the face, while the right side is dry consistent with anhidrosis. Slide48

Multiplanar

CT images demonstrate a soft tissue mass (red arrows) associated with the right aspect of the T1 vertebral body with osseous erosions (blue arrow-right).Slide49

Diagnosis: Mediastinal Abscess.

2

nd

order neuron lesion.

Axial T2WI (top) and sagittal STIR (bottom) demonstrate a hyperintense collection.

T1WI post contrast demonstrate peripheral enhancement of the collection.Slide50

Clinical photograph in followup demonstrating persistent ptosis and miosis of the right eye relative to the left.Slide51

Suggested AlgorithmAcute Isolated Horner syndrome: CTA or MRA of the neck to evaluate for arterial dissection, the most common cause of Horner syndrome in this clinical setting.Chronic Isolated Horner syndrome: CT of the neck with contrast may be the most cost-effective method to exclude the most common or life threatening pathologies such as dissection, neck masses/adenopathy, or Pancoast

tumor. At our institution, a modified neck CT protocol including the orbits through the level of T2 is used to include the entire oculosympathetic pathway. A two-bolus technique is used where 65 cc of contrast is given initially, followed by 30 cc thirty seconds later. This two-bolus technique improves the detection of vascular pathology such as dissection.Following a negative CT of the neck, attention should be given to a thorough neurologic exam to detect secondary symptoms which may localize to the hypothalamus, brainstem, or cervical cord which could guide further imaging work-up with MRI as necessary.Slide52

Suggested AlgorithmNonisolated

Horner syndrome: Patients presenting with Horner syndrome with additional symptomatology should be imaged primarily with MRI. The presenting symptoms may guide the initial imaging study, depending on whether the clinical scenario suggests involvement of the brachial plexus, cervical cord, or brainstem/hypothalamus.Slide53

Take Home PointsHorner syndrome is a heterogeneous entity clinically and radiologically. Detailed knowledge of the oculosympathetic pathway can help radiologists identify pathology which may add value to the care of patients presenting with anisocoria or ptosis.CT of the neck with contrast extending from the orbits through the level of T2 utilizing a double bolus technique may be the most cost effective initial imaging study to order in patients presenting with a chronic isolated Horner syndrome. Further work-up can be guided by any other localizing symptoms.

Despite a thorough imaging workup, a substantial portion (59% in one series) of patients may not have an identifiable cause of Horner syndrome which is then considered idiopathic.Slide54

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Neurographics 2015; 5(6): 282-289Pomeranz H. Isolated Horner syndrome and syrinx of the cervical spinal cord. Am J Ophthalmol 2002; 133: 702-04Nagy AN, Hayman LA, Diaz-Marchan PJ, et al.

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.

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