Horner's syndrome
Encyclopedia
Horner's syndrome is the combination of drooping of the eyelid
(ptosis) and constriction of the pupil
(miosis), sometimes accompanied by decreased sweating
of the face on the same side; redness of the conjunctiva
of the eye is often also present. It indicates a problem with the sympathetic nervous system
, a part of the autonomic nervous system
. Medical imaging
and response to particular eye drop
s may be required to identify the location of the problem and the underlying cause.
(drooping of the upper eyelid from loss of sympathetic innervation to the superior tarsal muscle
, also known as Müller's
muscle); upside-down ptosis (slight elevation of the lower lid); anhidrosis
(decreased sweating on the affected side of the face); miosis
(small pupils); enophthalmos
(the impression that the eye is sunk in); loss of ciliospinal reflex
; and bloodshot
conjunctiva
, depending on the site of lesion. Sometimes there is flushing
on the affected side of the face due to dilation of blood vessels under the skin. The pupil's light reflex is maintained as this is controlled via the parasympathetic nervous system.
In children, Horner's syndrome sometimes leads to heterochromia
: a difference in eye color between the two eyes. This happens because a lack of sympathetic stimulation in childhood interferes with melanin
pigmentation of the melanocyte
s in the superficial stroma
of the iris
.
In veterinary medicine, signs can include partial closure of the third eyelid, or nictitating membrane
.
(tumor in the apex of the lung) or thyrocervical venous dilatation).
activity.
The site of lesion to the sympathetic outflow is on the ipsilateral side of the symptoms.
The following are examples of conditions that cause the clinical appearance of Horner's syndrome:
If someone has impaired sweating above the waist affecting only one side of the body, yet they do not have a clinically apparent Horner's syndrome, then the lesion is just below the stellate ganglion
in the sympathetic chain.
It is important to distinguish the ptosis
caused by Horner's syndrome from the ptosis caused by a lesion to the oculomotor nerve
. In the former, the ptosis occurs with a constricted pupil (due to a loss of sympathetics to the eye), whereas in the latter, the ptosis occurs with a dilated pupil (due to a loss of innervation to the sphincter pupillae). In a clinical setting, these two ptoses are fairly easy to distinguish. In addition to the blown pupil in a CNIII (oculomotor nerve
) lesion, this ptosis is much more severe, occasionally occluding the whole eye. The ptosis of Horner syndrome can be quite mild or barely noticeable (partial ptosis).
When anisocoria
occurs and the examiner is unsure whether the abnormal pupil is the constricted or dilated one, if a one-sided ptosis is present then the abnormally sized pupil can be presumed to be on the side of the ptosis.
Johann Friedrich Horner
, the Swiss
ophthalmologist
who first described the syndrome in 1869. Several others had previously described cases, but "Horner's syndrome" is most prevalent. In France
and Italy
, Claude Bernard
is also epitomized with the condition ("Claude Bernard-Horner syndrome").
Ptosis (eyelid)
Ptosis is a drooping of the upper or lower eyelid. The drooping may be worse after being awake longer, when the individual's muscles are tired. This condition is sometimes called "lazy eye", but that term normally refers to amblyopia...
(ptosis) and constriction of the pupil
Miosis
Miosis is the constriction of the pupil of the eye to two millimeters or less...
(miosis), sometimes accompanied by decreased sweating
Anhidrosis
Anhidrosis means lack of sweating. It is also known by a number of other names including Adiaphoresis, Ischidrosis, Hypohidrosis, Oligidria, Oligohidrosis and Sweating deficiency.-Causes:...
of the face on the same side; redness of the conjunctiva
Conjunctiva
The conjunctiva covers the sclera and lines the inside of the eyelids. It is composed of rare stratified columnar epithelium.-Function:...
of the eye is often also present. It indicates a problem with the sympathetic nervous system
Sympathetic nervous system
The sympathetic nervous system is one of the three parts of the autonomic nervous system, along with the enteric and parasympathetic systems. Its general action is to mobilize the body's nervous system fight-or-flight response...
, a part of the autonomic nervous system
Autonomic nervous system
The autonomic nervous system is the part of the peripheral nervous system that acts as a control system functioning largely below the level of consciousness, and controls visceral functions. The ANS affects heart rate, digestion, respiration rate, salivation, perspiration, diameter of the pupils,...
. Medical imaging
Medical imaging
Medical imaging is the technique and process used to create images of the human body for clinical purposes or medical science...
and response to particular eye drop
Eye drop
Eye drops are saline-containing drops used as a route to administer medication in the eye. Depending on the condition being treated, they may contain steroids, antihistamines, sympathomimetics, beta receptor blockers, parasympathomimetics, parasympatholytics, prostaglandins, non-steroidal...
s may be required to identify the location of the problem and the underlying cause.
Signs and symptoms
Signs that are found in all patients on the affected side of the face include partial ptosisPtosis (eyelid)
Ptosis is a drooping of the upper or lower eyelid. The drooping may be worse after being awake longer, when the individual's muscles are tired. This condition is sometimes called "lazy eye", but that term normally refers to amblyopia...
(drooping of the upper eyelid from loss of sympathetic innervation to the superior tarsal muscle
Superior tarsal muscle
The superior tarsal muscle is a smooth muscle adjoining the levator palpebrae superioris muscle that helps to raise the upper eyelid.-Structure:...
, also known as Müller's
Johannes Peter Müller
Johannes Peter Müller , was a German physiologist, comparative anatomist, and ichthyologist not only known for his discoveries but also for his ability to synthesize knowledge.-Early years and education:...
muscle); upside-down ptosis (slight elevation of the lower lid); anhidrosis
Anhidrosis
Anhidrosis means lack of sweating. It is also known by a number of other names including Adiaphoresis, Ischidrosis, Hypohidrosis, Oligidria, Oligohidrosis and Sweating deficiency.-Causes:...
(decreased sweating on the affected side of the face); miosis
Miosis
Miosis is the constriction of the pupil of the eye to two millimeters or less...
(small pupils); enophthalmos
Enophthalmos
Enophthalmos is the recession of the eyeball within the orbit.It may be a congenital anomaly, or be acquired as a result of trauma , Horner's syndrome, silent sinus syndrome, or phthisis bulbi....
(the impression that the eye is sunk in); loss of ciliospinal reflex
Ciliospinal reflex
The ciliospinal reflex consists of dilation of the ipsilateral pupil in response to pain applied to the neck, face, and upper trunk. If the right side of the neck is subjected to a painful stimulus, the right pupil dilates . This reflex is absent in Horner's syndrome and lesions involving the...
; and bloodshot
Red eye (medicine)
In medicine, red eye is a non-specific term to describe an eye that appears red due to illness, injury, or some other condition. Conjunctivitis and subconjunctival hemorrhage are two forms of a red eye....
conjunctiva
Conjunctiva
The conjunctiva covers the sclera and lines the inside of the eyelids. It is composed of rare stratified columnar epithelium.-Function:...
, depending on the site of lesion. Sometimes there is flushing
Flushing (physiology)
For a person to flush is to become markedly red in the face and often other areas of the skin, from various physiological conditions. Flushing is generally distinguished, despite a close physiological relation between them, from blushing, which is milder, generally restricted to the face, cheeks or...
on the affected side of the face due to dilation of blood vessels under the skin. The pupil's light reflex is maintained as this is controlled via the parasympathetic nervous system.
In children, Horner's syndrome sometimes leads to heterochromia
Heterochromia
In anatomy, heterochromia refers to a difference in coloration, usually of the iris but also of hair or skin. Heterochromia is a result of the relative excess or lack of melanin...
: a difference in eye color between the two eyes. This happens because a lack of sympathetic stimulation in childhood interferes with melanin
Melanin
Melanin is a pigment that is ubiquitous in nature, being found in most organisms . In animals melanin pigments are derivatives of the amino acid tyrosine. The most common form of biological melanin is eumelanin, a brown-black polymer of dihydroxyindole carboxylic acids, and their reduced forms...
pigmentation of the melanocyte
Melanocyte
-External links: - "Eye: fovea, RPE" - "Integument: pigmented skin"...
s in the superficial stroma
Stroma of iris
The stroma of the iris consists of fibers and cells.The former are made up of delicate bundles of fibrous tissue; a few fibers at the circumference of the iris have a circular direction; but the majority radiate toward the pupil, forming by their interlacement delicate meshes in which the vessels...
of the iris
Iris (anatomy)
The iris is a thin, circular structure in the eye, responsible for controlling the diameter and size of the pupils and thus the amount of light reaching the retina. "Eye color" is the color of the iris, which can be green, blue, or brown. In some cases it can be hazel , grey, violet, or even pink...
.
In veterinary medicine, signs can include partial closure of the third eyelid, or nictitating membrane
Nictitating membrane
The nictitating membrane is a transparent or translucent third eyelid present in some animals that can be drawn across the eye for protection and to moisten it while maintaining visibility. Some reptiles, birds, and sharks have a full nictitating membrane; in many mammals, there is a small...
.
Causes
Horner syndrome is acquired as a result of disease but may also be congenital (inborn) or iatrogenic (caused by medical treatment). Although most causes are relatively benign, Horner syndrome may reflect serious disease in the neck or chest (such as a Pancoast tumorPancoast tumor
A Pancoast tumor, also called a pulmonary sulcus tumor or superior sulcus tumor, is a tumor of the pulmonary apex. It is a type of lung cancer defined primarily by its location situated at the top end of either the right or left lung. It typically spreads to nearby tissues such as the ribs and...
(tumor in the apex of the lung) or thyrocervical venous dilatation).
- Due to lesion or compression of one side of the cervical or thoracic sympathetic chain, which generates symptoms on the ipsilateral (same side as lesion) side of the body.
- Lateral medullary syndromeLateral medullary syndromeLateral medullary syndrome is a disease in which the patient has a constellation of neurologic symptoms due to injury to the lateral part of the medulla in the brain, resulting in tissue ischemia and necrosis.-Signs and symptoms:This syndrome is characterized by sensory deficits affecting...
- Cluster headacheCluster headacheCluster headache, nicknamed "suicide headache", is a neurological disease that involves, as its most prominent feature, an immense degree of pain in the head. Cluster headaches occur periodically: spontaneous remissions interrupt active periods of pain. The cause of the disease is currently unknown...
- combination termed Horton's headache - TraumaPhysical traumaTrauma refers to "a body wound or shock produced by sudden physical injury, as from violence or accident." It can also be described as "a physical wound or injury, such as a fracture or blow." Major trauma can result in secondary complications such as circulatory shock, respiratory failure and death...
- base of neck, usually blunt trauma, sometimes surgery. - Middle ear infection
- Tumors - often bronchogenic carcinoma of the superior fissure (Pancoast tumorPancoast tumorA Pancoast tumor, also called a pulmonary sulcus tumor or superior sulcus tumor, is a tumor of the pulmonary apex. It is a type of lung cancer defined primarily by its location situated at the top end of either the right or left lung. It typically spreads to nearby tissues such as the ribs and...
) on apex of lung - Aortic aneurysmAortic aneurysmAn aortic aneurysm is a general term for any swelling of the aorta to greater than 1.5 times normal, usually representing an underlying weakness in the wall of the aorta at that location...
, thoracic - Neurofibromatosis type 1
- GoitreGoitreA goitre or goiter , is a swelling in the thyroid gland, which can lead to a swelling of the neck or larynx...
- Dissecting aortic aneurysm
- Thyroid carcinoma
- Multiple sclerosisMultiple sclerosisMultiple sclerosis is an inflammatory disease in which the fatty myelin sheaths around the axons of the brain and spinal cord are damaged, leading to demyelination and scarring as well as a broad spectrum of signs and symptoms...
- Cervical ribCervical ribA cervical rib is a supernumerary rib which arises from the seventh cervical vertebra. It is a congenital abnormality located above the normal first rib. A cervical rib is present in only about 1 in 500 of people; in even rarer cases, an individual may have two cervical ribs...
traction on stellate ganglion - Carotid artery dissectionCarotid artery dissectionCarotid artery dissection is a separation of the layers of the artery wall supplying oxygen-bearing blood to the head and brain, and is the most common cause of stroke in young adults...
- Klumpke paralysisKlumpke paralysisNamed after Augusta Déjerine-Klumpke, Klumpke's paralysis is a variety of partial palsy of the lower roots of the brachial plexus. The brachial plexus is a network of spinal nerves that originates in the back of the neck, extends through the axilla , and gives rise to nerves to the upper limb...
- Cavernous sinus thrombosisCavernous sinus thrombosisCavernous sinus thrombosis is the formation of a blood clot within the cavernous sinus, a cavity at the base of the brain which drains deoxygenated blood from the brain back to the heart. The cause is usually from a spreading infection in the nose, sinuses, ears, or teeth. Staphylococcus aureus...
- SympathectomySympathectomyA Sympathectomy is a procedure during which at least one sympathetic ganglion is removed.An example is endoscopic thoracic sympathectomy....
- SyringomyeliaSyringomyeliaSyringomyelia is a generic term referring to a disorder in which a cyst or cavity forms within the spinal cord. This cyst, called a syrinx, can expand and elongate over time, destroying the spinal cord. The damage may result in pain, paralysis, weakness, and stiffness in the back, shoulders, and...
- Nerve blockNerve blockRegional nerve blockade, or more commonly nerve block, is a general term used to refer to the injection of local anesthetic onto or near nerves for temporary control of pain. It can also be used as a diagnostic tool to identify specific nerves as pain generators...
s, such as cervical plexus block, stellate ganglion or interscalene block - As a complication of tube thoracostomy
- A Horner's syndrome may occur during a MigraineMigraineMigraine is a chronic neurological disorder characterized by moderate to severe headaches, and nausea...
attack and be relieved afterwards
Pathophysiology
Horner syndrome is due to a deficiency of sympatheticSympathetic nervous system
The sympathetic nervous system is one of the three parts of the autonomic nervous system, along with the enteric and parasympathetic systems. Its general action is to mobilize the body's nervous system fight-or-flight response...
activity.
The site of lesion to the sympathetic outflow is on the ipsilateral side of the symptoms.
The following are examples of conditions that cause the clinical appearance of Horner's syndrome:
- First-order neuron disorder: Central lesions that involve the hypothalamospinal tractHypothalamospinal tractThe hypothalamospinal tract connects the thalamus to the ciliospinal center of the intermediolateral cell column in the spinal cord . It is found in the dorsolateral quadrant of the lateral funiculus, in the lateral tegmentum of the medulla, pons and midbrain. Lesions of the hypothalamospinal tract...
(e.g. transection of the cervical spinal cord). - Second-order neuron disorder: Preganglionic lesions (e.g. compression of the sympathetic chain by a lung tumor).
- Third-order neuron disorder: Postganglionic lesions at the level of the internal carotid artery (e.g. a tumor in the cavernous sinusCavernous sinusThe cavernous sinus , within the human head, is a large collection of thin-walled veins creating a cavity bordered by the temporal bone of the skull and the sphenoid bone, lateral to the sella turcica.-Contents:...
or a carotid artery dissection). - Partial Horner's syndrome In case of a third-neuron disorder, anhidrosis is limited to the middle part of the forehead or can be absent, resulting in a partial Horner's syndrome.
If someone has impaired sweating above the waist affecting only one side of the body, yet they do not have a clinically apparent Horner's syndrome, then the lesion is just below the stellate ganglion
Stellate ganglion
The stellate ganglion is a sympathetic ganglion formed by the fusion of the inferior cervical ganglion and the first thoracic ganglion...
in the sympathetic chain.
Diagnosis
Three tests are useful in confirming the presence and severity of Horner syndrome:- Cocaine drop test: CocaineCocaineCocaine is a crystalline tropane alkaloid that is obtained from the leaves of the coca plant. The name comes from "coca" in addition to the alkaloid suffix -ine, forming cocaine. It is a stimulant of the central nervous system, an appetite suppressant, and a topical anesthetic...
eyedrops block the reuptake of norepinephrineNorepinephrineNorepinephrine is the US name for noradrenaline , a catecholamine with multiple roles including as a hormone and a neurotransmitter...
resulting in the dilationMydriasisMydriasis is a dilation of the pupil due to disease, trauma or the use of drugs. Normally, the pupil dilates in the dark and constricts in the light to respectively improve vividity at night and to protect the retina from sunlight damage during the day...
of a normal pupil. However, in Horner's syndrome the lack of norepinephrine in the synaptic cleft causes mydriaticMydriasisMydriasis is a dilation of the pupil due to disease, trauma or the use of drugs. Normally, the pupil dilates in the dark and constricts in the light to respectively improve vividity at night and to protect the retina from sunlight damage during the day...
failure. A more recently introduced approach that is more dependable and obviates the difficulties in obtaining cocaine is to apply the alpha-agonist apraclonidineApraclonidineApraclonidine , also known as Iopidine, is a sympathomimetic used in glaucoma therapy. It is an α2-adrenergic agonist and a weak alpha-1 adrenergic receptor agonist....
to both eyes and observe the reversal of miosis on the affected side of Horner syndrome (the opposite effect to what the cocaine test would produce in the presence of Horner's). - Paredrine test: This test helps to localize the cause of the miosis. If the third order neuron (the last of three neurons in the pathway which ultimately discharges norepinephrine into the synaptic cleft) is intact, then the amphetamine causes neurotransmitter vesicle release, thus releasing norepinephrine into the synaptic cleft and resulting in robust mydriasis of the affected pupil. If the lesion itself is of the third order neuron, then the amphetamine will have no effect and the pupil remains constricted. There is no pharmacological test to differentiate between a first and second order neuron lesion.
- Dilation lag test
It is important to distinguish the ptosis
Ptosis (eyelid)
Ptosis is a drooping of the upper or lower eyelid. The drooping may be worse after being awake longer, when the individual's muscles are tired. This condition is sometimes called "lazy eye", but that term normally refers to amblyopia...
caused by Horner's syndrome from the ptosis caused by a lesion to the oculomotor nerve
Oculomotor nerve
The oculomotor nerve is the 3rd of 12 paired cranial nerves. It enters the orbit via the superior orbital fissure and controls most of the eye's movements, including constriction of the pupil and maintaining an open eyelid by innervating the Levator palpebrae superiors muscle. The optic nerve is...
. In the former, the ptosis occurs with a constricted pupil (due to a loss of sympathetics to the eye), whereas in the latter, the ptosis occurs with a dilated pupil (due to a loss of innervation to the sphincter pupillae). In a clinical setting, these two ptoses are fairly easy to distinguish. In addition to the blown pupil in a CNIII (oculomotor nerve
Oculomotor nerve
The oculomotor nerve is the 3rd of 12 paired cranial nerves. It enters the orbit via the superior orbital fissure and controls most of the eye's movements, including constriction of the pupil and maintaining an open eyelid by innervating the Levator palpebrae superiors muscle. The optic nerve is...
) lesion, this ptosis is much more severe, occasionally occluding the whole eye. The ptosis of Horner syndrome can be quite mild or barely noticeable (partial ptosis).
When anisocoria
Anisocoria
-Causes:In the absence of the iris or eyeball proper, anisocoria is usually the result of a defect in efferent nervous pathways controlling the pupil traveling in the oculomotor nerve or the sympathetic pathways...
occurs and the examiner is unsure whether the abnormal pupil is the constricted or dilated one, if a one-sided ptosis is present then the abnormally sized pupil can be presumed to be on the side of the ptosis.
History
It is named afterEponym
An eponym is the name of a person or thing, whether real or fictitious, after which a particular place, tribe, era, discovery, or other item is named or thought to be named...
Johann Friedrich Horner
Johann Friedrich Horner
Johann Friedrich Horner was an ophthalmologist based at the University of Zurich, Switzerland.After receiving his medical degree from the University of Zurich in 1854, Horner continued his studies in Vienna and Berlin. While in Berlin, he was an assistant to the renowned ophthalmologist Albrecht...
, the Swiss
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....
ophthalmologist
Ophthalmology
Ophthalmology is the branch of medicine that deals with the anatomy, physiology and diseases of the eye. An ophthalmologist is a specialist in medical and surgical eye problems...
who first described the syndrome in 1869. Several others had previously described cases, but "Horner's syndrome" is most prevalent. In France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
and Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
, Claude Bernard
Claude Bernard
Claude Bernard was a French physiologist. He was the first to define the term milieu intérieur . Historian of science I. Bernard Cohen of Harvard University called Bernard "one of the greatest of all men of science"...
is also epitomized with the condition ("Claude Bernard-Horner syndrome").