Claude Bernard-Horner syndrome: causes, symptoms, diagnosis and treatment

What is Horner's syndrome?

Horner syndrome ( Bernard-Horner syndrome , oculosympathetic syndrome ) is a rare disease characterized by miosis (constriction of the pupil), ptosis (drooping of the upper eyelid), ahidrosis (lack of facial sweating) and enophthalmos (deeper than normal immersion of the eyeball in the bone cavity (orbit) protecting the eye). These are the four classic signs of the disorder.

The syndrome is caused by damage to the sympathetic nerves of the face. The underlying causes of Horner's syndrome vary greatly and can include anything from a snake or insect bite to blunt force trauma to the neck, tumor, stroke, and underlying diseases affecting the areas surrounding the sympathetic nerves.

In rare cases, oculosympathetic syndrome is congenital (present from birth) and may be associated with a lack of pigmentation in the iris (the colored part of the eye). Treatment for Horner's syndrome depends on the underlying cause.

Classification

In addition to the idiopathic (pathology independent of other diseases) and secondary type (the symptom complex acts as a consequence of another disease), the syndrome is classified according to the degree of damage to the neural chain. If the first neuron is affected, then most likely the disease arose against the background of damage to the spinal cord. If it is possible to establish that the second neuron is affected, then we can say that compression of the sympathetic nerve occurs against the background of an increase in the tumor. Damage to the third neuron often occurs against the background of damage to motor fibers.

Symptoms and signs

The characteristic physical signs and symptoms associated with oculosympathetic syndrome usually affect only one side of the face. These include:

• drooping upper eyelid;
• constriction of the pupil;
• dryness (lack of sweating) on ​​the same side of the face (ipsilateral) as the affected eye;
• and a deeper position of the eyeball in the orbit than normal.

If Horner's syndrome occurs before the age of two, the colored parts of the eyes (iris) may be different colors (heterochromia). In most cases, the iris on the affected side lacks color (hypopigmentation).

Prevention of enophthalmos

There is no specific prevention for Horner's syndrome. Nonspecific methods boil down to timely detection and treatment of pathologies of the ENT organs and thyroid gland. Correction of hormonal levels is of no small importance. If there are space-occupying formations in the orbit, the person should be registered with an ophthalmologist.

Horner's syndrome is a serious pathology that can lead to negative health consequences. To cope with the disorder, you need to consult a doctor in a timely manner and follow his recommendations.

Causes of Horner's syndrome

Oculosympathetic syndrome can be caused by any of a variety of factors. The main reasons are described in the table below:

Possible complications

Every person diagnosed with the syndrome should understand the risk if left untreated. First of all, the disease is dangerous because an inflammatory process can begin in the organs of vision: blepharitis, conjunctivitis or keratitis. Recession of the eyeball promotes increased penetration of infectious agents into the organ of vision. In severe cases, even an orbital abscess develops or phlegmon forms.

There is a certain risk of developing xerophthalmia due to changes in the topography of the eyeball.

The congenital syndrome, which is quite rare, often leads to the development of heterochromia.

One of the most common complications is secondary hemeralopia. This disease is difficult to respond to traditional methods of treatment.

Diagnostics

The doctor suspects Bernard-Horner syndrome based on the symptoms.

To confirm the diagnosis of Horner's syndrome and find out the location of the damage, the doctor conducts a two-part study:

1. First, the doctor puts drops containing a small amount of cocaine or apraclonidine into both eyes.
2. If oculosympathetic syndrome is possible, then after 48 hours the doctor conducts another study. He puts hydroxyamphetamine drops in both eyes.

The reaction of the pupils to drugs allows us to determine whether an oculosympathetic syndrome is likely and helps to determine the location of the damage.

To rule out tumors and other serious diseases that can destroy the nerve fibers connecting the brain and eye, the patient has a magnetic resonance imaging (MRI) or computed tomography (CT) scan of the brain, spinal cord, chest, or neck.

Diagnostic tests

The diagnosis is established if Horner's triad is identified:

• ptosis of the upper and lower eyelids;
• constriction of the pupil;
• lag in pupil dilatation.

The photo shows three clear signs of the syndrome.

There are several diagnostic techniques to clarify the true syndrome:

1. Instillation of an M-anticholinergic solution into the eyes, which causes dilatation of the pupil. If there is no reaction, then the syndrome is confirmed, since it reduces the ability to adapt to changes in lighting.
2. The drug "Apraclonidine" is an alpha-adrenergic agonist. Under its action, the pupil affected by the syndrome dilates due to increased sensory denervation, and the normal pupil narrows slightly.
3. There is a test to differentiate the affected neuron using "Hydroxyamphetamine", which causes the release of norepinephrine from intact adrenergic nerve endings and dilation of the pupil. If, an hour after exposure to eye drops, both pupils are dilated, then a 1st or 2nd order neuron is affected. If the constricted pupil cannot dilate, then this is a 3rd order neuron lesion.

Horner's syndrome must be differentiated from chronic uveitis, third cranial nerve palsy, aponeurotic ptosis, and ocular myasthenia. Magnetic resonance imaging reveals tumors and vascular changes that could provoke Horner's syndrome.

Disorders with similar symptoms

Symptoms of the following disorders may be similar to those of Horner syndrome. Comparisons may be useful for differential diagnosis.

• Adie syndrome (also called Holmes-Adie syndrome or Adie tonic pupil) is a rare neurological disorder that affects the pupil of the eye. Symptoms of the syndrome include a large (dilated) pupil and slow reaction to light or focusing on nearby objects. In some patients, the pupil may be smaller rather than dilated. Absent or poor reflexes are also associated with the disorder.
• Wallenberg-Zakharchenko syndrome (dorsolateral medullary syndrome, lateral medullary infarction syndrome) is a rare disease caused by a thrombus (blood clot). It is characterized by difficulty pronouncing words due to a disease of the central nervous system, difficulty swallowing, staggering gait, dizziness, low fluid pressure in the eyeball, giving it a round shape, lack of coordination during voluntary movements, rapid involuntary movement of the eyeball, signs of Horner's syndrome on the side where the lesion is present, and loss of pain and temperature sensations on the side of the body opposite to the lesion.

Other techniques

Treatment of Claude Bernard-Horner syndrome can be carried out using kinesitherapy together with neurostimulation. The essence of the technique is the effect of electric current on the affected nerves and muscles. At the same time it is possible to influence the transverse and smooth muscles. This type of treatment improves the circulation of lymph and blood and activates metabolism. However, you should know that this technique is quite painful, which the doctor must warn the patient about. The doctor himself who performs such procedures must be very highly qualified, since even one wrong movement can lead to aesthetic and cosmetic damage to the face.

Kinesiotherapy is a special therapeutic load (stimulating massage) on the organs of vision.

Treatment of Horner's syndrome

In general, the appropriate treatment for Horner's syndrome depends on the underlying cause. The goal of treatment is to eliminate the underlying disease or injury. However, in many cases there is no effective treatment. Rapid recognition of the syndrome and appropriate referral to appropriate specialists are vital.

Whether surgery is required and what type of surgery is needed depends on the specific cause of Horner's syndrome. Potential surgical interventions include neurosurgical treatment of aneurysm-related oculosympathetic syndrome and vascular surgical treatment of causative conditions such as carotid artery dissection or aneurysm.

Patients and their families may benefit from genetic counseling if a genetic form of this disorder is present. Other treatment is symptomatic and supportive.

Plastic surgery

In the presence of Claude Bernard-Horner syndrome, it is advisable to resort to plastic surgery if the manifestations of the disease are too pronounced. The operation allows you to restore the normal shape of the eyelid and palpebral fissure.

As a result, the patient is saved from ptosis and the cosmetic defect is eliminated, which radically changes the patient’s appearance for the better. However, surgery is indicated in late, advanced stages of the disease.

Clinical features

Ptosis

The ipsilateral upper eyelid appears slightly drooping due to paresis of the Müller muscle, a sympathetically innervated smooth muscle that also functions as an upper eyelid retractor.

This ptosis can be subtle, variable, and go unnoticed. Additionally, one study noted that 12% of patients with Horner syndrome had virtually no ptosis (Figure 1).

The smooth muscle fibers of the lower eyelid retractors also lose sympathetic supply, and the lower eyelid appears slightly raised. This type has been called "inverted ptosis" or "inverse ptosis".

The combination of upper eyelid ptosis and lower eyelid elevation narrows the palmar fissure, resulting in visible enophthalmos. This apparent enophthalmos has no measurable significance and is not true enophthalmos.

Signs

Oculosympathetic paresis results in weakness of the iris dilator muscle on the affected side. The unmatched parasympathetic action of the iris constrictor muscle produces a smaller ipsilateral pupil. The resulting anisocoria is most obvious in the dark and may be missed if the patient is assessed in bright light.

Several factors influence the degree of anosocoria in patients with Horner's syndrome. For example, when there is fatigue or drowsiness, the size of the pupils and the degree of anisocoria decrease as the hypothalamic sympathetic outflow to both eyes decreases and the parasympathetic is weakened.

The actual degree of anisocoria varies depending on the size of the resting pupils, alertness, fixation of the patient at a distance and near, the brightness of the light, the completeness of the damage, and the concentration of circulating adrenergic substances in the blood.

Paresis of the iris dilator musculature also impairs pupillary movement during dilatation—called lag dilatation.

Dilatation can be seen clinically by illuminating the patient's eyes tangentially from below with a hand-held flashlight, then sharply turning the room light.

A normal pupil will dilate immediately, but with Horner it begins to dilate after a few seconds. The difference in anisocoria is greater after 4-5 seconds of darkness.

If both pupils are observed simultaneously within 15-20 seconds after turning off the lights in the room, then an initial increase in the degree of anisocoria is observed, followed by a decrease in anisocoria.

Photographing in the dark after 5 seconds, again after 15 seconds, reveals a decrease in anisocoria in the later phase of dilatation. A single anisocoria measurement taken during the first 5 seconds of darkness is adequate to determine dilatation lag. The diagnosis should not be dismissed in the absence of obvious lag in substitution of the smaller pupil.

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Irochomia Iris

It is hypothesized that sympathetic innervation is required for melanin production by stromal melanocytes. Interruption of sympathetic supply leads to hypochromia of the iris on the affected side. This is a typical feature of congenital Horner's syndrome.

Sometimes observed in patients with acquired syndrome, never in patients with acute or recently acquired Horner's syndrome.

Anhidrosis

Characteristic vasomotor and sudomotor changes in facial skin occur on the affected side in some patients with Horner's syndrome. Immediately after sympathetic denervation, skin temperature rises lateral to the lesion due to loss of vasomotor control and subsequent dilation of blood vessels.

In addition, during the acute stage it happens:

• conjunctival hyperemia,
• epiphora,
• nasal congestion.

Some time after the injury, the skin of the face and neck has a lower temperature and is paler than that of the normal side. This comes from the hypersensitivity of the blood vessels. However, in modern temperature-controlled environments, patients rarely complain of sweating problems.

Paradoxical unilateral sweating with redness of the face, neck, shoulders, and arms may be late, caused by surgery, after cervical sympathectomy.