Horner’s syndrome is a rarely diagnosed neurological condition that can have serious consequences for a patient’s health. Learn about its main symptoms, causes and treatment methods.
Horner syndrome – what is it?
Horner syndrome, also known as Claude Bernard-Horner syndrome, is a neurological disorder characterized by interruption of the sympathetic innervation of the eye between the center in the brainstem and the eye itself. The disease can have different causes and manifest at different levels of the nervous system. Damage can occur at the level of the first neuron of the hypothalamus-spinal pathway, for example, with damage to the cervical spinal cord. It can also occur at the level of the second neuron before the ganglion, such as when the sympathetic trunk is compressed by a lung tumor, or after switching fibers in the ganglia, such as at the level of the internal carotid artery or in tumors of the cavernous sinus.
In children, Horner’s syndrome can lead to a phenomenon called heterochromia, which is different colored irises. In this disease, the iris on the side affected by the syndrome is paler. The syndrome is named after Johann Friedrich Horner, who first described it in 1869.
Symptoms related to the organ of vision in Horner syndrome include ptosis, a narrowing of the eyelid strabismus on the affected side, caused by weakness of the upper and lower thyroid muscles. Another symptom is miosis, or narrowing of the pupil of the eye on the affected side. In Horner syndrome, enophthalmus, an apparent collapse of the eyeball into the orbit, is also described, but this is an illusion due to narrowing of the eyelid stroma.
One tumor that can compress the sympathetic nerve and lead to Horner’s syndrome is Pancoast’s tumor. In this case, sympathetic activity in the area innervated by the sympathetic trunk disappears, leading to the ocular symptoms mentioned earlier, as well as additional symptoms such as impaired perspiration on the part of the face on the affected side or diastasis of the cutaneous vasculature resulting in dilation.
Symptoms of Horner’s syndrome
Horner ‘s syndrome is characterized by a number of symptoms mainly related to the organ of vision. Among the most characteristic of these are:
- ptosis – narrowing of the eyelid stroma on the affected side, caused by paralysis or weakness of the upper and lower thyroid muscles innervated sympathetically,
- miosis – constriction of the pupil of the eye on the affected side, caused by the action of the pupil sphincter muscle without dilation opposition, resulting in pupillary inequality (anisocoria); the pupil does not dilate in the dark,
- deficient iris pigmentation – the iris on the side affected by the syndrome is lighter, which is particularly noticeable if the lesion is congenital or long-standing,
- the pupil dilates very slowly,
- enophthalmus – an apparent collapse of the eyeball into the orbit, which is an illusion resulting from narrowing of the eyelid strabismus due to paralysis of the upper and lower thyroid muscles.
In addition to these symptoms, Horner’s syndrome may present with additional symptoms such as anhidrosis – impaired perspiration on the part of the face on the affected side, and vasodilatio – diastasis of the cutaneous vascular musculature resulting in dilation. It is also worth noting the apparent exophthalmos and a transient decrease in ocular pressure, as well as changes in the composition of tears.
Causes of Horner syndrome
Hornersyndrome can result from a number of different causes that lead to interruption of the sympathetic innervation of the eye. The key factor is damage to the nerve pathways, which can be caused by a variety of factors:
- Injury: Direct damage to nerves or tissues in the area can lead to symptoms of Horner’s syndrome. For example, an injury to the neck or head can damage the nerve pathways leading to the eye.
- Pancoast tumor: This is a tumor that develops in the top of the lung that can compress the sympathetic nerve, leading to symptoms of Horner’s syndrome.
- Stroke: A stroke in the brain or spinal cord can damage the nerve pathways responsible for the sympathetic innervation of the eye.
- Surgery: Surgery in the neck, chest or head area can lead to nerve damage and Horner syndrome symptoms.
- Other neurological conditions: Diseases such as multiple sclerosis, brain or spinal cord tumors and neuritis can lead to Horner syndrome symptoms.
It is important to understand that Horner’s syndrome is a set of symptoms, not an independent disease. This means that it is the result of other conditions or injuries. Therefore, diagnosing the cause of Horner’s syndrome is crucial for appropriate treatment and management of the patient’s condition.
Horner syndrome in the dog
Horner ‘s syndrome in dogs is a neurological condition that can occur in any breed, although some breeds may be more susceptible. Although the causes of this syndrome in dogs can vary, it is most often the result of trauma, tumor, inflammation or spinal cord disease.
The symptoms of Horner syndrome in dogs are similar to those in humans. The most characteristic symptoms include drooping eyelids, narrowing of the pupil and lack of sweating on the affected side of the face. Dogs may also experience a change in the color of the iris and variegated irises. In many cases, these symptoms can be subtle and difficult to notice without an accurate diagnosis.
Diagnosis of Horner’s syndrome in dogs includes a neurological examination, an eye examination and additional imaging studies such as CT scans and MRIs. Treatment depends on the cause of the syndrome and may include drug treatment, surgery or radiation therapy. In the case of injuries or tumors, early detection and treatment is important to prevent further complications.
It is also worth noting that Horner’s syndrome in dogs is not a life-threatening condition, but can be a symptom of a more serious condition. Therefore, it is important for dog owners to be aware of the symptoms and seek veterinary help if they occur.
Treatment of Horner syndrome
Horner ‘s syndrome is a set of symptoms, not a stand-alone disease, so treatment is mainly about addressing the cause of the syndrome. The key element is an accurate diagnosis to identify the source of the problem and treat it accordingly.
If the cause of the syndrome is a tumor, as in the case of Pancoast’s tumor, treatment may include surgery to remove the tumor, followed by radiation or chemotherapy to destroy any remaining cancer cells. In cases of injury, rehabilitation and physiotherapy may be necessary to restore normal nerve and muscle function.
In cases where the cause is a neurological disease, like multiple sclerosis, drug treatment may be used to control symptoms and slow the progression of the disease. Painkillers and anti-inflammatory drugs may also be prescribed to alleviate the symptoms associated with Horner’s syndrome.
It is important that patients undergo regular checkups and keep track of any new symptoms or changes in existing symptoms. Early detection and treatment can help prevent further complications and improve a patient’s quality of life.
Summary – Horner syndrome
Horner syndrome is a serious neurological condition that can have a variety of causes. Its early detection and treatment is key to successful therapy. Both humans and animals can suffer from this syndrome, so it is important to be aware of its symptoms and treatment options.