Horner’s Syndrome – Symptoms and Causes
Overview
Horner syndrome affects one side of the face and eye when certain nerve pathways between the brain and the face are disrupted. The most noticeable sign is a smaller pupil size on the affected side.
People with this condition typically show three main symptoms:
- Decreased pupil size (miosis)
- Drooping of the upper eyelid (ptosis)
- Reduced sweating on the affected side of the face
These symptoms appear only on one side of the face, creating an asymmetrical appearance. Medical professionals can identify Horner syndrome by looking for these characteristic changes.
There is no specific treatment designed only for Horner syndrome itself. Instead, doctors focus on finding and treating the underlying cause.
Sometimes doctors cannot identify what causes the condition. If the underlying problem can be successfully treated, nerve function may improve or return to normal. This condition is sometimes called oculosympathetic palsy by medical professionals.
Signs and Symptoms
Horner syndrome typically affects just one side of the face. People with this condition often show several noticeable changes.
The affected eye usually has a smaller pupil than normal. This creates a visible difference in pupil size between the two eyes. The smaller pupil also responds poorly in dim lighting, opening slowly or very little.
Other common signs include:
- Drooping of the upper eyelid
- Slight raising of the lower eyelid
- A sunken appearance of the affected eye
- Reduced or absent sweating on the affected side of the face
These symptoms can sometimes be hard to notice, especially the drooping eyelid and sweating problems.
In Children
Children with Horner syndrome may show additional signs:
- Babies under 1 year old might have a lighter-colored iris in the affected eye
- The affected side of the face may not change color normally during:
- Physical activity
- Exposure to heat
- Emotional responses
These color-related symptoms are unique to young patients and can help with early diagnosis.
When to See a Doctor
You should get emergency medical help if you notice signs of Horner syndrome that come on suddenly. This is especially important after an injury or if you have other symptoms at the same time.
Contact a doctor right away if you experience:
- Vision problems
- Feeling dizzy
- Trouble speaking clearly
- Problems walking
- Muscle weakness
- Loss of muscle control
- Sudden severe headache
- Intense neck pain
Getting a quick and accurate diagnosis is important since Horner syndrome can be caused by various conditions, ranging from mild to serious.
What Causes Horner Syndrome
Horner syndrome happens when the sympathetic nervous system gets damaged. This part of the nervous system controls many automatic body functions like heart rate, pupil size, and sweating. The damage can occur in different parts of the nerve pathway.
Possible causes include:
| Potential Causes | Description |
|---|---|
| Stroke | Disruption of blood flow to the brain |
| Tumors | Abnormal growths that press on nerves |
| Spinal cord injury | Trauma affecting nerve pathways |
Problems in the Brain and Upper Spinal Cord
Damage to the first set of nerve cells can cause Horner syndrome. These nerves run from the hypothalamus through the brainstem and into the upper spinal cord. Several issues can harm these nerves:
- Stroke
- Tumors
- Diseases that damage nerve coverings
- Neck injuries
- Spinal cysts
Chest and Neck Issues
The second group of nerve cells goes from the spine across the upper chest to the neck. Damage here might come from:
- Lung cancer
- Nerve sheath tumors
- Aorta damage
- Chest surgery complications
- Injuries to the area
Face and Eye Connection Problems
The third set of nerve cells runs along the neck to the face, affecting the eyes and skin. Problems here can include:
- Carotid artery damage
- Jugular vein injuries
- Tumors or infections near the skull base
- Migraine headaches
- Cluster headaches
Childhood Causes
Children may develop Horner syndrome from different sources:
- Birth injuries affecting the neck or shoulders
- Born with aorta defects
- Neuroblastoma (a type of tumor affecting nerve cells)
When the Cause Isn’t Found
Sometimes doctors cannot identify why Horner syndrome develops. This is called idiopathic Horner syndrome. Some cases remain unexplained despite modern testing.
