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A chronic cough can be frustrating, exhausting, and difficult to explain. For some patients, the coughing continues for months despite treatment for common causes such as asthma, allergies, postnasal drip, or acid reflux.

When the usual treatments do not provide relief, the problem may not be coming from the lungs at all. Instead, an overly sensitive nerve in the throat may be contributing to the cough.

For certain patients with a neurogenic chronic cough, superior laryngeal nerve (SLN) injections may offer an additional treatment option.

What Is a Neurogenic Cough?

A neurogenic cough, often associated with cough hypersensitivity or laryngeal sensory dysfunction, occurs when the nerves involved in throat sensation and the cough reflex become overly sensitive.

Normally, coughing is an important protective reflex that helps clear irritants from the airway. However, when the cough pathway becomes hypersensitive, everyday triggers that would not normally cause a problem may produce an intense urge to cough.

Common triggers may include:

• Talking or laughing
• Cold air
• Strong scents or cleaning products
• Eating or drinking
• Exercise
• Changes in temperature
• A persistent “tickle” or irritation in the throat

Some patients notice that their symptoms began after a viral or respiratory infection. Even after the original illness resolves, the cough may persist.

What Is the Superior Laryngeal Nerve?

The superior laryngeal nerve, or SLN, plays an important role in providing sensation to the larynx, commonly known as the voice box.

This sensory information helps protect the airway and contributes to triggering the cough reflex when an irritant is detected. In patients with cough hypersensitivity, this pathway may become overly responsive, causing the cough reflex to activate too easily.

This is where an SLN injection may help.

How Does an SLN Injection Help Chronic Cough?

A superior laryngeal nerve injection is an office-based treatment used in selected patients with suspected neurogenic chronic cough.

The goal of the injection is to reduce hypersensitivity within the laryngeal sensory pathway. By targeting the area surrounding the superior laryngeal nerve, treatment may help decrease the exaggerated nerve signaling contributing to the persistent urge to cough.

In simple terms, the injection aims to calm an overly sensitive cough pathway.

Rather than treating asthma, reflux, or allergies, an SLN injection targets a different possible contributor to chronic cough: abnormal nerve sensitivity in the throat.

What Happens During an SLN Injection?

SLN injections are typically performed in an ENT clinic and usually take only a few minutes.

The ENT specialist identifies the appropriate area of the neck and administers medication near the internal branch of the superior laryngeal nerve. The specific medication and treatment approach may vary depending on the physician and the individual patient’s needs.

Some patients may require more than one injection, and injections may be performed on different sides depending on symptoms and response to treatment.

Your ENT specialist will determine the most appropriate treatment plan for you.

Does the Injection Work Right Away?

Response to treatment varies.

Some patients notice improvement in the frequency or severity of their cough following treatment, while others may require additional injections. The goal is not necessarily to eliminate every cough but to reduce cough hypersensitivity and help patients regain better control over the cough reflex.

SLN injections may also be used alongside other treatments, including cough suppression therapy with a speech-language pathologist.

Who May Be a Candidate for an SLN Injection?

An SLN injection may be considered when a chronic cough:

• Has lasted more than eight weeks
• Persists despite evaluation or treatment for common causes
• Is triggered by talking, laughing, smells, temperature changes, or other everyday stimuli
• Is associated with a persistent throat tickle or urge to cough
• Is suspected to be related to laryngeal hypersensitivity or a neurogenic cough

There is no single test that diagnoses a neurogenic cough. Before recommending an SLN injection, an ENT specialist will typically review your medical history, symptoms, previous treatments, and other possible causes of chronic cough.

A laryngeal examination may also be performed using a flexible camera to examine the throat and vocal folds.

Are There Other Treatments for Neurogenic Cough?

Yes. Treatment is individualized and may include speech-language pathology, where patients learn cough suppression techniques and strategies to interrupt the cough cycle.

Certain medications that affect nerve signaling may also be considered. However, medication side effects or an inadequate response may lead some patients and physicians to explore other options, including SLN injections.

The appropriate treatment depends on the cause of the cough, previous therapies, and the patient’s individual symptoms.

When Should You See an ENT Specialist?

A cough lasting longer than eight weeks should be medically evaluated, particularly if it is affecting sleep, work, speaking, or daily activities.

You should also seek medical attention for concerning symptoms such as coughing up blood, unexplained weight loss, significant difficulty breathing, or persistent voice changes.

The Bottom Line

Sometimes, a chronic cough is more than a lingering cold or throat irritation. In certain patients, an overly sensitive laryngeal nerve pathway may continue triggering the cough reflex long after the original cause has resolved.

Superior laryngeal nerve injections offer a targeted treatment option for selected patients with neurogenic chronic cough by addressing the nerve hypersensitivity contributing to their symptoms.

If your cough simply will not go away despite treatment, an ENT specialist with expertise in voice and laryngeal disorders can help determine whether cough hypersensitivity and potentially an SLN injection—may be part of the solution.