Chronic Cough. Is It Neurogenic?

What is Chronic Cough?

Chronic Cough simply means a cough that lasts longer than 8 weeks. There are many reasons why people can end up with a chronic cough. Well known causes of chronic cough include COPD, viral infection, post nasal drip, asthma, GERD, and more. But did you know that chronic cough can also be neurogenic in origin? Neurogenic cough (also known as Laryngeal Hyperresponsiveness or Neurogenic Laryngeal Hypersensitivity) is a condition in which the nerve that innervates the larynx becomes hypersensitive, causing you to cough more frequently. 

What is Neurogenic Cough?

The vagus nerve is the longest cranial nerve in your body and it has many different functions. It sends taste signals to the brain, sends motor signals to the soft palate and larynx, and even helps to regulate digestion and heart rhythm. It also sends sensory information from your throat (your larynx) to your brain. This is an important job! When there is something in your throat that shouldn’t be there, like mucus or food, the vagus nerve senses it and sends a signal to the brain saying, “Help! There’s a foreign body in our throat! We need to cough!!” Then, fast as lightning, the brain responds by sending a cough reflex down to the larynx. Cough! This is what is happening when we swallow something down wrong or when we get a cold and have mucus to cough up. But with Neurogenic cough, the vagus nerve has become so hypersensitive that even the smallest stimulus (cold air, a strong scent, normal body secretions, or vibrations from talking) can now trigger a cough. This often means that people with neurogenic cough end up coughing all the time! In fact, the cough can be so severe that it can truly disrupt quality of life. 

So what causes the vagus nerve to become so hypersensitized?

Great question. There is a lot of new research going on right now about what causes Neurogenic cough and how to fix it. It is believed that inflammatory, infective, or allergic factors (or some combination) can create a hypersensitive nerve. Initial causes may include an upper respiratory tract infection, inhalation of toxic fumes, allergic reactions, and more. But once the vagus nerve has become hypersensitized, the cough itself can then make it worse! The constant coughing can cause increased laryngeal inflammation, making the nerve even more sensitive, which leads to more coughing. I call it the “runaway cough train” and it can lead to a chronic severe cough that lasts months or even years. 

What can people suffering from Neurogenic cough do about it? 

First it’s important to get an accurate diagnosis. Your doctor needs to rule out any other possible factors that could be causing your cough. They will work with you to eliminate anything causing inflammation or irritation to your throat. This might include prescribing medications to reduce post nasal drip, GERD, or seasonal allergies. If you end up with a diagnosis of Neurogenic cough, your doctor will likely refer you to a specialty trained Speech Pathologist for behavioral cough therapy, including breathing retraining and cough suppression training. These therapies consist of strategies to help you stifle the cough, so that you can start to slow that runaway cough train and allow the vagus nerve time to heal. Aside from behavioral cough therapy, your doctor may prescribe a neuromodulator medication to reduce the nerve sensitivity or they may even suggest performing a superior laryngeal nerve block to dull the reactiveness of one section of your vagus nerve. 

Conclusion

If you or a loved one is diagnosed with Neurogenic chronic cough, fear not. Gaining control of your cough is possible! Reach out to a specialty trained Speech Language Pathologist to help you stop the runaway cough train and put you on the track to wellness.