A Potential Innovation in Treatment for Neurogenic Cough: Superior Laryngeal Nerve Block

long hacking spells

To perform a superior laryngeal nerve block, a lidocaine derivative mixed with a triamcinolone steroid is injected into the superior laryngeal nerve.

Neurogenic cough might begin as barely a tickle, or long hacking spells — but after weeks, months or years, how it can be remedied is often a puzzle for doctors and patients, says laryngologist and endocrine surgeon Vaninder Dhillon

“These patients experience a lot of social, professional and personal dysfunction,” Dhillon says. “Coughing takes over their lives, with no relief in sight.”

Patients with this condition — marked by hypersensitivity of sensory receptors of the larynx — usually see Dhillon after other providers can’t find evidence for more common diagnoses of chronic cough, such as gastroesophageal reflux, sinonasal allergy, or reactive airway conditions such as asthma or chronic obstructive pulmonary disease. If her work-up mirrors these findings, Dhillon says, patients have a few options.

The standard of care is currently two treatments used together or separately: therapy with a speech-language pathologist to help patients make behavioral shifts, such as changes in hydration and cough suppression techniques; and neuromodulators, a class of medications often prescribed for neuropathies and other forms of chronic pain. Although these treatments can be successful in reducing cough, they have major drawbacks, Dhillon says. Behavioral therapy requires a significant commitment from patients, and medications come with side effects such as drowsiness, nausea, headaches and memory loss.

Nerve Block May Have Advantages over Existing Approaches

Dhillon and colleagues including Lee Akst, Simon Best and Alexander Hillel, have begun exploring another option to treat patients with neurogenic cough: superior laryngeal nerve block, a procedure sometimes used to anesthetize the larynx during intubation and for throat pain control. Several years ago, doctors at Johns Hopkins and a few other academic medical centers across the country started investigating this treatment as an alternative for patients who haven’t been successfully treated using behavioral therapy and neuromodulators. Johns Hopkins is currently the only center in the mid-Atlantic region offering this procedure for neurogenic cough.

Dhillon explains that nerve blocks offer several advantages when compared with the current standard of care, including essentially no side effects and high patient compliance. The technique is also feasible, fast and relatively safe to do in-office, she adds.

To perform a nerve block, Dhillon typically uses a combination of a lidocaine derivative mixed with a triamcinolone steroid in a 1-to-1 ratio. She then injects 2 milliliters of this solution into the superior laryngeal nerve, located through manual palpation on the lateral edges between the hyoid bone and thyroid cartilage. Many patients have a trigger point activated through palpation, providing another clue to pinpoint the injection site.

Every two weeks, patients receive an injection contralaterally until the severity of their symptoms, gauged by scores on the Cough Severity Index, reduces by at least 50%. Most patients receive relief after an average of three injections, Dhillon says, a result she recently reported in the journal OTO Open. Although the mechanism for this effect isn’t yet known, she says, the improvement in patients’ quality of life is clear.

“They can do things they’ve had to give up, like eating out, public speaking or singing in a choir,” Dhillon says. “Patients feel like they have control over their cough and that their cough doesn’t control them.”

To refer a patient or schedule an appointment, call 443-997-6467