Supraglottic Botulinum Toxin Improves Symptoms in Patients with Laryngeal Sensory Dysfunction Manifesting as Abnormal Throat Sensation and/or Chronic Refractory Cough

Laryngeal sensory dysfunction (LSD) encompasses disorders of the vagal sensory pathways. Common manifestations include chronic refractory cough (CRC) and abnormal throat sensation (ATS). This study examined clinical characteristics and treatment outcomes of LSD using a novel approach of laryngeal supraglottic Onabotulinum toxin Type A injection (BTX). This was a retrospective review of clinical data and treatment outcomes of supraglottic BTX in patients with LSD. Between November 2019 and May 2021, 14 patients underwent 25 injection cycles of supraglottic BTX for treatment of symptoms related to LSD, including ATS and CRC. Primary outcome measures included the Newcastle Laryngeal Hypersensitivity Questionnaire (LHQ), Cough Severity Index (CSI), Reflux Symptom Index (RSI), and Voice Handicap Index-10 (VHI-10) at baseline and within three months of treatment. Pre- and post-treatment data were compared using a linear mixed model. After supraglottic BTX, LHQ scores improved by 2.6. RSI and CSI improved by 8.0 and 5.0, respectively. VHI-10 did not change as a result of treatment. Short-term response to SLN block was significantly associated with longer term response to BTX treatment. These findings suggest that LSD presents clinically as ATS and CRC along with other upper airway symptoms. Supraglottic BTX injection is a safe and effective technique in the treatment of symptoms of LSD.

When is cough functional, and how should it be treated?

Key points

Educational aims

Summary

Involuntary cough without an identified underlying organic reason has been given various names and recommended treatments. Current experience in children and adolescents suggests that “habit cough” best describes this entity, and suggestion therapy is a highly effective treatment that most physicians can learn.

Diagnosis of the functional disorder called habit cough can be readily made by the unique clinical characteristicshttp://ow.ly/Al5B3094oxj

Management and diagnosis of psychogenic cough, habit cough, and tic cough: a systematic review

BACKGROUND

Several pharmacologic and nonpharmacologic therapeutic options have been used to treat cough that is not associated with a pulmonary or extrapulmonary etiology.

METHODS

We conducted a systematic review to summarize the evidence supporting different cough management options in adults and children with psychogenic, tic, and habit cough. Medline, EMBASE, the Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and Scopus were searched from the earliest inception of each database to September 2013. Content experts were contacted, and we searched bibliographies of included studies to identify additional references.

RESULTS

A total of 18 uncontrolled studies were identified, enrolling 223 patients (46% male subjects, 96% children and adolescents). Psychogenic cough was the most common descriptive term used (90% of the studies). Most of the patients (95%) had no cough during sleep; barking or honking quality of cough was described in only eight studies. Hypnosis (three studies), suggestion therapy (four studies), and counseling and reassurance (seven studies) were the most commonly used interventions. Hypnosis was effective in resolving cough in 78% of the patients and improving it in another 5%. Suggestion therapy resolved cough successfully in 96% of the patients. The greatest majority of improvements noted with these forms of therapy occurred in the pediatric age group. The quality of evidence is low due to the lack of control groups, the retrospective nature of all the studies, heterogeneity of definitions and diagnostic criteria, and the high likelihood of reporting bias.

CONCLUSIONS

Only low-quality evidence exists to support a particular strategy to define and treat psychogenic, habit, and tic cough. Patient values, preferences, and availability of potential therapies should guide treatment choice.

Surface-evoked laryngeal sensory action potential evaluation in neurogenic chronic cough

OBJECTIVES

Neurogenic chronic cough is currently a diagnosis of exclusion. We hypothesized that surface-evoked laryngeal sensory action potential (SELSAP) testing could be used to help establish a diagnosis of laryngeal sensory neuropathy as a cause of chronic cough, based on altered SELSAP waveform morphology.

STUDY DESIGN

Retrospective cohort study.

METHODS

Laryngeal electromyographic (EMG) data including SELSAP waveform testing from patients with chronic cough were directly compared with a control population without significant laryngeal symptoms, and statistical analysis of unilateral and bilateral neuropathy injury subgroups was performed.

RESULTS

Thirty patients with a chief complaint of chronic cough underwent laryngeal EMG testing since January 2000 with needle EMG and surface nerve conduction studies. SELSAP waveform analysis of unilateral and bilateral laryngeal neuropathy demonstrated significantly lowered median SELSAP peak amplitude compared with controls (P < 0.01).

CONCLUSIONS

Patients with suspected neurogenic chronic cough demonstrate statistically significant alterations in SELSAP waveform that can support a diagnosis of laryngeal sensory neuropathy.

Antitussive drugs--past, present, and future

Cough remains a serious unmet clinical problem, both as a symptom of a range of other conditions such as asthma, chronic obstructive pulmonary disease, gastroesophageal reflux, and as a problem in its own right in patients with chronic cough of unknown origin. This article reviews our current understanding of the pathogenesis of cough and the hypertussive state characterizing a number of diseases as well as reviewing the evidence for the different classes of antitussive drug currently in clinical use. For completeness, the review also discusses a number of major drug classes often clinically used to treat cough but that are not generally classified as antitussive drugs. We also reviewed a number of drug classes in various stages of development as antitussive drugs. Perhaps surprising for drugs used to treat such a common symptom, there is a paucity of well-controlled clinical studies documenting evidence for the use of many of the drug classes in use today, particularly those available over the counter. Nonetheless, there has been a considerable increase in our understanding of the cough reflex over the last decade that has led to a number of promising new targets for antitussive drugs being identified and thus giving some hope of new drugs being available in the not too distant future for the treatment of this often debilitating symptom.