Factors influencing behavioral cough suppression therapy in children with nonspecific chronic cough

Diagnostic utility of spirometry for children with induced laryngeal obstruction or chronic non-specific cough

PURPOSE

To determine the diagnostic utility of spirometry in distinguishing children with Induced Laryngeal Obstruction (ILO) or chronic non-specific cough (a.k.a. tic cough) from those with mild or moderate to severe asthma.

METHODS

Retrospective cross sectional design. Children diagnosed with ILO (N = 70), chronic non-specific cough (N = 70), mild asthma (N = 60), or moderate to severe asthma (N = 60) were identified from the electronic medical record of a large children's hospital. Spirometry was completed before ILO, non-specific cough, or asthma diagnoses were made by pediatric laryngologists or pulmonologists. Spirometry was performed following American Thoracic Society guidelines and was interpreted by a pediatric pulmonologist. Forced Vital Capacity (FVC), Forced Expiratory Volume in 1 Second (FEV1), FEV1/FVC Ratio (FEV1/FVC), Forced Mid-Expiratory Flow 25--75 % (FEF25-75%), pulmonologist interpretation of flow volume loops, and overall exam findings were extracted from the medical record.

RESULTS

Ninety seven percent of children with ILO or chronic non-specific cough presented with spirometry values within normative range. Patients with ILO, non-specific cough, and mild asthma presented with FVC, FEV1, FEV1/FVC, and FEF25-75% values in statistically similar range. Children with moderate to severe asthma presented with significantly reduced FVC (p < .001), FEV1 (p < .001), FEV1/FVC (p < .001), and FEF25-75% (p < .001) values when compared with patients in the other groups. Flow volume loops were predominantly normal for children with ILO and non-specific cough.

CONCLUSIONS

Findings indicate that ILO and chronic non-specific cough can neither be diagnosed nor differentiated from mild asthma using spirometry alone. Spirometry should therefore be used judiciously with this population, bearing in mind the limitations of the procedure. Future research should determine the most effective and efficient ways of delineating ILO and non-specific cough from other respiratory conditions in children.

Evaluation and management of exercise-induced dyspnea in otherwise healthy adolescents and young adults: A critical review

Dyspnea on exertion in otherwise healthy adolescents and young adults is often brought to the attention of a pediatric pulmonologist when it interferes with an athletic activity. Assessment of the cause and management has been controversial. Skilled pediatric pulmonologists may suspect the cause from a careful history, but a more definite diagnosis is needed to provide the most appropriate management. Suspecting that laryngeal obstruction is the major cause, continuous laryngoscopy during exercise has been proposed. However, that method tends to over diagnose laryngeal obstruction and does not consider that the larynx is not the major cause of dyspnea on exertion (DOE). The cause of DOE can generally be best identified by a treadmill test using cardiopulmonary monitoring to determine the physiology associated with reproduced symptoms. Management of DOE requires a specific diagnosis and may involve medication, surgery, or education and training.

Tic Cough in an Adolescent with Organic Brain Pathology-A Case Report and Literature Review

Chronic cough in children and adolescents can be troublesome both to the patient and the whole family. The most common causes of chronic cough in children are protracted bacterial bronchitis and bronchial asthma. However, differential diagnostic workup and treatment can become complicated when a cough of different etiology is encountered, especially in a child having a complex medical history for an unrelated pathology. A cough lacking any identified somatic cause and response to medical treatment in combination with core clinical features of tics that include suppressibility, distractibility, suggestibility, variability, and the presence of a premonitory sensation is labeled tic cough. Here we discuss a case of an adolescent who had atrophy of the corpus callosum and a history of ventriculoperitoneal shunting due to hydrocephalus caused by stenosis of the sylvian aqueduct, but now presented with a debilitating dry cough lasting for several months. After physical causes of cough were ruled out, the diagnosis of tic cough was reached, and multidisciplinary treatment ensured complete recovery. To the best of our knowledge, this is the first reported case showing coincidence of tic cough and hydrocephalus. The co-occurrence of non-syndromic corpus callosum atrophy and tic cough might hypothetically suggest a predisposing pathogenetic link via reduced signaling through cortical inhibitory neurons; further studies are needed. The importance of careful assessment of medical history, clinical picture, and features of the cough itself are emphasized in order to reach the correct diagnosis. Increased awareness of medical society is mandatory to recognize tic cough and to distinguish it from the neurologic manifestations of organic brain pathology.