Overview
Definition:
Vocal cord dysfunction (VCD) is a condition characterized by the inappropriate adduction of the vocal cords during inspiration, leading to upper airway obstruction and symptoms mimicking asthma.
Epidemiology:
VCD is estimated to affect 1-12% of patients diagnosed with asthma, with a higher prevalence in adolescents and young adults, particularly females
It is often underdiagnosed.
Clinical Significance:
Misdiagnosis of VCD as asthma can lead to unnecessary and ineffective treatment, delayed appropriate management, and significant patient distress
Recognition is crucial for effective patient care and exam success.
Clinical Presentation
Symptoms:
Episodic inspiratory stridor or wheezing
Sense of throat tightness or choking
Dyspnea, often more pronounced on inspiration
Hoarseness or voice changes
Cough
Symptoms may be triggered by exercise, irritants, or emotional stress
Often coexists with asthma.
Signs:
Inspiratory stridor or wheezing, typically loudest over the anterior neck
Paradoxical vocal cord movement observed during laryngoscopy
Absence of typical asthma findings like diffuse expiratory wheezing
Normal oxygen saturation during asymptomatic periods.
Diagnostic Criteria:
Diagnosis is primarily clinical, supported by laryngoscopic findings
No universally established diagnostic criteria exist, but suspicion arises from symptoms not responding to asthma therapy and confirmed by visualization of inspiratory vocal cord closure during an episode.
Diagnostic Approach
History Taking:
Detailed symptom description including triggers, duration, and severity
Past medical history, particularly for asthma or other respiratory conditions
Family history of respiratory or voice disorders
Inquire about psychological stressors or anxiety
Red flags include inspiratory stridor, throat tightness, and lack of response to bronchodilators.
Physical Examination:
Assess the patient during an episode if possible
Listen for inspiratory stridor or wheezing predominantly at the neck
Examine for paradoxical vocal cord movement during breathing
Assess for signs of anxiety or distress
Evaluate for other respiratory conditions.
Investigations:
Spirometry may show a flattened inspiratory loop, but can be normal
Laryngoscopy (flexible or rigid) is the gold standard, ideally performed during an episode, showing adduction of the vocal cords during inspiration
Provocative laryngoscopy with exercise challenge may be used
Allergy testing if concurrent allergies are suspected
Chest X-ray to rule out other pulmonary pathology.
Differential Diagnosis:
Asthma
Bronchomalacia/Tracheomalacia
Laryngeal papillomatosis
Foreign body aspiration
Anaphylaxis
Psychogenic stridor
Vocal cord paralysis
GERD-related laryngitis.
Management
Initial Management:
Acute exacerbations may require observation
Reassurance and patient education are paramount
Avoidance of triggers if identified.
Medical Management:
Inhaled corticosteroids and bronchodilators are generally ineffective and should be discontinued if VCD is confirmed
Speech therapy focusing on breathing exercises, vocal hygiene, and relaxation techniques is the cornerstone of treatment
Management of comorbid anxiety or psychological issues.
Surgical Management:
Rarely indicated
Surgical interventions such as vocal cord stripping or botulinum toxin injection are reserved for refractory cases and are not standard of care.
Supportive Care:
Psychological support for the adolescent and family
Education on the nature of the condition and management strategies
Encouragement of participation in speech therapy and stress management techniques.
Complications
Early Complications:
Prolonged and severe airway obstruction requiring emergency intervention
Anxiety and panic attacks related to dyspnea.
Late Complications:
Chronic hoarseness
Persistent vocal symptoms
Psychological distress including depression and social withdrawal
Under-treatment due to misdiagnosis leading to chronic respiratory symptoms.
Prevention Strategies:
Accurate and timely diagnosis
Comprehensive patient and family education
Consistent adherence to speech therapy and stress management techniques
Prompt recognition and management of psychological comorbidities.
Prognosis
Factors Affecting Prognosis:
Severity and chronicity of symptoms
Patient's adherence to speech therapy and psychological interventions
Presence of comorbid anxiety disorders
Accurate diagnosis and early intervention.
Outcomes:
With appropriate speech therapy and psychological support, most adolescents can achieve significant symptom improvement and a return to normal activity levels
Long-term outcomes are generally good.
Follow Up:
Regular follow-up with speech therapy and the treating physician
Monitoring for symptom recurrence or development of new issues
Adjustment of therapy as needed
Long-term follow-up may be required in complex or refractory cases.
Key Points
Exam Focus:
Key differentiator between asthma and VCD is the inspiratory nature of stridor/wheezing and lack of response to bronchodilators
Laryngoscopy is diagnostic
Speech therapy is the primary treatment.
Clinical Pearls:
Always consider VCD in adolescents presenting with refractory asthma-like symptoms, especially if inspiratory stridor is present
A high index of suspicion is crucial
The patient's voice and breathing sounds during the interview can be very revealing.
Common Mistakes:
Over-reliance on spirometry without considering clinical presentation
Continuing ineffective asthma medications for prolonged periods
Delaying referral for laryngoscopy
Underestimating the psychological component of VCD.