Voice Disorders and Alterations in Vocal Cords

Classification of Voice Disorders

• The American Academy of Otolaryngology-Head and Neck Surgery notes that disfonía can be acute (less than 3 weeks) or chronic (more than 3 months) 1
• The American Academy of Otolaryngology-Head and Neck Surgery reports that disfonía affects approximately 23.4% of children at some point, with higher prevalence in males between 8-14 years 2
• The American Academy of Otolaryngology-Head and Neck Surgery states that in older adults, the prevalence increases to 2.5% in those over 70 years 3
• The American Academy of Otolaryngology-Head and Neck Surgery indicates that disfonía significantly impacts quality of life, causing social isolation, depression, anxiety, and loss of productivity 3

Structural Alterations of Vocal Cords

• Nódulos vocales represent 77% of the causes of disfonía in children, according to the American Academy of Otolaryngology-Head and Neck Surgery 4
• The American Academy of Otolaryngology-Head and Neck Surgery notes that nódulos vocales develop mainly due to vocal abuse, especially in voice professionals 5
• The American Academy of Otolaryngology-Head and Neck Surgery describes nódulos vocales as benign bilateral lesions on the edge of the vocal cords 6
• The American Academy of Otolaryngology-Head and Neck Surgery states that nódulos vocales produce a hoarse, rough voice with vocal fatigue 7

Neurológical Alterations of Vocal Cords

• The American Academy of Otolaryngology-Head and Neck Surgery reports that parálisis or paresia of vocal cords can be caused by iatrogenic factors, such as post-thyroid surgery (up to 2.1%) and cervical anterior surgery (1.69-24.2%) 7
• The American Academy of Otolaryngology-Head and Neck Surgery notes that prolonged intubation can cause disfonía in up to 94% of patients 7
• The American Academy of Otolaryngology-Head and Neck Surgery states that tumors compressing the recurrent laryngeal nerve can cause parálisis of vocal cords 8
• The American Academy of Otolaryngology-Head and Neck Surgery indicates that parálisis of the left recurrent laryngeal nerve is more common due to its longer path around the aortic arch 7

Diagnosis of Voice Disorders

• The American Academy of Otolaryngology-Head and Neck Surgery recommends that the clinical history should include duration of symptoms (acute vs. chronic) 5
• The American Academy of Otolaryngology-Head and Neck Surgery notes that laringoscopia is fundamental in patients with disfonía that persists for more than 3 months or when a serious underlying cause is suspected 4
• The American Academy of Otolaryngology-Head and Neck Surgery states that laringoscopia with estroboscopia allows for the detection of subtle alterations in vocal cord movement 9

Treatment of Voice Disorders

• The American Academy of Otolaryngology-Head and Neck Surgery recommends voice therapy for most voice disorders, especially nódulos vocales and disfonía by muscular tension 6
• The Journal of Neurology, Neurosurgery and Psychiatry notes that voice therapy should be directed by a specialized speech-language pathologist 10
• The American Academy of Otolaryngology-Head and Neck Surgery indicates that surgical treatment is indicated in cases of suspected malignancy, benign lesions that do not respond to conservative therapy, and glottal insufficiency (vocal cord paralysis) 6

Special Considerations

• The American Academy of Otolaryngology-Head and Neck Surgery reports that disfonía affects 15-24% of children, with nódulos vocales being the most common cause (77%) 4
• The American Academy of Otolaryngology-Head and Neck Surgery states that in older adults, the prevalence of disfonía increases to 2.5% in those over 70 years, and that atrophy of vocal cords (presbylarynx) is common and often underdiagnosed 3
• The American Academy of Otolaryngology-Head and Neck Surgery notes that neurological disorders such as stroke and Parkinson's disease increase the risk of disfonía 4

Causes of Dysphonia

Life-Threatening and High-Morbidity Causes

• Head and neck cancer is the most critical diagnosis to exclude, as delayed diagnosis results in higher staging, more aggressive treatment requirements, and reduced survival rates, according to the American Academy of Otolaryngology-Head and Neck Surgery 11, 12
• Smoking increases the odds of head and neck cancer 2- to 3-fold and is the strongest risk factor for malignancy, as reported by the American Academy of Otolaryngology-Head and Neck Surgery 11, 12
• Laryngeal cancer, lung cancer, and thyroid cancer can all present with dysphonia, as stated by the American Academy of Otolaryngology-Head and Neck Surgery 13
• Vocal fold paralysis from various causes, including stroke, tumors compressing the recurrent laryngeal nerve, or progressive neurologic disease, can cause dysphonia, according to the American Academy of Otolaryngology-Head and Neck Surgery 14

Common Benign Causes

• Acute viral laryngitis associated with upper respiratory tract infection is the most common cause and typically self-limited, resolving in 7-10 days, as reported by the American Academy of Otolaryngology-Head and Neck Surgery 13
• Voice overuse is perhaps the most common cause of chronic dysphonia, affecting >50% of teachers with 20% missing work as a result, according to the American Academy of Otolaryngology-Head and Neck Surgery 15, 13
• Muscle tension dysphonia (MTD) constitutes 10-40% of voice center caseloads and involves increased laryngeal musculoskeletal tension with excessive recruitment, as stated by the American Academy of Otolaryngology-Head and Neck Surgery 14, 16

Systemic and Medication-Related Causes

• Inhaled steroids can cause dose-dependent mucosal irritation and fungal laryngitis, as reported by the American Academy of Otolaryngology-Head and Neck Surgery 11
• ACE inhibitors can cause chronic cough leading to voice changes, according to the American Academy of Otolaryngology-Head and Neck Surgery 15
• Antihistamines, diuretics, anticholinergics can cause drying effect on mucosa, as stated by the American Academy of Otolaryngology-Head and Neck Surgery 12

High-Risk Populations Requiring Lower Threshold for Evaluation

• Professional voice users (singers, teachers, legal professionals, clergy, coaches) who cannot adequately perform required duties require a lower threshold for evaluation, as reported by the American Academy of Otolaryngology-Head and Neck Surgery 14, 15
• Smokers and alcohol users given 2-3 fold increased cancer risk require a lower threshold for evaluation, according to the American Academy of Otolaryngology-Head and Neck Surgery 11, 12

Critical Clinical Pitfall

• The most dangerous error is failing to recognize dysphonia as a potential presenting symptom of head and neck cancer, particularly in smokers, as delayed laryngeal evaluation results in higher cancer staging and reduced survival, as stated by the American Academy of Otolaryngology-Head and Neck Surgery 11, 12