From the Guidelines
A neurological workup for dysphonia should begin with a comprehensive evaluation by both an otolaryngologist and a neurologist, including a detailed history, thorough neurological examination, and diagnostic testing such as flexible laryngoscopy and electromyography (EMG) of the laryngeal muscles, as recommended by the most recent guidelines 1.
Key Components of the Workup
- Initial assessment includes a detailed history focusing on onset, progression, and associated symptoms, followed by a thorough neurological examination with special attention to cranial nerves IX, X, and XII.
- Diagnostic testing should include flexible laryngoscopy to visualize vocal cord function, which is essential for distinguishing between structural and neurological causes.
- Electromyography (EMG) of the laryngeal muscles can help identify neurogenic patterns in conditions like vocal fold paralysis or spasmodic dysphonia.
- Brain and neck MRI with contrast is recommended to rule out lesions affecting the vagus nerve pathway or central nervous system pathologies.
Additional Considerations
- Additional tests may include videostroboscopy for detailed vocal fold vibration assessment, swallowing studies if dysphagia is present, and blood tests to screen for autoimmune or metabolic disorders.
- For suspected spasmodic dysphonia, a diagnostic trial of botulinum toxin injection may be considered, as supported by recent consensus recommendations for speech and language therapy 1.
- The comprehensive approach is necessary because dysphonia can result from various neurological conditions, including vagal neuropathy, brainstem lesions, Parkinson's disease, or dystonia, each requiring specific management strategies.
From the Research
Neurological Workup for Dysphonia
- The primary movement disorders affecting the voice are laryngeal dystonia, essential voice tremor, and Parkinson disease, which can be diagnosed clinically based on a detailed history, voice evaluation, and physical and laryngoscopic examination 2.
- A complete medical and vocal history is essential in the evaluation of dysphonia, including the history of present illness, past medical history, past surgical history, review of systems, medications, and social history 3.
- Parkinson's disease is a degenerative disorder that can affect the voice, with laryngeal changes occurring gradually throughout the course of disease progression, and may be helped by therapeutic and surgical interventions 4.
Diagnostic Tools
- Laryngeal electromyography (LEMG) can be used to assess laryngeal function in patients with Parkinson's disease, with rest hypertonicity being the main electromyographic pattern observed 5.
- Acoustic voice analysis can also be used to evaluate vocal function in patients with Parkinson's disease, with vocal tremor being the main acoustic change observed 5.
- The Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V) instrument can be used to perceptually evaluate voice characteristics in patients with Parkinson's-related dysphonia 6.
Treatment Options
- Botulinum toxin injections are commonly used to treat laryngeal dystonia and essential voice tremor 2.
- Lee Silverman Voice Treatment is commonly used to treat Parkinson disease-related voice disorders 2.
- Vocal fold injection of Cymetra (micronized form of collagen, elastin, proteoglycans) can be an effective temporary method of improving voice and speech in selected patients with Parkinson's-related dysphonia 6.