Overview of Voice Dysfunction in Neurological Disorders
What are neurological problems of the voice?
Normal speech production requires precise control and coordination
of the muscles of the voice box, throat, palate, jaw, tongue, and lips.
Neurological disorders are due to abnormalities of the brain and/or the
nerves of the body. These abnormalities result in impaired control of
the muscles of the voice box, throat, palate, jaw, tongue, or lips,
causing a variety of voice and/or speech problems.
Coordination Problems Affecting Voice and Speech Functions
- A neurologic voice abnormality is an abnormality of the coordination, control, or strength of the voice box muscles.
- A speech disorder is the result of a malfunction of the tongue and lip muscles that causes abnormal articulation of words or parts of words.
- Dysarthria, or difficulty in forming words, is a neurological problem commonly seen in stroke patients.
Voice Problems in Neurological Diseases – Different Underlying Problems
The type of voice problem varies with the underlying disease process and the specific muscles and actions that are affected.
- Weakness of voice box muscles: When neurological voice disorders lead to weakness of the voice box
muscles, the voice may be very weak, breathy, and subject to fatigue.
- Spasm of voice box muscles: A harsh and strained voice may be present due to vocal fold spasms caused by an underlying neurological condition.
- Weakness of palate muscles: The voice may also sound too nasal as a result of weakness of the palate muscles.
- Weakness of tongue/jaw/lip muscles: Speech patterns may be slurred or monotonous from neurological problems affecting the tongue, jaw, and/or lip muscles.
What are the symptoms of neurological voice disorders?
- Isolated hoarseness is usually due to a problem
within the larynx, but could be a sign of neurologic disease affecting
the muscles of the larynx.
- Neurologic hoarseness is usually accompanied by other symptoms, such as:
- Speech distortion
- Swallowing problems
- Choking when drinking liquids
- Neurological problems elsewhere in the body (i.e., arm or leg weakness or tremor)
- The
onset of difficulty forming words in adults virtually always indicates
a neurologic problem. These problems are usually the result of a
stroke.
- Poor control of the muscles that shape words
(dysarthria) – symptoms may range from slurring of speech to imprecise
consonants to completely incomprehensible speech
- Stuttering or stammering (dysfluent speech)
- Know what you want to say, but inability to the words out (aphasia)
- Inability to remember words
- A change in resonance, such as an overly "nasal" sounding voice, often indicates impaired control of throat or palate muscles.
- A shaking, tremulous voice indicates a tremor, which is seen in a variety of neurological disorders.
- Abrupt
voice spasms are also signs of neurological dysfunction, although
sometimes patients with emotional problems could have similar changes
in voice sound.
- Difficulty breathing can be a sign of an
underlying neurological disease and may be due to weakness or paralysis
of both vocal folds, which results in a narrow, compromised airway.
What are some of the more common neurological diseases that affect the voice?
The more common neurological diseases that affect the voice are:
- Stroke or cerebrovascular accidents
- Parkinson's disease
- Myasthenia gravis
- Benign essential tremor
- Amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease
- Multiple sclerosis
- Spasmodic dysphonia
Because of the complex and diverse nature of neurological voice
disorders, the more common conditions will be covered individually,
addressing the following areas:
- Cause and risk factors for voice dysfunction
- Voice symptoms
- Diagnosis of voice dysfunction
- Treatment of voice dysfunction
What is the role of the voice care team in neurological disorders with voice dysfunction?
Addressing Quality of Life Issues as Disease Prognosis Improves
Traditionally, many progressive degenerative neurological diseases
have not been referred to laryngologists or other voice specialists
because clinicians believed that voice improvements could not be
achieved. In reality, as patients' life expectancy and prognoses
improve, quality of life issues such as voice and communication become
more important problems to the patient.
Improving Voice and Speech Function can Contribute to Quality of Life
Many excellent minimally invasive treatments currently exist to
treat both vocal fold spasms (Botox) and vocal fold weakness (injection
laryngoplasty/medialization laryngoplasty). In addition, in many cases,
a speech-language pathologist can help the patient significantly
improve speech, voice, and/or swallowing, thus enhancing quality of
life
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Key Glossary Terms
