Overview & Cause:
- Parkinson's Disease (PD): a degenerative disorder of the central nervous system, symptoms include motor impairments due to death of dopamine generating cells in the mid brain. Motor impairments include: shaking, rigidity, slowness of initiation to start moving or speaking. Can see tremor in the hands or entire body and gait when walking. The voice can become dysphonic or in severe cases aphonic. The voice may be hoarse and breathy, monopitch and monoloud.
- Myasthenia Gravis (MG): chronic autoimmune disease causing weakness and fatigue. Can affect voluntary muscles of the body such as: the eyes, the mouth, the throat and the limbs. Voice may be breathy, monotone. monoloudness, voice fatigues with use- recover with rest.
- Amyotrophic Lateral Sclerosis (ALS, a.k.a. Lou Gherig's disease): neurodegenerative disease that affects nerve cells in the brain and spinal cord, upper motor neuron (UMN) or lower motor neuron (LMN). Symptoms include: LMN symptoms: atrophy, fasciculations, weakness and UMN symptoms: tight, stiff muscles, spasticity/rigidity and exaggerated reflexes (Hypereflexia) dysphagia (swallowing difficulty), and difficulty speaking. These patients can exhibit pseudobulbar affect or "emotional lability". Voice quality can present in a mixed fashion since this is characterized as a Mixed Dysarthria: the voice can be hypernasal, strain/strangled, slow effortful, monopitch, monoloudness, decreased range of motion.
- Stroke (Cerebrovascular Accident CVA): limited or no brain function due to loss of blood supply to the brain. This can be due to Ischemia - lack of blood flow caused by, a blockage (Thrombosis or Arterial Embolism or hemorrhage. Symptoms of strokes vary as does severity but they include inability to move one side of the body, inability to understand or formulate speech and inability to see one side of the visual field. Voice qualities and problems can vary dependent on the stoke, lesion location and severity.
- Traumatic Brain Injury (TBI): this is a closed or penetrating injury to the brain which can have varying symptoms and outcomes. It can be widespread or focal damage. It is a major cause of disability and death. It is more common in males than females. Voice disorders concomitant with TBI vary depending on each patient. Often times a voice disorder that coexists with these disorders is termed as dysarthria.
- Breathy voice
- Short, fast rushes of speech
- Trouble with initiating speech
- Fatigue with vocal use
Amyotrophic Lateral Sclerosis:
- Strained and strangled sounding voice
- Hyponasal vocal quality
- Slow and effortful speech
- Monoloudness (reduced volume)
- Breathy voice