By Stephanie Ciccarelli
August 14, 2008
In Dr. Arlene Barr's lecture, she discussed how neurological diseases are related to voice disorders, featuring Stroke and Parkinson's Disease, among others.
Learn more about how neurological disorders affect speech at VOX Daily.
à¹ Parkinson's Disease
à¹ Essential Tremor
à¹ Spasmodic Dysphonia
à¹ Amyotrophic Lateral Sclerosis
à¹ Myasthenia Gravis
We'll be focusing on Stroke and Parkinson's Disease in this article.
à¹ After a stroke the can be cortical impairment of comprehension (receptive aphasia) and articulation (expressive aphasia).
à¹ Production of sound can be affected by impairment of subcortical structures that are coordinated by the cortex. These structures include:
- brainstem structures
- the phrenic nerve which innervates the diaphragm
à¹ Cortex - left: production of speech, right: prosody (inflection, intonation, and timing)
à¹ Corticobulbar tracts: communication between the cortex and brainstem
à¹ Cerebellum and basal ganglia - modulate motor control of speech
See if you can connect the dots! CN is for "central nerve".
Component: Diaphragm, lungs
Nerves: Phrenic (C 3-5)
Role: Source Generation
Component: Vocal Folds
Nerves: CN: X
Role: Pitch, phonation
Component: Supraglottis, pharynx, oral and nasal cavities
Nerves: CN: VII, X
Role: Shape, resonance
Component: Lips, cheeks, mandible (jaw), tongue
Nerves: V, VII, XII
When you think about it, there's a lot that goes into speech production and phonation, and you can see from the information above just how complex voice production is.
à¹ Vascular disease of either the cortex or brainstem can have a direct effect on speech
à¹ Indirect complications of stroke include: intubation, ventilation, aspiration risk, nasogastric nutrition, pneumonia, and medication side effects
à¹ Rehabilitation is handled by the speech pathologist
à¹ Laryngeal paralysis or vocal fold paralysis due to a CNS lesion can require surgical intervention
Let's take a look now at how Dr. Barr explains Parkinson's Disease and its affects on the voice.
à¹ A progressive disorder of the substantia nigra in the brainstem
à¹ Typical symptoms include: pill-rolling tremor, rigidity, shuffling gait, poor balance, stooped posture, slowness of movement (bradykinesia)
à¹ Approximately 70% - 80% have speech problems
à¹ Greater than 30% find the speech problems very disabling
à¹ Related to bradykinesia
à¹ Soft, breathy, monotone voice, can have a tremor or stuttering-like quality
à¹ Poor articulation, difficulty in initiating speech
à¹ Vocal fold adduction is weak
à¹ Vocal folds appear thin and bowed due to vocalis muscle atrophy
à¹ Articulation is sluggish
à¹ Voice is strained and can sound like spasmodic dysphonia
à¹ Dopaminergic medications
à¹ Speech therapy
à¹ Injection laryngoplasty
à¹ Botulinum toxin (Botox) injection of laryngeal muscles in patients with hyperkinetic dysphonia (vocal rigidity predominates over hypokinesia)
Associate Professor of Clinical Neurology
University of Illinois at Chicago
Department of Neurology
Dr. Barr is a part-time Associate Professor in Clinical Neurology at the University of Illinois at Chicago since her retirement in 2004. She specializes in electromyography, peripheral neuropathy, and movement disorders. Throughout her career at UIC, she has held various academic positions, which included Director of Electrodiagnostic Laboratory from 1991-2004 and Co-Director of Clinical Neurophysiology Fellowship, Department of Neurology from 1994-2004. Also, she has been named one of America's Best Doctors in 2006 and 2007.
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