unit 5 neurogenic voice disorders power point
TRANSCRIPT
Neurogenic Voice Disorders
CDIS 700
Review of the Nervous System
Review your motor speech and anatomy/physiology notes. Neurotransmitter issues in the CNS can cause hypo- and
hyperkinetic dysarthrias. Spasticity of vocal folds results from UMN lesions Flaccidity of VFs and VF paralysis result from LMN lesions The PNS cranial nerves can have an effect on the voice if
they are damaged: IX (Glossopharyngeal)—taste, sensation, innervation of pharynx X (Vagus)—SLN and RLN branches affect sensory and motor
systems related to the pharynx, larynx, and respiratory structures
XI (Spinal Accessory)—resonance/respiration XII (Hypoglossal)—resonance and quality of the voice;
positioning of the larynx and tongue
SLN and RLN
SLN innervates the cricothyroid muscles. Recall that CT contraction lengthens the VFs and increases pitch and contribute to VF adduction.
RLN innervates the thyroarytenoid, lateral cricoarytneoid, transverse/oblique arytenoids, and the posterior cricoarytenoid muscles.
Dysarthrias
Flaccid Unilateral upper motor neuron Spastic Ataxic Hypokinetic Hperkinetic Mixed
Flaccid DysarthriaDisorder Cause Effects Treatment
Bilateral vocal fold paralysis
Lesions to Vagus nerve
VFs paralyzed in adducted or abducted position
Medical and/or surgical
Unilateral vocal fold paralysis
Surgical trauma to left RLN, also viral infections, smoking
Aphonia, monotone, hoarse/breathy voice, pitch breaks, vocal hyperfunction
Voice therapy; perhaps surgery
Cricothyroid paralysis
Viral infection of SLN
Difficulty with pitch change; breathiness
Resolves in time; voice therapy helps
Myasthenia Gravis Antibodies block acetylcholine from binding to muscles
Dysphonia and voice fatigue; weakness increases with use
Medical. SLP may recognize symptoms and refer; could monitor symptoms
Guillain-Barre Syndrome
Body’s immune system attacks nerves
Possibly dysarthric speech and weak voice
Focus on clear speech and safe swallowing
Unilateral Upper Motor Neuron Dysarthria
Often due to unilateral lesions in the CNS, caused by CVAs, tumors, or trauma.
Symptoms include a harsh, strained voice that may be accompanied by reduced loudness.
Good breath support is an essential form of voice therapy for these patients.
Hypokinetic Dysarthria Occurs when there is not enough dopamine to regulate
basal ganglia functioning = Parkinson’s disease. Physical manifestations include rigidity, bradykinesia,
limited range of motion, and tremor. Voice symptoms include decreased loudness, breathy
voice, monotone, rapid rushes of speech, and soft/imprecise consonants.
Bowed vocal folds accompanied by respiration difficulties may accompany voice symptoms.
Treatments include the Lee Silverman Voice Treatment program for increased loudness, quality, and intelligibility. The Pitch Limiting Voice Treatment also has good results.
Hyperkinetic DysarthriaDisorder Cause Effects Treatment
Huntington’s Disease
Overabundance of dopamine
Jerky, irregular bursts of loud voice; strained/strangled voice; monopitch; poor breath control.
Behavioral voice therapy in early stages (slower speech and easier voice production)
Adductor Spasmodic Dysphonia
Generally neurogenic
Strained, tight voice produced when VFs (true and sometimes false) adduct during phonation
Vocal hygiene therapy, including easy voice production); Botox injections
Abductor Spasmodic Dysphonia
Generally neurogenic
Intermittent aphonia Botox, possible voice therapy
Essential tremor Neurogenic Alternating changes in pitch; shaky voice quality
Behavioral voice therapy-talk less loudly with a higher pitch and shortened vowel duration
Mixed Dysarthrias Amyotrophic Lateral Sclerosis (ALS) and
Multiple Sclerosis (MS) are examples. A hoarse voice due to hyperfunction is
typical of both of these disorders. Breath support and easy onset of voice is recommended.
Voice symptoms associated with Traumatic Brain Injuries (TBIs) are typically treated behaviorally.