eMedicine Specialties > Otolaryngology and Facial Plastic Surgery > Laryngology

Laryngeal Manifestations of Parkinson Disease

Thomas L Carroll, MD, Assistant Professor, Department of Otolaryngology-Head and Neck Surgery, Tufts Medical Center, Tufts University School of Medicine
Arlen D Meyers, MD, MBA, Professor, Department of Otolaryngology-Head and Neck Surgery, University of Colorado School of Medicine; Lorraine Ramig, PhD, Professor, Department of Speech Language Hearing Sciences, University of Colorado at Boulder; Senior Scientist, National Center for Voice and Speech (NCVS); Adjunct Professor, Department of Biobehavior, Columbia University Teacher's College

Updated: Oct 7, 2009

Introduction

Background

First described by James Parkinson in 1817, parkinsonism is a neurological syndrome that manifests as a combination of bradykinesia, rigidity, resting tremor, and loss of postural reflexes. For the diagnosis of parkinsonism to be made, at least 2 of these features should be present, with one of the two being either rigidity or tremor.

The cause of parkinsonism can be divided into the following 3 areas:

• Idiopathic Parkinson disease (IPD) is the most common form and serves as the focus of this article.
• Secondary Parkinson disease includes the features of IPD but has an identifiable cause such as a medication's side effect, a head trauma, or a tumor.
• Parkinsonism-plus syndromes (PPS) include diseases in which the symptoms of IPD have a known genetic defect or distinctive pathologic changes such as multiple system atrophy, corticobasal ganglionic degeneration, or progressive supranuclear palsy.

IPD often begins insidiously, with tremor as the first presenting symptom. The tremor is first seen in the distal parts of the extremities and in the lips and is commonly described as "pill rolling" in the hands. Unlike other tremors, the extremity tremors cease upon active limb movement. Bradykinesia (masked facies, drooling, decreased blinking, shuffling gate, trouble with transfers from chairs and automobiles, difficulty with dexterous hand movements), rigidity (resistance to passive movement), and loss of postural reflexes (leading to a tendency to fall, stooped posture, and festination) all contribute to the morbidity associated with IPD. Interestingly, patients with IPD and their families often report reduced ability to communicate as the most significant associated problem.

Elliptical closure pattern pre–Lee Silverman Voice Treatment (LSVT) and resolved post-LSVT.

Video available at http://img.medscape.com/pi/emed/ckb/otolaryngology/834279-863537-867345-867444.flv.

Most patients with IPD do not recognize the problems that need to be overcome for them to effectively communicate; these problems include decreased neural drive to the larynx muscles, decreased sensory feedback that allows vocal shortcoming correction, and difficulty internally generating an acceptable speech volume. Treatments for IPD, including neuropharmacological and neurosurgical methods, offer effective therapy for limb symptoms, but their effects on vocal symptoms are not consistently or significantly effective and are not as well studied. Speech therapy is effective in treating the laryngeal manifestations of IPD.

Pathophysiology

Parkinson disease is primarily a result of the loss of pigmented dopaminergic neurons in the substantia nigra. Lewy bodies, eosinophilic inclusions in the cytoplasm of intact neurons, are often present. Lewy bodies are characteristic but not pathognomonic of IPD. A loss of dopamine allows an increased inhibitory output from the globus pallidus, causing the hypokinetic symptoms.

Frequency

United States

IPD is the most common movement disorder in patients older than 55 years. The incidence is estimated to be 4.5-21 cases per 100,000 persons per year. The prevalence is estimated to be 120 per 100,000 persons. Prevalence increases with age.

Sex

IPD is 1.5 times more common in men than in women.

Age

The average age of onset is in the seventh decade of life.

Clinical

History

A complete neurolaryngological evaluation must be completed. This includes a detailed history, evaluation of the voice, neurolaryngeal evaluation, and stroboscopy.

Patients are usually diagnosed with idiopathic Parkinson disease (IPD) before examination, although some patients are diagnosed based on their presenting vocal symptoms. The physician evaluating the voice must be vigilant about the possibility of IPD in patients who do not yet carry the diagnosis, and physicians should refer to a neurologist appropriately. As with any other medical history, discovering the nature of the symptoms (including when the symptoms began, if anything improves or worsens the symptoms, if the symptoms fluctuate, or if the symptoms are constant) is important. Particularly in patients with IPD, the physician must elicit the frustrations that the patient and patient's family are experiencing. Often, rather than recognizing their vocal shortcomings, patients feel like those around them are not listening or are becoming hard of hearing.

Evaluation of the voice 

• As the patient is speaking, the vocal loudness, intonation, and vocal quality, including fluidity of speech and articulation, should be assessed. Sustaining vowel phonation (eg, "ah") for maximum duration, counting to 50, and reading passages such as the rainbow passage provide reasonable speech samples. Closely listening for reduced and diminishing loudness and intonation and increasing breathiness and hoarseness helps to differentiate IPD from hyperkinetic disorders such as spasmodic dysphonia.¹  
• A soft, monotone voice, vocal tremor, poor articulation, variable speech rate, trouble with the initiation of speech, stutteringlike qualities, and masked facies or flat affect are all characteristics of IPD. Perhaps the most telling vocal symptom is the marked contrast in vocal loudness between habitual loudness (soft and diminishing) and the patient's response to a request to increase loudness. A request to "say that again, twice as loud" often results in increased loudness, improved voice quality, and a dramatic improvement in speech intelligibility.
• Neurolaryngeal examination
  • Because distortion can occur when the tongue is held forward during rigid stroboscopy, the neurolaryngeal examination is best performed by viewing the larynx with a flexible laryngoscope. The larynx is evaluated for vocal fold mobility, paresis or paralysis, coordination of movement, agility, fatigability, flexibility, and use of accessory muscles during phonation while the patient says various phrases and syllables. Hyperfunctional and hypofunctional disorders can often be differentiated by isolating the abductor and adductor muscle groups. The larynx is also visualized at rest. Perez et al found that vocal tremor is present in 55% of patients with IPD.² They found that only 35% of patients with IPD exhibit a resting tremor, while the remainder exhibited kinetic tremor (a goal-directed movement tremor). The tremor is primarily a vertical laryngeal movement. This is somewhat unexpected because limb tremor in IPD is usually a resting tremor and not a kinetic tremor.
  • Parkinson-plus syndromes (PPS) are found to carry a higher incidence of tremor (64%). Most tremors are located in the arytenoids. Perez et al found no vertical laryngeal tremor in patients with PPS.²
• Stroboscopy: Rigid stroboscopy plays a key role in the assessment of the vibratory characteristics of the vocal folds, including the presence of masses, lesions, or scar and glottic configuration abnormalities, including an elliptical closure pattern, phase asymmetry, and abnormal phase closure. Stroboscopy and neurolaryngeal examination are complementary in the evaluation of the patient with IPD. Common stroboscopy findings in IPD include true vocal fold atrophy or other evidence of glottal incompetence, including a chasing wave or a shorter closed phase. Pooling of secretions, decreased sensation, and aspiration are also characterizations of the IPD larynx. A paralyzed vocal fold suggests PPS as the etiology for the parkinsonism if other aspects of the diagnosis are present.

Causes

Most cases of IPD are believed to be caused by a combination of genetic and environmental factors.

Differential Diagnoses

Other Problems to Be Considered

Included below is a list of other movement disorders that affect the larynx. Only parkinsonism and chorea are hypokinetic disorders. The remaining conditions on the list are considered hyperkinetic disorders. The disorders are as follows:

• Secondary Parkinson disease
• Parkinson-plus syndrome
• Chorea
• Essential tremor
• Dystonia, including spasmodic dysphonias
• Stuttering
• Myoclonus
• Tics
• Tardive dyskinesia

Workup

Laboratory Studies

Laboratory studies have no role in the workup of idiopathic Parkinson disease (IPD).

Imaging Studies

No imaging studies are needed in the workup of a typical patient, who usually presents when older than 55 years and responds to basic therapies.

Other Tests

MRI can assist in ruling out other neurologic conditions, such as multi-infarct dementia. MRI can also assist in cases of atypical presentation.

Treatment

Medical Care

The medical care of idiopathic Parkinson disease (IPD) includes neuropharmacologic therapy, which is often started when a patient finally experiences functional impairment. The benefit of these medications is seen in their ability to help with IPD’s limb manifestations. Although some voice analysis studies have reported improvement in tremor, noise, and fundamental frequency, neuropharmacologic therapy has limited efficacy in treating the laryngeal manifestations of IPD, and the literature is inconsistent. Nondopaminergic pathways may be responsible for the laryngeal manifestations of IPD, which explains why neuropharmacologic therapies are ineffective. This alternative theory may explain why the prevalence of voice and articulation abnormalities is nearly identical in medicated and nonmedicated patients with IPD. Medications can offer their symptomatic limb benefits for 4-6 years before the disease progresses beyond their aid.

Because many patients are taking medications when seen by their otolaryngologist, a brief review is included. Levodopa, with the addition of a peripheral decarboxylase inhibitor such as carbidopa, remains the mainstay of treatment. Levodopa is a dopamine precursor and is believed to be converted to dopamine in the substantia nigra, although the exact mechanism of action is unknown. Other drug categories used in the treatment of IPD include dopamine agonists, monoamine oxidase B (MAO-B) inhibitors, anticholinergics, N-methyl-D-aspartate (NMDA) receptor inhibitors, and catechol-O-methyltransferase (COMT) inhibitors. For more specific drugs and their descriptions, please refer to the eMedicine article Parkinson Disease.

Surgical Care

Like neuropharmacologic therapies, neurosurgical therapies can primarily offer benefits to the limb symptoms of IPD; however, unlike medications, neurosurgical therapies can potentially worsen the laryngeal manifestations of the disease. The neurosurgical procedures available today are stereotactic surgeries that either create lesions or place deep brain stimulation wires into the thalamus, globus pallidus, or subthalamic nucleus. The details of these procedures are beyond the scope of this article. Only deep brain stimulation of the subthalamic nucleus has been shown, in some studies, to offer improvement of speech production.

The otolaryngologist can offer vocal fold bulking procedures in the form of vocal fold injection or Gore-Tex thyroplasty as a possibility in treating refractory true vocal fold bowing. Bilateral injections to medialize the vocal fold can offer improvement, unless the patient is already aphonic due to advanced disease. Bilateral collagen, gel, fat and hydroxyapatite injections have been described used for this purpose.³ Articulatory problems can persist, and the result of surgery can be disappointing.

Consultations

• Speech therapy  
  • Medications and surgeries cannot effectively treat the laryngeal manifestations of IPD. For this reason, speech therapy plays the key role in the disease's vocal treatment regimen. The Lee Silverman Voice Treatment (LSVT) is a program designed to increase vocal intensity in patients with IPD. The treatment focuses on a simple set of tasks that are practiced intensively, 4 sessions per week during a 4-week period, resulting in maximization of phonatory and respiratory functions.
    
  • The goal of LSVT is to improve vocal performance for 6-24 months without interval intervention. LSVT focuses on maximizing vocal effort ("think loud, think shout") and maximizing sensory perception of vocal effort and loudness by therapists. Therapists who quantify results give constant feedback to patients during sessions and encourage patients to self-monitor and internally calibrate their loudness. After LSVT, patients with IPD speak at a normal volume and with a healthy voice quality despite the need to "think loud, think shout."
  • In studies with a 2-year follow-up, patients who received LSVT maintained or improved vocal intensity compared with pretreatment levels. Glottal incompetence and swallowing ability both improve after LSVT without any significant change in supraglottal hyperfunction. Preliminary positron emission tomography (PET) scans after LSVT training in patients with IPD show reduced activity in the globus pallidus, an effect similar to pallidotomy. LSVT may also stimulate coordination of motor output beyond the phonatory system in the form of increased orofacial expression.
  • Other therapies have been suggested for the treatment of the vocal symptoms in IPD, but most data so far support LSVT as the promising therapy for IPD laryngeal symptoms. Larger prospective studies are needed to confirm the already encouraging results. Alternative methods of delivering therapy that do not involve 16 face-to-face sessions with a therapist are currently being studied. These methods incorporate  webcam  delivery of LSVT (eLOUD) and software programs that patients can perform at home. These technologically enhanced methods, when used to replace half of the face-to-face sessions, have documented outcomes that are equivalent to classic LSVT. Such alternatives will hopefully be implemented to allow a less transportation-intensive therapy course for the patient and to allow follow-up review of the LSVT techniques as needed.

Medication

The principal drug used in the treatment of idiopathic Parkinson disease (IPD) is combination of levodopa and carbidopa.

Dopamine agonist and peripheral decarboxylase inhibitor

These agents increase dopamine levels in affected areas of basal ganglion.

Levodopa and carbidopa (Sinemet, Parcopa)

Dopamine precursor believed to increase dopamine levels in affected areas of basal ganglion. An empiric trial, titrated to high dose (many advocate minimum 4 g daily), is recommended in every patient.

Dosing

Adult

10 mg carbidopa/100 mg levodopa PO tid, increase to 25 mg carbidopa/250 mg levodopa PO tid during 2-wk period, then increase by 25 mg carbidopa/250 mg levodopa q3-4d or weekly until change in motor symptoms or dose of 4 tab 25 mg carbidopa/250 mg levodopa tid is reached without any response

Pediatric

Not established

Interactions

Hydantoins, pyridoxine, phenothiazine, and hypotensive agents may decrease effects of levodopa; levodopa toxicity increases with antacids and MAOIs

Contraindications

Documented hypersensitivity; narrow-angle glaucoma; malignant melanoma; undiagnosed skin lesions

Precautions

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Certain adverse CNS effects (eg, dyskinesias) may develop at lower dosages and earlier in therapy with SR form; caution in patients with history of myocardial infarction, arrhythmias, asthma, and peptic ulcer disease; sudden discontinuation of levodopa may cause worsening of Parkinson disease; high-protein diets should be distributed throughout the day to avoid fluctuations in levodopa absorption

Follow-up

Further Outpatient Care

Patients with idiopathic Parkinson disease (IPD) who undergo speech therapy are often closely observed during their treatment period and during the long course of their disease. The Lee Silver Voice Treatment (LSVT) offers up to 2 years of continued success in many patients without the need for regular sessions. The home review recordings may significantly aid in the maintenance of effective speech after LSVT. The otolaryngologist plays a lesser role in the follow-up period but serves to add posttreatment documentation of function after initial and potentially future therapy sessions.

Multimedia

Media file 1: Elliptical closure pattern pre–Lee Silverman Voice Treatment (LSVT) and resolved post-LSVT.

Video available at http://img.medscape.com/pi/emed/ckb/otolaryngology/834279-863537-867345-867444.flv.

Media file 2: Vocal fold hyperfunction pre–Lee Silverman Voice Treatment and resolved post-LSVT.

Video available at http://img.medscape.com/pi/emed/ckb/otolaryngology/834279-863537-867345-867445.flv.

Media file 3: Patient with idiopathic Parkinson disease (IPD) before and after Lee Silverman Voice Treatment.

Video available at http://img.medscape.com/pi/emed/ckb/otolaryngology/834279-863537-867345-867446.flv.

References

1. Brin MF, Velickovic M, Ramig LO. Dysphonia due to Parkinson's disease: pharmacological, surgical, and behavioral management perspectives. In: Vocal rehabilitation in medical speech-language pathology. Austin: Pro-Ed; 2004:209-69.

2. Perez KS, Ramig LO, Smith ME, Dromey C. The Parkinson larynx: tremor and videostroboscopic findings. J Voice. Dec 1996;10(4):354-61. [Medline].

3. Berke GS, Gerratt B, Kreiman J, Jackson K. Treatment of Parkinson hypophonia with percutaneous collagen augmentation. Laryngoscope. Aug 1999;109(8):1295-9. [Medline].

4. Belafsky PC, Postma GN. Vocal fold augmentation with calcium hydroxylapatite. Otolaryngol Head Neck Surg. Oct 2004;131(4):351-4. [Medline].

5. Brin MF, Fahn S, Blitzer A. Movement disorders of the larynx. In: Neurologic disorders of the larynx. New York: Thieme Medical Publishing; 1992:248-78.

6. de Swart BJ, Willemse SC, Maassen BA, Horstink MW. Improvement of voicing in patients with Parkinson's disease by speech therapy. Neurology. Feb 11 2003;60(3):498-500. [Medline].

7. Fox CM, Morrison CE, Ramig LO. Current perspectives on the Lee Silverman Voice Treatment (LSVT) for individuals with idiopathic parkinson disease. Am J Speech Lang Pathol. 2002;11:111-23.

8. Kim SH, Kearney JJ, Atkins JP. Percutaneous laryngeal collagen augmentation for treatment of parkinsonian hypophonia. Otolaryngol Head Neck Surg. Jun 2002;126(6):653-6. [Medline].

9. Liotti M, Ramig LO, Vogel D, et al. Hypophonia in Parkinson's disease: neural correlates of voice treatment revealed by PET. Neurology. Feb 11 2003;60(3):432-40. [Medline].

10. Merati AL, Heman-Ackah YD, Abaza M, Altman KW, Sulica L, Belamowicz S. Common movement disorders affecting the larynx: a report from the neurolaryngology committee of the AAO-HNS. Otolaryngol Head Neck Surg. Nov 2005;133(5):654-65. [Medline].

11. Pinto S, Gentil M, Fraix V, Benabid AL, Pollak P. Bilateral subthalamic stimulation effects on oral force control in Parkinson's disease. J Neurol. Feb 2003;250(2):179-87. [Medline].

12. Pinto S, Ozsancak C, Tripoliti E, Thobois S, Limousin-Dowsey P, Auzou P. Treatments for dysarthria in Parkinson's disease. Lancet Neurol. Sep 2004;3(9):547-56. [Medline].

13. Pützer M, Barry WJ, Moringlane JR. Effect of bilateral stimulation of the subthalamic nucleus on different speech subsystems in patients with Parkinson's disease. Clin Linguist Phon. Dec 2008;22(12):957-73. [Medline].

14. Ramig LO, Fox C, Sapir S. Parkinson's disease: speech and voice disorders and their treatment with the Lee Silverman Voice Treatment. Semin Speech Lang. May 2004;25(2):169-80. [Medline].

15. Ramig LO, Fox C, Sapir S. Speech treatment for Parkinson's disease. Expert Rev Neurother. Feb 2008;8(2):297-309. [Medline].

16. Sanabria J, Ruiz PG, Gutierrez R, et al. The effect of levodopa on vocal function in Parkinson's disease. Clin Neuropharmacol. Mar-Apr 2001;24(2):99-102. [Medline].

17. Sapir S, Ramig LO, Hoyt P, Countryman S, O'Brien C, Hoehn M. Speech loudness and quality 12 months after intensive voice treatment (LSVT) for Parkinson's disease: a comparison with an alternative speech treatment. Folia Phoniatr Logop. Nov-Dec 2002;54(6):296-303. [Medline].

18. Smith ME, Ramig LO, Dromey C, Perez KS, Samandari R. Intensive voice treatment in Parkinson disease: laryngostroboscopic findings. J Voice. Dec 1995;9(4):453-9. [Medline].

Keywords

laryngeal manifestations, Parkinson disease, Parkinsons disease, Parkinson’s disease, bradykinesia, resting tremor, Parkinsonism, idiopathic Parkinson disease, IPD, vocal tremor, tremor, rigidity, postural reflexes, hypokinesia, hypokinetic, stroboscopy

Contributor Information and Disclosures

Author

Thomas L Carroll, MD, Assistant Professor, Department of Otolaryngology-Head and Neck Surgery, Tufts Medical Center, Tufts University School of Medicine
Thomas L Carroll, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Otolaryngology-Head and Neck Surgery, and American Medical Association
Disclosure: Nothing to disclose.

Coauthor(s)

Arlen D Meyers, MD, MBA, Professor, Department of Otolaryngology-Head and Neck Surgery, University of Colorado School of Medicine
Arlen D Meyers, MD, MBA is a member of the following medical societies: American Academy of Facial Plastic and Reconstructive Surgery, American Academy of Otolaryngology-Head and Neck Surgery, and American Head and Neck Society
Disclosure: Covidien Corp Consulting fee Consulting; US Tobacco Corporation unstricted gift unknown; Axis Three Corporation Ownership interest Consulting; Omni Biosciences Ownership interest Consulting; Sentegra Ownership interest Board membership; Syndicom Ownership interest Consulting; Oxlo  Consulting; Medvoy Ownership interest Management position

Lorraine Ramig, PhD, Professor, Department of Speech Language Hearing Sciences, University of Colorado at Boulder; Senior Scientist, National Center for Voice and Speech (NCVS); Adjunct Professor, Department of Biobehavior, Columbia University Teacher's College
Disclosure: Nothing to disclose.

Medical Editor

B Viswanatha, MBBS, MS, DLO, Professor of ENT, Sri Venkateshwara ENT Institute, Victoria Hospital, Bangalore Medical College and Research Institute, India
B Viswanatha, MBBS, MS, DLO is a member of the following medical societies: Association of Otolaryngologists of India, Indian Medical Association, and Indian Society of Otology
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: eMedicine Salary Employment

Managing Editor

Robert M Kellman, MD, Professor and Chair, Department of Otolaryngology and Communication Sciences, State University of New York, Upstate Medical University
Robert M Kellman, MD is a member of the following medical societies: American Academy of Facial Plastic and Reconstructive Surgery, American Academy of Otolaryngology-Head and Neck Surgery, American College of Surgeons, American Medical Association, American Neurotology Society, American Rhinologic Society, American Society for Head and Neck Surgery, Medical Society of the State of New York, and Triological Society
Disclosure: GE Healthcare Honoraria Review panel membership

CME Editor

Christopher L Slack, MD, Otolaryngology-Facial Plastic Surgery, Private Practice, Associated Coastal ENT; Medical Director, Treasure Coast Sleep Disorders
Christopher L Slack, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Facial Plastic and Reconstructive Surgery, American Academy of Otolaryngology-Head and Neck Surgery, and American Medical Association
Disclosure: Nothing to disclose.

Chief Editor

Arlen D Meyers, MD, MBA, Professor, Department of Otolaryngology-Head and Neck Surgery, University of Colorado School of Medicine
Arlen D Meyers, MD, MBA is a member of the following medical societies: American Academy of Facial Plastic and Reconstructive Surgery, American Academy of Otolaryngology-Head and Neck Surgery, and American Head and Neck Society
Disclosure: Covidien Corp Consulting fee Consulting; US Tobacco Corporation unstricted gift unknown; Axis Three Corporation Ownership interest Consulting; Omni Biosciences Ownership interest Consulting; Sentegra Ownership interest Board membership; Syndicom Ownership interest Consulting; Oxlo  Consulting; Medvoy Ownership interest Management position

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