Dysarthria
Dysarthria, poorly articulated speech, is characterized by slurring and labored, irregular rhythm. It may be accompanied by a nasal voice tone caused by palate weakness. Whether it occurs abruptly or gradually, dysarthria is usually evident in ordinary conversation. It's confirmed by asking the patient to produce a few simple sounds and words, such as “ba,” “sh,” and “cat.” However, dysarthria is occasionally confused with aphasia, the loss of the ability to produce or comprehend speech.
Dysarthria results from damage to the brain stem that affects cranial nerves IX, X, or XII. Degenerative neurologic disorders and cerebellar disorders commonly cause dysarthria. In fact, dysarthria is a chief sign of olivopontocerebellar degeneration. It may also result from ill-fitting dentures.
Emergency interventions
If the patient displays dysarthria, ask him about associated difficulty swallowing. Then determine his respiratory rate and depth. Measure his vital capacity with a Wright respirometer, if available. Assess the patient's blood pressure and heart rate. Usually, tachycardia, slightly increased blood pressure, and shortness of breath are early signs of respiratory muscle weakness.
Ensure a patent airway. Place the patient in Fowler's position and suction him if necessary. Administer oxygen, and keep emergency resuscitation equipment nearby. Anticipate intubation and mechanical ventilation in progressive respiratory muscle weakness. Withhold oral fluids in the patient with associated dysphagia.
If dysarthria isn't accompanied by respiratory muscle weakness and dysphagia, continue to assess for other neurologic deficits. Compare muscle strength and tone in the limbs. Then evaluate tactile sensation. Ask the patient about numbness or tingling. Test deep tendon reflexes (DTRs), and note gait ataxia. Assess cerebellar function by observing rapid alternating movement, which should be smooth and coordinated. Next, test visual fields and ask about double vision. Check for signs of facial weakness such as ptosis. Finally, determine the patient's level of consciousness (LOC) and mental status.
History and physical examination
Explore dysarthria completely. When did it begin? Has it gotten better? Speech improves with resolution of a transient ischemic attack, but not in a completed stroke. Ask if dysarthria worsens during the day. Then obtain a drug and alcohol history. Also, ask about a history of seizures. Check dentures for a proper fit.
Medical causes
Alcoholic cerebellar degeneration
Alcoholic cerebellar degeneration commonly causes chronic, progressive dysarthria along with ataxia, diplopia, ophthalmoplegia, hypotension, and an altered mental status.
Amyotrophic lateral sclerosis (ALS)
Dysarthria occurs when ALS affects the bulbar nuclei; it may worsen as the disease progresses. Other signs and symptoms include dysphagia; difficulty breathing; muscle atrophy and weakness, especially of the hands and feet; fasciculations; spasticity; hyperactive DTRs in the legs; and, occasionally, excessive drooling. Progressive bulbar palsy may cause crying spells or inappropriate laughter.
Basilar artery insufficiency.
Basilar artery insufficiency causes random, brief episodes of bilateral brain stem dysfunction, resulting in dysarthria. Accompanying it are diplopia, vertigo, facial numbness, ataxia, paresis, and visual field loss, all of which last for minutes to hours.
Botulism.
The hallmark of botulism is acute cranial nerve dysfunction causing dysarthria, dysphagia, diplopia, and ptosis. Early findings include a dry mouth, a sore throat, weakness, vomiting, and diarrhea. Later, descending weakness or paralysis of muscles in the extremities and trunk causes hyporeflexia and dyspnea.
Mercury poisoning
Chronic mercury poisoning causes progressive dysarthria accompanied by weakness, fatigue, depression, lethargy, irritability, confusion, ataxia, and tremors.
Multiple sclerosis
When demyelination affects the brain stem and cerebellum, the patient displays dysarthria accompanied by nystagmus, blurred or double vision, dysphagia, ataxia, and intention tremor. Exacerbations and remissions of these signs and symptoms are common. Other findings include paresthesia, spasticity, intention tremor, hyperreflexia, muscle weakness or paralysis, constipation, emotional lability, and urinary frequency, urgency, and incontinence.
Myasthenia gravis
Myasthenia gravis is a neuromuscular disorder that causes dysarthria associated with a nasal voice tone. Typically, the dysarthria worsens during the day and may temporarily improve with short rest periods. Other findings include dysphagia, drooling, facial weakness, diplopia, ptosis, dyspnea, and muscle weakness.
Olivopontocerebellar degeneration
Dysarthria, a major sign, accompanies cerebellar ataxia and spasticity.
Parkinson's disease
Parkinson's disease produces dysarthria and a monotone voice. It also produces muscle rigidity, bradykinesia, involuntary tremor usually beginning in the fingers, difficulty walking, muscle weakness, and a stooped posture. Other findings include masklike facies, dysphagia, and occasionally drooling.
Shy-Drager syndrome
Marked by chronic orthostatic hypotension, Shy-Drager syndrome eventually causes dysarthria as well as cerebellar ataxia, bradykinesia, masklike facies, dementia, impotence and, possibly, a stooped posture and incontinence.
Stroke (brain stem).
A brain stem stroke is characterized by bulbar palsy, resulting in the triad of dysarthria, dysphonia, and dysphagia. Dysarthria is most severe at its onset; it may lessen or disappear with rehabilitation and training. Other findings include facial weakness, diplopia, hemiparesis, spasticity, drooling, dyspnea, and a decreased LOC.
Stroke (cerebral).
A massive bilateral stroke causes pseudobulbar palsy. Bilateral weakness produces dysarthria that's most severe at onset. This sign is accompanied by dysphagia, drooling, dysphonia, bilateral hemianopsia, and aphasia. Sensory loss, spasticity, and hyperreflexia may also occur.
Other causes
Drugs
Dysarthria can occur when the anticonvulsant dosage is too high. Ingestion of large doses of barbiturates may also cause dysarthria.
Special considerations
Encourage the patient with dysarthria to speak slowly so that he can be understood. Give him time to express himself, and encourage him to use gestures. Dysarthria usually requires consultation with a speech pathologist.
Pediatric pointers
Dysarthria in children usually results from brain stem glioma, a slow-growing tumor that primarily affects children. It may also result from cerebral palsy.
Dysarthria may be difficult to detect, especially in an infant or a young child who hasn't perfected speech. Make sure to look for other neurologic deficits as well. Encourage speech in a child with dysarthria; a child's potential for rehabilitation is typically greater than an adult's.
Book Source Details
- Book Title: Handbook of Signs & Symptoms (Third Edition)
- Author(s): Springhouse
- Year of Publication: 2006
- Copyright Details: Handbook of Signs & Symptoms (Third Edition), Copyright © 2006 Lippincott Williams & Wilkins.
Other Book Chapters Related to Speech symptoms
Read excerpts from these other book chapters related to Speech symptoms:
Medical Books Excerpts
- DYSARTHRIA
- "Algorithmic Diagnosis of Symptoms and Signs" (2003)
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- HOARSENESS
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- "Handbook of Signs & Symptoms (Third Edition)" (2006)
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- Hoarseness
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- "Professional Guide to Signs & Symptoms (Fifth Edition)" (2006)
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- "Professional Guide to Signs & Symptoms (Fifth Edition)" (2006)
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- Hoarseness
- "The 10-Minute Diagnosis Manual: Symptoms and Signs in the Time-Limited Encounter" (2000)
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- Dysarthria
- "Alarming Signs and Symptoms: Lippincott Manual of Nursing Practice Series" (2007)
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- "Signs & Symptoms: A 2-in-1 Reference for Nurses" (2007)
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- Hoarseness
- "Signs & Symptoms: A 2-in-1 Reference for Nurses" (2007)
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- Hoarseness
- "The Diagnostic Approach to Symptoms and Signs in Pediatrics" (2006)
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Copyright Details: Handbook of Signs & Symptoms (Third Edition), Copyright © 2008 Williams & Wilkins.
More About Causes of Speech symptoms
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Hoarseness (Handbook of Signs & Symptoms (Third Edition))
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