What Causes Slurred Speech (Dysarthria)? | District Speech & Language Therapy | Speech Therapy Clinic in Washington DC (2024)

Coherent speech requires the coordination of a variety of muscle.

These include your:

• Laryngeal muscles
• Diaphragm
• Intercostal muscles
• Abdominal muscles
• Sternocleidomastoid and scalene muscles
• Trapezius muscles
• Suprahyoid muscles
• Infrahyoid muscles
• Pharyngeal muscles
• Tongue
• Lips
• Cheeks
• Jaw
• Soft palate

A deficiency with any one of these muscles can cause a variety of speech and communication related problems.

Slurred speech, also known as dysarthria, is one such example.

We’re District Speech, a DC speech therapy clinic, and we can help you get to the bottom of your speech and language challenges.

Below, we’ve put together a list of dysarthria’s most common causes.

Let’s take a look.

What Is Slurred Speech?

Slurred speech describes slow, garbled, or distorted speech.

Dysarthria is the medical term for this phenomenon.

It may also lead to pronunciation difficulty and irregularities in fluency – the rate at which you speak.

The severity of dysarthria can vary widely.

Some people with dysarthria experience minimal speech deficiencies while others are significantly more affected.

Why Is My Speech Slurred

Dysarthria may occur due to a variety of factors.

Below, we’ll explore the most common causes.

1. Stroke

A stroke is a serious medical condition which may cause a variety of speech and language difficulties.

It occurs when the blood flow to your brain is weakened or otherwise disrupted.

Common causes include blood clots, ruptured blood vessels, or even blunt force trauma.

A stroke is a life threatening medical emergency.

It’s currently the fifth leading cause of death in the United States.

Therefore, it’s important that you familiarize yourself with the symptoms of a stroke so that you can recognize the early signs.

Symptoms include:

• Speaking difficulties
• Confusion
• Severe headache
• Nausea and vomiting
• Walking difficulties
• Numbness in your face, arms, or legs
• Vision impairments

RELATED: Stroke Signs And Risks

Strokes commonly cause long term complications, especially with your speech.

Your brain’s left hemisphere manages your speech.

Therefore, speech impairments are more likely in left hemisphere strokes.

Nonetheless, people who experience a stroke on the right side of their brain may also experience speech difficulties.

In addition to dysarthria, common speech impairments associated with strokes include difficulty writing, remembering words, and speaking in full sentences.

Fortunately, speech therapy for stroke recovery can help you regain your speech and language skills following a stroke.

2. Traumatic Brain Injury

At District Speech, we also commonly provide speech therapy for traumatic brain injury.

A traumatic brain injury occurs when your brain experiences some form of physical trauma.

Examples include car accidents, physical assaults, and oxygen deprivation following a near drowning experience.

Symptoms depend on the type, location, and severity of the injury.

They may include:

• Sensitivity to lights, sound, touch, and changes in vision
• Tinnitus
• Anxiety, depression, and mood swings
• Social communication impairments, such as difficulty recognizing nonverbal communication
• Swallowing impairments, such as coughing and choking
• Headaches, dizziness, and fainting
• Nausea and vomiting
• Vertigo
• Muscle weakness
• Memory and attention impairments

Traumatic brain injuries also commonly cause speech difficulties in children as well as adults, such as dysarthria.

This is especially true in cases where the injury occurs in the nerves that control your muscles.

RELATED: Therapy For Pediatric Traumatic Brain Injury

3. Parkinson’s Disease

Parkinson’s disease is a progressive neurological disorder.

It causes impaired movement, tremors, stiffness, and balance and coordination difficulties.

It occurs when the part of your brain known as the “substantia nigra” declines.

This area of your brain is responsible for dopamine production, which is an essential component for muscle movement and coordination.

A variety of factors play a role in the development of Parkinson’s disease, such as:

• Advanced age
• Genetic predisposition
• History of head injuries
• Environmental toxin exposure, such as rotenone and permethrin

Parkinson’s disease is a progressive condition, meaning symptoms will worsen over time.

Symptoms include:

• Slow movement
• Body tremors
• Balance difficulties
• Muscle stiffness
• Loss of smell
• Poor posture
• Constipation
• Psychological impairments, such as depression, anxiety, and psychosis
• Memory loss
• Frequent falls
• Walking impairments
• Visual impairments

Parkinson’s disease affects a variety of your body’s muscles, including your facial muscles.

Therefore, it commonly causes dysarthria and other speech problems.

4. Cerebral Palsy

Cerebral palsy describes a spectrum of brain disorders.

They primarily affect your muscle movement and coordination.

Hence, cerebral palsy is considered a motor disability.

Medical professionals categorize cerebral palsy into one of four subtypes: spasticity, ataxia, dyskinesia, and hypotonia.

The type and severity of symptoms depends on the specific subtype.

Speech impairments, such as dysarthria, are a common symptom of all four subtypes.

Other common symptoms include:

• Developmental delays
• Walking impairments
• Limp or stiff muscles
• Swallowing disorders and drooling
• Seizures
• Blindness
• Intellectual disabilities

Cerebral palsy typically develops before or shortly after birth.

Potential causes include:

• Brain bleeds
• Brain infections, such as meningitis
• Prenatal infections, such as rubella and herpes simplex
• Oxygen loss during delivery
• Brain defects
• Severe childhood jaundice

5. Muscular Dystrophy

Muscular dystrophy is a rare muscle disorder.

It’s a genetic condition caused by gene mutations.

Most importantly, it impairs your body’s protein production.

Without proteins, your body can’t adequately support muscle function and development.

Over time, muscular dystrophy leads to progressive muscle weakness and degeneration, specifically in your arms, legs, head, face, and neck.

In terms of speech, muscular dystrophy can progressively weaken your tongue, lips, soft palate, cheeks, and diaphragm.

Ultimately, it can lead to a variety of speech disorders, including dysarthria.

6. Brain Tumors

A brain tumor is an atypical growth in your brain.

Some brain tumors are benign, or noncancerous, and others are malignant, or cancerous.

Regardless of type, brain tumors cause an increase of pressure inside your skull.

This results in a variety of symptoms, including:

• Headaches
• Seizures
• Cognitive impairments
• Personality changes
• Weakness or numbness on one side of the body
• Dizziness and balance impairments
• Hearing loss
• Vision impairments
• Confusion
• Memory loss

Depending on the location of the tumor, you may also experience dysarthria and other speech difficulties.

Brain tumor speech therapy can help correct some of these issues.

7. Bell’s Palsy

Muscle damage is the primary culprit of Bell’s palsy.

It mostly affects your facial muscles and causes inflammation, swelling, and compression.

As a result, Bell’s palsy can weaken or paralyze your facial muscles.

It occurs following damage to your seventh cranial nerve.

This nerve runs throughout your brain stem, skull, and into your facial muscles.

It sends messages from your brain to your muscles.

Bell’s palsy interrupts this process and can lead to a variety of symptoms, such as dysarthria.

Other symptoms include:

• Facial numbness and loss of feeling
• Stiffness in your facial muscles
• Drooling
• Headaches
• Eye stiffness
• Vocal weakness and mumbling
• Speech articulation difficulties
• Difficulty smiling

Bell’s palsy may occur as a result of a variety of conditions, such as:

• HIV
• Herpes simplex
• Epstein Barr virus
• Sarcoidosis
• Bacterial and viral infections
• Physical trauma
• Sleep disorders
• Autoimmune disorders, such as Lyme disease

Fortunately, this condition is often temporary and resolves once you treat the underlying issue.

8. ALS (Lou Gehrig’s Disease)

Amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s disease, is a rare degenerative disease.

It affects your brain’s motor neurons as well as your spinal cord.

Specifically, the damaged neurons critically impair your brain’s functions.

Over time, your brain completely stops communicating with the rest of your body.

It impacts your respiratory system, mobility, eating skills, mood, and cognitive function.

It also drastically impairs your speech and language skills.

As your muscles weaken, your larynx stops working and a variety of speech issues can emerge.

Other symptoms include:

• Muscle twitching and cramping
• Hand and feet weakness
• Frequent trips and falls
• Frequently dropping things
• Chronic fatigue
• Uncontrollable laughter or crying

The exact cause of ALS remains unknown.

However, a variety of factors may increase your risk of developing the disorder, such as:

• Advanced age
• Smoking
• Genetic predisposition
• Being of European descent
• Being assigned male at birth

9. Autism Spectrum Disorder

Autism spectrum disorder is a developmental condition.

It causes social communication difficulties and repetitive patterns of behaviors.

The exact cause of autism spectrum disorder remains unknown; however, experts believe both genetics and environmental factors play important roles.

It’s common for autistic people to have difficulty with motor skills.

In fact, it’s suggested that 87% of autistic people will have some sort of motor skills concern.

That can relate to fine motor skills, gross motor skills, and/or oral motor skills.

If you or your child is autistic and you have slurred speech, it may be caused by oral motor skills deficits.

In this case, both speech therapy and physical therapy for autism can help.

10. Other Possible Causes

Other possible causes for dysarthria include:

• Alcohol intoxication
• Certain medications, such as barbiturates and benzodiazepines
• Extreme emotional distress
• Mouth and throat injuries
• Brain infections, such as meningitis
• And more

What To Do If You Have Slurred Speech

If you suddenly develop dysarthria without any clear cause, call 911 or go to your nearest emergency department.

This is especially important if you are also experiencing other stroke symptoms, such as a severe headache or weakness on one side of your body.

Once diagnosed, a speech therapist can help you overcome your dysarthria related speech difficulties.

At District Speech, we can help you discover a variety of exercises aimed at improving your slurred speech.

We can help strengthen your facial muscles and practice correct speech speed and volume.

Book Your Appointment With District Speech Today

Has a doctor recently diagnosed you or a loved one with dysarthria?

Are you interested in hearing more about the numerous ways speech therapy can help?

At District Speech, we welcome any and all questions and look forward to helping you navigate your speech and language difficulties.

Book your appointment with District Speech today and let’s get started on improving your speech.