A weak tongue, also known as tongue weakness, can make it difficult to move the tongue or use it properly for speech and swallowing. There are a few different tests that doctors can use to evaluate tongue weakness:
Physical Examination
The first step is usually a physical examination of the tongue. The doctor will visually inspect the tongue at rest and during movement. They will look for signs like:
- Tongue tremor – Shaking or quivering of the tongue
- Fasciculations – Small, local muscle twitches under the tongue surface
- Atrophy – Thinning or wasting away of the tongue muscles
- Dysarthria – Slurred or slow speech
- Difficulty moving the tongue side to side
The doctor may also feel the tongue and underlying muscles by palpating inside the mouth. Weakness is indicated if the tongue has poor mobility or tone during this examination.
Manual Muscle Testing
Manual muscle testing allows the doctor to assess tongue strength more quantitatively. While inside the mouth, the doctor will press down on the tongue while you try to push it up against resistance. The strength is graded on a scale of 0 to 5:
- 0 – No visible or palpable contraction
- 1 – Faint contraction but no movement
- 2 – Full ROM against gravity only
- 3 – Full ROM against mild resistance
- 4 – Full ROM against moderate resistance
- 5 – Full ROM against strong resistance
A grade of 3 or lower indicates significant weakness.
Speech Evaluation
The doctor will evaluate your ability to produce sounds that require tongue movement and elevation, such as L, N, T, D sounds. Slurring, distortion or omission of these sounds may indicate weakness or improper tongue mobility.
You may be asked to stick out your tongue and move it rapidly from side to side. Inability to perform this rapid movement is another sign of weakness.
Swallow Evaluation
A speech pathologist may perform a clinical or video fluoroscopic swallow evaluation. This analyzes the swallowing mechanism to look for impairment caused by tongue weakness. They will have you swallow various food and liquid consistencies while assessing ability to control bolus, chewing and any coughing or choking. Difficulty controlling food with the tongue, residue left in mouth and penetration or aspiration can all indicate tongue weakness.
Tongue Ultrasound
Ultrasound imaging can be used to look at muscle thickness and detect atrophy of the tongue over time. Portable ultrasound placed under the chin provides images of the internal tongue muscles at rest and in motion. Thin or asymmetrical muscles indicate muscle loss.
Ultrasound can also assess how far the tongue can protrude from the mouth and its velocity during side-to-side movements. All of these measurements help quantify tongue weakness.
Electromyography
Electromyography (EMG) measures the electrical activity of muscles. Needle electrodes are inserted into the tongue to assess motor unit potential and recruitment. Reduced potentials or recruitment can confirm a myopathic tongue disorder like muscle atrophy.
The neurophysiological data from EMG provides useful information about the severity and nature of tongue weakness.
Lab Testing
Blood tests may be ordered to evaluate possible reasons for tongue weakness:
- CBC, metabolic panel to assess overall health
- Vitamin B12, folate levels to check for deficiency
- Thyroid hormone levels to check for hypothyroidism
- Creatine kinase (CK) to assess muscle breakdown
Abnormal results can help diagnose medical conditions causing weakness.
Imaging
Imaging like MRI or CT scans might be ordered to evaluate the tongue and associated nerves and muscles. This can detect atrophy, inflammation, tumors, or injury that may be the root cause.
Conclusion
Tongue weakness can significantly impact speech and swallowing, so early diagnosis is important. There are many tests available to assess tongue mobility and strength, pinpoint areas of weakness, and determine the underlying disorder. A combination of a thorough history and physical examination, speech evaluation, lab work and imaging will help identify the cause of weakness and guide appropriate treatment.
With focused rehabilitation with speech therapy, many patients can regain tongue strength and function. Treatment may also include strategies to make swallowing and speaking easier and safer.
While tongue weakness presents challenges, the right testing and personalized treatment plan can help patients adapt and work around muscle limitations.
| Test | What it evaluates |
|---|---|
| Physical exam | Appearance, tone, mobility, tremors, fasciculations, atrophy |
| Manual muscle testing | Strength graded 0-5 |
| Speech evaluation | Articulation of sounds requiring tongue elevation |
| Swallow evaluation | Chewing, controlling bolus, residue, penetration/aspiration |
| Tongue ultrasound | Muscle thickness, atrophy, protrusion distance, velocity |
| Electromyography | Motor unit potential, recruitment in tongue |
| Lab testing | CBC, metabolic, B12, folate, thyroid, CK levels |
| Imaging – MRI, CT | Structural abnormalities of tongue and associated anatomy |
Here are some key points about testing for tongue weakness:
- Physical exam looks for visual signs of atrophy, tremor, and reduced mobility
- Manual tests specifically grade strength from 0-5
- Speech testing assesses articulation of sounds requiring tongue elevation
- Swallow evaluations test control of food bolus and residue
- Ultrasound quantifies thickness and movement
- EMG evaluates electrical activity in tongue muscles
- Lab work identifies nutritional and hormonal deficiencies
- Imaging detects structural causes like tumors
- Multimodal testing thoroughly characterizes weakness and guides treatment
Early detection and personalized treatment plans help manage tongue weakness and maintain function. Testing methods like ultrasound and EMG provide objective data to supplement clinical examination. This comprehensive assessment ensures patients get optimal rehabilitation therapy and adaptive strategies.
What causes tongue weakness?
Some potential causes of tongue weakness include:
- Motor neuron disease like amyotrophic lateral sclerosis
- Myasthenia gravis – autoimmune neuromuscular disorder
- Muscular dystrophies like bulbar muscular atrophy
- Stroke – damage to hypoglossal nerve
- Brain or head/neck tumors compressing nerves
- Multiple sclerosis – damage to brainstem and nerves
- Guillain-Barre syndrome – autoimmune nerve damage
- Neurodegenerative diseases like Parkinson’s, Huntington’s
- Nutritional deficiencies like vitamin B12, folate, thiamine
- Hypothyroidism
- Sjogren’s syndrome – autoimmune disorder affecting salivary glands
- Infections like lyme disease, HIV, syphilis
- Diabetes mellitus
- Traumatic injury, radiation therapy, surgery in head and neck area
- Cranial nerve palsies
- Medications like Dilantin, phenothiazines, chemotherapy
Identifying the underlying cause through testing can help determine appropriate treatments for tongue weakness.
How is tongue weakness treated?
Treatment focuses on both direct rehabilitation of the tongue muscles as well as compensatory strategies. Some approaches include:
- Speech therapy – Exercises to improve tongue mobility, coordination and strength such as tongue presses, chewing exercises, speech drills.
- Swallow therapy – Techniques to improve control of food bolus and saliva.
- Diet modification – Adjusting food textures and viscosities to make eating safer.
- Biofeedback – Using tools and cues to re-train tongue movements.
- Medications – Cholinesterase inhibitors for myasthenia gravis, steroids for autoimmune conditions.
- Surgery – In some cases, surgical procedures may help release compressed nerves or remove tumors contributing to weakness.
Patients also need to manage risks like choking and aspiration that can occur with tongue dysfunction. Strategies include eating upright, taking small bites, thickening liquids, and monitoring intake. With a customized program focused on adaption and strengthening, most people with tongue weakness can stabilize or improve function.
What are the consequences of untreated tongue weakness?
Leaving tongue weakness untreated can result in further complications such as:
- Progressive loss of tongue mobility
- Worsening dysarthria – slurred speech
- Difficulty chewing and controlling food in mouth
- Food residue collecting in mouth after meals
- Aspiration pneumonia due to food or saliva entering lungs
- Malnutrition and weight loss from inadequate intake
- Dehydration from difficultly swallowing liquids
- Social isolation due to inability to communicate effectively
- Depression due to reduced quality of life
Seeking medical evaluation for persistent tongue problems is important to determine the cause and start appropriate therapy. With proper treatment, people can learn techniques to compensate for weakness and potentially improve tongue strength over time.
When should someone see a doctor?
Anyone experiencing tongue problems like slurred speech, difficulty swallowing, or tongue muscle twitching should consult a doctor. Seek prompt medical attention if tongue weakness comes on suddenly or progressively worsens over a short period. This can indicate a neurological condition like stroke that requires urgent evaluation. Schedule an appointment with your doctor if you have:
- Tremors, involuntary movements or fasciculations of the tongue
- Tongue deviates to one side when stuck out
- Wasting away or thinning of the tongue
- Tingling, numbness or loss of sensation in the tongue
- Difficulty moving the tongue or sticking it out
- Speech is distorted, slurred or unclear
- Gagging, choking or coughing when eating or drinking
- Food caught in cheeks or sticking to teeth after meals
- Unexplained weight loss or malnutrition
- Excess saliva or drooling from the mouth
A neurologist, speech pathologist or otolaryngologist can evaluate, diagnose and provide specialized treatment for tongue weakness. Prompt medical care can help prevent complications and further tongue damage in conditions like myasthenia gravis, strokes and neurodegenerative disorders.
Tongue Anatomy
The tongue is a complex muscular organ located in the mouth. It is involved in functions like chewing, swallowing and speech. Understanding the anatomy helps clarify what structures are impacted in tongue weakness.
The tongue is made up of interwoven internal and external muscles including:
- Genioglossus – Fan shaped muscle, main protruder of the tongue
- Hyoglossus – Depresses the tongue
- Styloglossus – Retracts and elevates the tongue
- Palatoglossus – Elevates the back of the tongue
- Inferior longitudinal – Shortens the tongue
- Verticalis – Flattens and broadens the tongue
- Transversus – Narrows the tongue
These muscles work together to allow the tongue to move in all directions and manipulate food. The tongue muscles are innervated by the hypoglossal cranial nerve, which originates from the brainstem. Upper motor neuron damage like stroke or brain injury can affect the neural input to the tongue. Peripheral injuries to the hypoglossal nerve itself can also cause weakness.
Disorders of the muscles like atrophy, fibrosis, or myasthenia gravis directly impact tongue strength and mobility as well.
Key Points
- Tongue weakness impairs speech and swallowing function
- A clinical examination assesses appearance, tone, tremor and mobility
- Manual muscle testing grades strength from 0-5
- Ultrasound and EMG provide objective data on muscle thickness and activity
- Causes include neurological conditions, nerve damage, and muscle disorders
- Speech therapy, diet modifications, and biofeedback help manage symptoms
- Prompt diagnosis and treatment improves outcomes
Early evaluation of persistent tongue difficulties is crucial. A combination of tests can pinpoint areas of weakness and guide appropriate therapy. With proper rehabilitation, most patients can stabilize tongue function and prevent complications.