The key difference between hypertonia and hypotonia is that hypertonia is a medical condition characterized by increased muscle tone, while hypotonia is a medical condition characterized by low muscle tone.
Hypertonia and hypotonia are two medical conditions due to altered muscle tone. Muscle tone is a property of muscles defined as the tension in a muscle at rest. Muscle tone is also the muscle’s response to an outside force, like a stretch or change in direction. When there is sufficient muscle tone, it enables the human body to respond to a stretch quickly. A person with high muscle tone has a condition called hypertonia. In contrast, a person with low muscle tone has a condition called hypotonia.
What is Hypertonia?
Hypertonia is a medical condition in which there is too much muscle tone. In this condition, arms and legs are stiff and difficult to move. The muscle tone is usually regulated by signals that travel from the brain to nerves in the muscles that tell how the muscle should contract. Hypertonia arises when the region of the brain or spinal cord that regulates these signals is damaged. Hypertonia can occur due to various reasons such as a blow to the head, stroke, brain tumors, toxins that affect the brain, neurodegenerative disorders (multiple sclerosis and Parkinson’s disease), and neurodevelopmental abnormalities as in cerebral palsy, etc.
Hypertonia normally limits how easily the joints can move. Moreover, hypertonia can cause joints to become frozen. This condition is called joint contracture. When hypertonia affects the legs, walking becomes stiff, and the person may fall as it is difficult for the body to respond too quickly to regain balance. Spasticity and rigidity are two types of hypertonia. The symptoms of this medical condition are loss of muscle function, decreased range of movement, the rigidity of muscles, spasticity of muscles, deformity, tenderness and pain in the affected muscle, rapid muscle contractions, and involuntary crossing of the leg. The diagnosis of this condition is through clinical examinations, neuroimaging, and EMG. Furthermore, treatment options for hypertonia may include drugs like baclofen, diazepam, and dantrolene to reduce spasticity, drugs like levodopa/carbidopa, or entacapone to reduce rigidity, frequent exercises within limits, and physical therapy.
What is Hypotonia?
Hypotonia is a medical condition that involves decreased muscle tone. It is a state of low muscle tone. Healthy muscles are never fully relaxed, and they retain a certain amount of muscle tone that can be felt as resistance to movement. Hypotonia is not often considered a specific medical disorder. But it is a potential manifestation of many different diseases that affect the motor nerve controlled by the brain. Hypertonia can happen due to damages to the brain, spinal cord nerves, or muscles. These damages can be a result of trauma, environmental or genetic factors, or muscle or central nervous system disorders.
Hypotonia is often seen in medical conditions like Down syndrome, muscular dystrophy, cerebral palsy, Prader-Willi syndrome, myotonic dystrophy, and Tay Sachs disease. Central hypertonia is a result of the problems in the central nervous system, while peripheral hypotonia is a result of the problems in peripheral nerves. The severe hypotonia in infancy is known as a floppy baby syndrome. The signs and symptoms may include a decrease in muscle tone, decrease in muscle strength, poor reflexes, hyper flexibility, speech difficulties, decrease in activity endurance, and impaired posture. The diagnosis can be made through physical examinations, blood tests, CT scans, MRIs, electroencephalogram (EEG), EMG, nerve conduction tests, muscle biopsies, and genetic testing. The treatment options include physical therapy, occupational therapy, and speech and language therapy. Treatment for infants and young children may include sensory stimulation programs.
What are the Similarities Between Hypertonia and Hypotonia?
- Hypertonia and hypotonia are two medical conditions due to altered muscle tone.
- Both medical conditions are a result of the defects in the nervous system that guide muscles to contract.
- These medical conditions can be diagnosed through clinical examination.
- They are treatable medical conditions.
What is the Difference Between Hypertonia and Hypotonia?
Hypertonia is a medical condition that involves too much muscle tone, while hypotonia is a medical condition that involves decreased muscle tone. Thus, this is the key difference between hypertonia and hypotonia. Furthermore, arms and legs are stiff and difficult to move in hypertonia, while arms and legs are fully relaxed and very less resistant to movement in hypotonia.
The below infographic presents the differences between hypertonia and hypotonia in tabular form for side by side comparison.
Summary – Hypertonia vs Hypotonia
Hypertonia and hypotonia are two medical terms related to muscle tone or muscle tension. Hypertonia refers to a medical condition characterized by too much muscle tone. Hypotonia refers to a medical condition characterized by decreased muscle tone. So, this is the key difference between hypertonia and hypotonia.
1. “Hypertonia Information Page.” National Institute of Neurological Disorders and Stroke, U.S. Department of Health and Human Services.
2. Roddick, Julie. “What Is Hypotonia?” Healthline, Healthline Media.
1. “Spastic Hand” By Clfekete – I took this photo during physical therapy (CC BY-SA 3.0) via Commons Wikimedia
2. “6 m old baby with severe hypotonia, facial dysmorphism and developmental disability in HRB clinic” By Sadasiv Swain (CC BY 2.0) via Flickr