Hypertonicity

Hypertonicity
Illustration of muscle contraction
Synonyms	Hypertonia
Pronounce	N/A
Specialty	N/A
Symptoms	Increased muscle tone, stiffness, spasticity
Complications	N/A
Onset	N/A
Duration	N/A
Types	N/A
Causes	Neurological disorders, brain injury, spinal cord injury
Risks	N/A
Diagnosis	Clinical examination, electromyography
Differential diagnosis	N/A
Prevention	N/A
Treatment	Physical therapy, medications, surgery
Medication	N/A
Prognosis	N/A
Frequency	N/A
Deaths	N/A

Hypertonicity, also known as hypertonia, refers to an abnormal increase in muscle tone or stiffness, which can interfere with movement and posture. It is often a symptom of underlying neurological conditions and can significantly impact a person's quality of life.

Pathophysiology

Hypertonicity occurs when there is an imbalance in the signals that control muscle tone. Normally, the central nervous system (CNS) regulates muscle tone through a balance of excitatory and inhibitory signals. In hypertonicity, this balance is disrupted, often due to damage or dysfunction in the CNS, leading to excessive excitatory signals or reduced inhibitory signals.

Causes

Hypertonicity can be caused by a variety of conditions, including:

• Cerebral palsy
• Multiple sclerosis
• Stroke
• Traumatic brain injury
• Spinal cord injury
• Parkinson's disease

Clinical Features

Patients with hypertonicity may exhibit:

• Increased resistance to passive movement
• Muscle stiffness
• Spasticity, characterized by velocity-dependent increase in muscle tone
• Clonus, which is a series of involuntary muscle contractions

Diagnosis

Diagnosis of hypertonicity involves a thorough clinical examination. Physicians may use tools such as the Modified Ashworth Scale to assess the degree of muscle tone. Electromyography (EMG) can also be used to evaluate muscle activity and differentiate between different types of muscle tone abnormalities.

Management

Treatment of hypertonicity aims to reduce muscle tone and improve functional abilities. Approaches include:

• Physical therapy: Exercises and stretching to improve range of motion and reduce stiffness.
• Medications: Such as baclofen, tizanidine, and botulinum toxin injections to reduce muscle tone.
• Surgical interventions: In severe cases, procedures like selective dorsal rhizotomy may be considered.

Prognosis

The prognosis for individuals with hypertonicity depends on the underlying cause and the effectiveness of treatment. Early intervention and a multidisciplinary approach can improve outcomes and enhance quality of life.

Also see

• Hypotonia
• Spasticity
• Muscle tone
• Neurology