Hypertonia
Encyclopedia
Hypertonia a condition marked by an abnormal increase in muscle tension and a reduced ability of a muscle to stretch
. It is caused by lesions to upper motor neurons in the central nervous system
, which carry information from the central nervous system to the muscles and control posture, muscle tone
, and reflexes. When the injury occurs in children under the age of 2, the term cerebral palsy
is often used. Damage to the central nervous system results in the loss of control of motor neurons and gives rise to disordered spinal reflexes, increased excitability of muscle spindles and decreased synaptic inhibition
Hypertonia may result from injury, disease, or conditions that involve damage to the central nervous system. Examples include spasticity
, dystonia
(prolonged muscle contractions that cause twisting and repetitive movements or abnormal posture) and rigidity
.
Rigidity is a state of hypertonia where muscle resistance occurs throughout the entire range of motion and is independent of velocity (whereas spasticity is velocity-dependent). It is frequently associated with lesions of the basal ganglia
. People with rigidity present with stiffness, decreased functional ability and flexibility. There are two main forms of rigidity: leadpipe and cogwheel. With leadpipe rigidity, resistance from the muscle(s) remains throughout the entire range of movement and it is not velocity-dependent. When rigidity is present with Parkinson's disease it is often termed as cogwheel. Cogwheel rigidity is a hypertonic state with rachetlike movements, and is believed to be present when rigidity and tremor
occur together. Furthermore, the muscle(s) that have rigidity will not return to a fixed position after taken through range of motion
Spastic hypertonia involves uncontrollable muscle spasms, stiffening or straightening out of muscles, shock-like contractions of all or part of a group of muscles, and abnormal muscle tone
. It is seen in disorders such as cerebral palsy
, stroke
, and spinal cord injury
.
A form of hypertonia unrelated to spasticity is known as Paratonia
, which is associated with dementia
.
Dystonic hypertonia refers to muscle resistance to passive stretching (in which a therapist gently stretches the inactive contracted muscle to a comfortable length at very low speeds of movement) and a tendency of a limb to return to a fixed involuntary (and sometimes abnormal) posture following movement. It is seen is the different forms of dystonia and sometimes in parkinsonism
.
Rigidity
is an involuntary stiffening or straightening out of muscles, accompanied by abnormally increased muscle tone and the reduced ability of a muscle to stretch. This type of hypertonia is most common in parkinsonism
.
Hypertonia can be so severe that joint movement is not possible. Untreated hypertonia can lead to loss of function and deformity.
has been shown to be effective in controlling hypertonia with the use of static stretching which reduces motoneuron excitability. Other interventions include icing, inhibitory pressure (applying firm pressure over muscle tendon), promoting body heat retention, and rhythmic rotation (slow repeated rotation of affected body part to stimulate relaxation). A more unconventional method for limiting tone is to deploy quick repeated passive movements to an involved joint in cyclical fashion; this has also been demonstrated to show results on persons without physical disabilities. For a more permanent state of improvement, exercise and patient education is imperative. Isokinetic, aerobic
, and strength training
exercises should be performed as prescribed by a physiotherapist, and stressful situations that may cause increased tone should be minimized or avoided.
Stretching
Stretching is a form of physical exercise in which a specific skeletal muscle is deliberately elongated, often by abduction from the torso, in order to improve the muscle's felt elasticity and reaffirm comfortable muscle tone. The result is a feeling of increased muscle control, flexibility and...
. It is caused by lesions to upper motor neurons in the central nervous system
Central nervous system
The central nervous system is the part of the nervous system that integrates the information that it receives from, and coordinates the activity of, all parts of the bodies of bilaterian animals—that is, all multicellular animals except sponges and radially symmetric animals such as jellyfish...
, which carry information from the central nervous system to the muscles and control posture, muscle tone
Muscle tone
In physiology, medicine, and anatomy, muscle tone is the continuous and passive partial contraction of the muscles, or the muscle’s resistance to passive stretch during resting state. It helps maintain posture, and it declines during REM sleep.-Purpose:Unconscious nerve impulses maintain the...
, and reflexes. When the injury occurs in children under the age of 2, the term cerebral palsy
Cerebral palsy
Cerebral palsy is an umbrella term encompassing a group of non-progressive, non-contagious motor conditions that cause physical disability in human development, chiefly in the various areas of body movement....
is often used. Damage to the central nervous system results in the loss of control of motor neurons and gives rise to disordered spinal reflexes, increased excitability of muscle spindles and decreased synaptic inhibition
Hypertonia may result from injury, disease, or conditions that involve damage to the central nervous system. Examples include spasticity
Spasticity
Spasticity is a feature of altered skeletal muscle performance in muscle tone involving hypertonia, which is also referred to as an unusual "tightness" of muscles...
, dystonia
Dystonia
Dystonia is a neurological movement disorder, in which sustained muscle contractions cause twisting and repetitive movements or abnormal postures. The disorder may be hereditary or caused by other factors such as birth-related or other physical trauma, infection, poisoning or reaction to...
(prolonged muscle contractions that cause twisting and repetitive movements or abnormal posture) and rigidity
Rigidity
Rigid or rigidity may refer to:*Stiffness, the property of a solid body to resist deformation, which is sometimes referred to as rigidity*Structural rigidity, a mathematical theory of the stiffness of ensembles of rigid objects connected by hinges...
.
Rigidity is a state of hypertonia where muscle resistance occurs throughout the entire range of motion and is independent of velocity (whereas spasticity is velocity-dependent). It is frequently associated with lesions of the basal ganglia
Basal ganglia
The basal ganglia are a group of nuclei of varied origin in the brains of vertebrates that act as a cohesive functional unit. They are situated at the base of the forebrain and are strongly connected with the cerebral cortex, thalamus and other brain areas...
. People with rigidity present with stiffness, decreased functional ability and flexibility. There are two main forms of rigidity: leadpipe and cogwheel. With leadpipe rigidity, resistance from the muscle(s) remains throughout the entire range of movement and it is not velocity-dependent. When rigidity is present with Parkinson's disease it is often termed as cogwheel. Cogwheel rigidity is a hypertonic state with rachetlike movements, and is believed to be present when rigidity and tremor
Tremor
A tremor is an involuntary, somewhat rhythmic, muscle contraction and relaxation involving to-and-fro movements of one or more body parts. It is the most common of all involuntary movements and can affect the hands, arms, eyes, face, head, vocal folds, trunk, and legs. Most tremors occur in the...
occur together. Furthermore, the muscle(s) that have rigidity will not return to a fixed position after taken through range of motion
Spastic hypertonia involves uncontrollable muscle spasms, stiffening or straightening out of muscles, shock-like contractions of all or part of a group of muscles, and abnormal muscle tone
Muscle tone
In physiology, medicine, and anatomy, muscle tone is the continuous and passive partial contraction of the muscles, or the muscle’s resistance to passive stretch during resting state. It helps maintain posture, and it declines during REM sleep.-Purpose:Unconscious nerve impulses maintain the...
. It is seen in disorders such as cerebral palsy
Cerebral palsy
Cerebral palsy is an umbrella term encompassing a group of non-progressive, non-contagious motor conditions that cause physical disability in human development, chiefly in the various areas of body movement....
, stroke
Stroke
A stroke, previously known medically as a cerebrovascular accident , is the rapidly developing loss of brain function due to disturbance in the blood supply to the brain. This can be due to ischemia caused by blockage , or a hemorrhage...
, and spinal cord injury
Spinal cord injury
A spinal cord injury refers to any injury to the spinal cord that is caused by trauma instead of disease. Depending on where the spinal cord and nerve roots are damaged, the symptoms can vary widely, from pain to paralysis to incontinence...
.
A form of hypertonia unrelated to spasticity is known as Paratonia
Paratonia
Paratonia or gegenhalten is classified as a form of hypertonia with an involuntary variable resistance during passive movement . Paratonia develops during a period of dementia and the degree of effect is dependent upon the disease's progress...
, which is associated with dementia
Dementia
Dementia is a serious loss of cognitive ability in a previously unimpaired person, beyond what might be expected from normal aging...
.
Dystonic hypertonia refers to muscle resistance to passive stretching (in which a therapist gently stretches the inactive contracted muscle to a comfortable length at very low speeds of movement) and a tendency of a limb to return to a fixed involuntary (and sometimes abnormal) posture following movement. It is seen is the different forms of dystonia and sometimes in parkinsonism
Parkinsonism
Parkinsonism is a neurological syndrome characterized by tremor, hypokinesia, rigidity, and postural instability. The underlying causes of parkinsonism are numerous, and diagnosis can be complex...
.
Rigidity
Rigidity
Rigid or rigidity may refer to:*Stiffness, the property of a solid body to resist deformation, which is sometimes referred to as rigidity*Structural rigidity, a mathematical theory of the stiffness of ensembles of rigid objects connected by hinges...
is an involuntary stiffening or straightening out of muscles, accompanied by abnormally increased muscle tone and the reduced ability of a muscle to stretch. This type of hypertonia is most common in parkinsonism
Parkinsonism
Parkinsonism is a neurological syndrome characterized by tremor, hypokinesia, rigidity, and postural instability. The underlying causes of parkinsonism are numerous, and diagnosis can be complex...
.
Hypertonia can be so severe that joint movement is not possible. Untreated hypertonia can lead to loss of function and deformity.
Management
PhysiotherapyPhysical therapy
Physical therapy , often abbreviated PT, is a health care profession. Physical therapy is concerned with identifying and maximizing quality of life and movement potential within the spheres of promotion, prevention, diagnosis, treatment/intervention,and rehabilitation...
has been shown to be effective in controlling hypertonia with the use of static stretching which reduces motoneuron excitability. Other interventions include icing, inhibitory pressure (applying firm pressure over muscle tendon), promoting body heat retention, and rhythmic rotation (slow repeated rotation of affected body part to stimulate relaxation). A more unconventional method for limiting tone is to deploy quick repeated passive movements to an involved joint in cyclical fashion; this has also been demonstrated to show results on persons without physical disabilities. For a more permanent state of improvement, exercise and patient education is imperative. Isokinetic, aerobic
Aerobic exercise
Aerobic exercise is physical exercise of relatively low intensity that depends primarily on the aerobic energy-generating process. Aerobic literally means "living in air", and refers to the use of oxygen to adequately meet energy demands during exercise via aerobic metabolism...
, and strength training
Strength training
Strength training is the use of resistance to muscular contraction to build the strength, anaerobic endurance, and size of skeletal muscles. There are many different methods of strength training, the most common being the use of gravity or elastic/hydraulic forces to oppose muscle contraction...
exercises should be performed as prescribed by a physiotherapist, and stressful situations that may cause increased tone should be minimized or avoided.
External links
- "The Clasp Knife Phenomenon" at mcg.edu