I love talking about spasticity because I feel that it is the one thing I can never get tired of talking about. Also, it is something that most persons, even in medicine, are just not familiar with. And having dealt with it every day, all day for more than 10 years, I feel like I have a super-secret superpower when it comes to understanding and treating spasticity.
The Motor Disorder
Spasticity is classified as a motor disorder. This condition causes specific muscles to keep contracting. This results in tightness or stiffness of these muscles. This can interfere with the walk, speech, and normal movement of the individual. The cause is generally damage to a part of the spinal cord or brain responsible for voluntary movement. This damage changes the balance of the signals between the muscles and the nervous system. The imbalance results in an increase in muscle activity. This has a negative impact on the joints and muscles of the arms and legs. The condition can become worse due to a sudden change in position, extreme temperatures, tight clothing, sudden movement, tight muscles, infections, and humidity. This condition can also be caused by:
- Damage to the brain from a lack of oxygen
- (TBI) Traumatic brain injury
- (Lou Gehrig's disease) Amyotrophic lateral sclerosis
- (CP) Cerebral Palsy
- (SCI) Spinal cord injury
The symptoms can be mild such as a tightness in the muscles. The severe symptoms include uncontrollable, painful spasms in the arms and legs. There may also be lower back pain and tightness around or centered in the joints. The other symptoms include:
- Muscle spasms result in painful and uncontrollable muscle contractions
- Deformities of the joints and muscles
- Infections of the urinary tract
- Longitudinal muscle growth is inhibited
- Pressure sores
- Chronic constipation
- Crossing the legs involuntarily
- Muscle fatigue
- Protein synthesis in the muscle cells
- Systemic illnesses and fever
- Muscle stiffness results in less precise movements. Specific tasks become much harder to perform.
The gradual development of this condition is caused by an injury to the central nervous system. The spinal tracts including the rubrospinal and vestibulospinal tracts increase inactivity. This condition often results from an injury to the basal ganglia, brainstem, central white matter, cortex, thalamus, cerebellum, or spinal cord. The individuals affected by this condition have a serious injury to the brain, cerebrovascular episodes, (MS) multiple sclerosis, or an injury to the spinal cord among other conditions. This type of muscle overactivity is triggered by a disruption of the communication between the spinal cord and the brain due to an illness or an injury to the spinal cord.
The degree and development of this condition cause an immature motor response. This is especially obvious when a movement is in progress. This has a negative impact on normal posture, movements, and balancing the body. There are some benefits to this condition including helping to tone the muscles. This condition can result in numerous issues including fatigue and pain. The individual can have difficulties performing normal daily activities including sleeping, changing positions, sitting, and walking.
The Definition of Spasticity
In 1980, this condition was described by James Lance, MD as a motor disorder. The condition was characterized by an increase in the tone of the muscles and exaggerated jerks of the tendons. Another definition was introduced by Robert R. Young MD nine years later. This included abnormal posture, abnormal responses, and an increase in automatic and stretching reflexes. This condition is one of the elements of (UMN) upper motor neuron or changes in the skeletal muscle. This condition involves overactive muscles. The other factors of this condition are clonus which is a general term for any disease affecting the function of the brain, extensor and flexor spasms which are triggered by multiple sclerosis, the inability to relax the muscles, a neuromuscular disease called tendon hyperreflexia, and too much resistance when trying to flex a joint. Upper motor neuron syndrome has positive signs that should not be confused with this condition including disease affecting the brain.
When an individual makes a voluntary movement, the motor pattern is affected. This often triggers spontaneous movements such as contractions, misfiring nerves after experiencing trauma, spasms, and other associated reactions. This type of movement is irregular, massive, and generally has no impact on function. Abnormal tissues in the brain trigger involuntary overactivity of the muscle caused by the fusion of immature cells. This is what causes numerous neurological diseases. The pure form of this condition is the early, involuntary overactivity of the muscles when the individual makes a simple movement. The soft tissue elasticity is preserved and the movement can be completed. This has been clinically monitored when the acute phase of the disease is active.
The transition from one phase of this disease to the next happens when the individual is recovering. The involuntary movements are not as frequent during this period of time. According to the Ashworth scale, the classification of this condition is one or one+. The range of motion for the joint is not affected. When the muscle overactivity is spontaneous with no main trigger, abnormal positions are assumed by different parts of the body. This may result in a social handicap or disfigurement for these individuals. The clinical name for this condition is spastic dystonia. As time passes, there are changes in the composition of the muscle. The muscle shortens, limiting the range of motion in the joints. This can cause permanent fixation or abnormal immobility and stiffening of a joint. This happens because the bones become fused.
Once the soft tissues have shortened, chain reactions are triggered including the activation of the disease when the individual is walking. This results in either a muscle spasm or a major bending of the lower limbs. Either way, the individual will have an abnormal walk. This is referred to as hypertonia. The constant contraction of the muscles results in the development of muscular atrophy because the muscles are not being used. A good example is when the biceps permanently contract. When this is combined with the individual being unable to extend their elbow, the triceps will become inactive because they are unable to be used by the individual. This is referred to as a vicious circle. Hypertonia is an impacted muscle or muscle group most frequently found in individuals with this condition.
Depending on the degree and specifics of the condition, conservative treatment may be effective. This includes surgery for the transfer or lengthening of the tendons or injecting botulinum toxin into the overactive muscles. The option for surgery is dependent on if the condition is generalized or local and if the condition is manageable with either general or local treatment. This will help ensure satisfactory results from the surgery. A good example is if the extended position of the knee can be corrected by flexing the knee. This condition is centered over the Achilles tendon. As time passes, the Achilles tendon shrinks and results in the development of abnormal walk.
How does spasticity occur?
There are these amazing nerve cells in the body called gamma motoneurons, literally my favorite type of neurons. They are under the category of lower motor neurons because they arise from the spinal cord. There are 3 major types of nerve cells which are lower motor neurons: alpha, beta, and gamma.
Alpha motoneurons are the main neurons of a muscle, they signal the muscle to contract and generate force. Most of our muscles are under the control of alpha.
There are these special areas in the muscles that sense how long the muscle is -called muscle spindles, which is how we are able to test reflexes. The gamma motoneurons are neurons that go to these specific areas. It is not exactly clear what the gamma motoneuron is doing to the spindle, we know that it can alter the sensing threshold of the spindle.
We know that the gamma motoneuron probably has the biggest impact on the level of tightness in a muscle.
The Prevalence of the Condition
This condition impacts approximately twelve million individuals all over the world. Roughly eighty percent of these individuals have (CP) cerebral palsy. The estimation is 500,000 individuals within the United States have some form of cerebral palsy. This means approximately 400,000 individuals have this condition. Roughly eighty percent of all individuals with (MS) multiple sclerosis also have this condition in varying degrees. Since the estimation is 400,000 individuals in the United States have multiple sclerosis, around 320,000 individuals also have this condition to some degree.
Brain damage has occurred in individuals with cerebral palsy, usually at the time of birth. The damage is usually centered on the part of the brain controlling the movement and tone of the muscles in the arms and legs. The reason remains unknown. The muscle becomes spastic or too tense as opposed to having any weakness. Deformities in the arms and legs are not present when the individual is born. Any deformities are developed as time passes. The most common cause of the deformities includes a limited ability to use and stretch these muscles on a daily basis and spastic muscles.
Brain Trauma Injury
Spastic hypertonia is often a result when the brain stem, midbrain, or cerebellum are damaged. This damage impacts the brain's reflex centers. This causes an interruption in the messages sent using the numerous nerve pathways. The resulting disruption can lead to changes in movement, the tone of the muscle, reflex, and sensation although there will not be any weakness. The location of the damage determines the parts of the body impacted and the damage to the capabilities of the individual. The reflex centers in the spinal cord as not nearly as complicated as those in the brain. This makes the condition a lot harder to treat when the individual has a neurological disorder or an injury to the spinal cord.
A lot of individuals experience increased muscle tone after receiving a brain injury. This results in extremely rigid body posture. One of the most common positions is holding the elbows rigidly at the individual's side with the fingers clenched and the fingers and wrists bent. In most cases, the toes and ankles are flexed with the legs extended from the hips. During the recovery period, there may be a change in the nerve signals controlling the individual's motor functions. The brain's reflex center may not be reached by certain signals or too many signals can be sent by the brain resulting in the wrong response from the muscles.
This condition is extremely common among individuals with (MS) multiple sclerosis. There are two different types of spasms linked to this condition. These are extensor and flexor. Extensor spasms are when the legs are straightened involuntarily. This includes the muscles located on the front of the upper thigh or the quadriceps and the muscles on the inner thigh or the adductors. The legs will remain close together with the knees and hips straight and the ankles crossed over each other. This usually concerns the hamstring muscles located on the back of the upper thigh. This does not generally affect the arms of individuals with multiple sclerosis. Flexor spasms are when the hips or knees bend involuntarily. This usually centers on the muscles on the back of the upper thigh or the hamstrings. The knees and hips are bent upwards towards the chest.
The Clinical Evaluation
The clinical signs of this condition are different depending on whether the injury was progressive or sudden, the extent of the damage to the spinal cord or brain, and whether the injury is incomplete or complete. If the individual suffered a localized brain injury like a stroke or an incomplete injury of the spinal cord, the increase in muscular tone will not be the same for all the joints. The positioning of the joint is also affected by the muscles that were not injured. This type of injury has a higher risk of the joint becoming deformed. In some instances, the repetition of the abnormal movement as time passes can cause dystonia. This is when the normal adjacent muscles develop permanent contractions in an attempt to balance the body in a physically pleasing, fast, and safe motion such as walking.
The clinical examination has four separate stages including functional and static evaluation. The first stage is clinical observation. This is observing the body of the individual when they walk into the room and when in a supine position. This is when the individual is lying horizontally with their body and face turned upwards. Any muscle spasms or muscular atrophies are also noted. The second stage is when the range of the joint movements is examined such as the pathological and normal reflexes and the active movements. During this stage, the Modified Ashworth Scale, the Tardieu Scale, the motor test, and the adductor tone rating are used. The third step involves a motor skill test for the upper limbs while the individual is in a sitting position. The fourth stage is examining the individual's balance while walking for a shorter and a lengthier distance. One of the major signs of movement disturbance is fatigue.
This condition does not remain the same as time passes. The condition is constantly changing as the day goes by including when the individual is sleeping. The changes are dependent on irritant and pain factors including infection, inflammation, the individual's emotional state, and menstruation for females. The timing of the treatment is critical for managing this condition.
The Options for Treatment
The treatment is dependent on an evaluation for each individual. This is based on the age of the individual, the underlying cause, and the severity of the condition. All of the available treatments have the same goals. This includes;
- Providing relief for the symptoms and signs of this condition
- Improving ease of care and daily living activities such as hygiene and walking
- Helping ensure children achieve more normal muscle growth
- Decreasing the frequency and pain of the muscle contractions
- Decreasing the caregiver challenges including bathing, feeding, and dressing
- Preventing stroke
Oral medications are used for the treatment of this condition when the symptoms are interfering with the individual's ability to sleep or function on a daily basis. Managing the medications effectively often necessitates the usage of more than one drug or combining another kind of treatment with oral medications. It is extremely important to work closely with the physician or create a personalized treatment plan for each individual. Depending on the individual and the type of medication, there is a possibility of side effects. The medications include dantrolene sodium, gabapentin, baclofen, imidazolines and benzodiazepines.
Injections of Botulinum Toxin
Botulinum toxin is often referred to as Botox or BTA. When the amount used is tiny, the injections are effective for paralyzing spastic muscles. The sites of the injections must be determined extremely carefully. Instead of causing weakness, this condition causes the muscle to become overactive. The Botox releases acetylcholine to block the overactive muscles. This results in a relaxation of these muscles. In most cases, the effect of the injection can be seen in just a few days. The results last for approximately twelve to sixteen weeks. Eventually, the nerve endings will grow back and the muscle will recover. The functional benefits last for a much longer period of time. The number of injections the individual can receive is limited.
Occupational and Physical Therapy
Occupational and physical therapy are used to improve the range of mobility and motion, reduce muscle tone, improve the level of comfort and increase coordination and strength. The therapy may include temporary casts or braces, applying cold packs, biofeedback, strengthening exercises, limb positioning and electrical stimulation.
There are two main neurological procedures for treating this condition, These are (SDR) selective dorsal rhizotomy and (ITB) intrathecal baclofen pumps. If the condition is severe, a pump can be implanted surgically in the abdomen of the individual for the administration of baclofen. When baclofen is directly delivered to the spinal fluid, the result is often a powerful decrease in the impact of the condition and a decrease in pain without as many side effects. ITB treatment has been very effective in treating both the arms and the legs. Selective dorsal rhizotomy involves certain nerve roots being cut by a neurosurgeon. These nerve fibers are found just outside of the spinal column. The muscles can then send sensory messages to the spinal cord.
This treatment is used when the condition is severe enough to interfere with positioning or movement. This decreases the stiffness in the muscles without impacting any of the other functions. This may improve the function and mobility of the muscles while helping to prevent deformities of the bone and joint and severe scarring of the muscle. This treatment is extremely effective for individuals with cerebral palsy experiencing specific conditions. Individuals with certain conditions are not candidates for selective dorsal rhizotomy. This includes:
- Individuals with severe scoliosis.
- Individuals who have had a congenital brain infection, head trauma, meningitis, familial disease or congenital hydrocephalus separate from premature birth.
- Individuals with cerebral palsy with rigidity, a significant loss of muscle coordination or control or abnormal muscle contractions.
Surgery will not provide these individuals with any functional aid. According to controlled, random clinical trials, a large percentage of individuals with cerebral palsy have seen an improvement in function after having surgery. Surgery is not appropriate for all individuals with this condition.
The Options for Treatment
Treatment for this condition generally includes a combination of several different options. This includes:
- Oral medications may be prescribed to help decrease muscle issues associated with this condition.
- Injections into the peripheral nerve near the impacted muscles or neuromuscular junction may decrease muscle spasms. Botulinum toxin injections help to reduce the signals from the muscles causing the condition. This offers the individual temporary relief enabling them to strengthen and move the muscles. The injections can be given every ninety days.
- Occupational and physical therapists teach exercises for positioning and stretching the muscles to help the individual maintain their motion range and prevent the muscles from tightening or shortening.
- Intrathecal therapy is when the condition is treated using medications administered right into the fluid around the spinal cord 24 hours a day. A catheter system and implantable pump are used for the delivery of the medication.
- Orthopedic and neurosurgery procedures can be used during surgery for the destruction of the motor nerves to treat this condition.
The Specifics of Spasticity
Every aspect of this condition must be analyzed to ensure the right treatment is provided at the right time. This includes the nature of the condition, the differences with other disorders involving muscle tone, the development based on the severity and the site of the injury, the changes over time and during sleep, the symptoms including pain and the changes in intensity resulting from both internal and external sensory stimuli. The length of time between the injury and the treatment is extremely important. This is dependent on the clinical condition of the individual and the chosen plan for therapy. There are four different categories of treatment. These are:
- This involves the treatment or prevention of contractures, the treatment or prevention of posture developed when the individual is lying down, positioning the body correctly when in a wheelchair or on a bed, gently catheterizing the bladder, the orthotics fitting, making arrangements for a caregiver, relieving pain and improving sleep.
- The second category encompasses improving movement, speeding the process of recovery, improvements to the immature motor patterns, guiding the learning experience of the brain through the use of new techniques for recovery such as robotic rehabilitation and providing a new way for walking and moving.
- The third category involves the activities the individual participates in for their daily routine such as putting on clothing, driving, personal hygiene, etc.
- The fourth category is meant to improve the individual's quality of life including living independently and going back to their professional and social lives.
The rehabilitation team will set goals for the individual while considering not only the person but their family. The final goal is a successful outcome.