It is important to know the causes and effects of spasticity in order to provide a comprehensive treatment to counter its effects and improve the quality of life of those living with it.
What is spasticity?
Spasticity is a velocity-dependent disorder of the stretch reflex that results in increased muscle tone and exaggerated tendon jerks (Lance, 1980 cited in Physio-pedia.com)
Types of Spasticity
There are two types of spasticity:
- Static: Elevated muscle tone appears independently of muscular activity and in any position.
- Dynamic: Muscle stiffness manifests itself only in specific situations.
What are the causes of spasticity?
Spasticity is often related to chronic neurological disorders and injury to the primary motor cortex. It is usually caused by damage to the part of the brain dedicated to movement, although it can also occur through an injury to the nerves that connect the brain to the spinal cord.
Signs of spasticity
Spasticity results in muscle hypertonia (uncontrollable muscle spasms or stiffening of the muscles) and an increased resistance to stretching, causing the muscles to remain continuously contracted. This affects movement-related actions such as walking, but it can also affect speech, carrying out daily activities such as washing and dressing, as well as the use of walking braces and footwear, or stability whilst in the wheelchair.
This condition may appear in any muscle group, although it is most common in:
Lower extremities: extensor muscles of the quadriceps, the gemellus and hip abductor muscles.
Upper extremities: flexor muscles of the fingers, wrist, biceps and shoulder adductor muscles.
Some of the common symptoms of spasticity are:
- Generalised muscle weakness
- Loss of dexterity in the fingers
- Loss of selective movement control
- Abnormal posture
- Muscle tension during activity
- Abnormal angles of the shoulders, arms, wrists and fingers.
- Muscle contractions that reduce the degree of movement and / or immobilise the joints
- Deep tendon reflexes (involuntary muscle contractions)
- Sudden, repetitive and involuntary spasmodic movements
- Involuntary closing of the legs
- Muscular and joint pain
Who does spasticity affect?
Spasticity is associated with different neurodegenerative diseases and disabilities that can be either congenital or acquired.
It is estimated at present that twelve million people in the world suffer from spasticity, with cerebral palsy and multiple sclerosis being the most common causes. As such, those affected by spasticity are both numerous and varied, given that this condition may appear in greater or lesser degrees in cases of:
- Spina bifida
- Acquired brain damage
- Amyotrophic Lateral Sclerosis
- Traumatic brain injuries
- Pathologies that cause neurological damage
The intensity and severity of spasticity may vary between light, moderate or extreme, depending on different factors such as position, carrying out activities, environmental and psychological factors, etc.
In order for a proper diagnosis to be made, it is important to know the patient’s history and to carry out a detailed medical examination, evaluating the following factors:
- Muscle tone. This is measured via the Ashworth Scale (either in its original format or in the format modified in 1987). The scale goes from the absence of increased muscle tone (0) up to extreme rigidity in flexion and tension (4).
- Joint balance, diagnosed by the measurement of joint angles.
- Selective motor control, done by observing the ability to make different movements.
- Functional capacity, via the objective assessment of carrying out daily activities.
- Gait analysis
- Muscle spasms
- Signs of pain shown by the patient
Spasticity cannot be cured, but it can be treated. Prevention is very important to avoid major disorders such as permanent contractures or bone deformities. This approach must always be carried out in a multidisciplinary way, including the participation of a neurologist, a neurosurgeon, a physiotherapist, a traumatologist, a rehabilitation physician, and even a psychologist.
How is spasticity treated?
Among some of the treatments associated with improving the quality of life for people with spasticity are:
Non-pharmacological therapeutic interventions
Performing regular physical and physiotherapeutic activities such as swimming-hydrotherapy, muscle stretching, floor or standing exercises with weights, splints and prostheses, and the use of heat and cold to reduce muscle tone.
The administration of prescribed oral drugs such as baclofen, benzodiazepines, dantrolene or tizanidine. Although this therapy is effective, it has various side effects (drowsiness, nausea or fatigue). Botulinum toxin may also be injected directly into the affected muscles to paralyse or reduce the unwanted muscle activity
The most well-known is the baclofen pump, a minimally invasive surgical treatment that involves placing a small pump in the abdominal area that releases a drug into the spinal cord by way of a catheter. This system allows the medication to be directed to the muscles affected by spasticity using lower doses than those administered orally.