A to Z of MS Spasticity
Spasticity can be described as stiff muscles that resist passive movement. It is caused by damage to the nerves in the central nervous system that carry messages instructing muscles how to move. This can either lead to a lack of movement or to uncontrolled movements.
Spasticity is part of what is known as the upper motor neurone syndrome. Other symptoms related to the upper motor neurone syndrome include:
- Spasms - powerful uncontrollable muscle contractions which can be extremely painful and can be triggered in many ways eg coughing, sneezing or a full bladder
- Clonus - a repetitive movement, such as a constant tapping of the ball of the foot
- Contracture - when muscles become shortened and fix a limb in one position
Spasticity is a condition in which muscle tone becomes greatly increased. Muscle tone refers to the level of tension or resistance to movement in a muscle which allows people to move limbs or hold a position. For instance, to bend your arm, you must shorten or contract the biceps muscle at the front of the arm (increasing the tone) and at the same time lengthen or relax the triceps muscle at the back of the arm (reducing the tone).
When someone has spasticity in a muscle, the signals from the brain are interrupted and the muscle remains in its shortened, contracted state. This causes the affected muscle to feel stiff or tight and to be resistant to movement.
The instruction to contract a muscle can be triggered by sensory signals from peripheral nerves in the limb, which causes an automatic, reflex response initiated by the spinal cord. The message is also sent along the spinal cord to the brain, which then sends a message back to the muscle telling it when it is appropriate to relax again.
In MS, spasticity occurs if there is an area of scarring between the brain and the point where the nerve from the limb joins the spinal cord. The reflex action takes place but the message to or from the brain is interrupted. Thus no message to relax the muscle again is received or is delayed and the muscle remains contracted and stiff.
The degree of spasticity and spasms can vary from person to person, day to day, hour to hour and can impact on many activities. Nevertheless, spasticity can be successfully managed.
In an MS Society survey, 64% of people with MS reported muscle stiffness and 51% muscle spasms. Further, 17% stated that muscle stiffness caused them the most difficulty and distress on a daily basis and 14% reported similarly on muscle spasms
Consequences of spasticity
Spasticity can affect physical activities such as walking, transferring, picking up objects, washing, dressing and sexual activity. It can also have an emotional impact on, for example, mood, self-image and motivation.
Management of spasticity
It is important to prevent aggravating factors. Spasms, for example, can occur in response to sensory stimulation such as skin irritation, pressure sores, ingrowing toenails or visceral stimulation including incomplete bladder emptying, constipation, or urinary tract infections.
Physiotherapy
Physiotherapists can carry out specific treatments to assist an individual to manage muscle tone. Treatment may include appropriate exercise programmes that may encompass stretches, active exercises or standing. Advice can also be given regarding posture and positioning throughout the day.
Occupational therapy
Occupational therapists can play a role in assessing and recommending appropriate adaptations to an individual's environment and advising on how to make daily activities easier. Correct seating is of particular importance in managing spasticity.
Medication
The NICE Guideline states that the following should only be given if treatment with baclofen or gabapentin is unsuccessful or side effects are unmanageable:
- Tizanidine
- Diazepam
- Dantrolene
- Phenol
- Intrathecal baclofen
- Botulinum toxin is not mentioned by the NICE Guideline, but is sometimes used to treat spasticity and spasms in MS.
Diazepam can be used on its own or in combination with other drugs. It can be taken prior to sleep if spasms are particularly troublesome at night.
Dantrolene is the only antispasmodic drug that works directly on the muscles rather than on the central nervous system. It can be used in combination with other drugs. Often it is not well tolerated and can cause nausea, vomiting, diarrhoea and weakness. Regular blood tests need to be completed to ensure no adverse effect on liver function.