One Effect of this Huge and Life-changing Event – Weak Muscles After Stroke…
The Problem of Spasticity Following Stroke: A Painful Condition
What is spasticity, why does it occur after stroke and what can be done about this problem?
TABLE OF CONTENTS
- What is spasticity?
- Why does spasticity occur after stroke?
- A deeper look at the science
- How does spasticity present after stroke?
- Why is it a problem?
- What can be done about spasticity?
- Treatment options
What is spasticity?
Spasticity is an unpleasant and often debilitating symptom of stroke.
Its cause is complex and difficult to understand but perhaps the easiest way to describe spasticity is muscle tightness, stiffness or spasm.
There are several types of spasticity but commonly it presents as a persistent tightness in a muscle group meaning that it is difficult, or impossible, to relax. It may also cause intermittent spasms.
The severity can be very varied. For some it may be relatively mild stiffness while for others it is a strong and painful spasms or sustained contraction.
Why does spasticity occur following stroke?
Usually, messages from the brain travel down the spinal cord and out to our muscles via our nervous system. These signals from the brain are sent to tell the muscles to work. However, the messages not only to tell the muscles when to switch on but also when to switch off and relax, which they do by communicating with nerve cells in the spinal cord. Muscle control depends on a fine balance between these messages from the brain and spinal cord.
So, what goes wrong when we have a stroke? Following a stroke, there is damage to an area of the brain, or even the spinal cord depending on the location of the stroke. This damage interrupts the signals and upsets the fine balance of communication to the muscles telling them to contract and relax. This then leads to unwanted or uncontrolled muscle activity in certain muscle groups, meaning they switch on when you are not telling them to, or they switch on too much when you are.
A deeper look at the scientific theories of spasticity
If you want to understand even more about why spasticity occurs following stroke, this section will explain the scientific theories in a little more detail.
We all have spinal reflexes operating to control our movements and this is normal. These reflexes are designed to keep us safe and to ensure our movements are fine tuned and well controlled.
We have several motor reflexes all occurring in the nerve cells within our spinal cord. A few examples of these are briefly explained in the list below:
- Our ‘flexor withdrawal response’ – if we touch something hot or step on something sharp, it is this reflex that helps us to move our limb away quickly to minimise or avoid damage, without us needing to think about it. Our limb, whether that is the arm or the leg, quickly bends in order to withdraw from the hazard.
- Our ‘crossed extensor reflex’ – this is closely linked with the flexor withdrawal response outlined above. This time, the reflex has the opposite effect on the opposite limb.
For example, if we stand on a pin with our right foot, this foot is quickly withdrawn from the sharp pin to avoid pain and damage. At the same time, the opposite leg (the left leg in this case) must straighten to support our weight and continue to hold us up against gravity. So, these reflexes mean we simultaneously bend one leg and straighten the other.
- Our ‘stretch reflex’ – this reflex does what is says. It senses when our muscles are being stretched too much and it fires to tell our muscles to contract (shorten), thereby preventing damage from over-stretching. This reflex helps us to balance and move in a controlled way.
For example, if we are standing on a bus and it starts to slow down, our body is forced forwards due to the deceleration which puts a stretch on the muscles in the back of our calf (assuming we are facing the front of the bus). Our stretch reflex senses this stretch and tells the muscles to switch on to keep us upright despite the deceleration. It works in reverse when the force changes due to acceleration – the opposite muscle groups are stretched and must switch on.
The stretch reflex is also the reflex responsible for the fast muscle contraction seen with the tendon tap, which is when the doctor tests your reflexes using a reflex hammer. One example of this is the knee-jerk. The doctor taps the patella tendon using the hammer (giving the tendon a sudden stretch) and is able to assess the reflex response to determine whether the central nervous system is intact and functioning normally.
These reflexes are all normal and are usually present in healthy individuals.
Another important detail to understand is that, in the healthy individual, messages from the brain usually descend onto the spinal cord to control these reflexes. In other words, the brain sends messages down to the spinal cord to dampen the reflexes or keep them ‘in check’.
So, what goes wrong?
Following stroke, the damage to the brain means that these messages coming down to the spinal cord to keep the reflexes ‘in check’ are interrupted. The reflexes are allowed to fire more freely or to ‘run a mock’. It is this interruption in signal that is thought to lead to the involuntary muscle activity from the reflexes i.e. spasticity.
So, in this way, a limb might be bent or straight even when you are trying to relax the limb or move it in a different way.
Please see the section below for more detail on how this may present following stroke.
How does spasticity look or feel following stroke?
The way spasticity looks or feels depends on the type of spasticity, but following stroke, it very commonly presents in one of the following ways:
- Shoulder: Tightness in the muscles around your shoulder meaning your upper arm is held very tightly into your body.
It can be difficult for you or the person caring for you to move your arm away from your side to get dressed or wash under your arm.
- Elbow: Tightness in the elbow meaning your elbow is constantly bending and it is difficult to straighten the arm.
This can make dressing and positioning your arm on the chair arm rest difficult.
- Wrist: Tightness in the muscles that bend your wrist meaning your wrist is constantly bending forwards so that the palm of the hand is towards the inside of your forearm.
This can make getting your hand through a sleave difficult as well as finding a comfortable and natural position in which to rest your hand.
- Fingers: Tightness in the muscles that bend your fingers meaning your fingers are constantly bending.
This makes washing your hand particularly difficult and can lead to unpleasant symptoms of poor hand hygiene.
- Hip: Tightness in the muscles that bring your legs in and together is common. Your legs can be difficult to part and in severe cases may rest ‘clamped’ together.
This can make washing, dressing and toileting and personal hygiene very challenging.
- Knee: It is common for the muscles that either straighten or bend the knee to tighten due to spasticity following stroke.
When the muscles that bend the knee are tight, your leg may be constantly bending, making it difficult to dress, stand, walk and lie comfortably.
When the muscles that straighten the knee are tight, the leg can become stuck in a constantly straightened position. This also interferes with walking and can make it particularly difficult to sit comfortably in a chair.
- Ankle: Most commonly, the muscles around the ankle that can become tight due to spasticity following stroke are those that point your foot in and down. Your foot may rest as though the toe is being pointed down but can also turn in.
This makes it difficult to walk as you can find you are unable to achieve heel strike and you catch your toes on the floor. You may even struggle to get your foot flat on the floor in standing. It can also be difficult to position the foot well in sitting, particularly on wheelchair footplates.
Why is spasticity a problem?
As outlined above, spasticity can cause significant problems with positioning, both when lying in bed, or sitting in a chair, and when trying to mobilise. It can also make washing, dressing and toileting very difficult.
Furthermore, spasticity can be very painful.
As well as these direct problems resulting from spasticity, there is a very significant secondary problem caused by spasticity. That is the problem of contracture.
When we contract our muscles, the muscle itself becomes shortened as the contractile elements of the muscle fibres cross over each other. This is how force is generated by the muscle and the joint moves. When this muscle activity is prolonged by spasticity, it means the muscles stay in a shortened position. Over time this can result in secondary changes in the structure of the muscle as well as other soft tissue around the joint. Namely, the muscle loses some of its contractile components and fibrous tissue is laid down. For this reason, the muscle starts to permanently lose its ability to lengthen back out. This means that even if the muscle activity was relaxed or ‘switched off’ the muscle would still remain in its new, shortened position. In this way, the impact of spasticity becomes permanent and irreversible.
It is also important to mention that, as well as making relaxation difficult, spasticity can likewise make intentional muscle activity more difficult (or impossible), both in the spastic muscle itself but also in the opposing muscle groups. For this reason, spasticity can have a direct and profound effect on normal functional movement, be that reaching and grasping with your arm and hand or standing and walking.
What can be done about spasticity following a stroke?
Fortunately, there are several treatment options available that can go a long way towards minimising the impact of spasticity.
Some of the main treatment options are outlined below.
The treatment approach(es) suitable for you will depend on several factors including the type, location and severity of the spasticity you are experiencing, as well as whether any secondary contracture has stated to develop.
A specialist physiotherapist or occupational therapist can assess your needs and support you with the best treatment approach for you.
Please see our website for more information on how stroke and neuro therapists can help you:
Treatment options for spasticity
Therapy treatment options include:
- Stretching the spastic muscles
- Strengthening – especially the opposing muscles
- Positioning and splinting – to keep the muscles resting in their lengthened state
- Weight-bearing – this can have both a strengthening and stretching effect
- Use of electrical stimulation unit – again, this can have a strengthening and stretching effect
- Removal or management of external factors that may lead to worse spasticity – for example pain, discomfort or anxiety
- Self-management – it is important that you are given the tools to manage your own spasticity, as what you do between therapy sessions is key to success.
Your doctor may prescribe medication to help control your spasticity. In some cases this may be oral medication and in other cases it may be by injection of botulinum toxin into the problematic muscles. Other options include nerve block and, in more persistent or severe cases, intrathecal therapy – where a medication is pumped directly into the fluid around your spinal cord.
Your therapist will be able to discuss these treatment options with you, offer some education and guidance and support you to speak to your G.P or stroke consultant who can explore these options in full.
You may also be interested in our other blogs about the effects of stroke...
Please see the stroke association website for more information on spasticity and other effects of stroke: