Introduction
Spasticity is an unintentional tensing of the muscles beyond the normal level. In addition to increased muscle tension, muscle twitches, muscle cramps and muscle rigidity also occur. Spasticity can occur repeatedly in phases or be continuous.
They often occur in multiple sclerosis and are often combined with muscle weakness. The spasms can cause pain and lead to restrictions in physical mobility. The extent of spasticity is different for each multiple sclerosis patient. Some are severely affected by spasticity in their daily lives, while others have only slight limitations. Unfortunately, spasticity is one of the most common causes of disability in MS.
Why can spasticity occur in multiple sclerosis?
In MS, the central nervous system, i.e. the brain and spinal cord, is repeatedly affected by inflammation. These lead to the destruction of the connections between the nerve cells. In the true sense, the inflammation turns against the isolation of the nerve cell connections, the myelin.
This can be imagined like a cable. By destroying the insulation, the transmission between the nerve cells can no longer take place. The so-called motor neurons are responsible for the movements of the muscles.
There are always two motor neurons connected to each other. One is located in the brain, while the second is located in the spinal cord and is responsible for the movement of a specific muscle or group of muscles. If the connection between the first and second motor neuron is disrupted, e.g. in the context of inflammation in multiple sclerosis, the second motor neuron is no longer inhibited by the first. This leads to increased tension in the musculature. A spasticity develops.
Which muscles are most prone to spasticity?
In principle, all muscle groups can be affected by spasticity if the focus of inflammation is at the appropriate location. Therefore an individual picture of the affected muscle groups is created. More often, however, spasms occur in the leg muscles.
One reason for this is that the nerve connections here are particularly long. Spasms often occur there and are sometimes the first symptom of multiple sclerosis. The arms are usually affected as the disease progresses.
However, they are often not as severely affected by the spasms and muscle weakness. Spasticity in the trunk or neck muscles is less common. Usually one half of the body is more severely affected by the spasms than the other. However, there are also strong individual differences.
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