There are many causes for tremors and shakes and the fine rippling movements through a muscle called fasciculation. From an orthopaedic point of view, the following categories apply:
Damaged or trapped nerves
Direct compression or trauma of one or more “motor neurones,” the nerves that send messages from the brain to the muscles to make them move, will result in abnormal muscle contractions. If these affect posture and cause us loss of balance, then the subconscious attempts by the brain to regain balance causes an over –correction and ‘the shakes’ are the result. A surgical release can resolve this problem.
The categories are separated into direct trauma to the muscles where a laceration (significant cut) or tearing through the muscle can lead to scarring and permanent damage. Again there are medical problems that specifically affect the muscles including myositis, where the muscles become inflamed, or specific myopathies (weak muscles) of which there are several types that are diseases specifically reducing muscle function.
When we experience pain, two areas of the brain receive the pain message. The front of the brain is the processing area which thinks about the pain, what its cause may be, why it is persisting and what can be done about it. The subconscious part of the brain also receives a pain message and will then send a message back to the muscle. If these pain messages are sent frequently to the subconscious, for example by putting weight through a painful hip, then voluntary control of our muscles becomes impaired. Effectively we consciously want to move, but out subconscious does not want to, to avoid provoking more pain, hence the muscles gets a ‘mixed message’ and the shakes then result.
Other medical reasons
There are also more medical reasons for developing shakes and tremors:
- The commonest causes of tremor is a physiological response to cold weather. The muscles contract to burn energy and create heat, to try and keep the body temperature up.
- Muscle fatigue is when muscles over-exercise, the minerals in the blood become depleted and the muscles shake and cramp.
- “benign essential tremor” – in the majority of cases there is no explanation for the tremor and no specific treatment. However the severity of the tremor may be reduced by medications. This often involves the hands first.
- Age – when we get a little older it becomes progressively more difficult to retain muscle bulk and strength. The muscles simply can’t react to the messages from our brains to move, joints don’t lock out properly and the muscles repeatedly contract in an uncoordinated way, visible as shaking.
- Medical conditions or diseases that directly affect the nerves. The commonest medical problem affecting the nerves is referred to as a neuropathy. This can affect all the nerves of the body including the motor nerves. There are specific disease processes such as motor neurone disease, Parkinson’s disease and multiple sclerosis that prevent the normal nerve transmission, the messages from brain to muscles, and uncoordinated muscle contraction and shaking results.
- Low sugar or ‘hypoglcaemia’ associated with Diabetes
- Alcohol or drug with-drawl
- Dystonic tremor – sudden abnormal muscle contraction
- Cerebellar damage. This is the part of the brain that controls movement. Damage can occur with trauma, or a stroke.