Associated symptoms
Isolated muscle weakness occurs rather rarely. It is much more common that, in addition to muscle weakness, there are also muscle twitches and disturbances of consciousness, gait, swallowing, vision and speech resulting from the muscle weakness. With banal causes such as a magnesium deficiency, muscle weakness is also accompanied by muscle cramps.
In general, the symptoms accompanying muscle weakness are always related to the actual illness or the trigger. Therefore, a very broad spectrum of accompanying symptoms can occur. A first example is an underfunction of the thyroid gland (=hypothyroidism).
Here, muscle weakness is only one of many symptoms. In addition, complaints such as weight gain, constipation, a slowed heart rate (bradycardia) and lack of drive frequently occur. The body is slowed and restricted in its activity and performance in many aspects, so to speak.
In addition, so-called “neonatal myasthenia”, i.e. muscle weakness in the newborn child due to an autoimmune disease, can lead to weakness of suction, drooping eyelids and insufficient breathing.Lastly, accompanying symptoms in the context of long-term cortisone therapy should be mentioned as an example. Cortisone is considered to be a drug with many side effects, which means that in addition to muscle weaknesses, it can also lead to complaints such as glaucoma (= green cataract), palpitations and, in children, growth inhibition. Cortisone also weakens the immune system, which has corresponding consequences.
In old age, cortisone not only affects the muscles but also bone stability, making osteoporosis more likely. Not all muscle twitches are the same. They offer a wide variety of possible causes for sometimes harmless twitching but also for serious diseases.
What is decisive is the intensity of the muscle twitches, but also the frequency, i.e. whether the muscle twitches occur at regular intervals or rather sporadically. Depending on how much muscle tissue is involved in the twitching, it is not only noticeable to those affected, but for outsiders it is even recognizable as movement. Benign muscle twitches, for example, often occur in stressful phases of life, in hypoglycaemia, magnesium deficiency or as a side effect of medication.
Such muscle twitches are only unpleasant for the moment and disappear as soon as the triggering factors are reduced or eliminated. Muscle weakness does not occur in this context. The combination of muscle twitching and weakening or post-twitch weakness of certain muscles can be in the context of serious diseases.
An example is amyotrophic lateral sclerosis, a degenerative nervous system disease in which muscle twitching occurs classically. In the further course of the disease, muscle weakness due to muscular atrophy is the most common cause, which can continue until paralysis. Muscle twitches should be clarified by a doctor if they persist for a longer period of time without a banal connection such as stress or extreme tension.
In order to be able to determine the cause of a muscle weakness, it is important for the doctor to first take a detailed medical history (anamnesis). Questions that can be helpful in making a diagnosis include: since when the muscle weakness has existed, which muscles it affects, whether there was a specific event (such as an accident) that directly preceded the muscle weakness, whether there are other complaints (for example, sensory disturbances), whether there are medications that are taken regularly and whether the patient suffers from any known pre-existing conditions (such as diabetes mellitus, multiple sclerosis or others). Following the anamnesis, the doctor will conduct further examinations depending on the suspicion.
On the one hand, a physical examination is of great importance. Here, exactly the remaining strength in the muscles is checked, possible sensory disturbances are searched for and reflexes are checked. In addition, a blood test can be useful for many people.
More special examination methods are justified if there is a well-founded assumption of certain diseases. These include imaging procedures such as computed tomography (CT) or magnetic resonance imaging (MRI), removal of muscle tissue (muscle biopsies), electromyography (EMG), an examination of the cerebrospinal fluid (by means of liquor puncture), electroneurography (ENG) or electroencephalography (EEG). In addition, it may be useful to perform a genetic test or to have the examination performed by a specialist, such as an ear, nose and throat specialist or an ophthalmologist.
