What happens in motor neuron disease?
The command to move goes from the cerebral cortex along long processes to the neurons of the spinal cord and brainstem, and from there to the muscles. With this disease, both levels die. Damage to the upper motor neuron results in stiffness, increased tone and animated reflexes, while damage to the lower motor neuron results in weakness, muscle loss and characteristic twitching under the skin. The combination of these two groups of symptoms in one area and their gradual spread to neighboring areas is the main symptom of the disease.
- Classic form - a combination of signs of damage to both motor neurons
- Bulbar onset - speech and swallowing are affected first
- Cervical or lumbar onset - weakness in the arm or leg
- Progressive muscular atrophy
- Primary lateral sclerosis with predominant spasticity
First signs
The disease begins imperceptibly and is almost always asymmetrical. A person notices that one hand has become awkward: it is difficult to fasten a button, turn a key, or hold a pen. Or the toe of the foot begins to cling to the floor and the leg twists. With the bulbar onset, the voice is the first to change - speech becomes slurred, nasal, and choking appears. Often, even before weakness, muscle twitching and cramps in the calves are noticeable, as well as noticeable thinning of the muscles of the hand or shoulder.
- Weakness and clumsiness in one hand or foot
- Muscle loss, “dips” between the bones of the hand
- Twitching of muscles under the skin, night cramps
- Slurred speech, nasal tone, weak voice
- Choking, drooling
- Stiffness, muscle tension
- Forced laughter or crying for no reason
Diagnostics
There is no specific analysis for this disease; the diagnosis is made clinically and confirmed by electroneuromyography - it reveals damage to the lower motor neuron even in muscles where there is no weakness yet. Conditions with a similar picture must be excluded: compression of the spinal cord in the cervical region, polyneuropathy, myasthenia gravis, endocrine and inflammatory muscle diseases. To do this, MRI, blood tests and, if necessary, additional studies are performed. Due to its complexity, the diagnosis is usually confirmed in a specialized center, and a repeat consultation with a neurologist is fully justified.
- Examination by a neurologist over time
- Electroneuromyography (ENMG)
- MRI of the cervical and other parts of the spine, MRI of the brain
- Biochemical blood test, CPK, thyroid hormones
- Spirometry to assess respiratory function
- Genetic testing for familial cases
Treatment and support
There is disease-modifying therapy, which is prescribed by a neurologist and can somewhat slow down the course. Symptomatic care is no less important: drugs for spasticity and seizures, correction of drooling, pain relief, treatment of depression. Supporting breathing with non-invasive ventilation and promptly addressing nutritional issues when swallowing becomes unsafe are key. Rehabilitation is not aimed at increasing strength, but at maintaining mobility, preventing contractures and selecting technical means. A team of specialists provides assistance, and it is better to plan it in advance, without waiting for a crisis.
- Therapy is prescribed and adjusted by a neurologist
- Regular assessment of respiratory function
- Non-invasive ventilation according to indications
- Changing the consistency of food, if necessary, gastrostomy
- Therapeutic exercise without overwork, stretching
- Speech therapy assistance and means of alternative communication
- Psychological support for individuals and families
- Technical aids: orthoses, walkers, wheelchairs
Common misconceptions and what really helps
Muscle twitching in itself almost never means this disease: in healthy people they appear from fatigue, caffeine, stress and lack of sleep. The combination becomes alarming when there is increasing weakness and muscle loss. There are no diets, vitamins or treatments that stop neuronal death, and suggestions of “body cleanses” or stem cell treatments outside of clinical trials are dangerous. Proven therapy, breathing and nutrition support, as well as organization of everyday life bring real benefits.
- Isolated twitching without weakness - usually benign
- Intelligence and sensitivity are usually preserved during the disease
- The disease is not contagious
- Most cases are not hereditary
- Stem cells outside of research are unproven and risky
- Early contact helps to connect support on time