Motor neuron diseases

Motor Neuron Disease?


An incurable form of progressive neurodegeneration that causes nerves in the brain and spinal cord to lose functionality is termed as motor neuron disease. Motor neurons send electrical signals to muscles, thereby enabling the functioning of the muscles. Motor neuron disease occurs in men more than women of all ages.

The commonest type of motor neuron disease is amyotrophic lateral sclerosis (ALS) or Lou Gehrig's disease. It affects muscles of arms, legs, mouth and respiratory system. Individuals with ALS survive beyond diagnosis with supportive care.

Progressive bulbar palsy is mostly associated with ALS and it involves the brain stem. Wherein this condition will lead to recurrent choking, difficulty speaking, eating, and swallowing.

Progressive muscular atrophy causes muscle wasting and is considered to be a variation of ALS. Spinal muscular atrophy (SMA) is an inherited form of motor neuron disease affecting children. This condition caused due to an abnormal gene known as SMA1.

What are the Symptoms of Motor Neuron Disease
The symptoms of motor neuron disease develop slowly and begins in the arms and legs, the mouth (bulbar), or the respiratory system. Following are some of the common symptoms of motor neuron disease:

  • weakening grip
  • fatigue
  • muscle pain and cramps
  • slurred speech
  • increased clumsiness and stumbling
  • difficulty swallowing
  • shortness of breath
  • Mood swings

Within the people suffering from ALS, 50% have brain dysfunction and leading to difficulties with memory, planning, language, behavior, and spatial relationships. Almost 15% of people with ALS have frontotemporal dementia. In a few cases, the deterioration of the diaphragm leads to breathing problems.

Secondary symptoms of motor neuron disease include insomnia, anxiety, and depression. Eventually, the patient cannot move, eat, or breathe without assistive devices.

What are the Causes of Motor Neuron Disease
The causes for this condition are unclear, though some are inherited while others happen randomly.

After 40 years of age, the risk increases significantly with ALS most likely to appear between 55 and 75 years of age. Men are more susceptible to this neuro-degeneration disease than women. Further, sports like football, were head trauma is common, would suggest that footballers are more likely to acquire ALS, Alzheimer's disease and other neurodegenerative diseases.

How is Motor Neuron Disease Diagnosed?
Diagnosis of motor neuron disease is difficult in the early stages because the symptoms are similar to other conditions such as multiple sclerosis and Parkinson's disease. A complete history and physical examination of the brain with some of the other diagnostic tests that might be helpful to detect motor neuron disease:

Blood and urine tests are performed to detect an increase in the creatinine kinase levels as it is produced when muscles break down, and is also found in the blood of patients with motor neuron disease. An MRI scan of the brain helps to find or exclude stroke, brain tumor, brain circulation problems, or abnormal brain structure. Electromyography and nerve conduction study are carried out simultaneously to test the amount of electrical activity within muscles and the speed at which this electricity is passed through the muscles. A spinal tap or lumbar puncture aids in analyzing the cerebrospinal fluid for deformities. Furthermore, El Escorial criteria helps doctors check for distinctive neurological signs such as muscle shrinking and muscle stiffness or abnormal reflexes.

How is Motor Neuron Diseases Treated
Till date, there is no cure for motor neuron diseases. All treatment options focus on providing more comfort to the patient rather than curing the disease.

Occupational therapy helps alleviate the stiffness and stress caused by the condition. Breathing, feeding, mobility, and communication supportive devices are used to provide comfort. Mechanical ventilation is preferred to help with breathing. Some allopathic medications are used to alleviate the symptoms.

Stem Cells Therapy for Motor Neuron Disease
Stem cells have the capacity to repopulate as any desired cell type when infused in affected areas. These cells repopulate at the damaged areas of the brain and the spinal cord as they have strong paracrine effects. Then they differentiate into lost neurons to improve voluntary functions of the human body.

The nervous system is a very complex structure to be studied and understood. The complexity of circuits within the nervous system and replacing them with appropriate cells that correct functional interactions is highly risky and complicated. There is also a potentially toxic cellular environment that leads to neurodegeneration in MND. The transplanted cells can also degenerate once exposed to these factors. Stem cells for motor neuron disease treatment helps in the survival and functioning of the remaining motor neurons. This approach of stem cell therapy is expected to treat neurodegeneration better than just fighting the symptoms.