Paralysis is not an isolated event. This is a loss of voluntary muscle control. This can be due to nerve tissue damage, muscle damage or a slowing down of the metabolism of the nerve-muscle interaction. The impact varies wildly. You may lose movement in your legs (paraplegia). Another possibility is loss of control of the arms and legs (quadriplegia). Muscle weakness on one side of the body (hemiplegia) can also occur, affecting only one side of the body, such as the face, arm, or leg.
Most diseases that cause paralysis fall into two categories. First, there is structural damage to nerves or muscles. Second, metabolic disorders interfere with neuromuscular function. In some cases, the disease can systemically affect the entire motor system (upper neurons, lower neurons or muscles). More commonly, however, a single focal lesion damages one element or two adjacent parts in a small area.
How brain and spinal cord injuries lead to paralysis
The most common cause of hemiplegia is damage to the corticospinal tracts of the brain. This usually happens when a large cerebral artery becomes blocked by a blood clot or ruptures due to bleeding. Brain tumors can also cause hemiplegia, but they usually get worse over weeks or months. Damage to the left hemisphere in right-handers usually causes aphasia. This means you cannot speak, write or read properly.
Bilateral problems where both sides are affected are often indicative of diffuse brain disease. Severe cerebral arteriosclerosis or vascular syphilis can cause pseudobulbar palsy. Terms such as “cerebral palsy” and “spastic diplegia” refer to bilateral hemiplegia resulting from prenatal abnormalities or birth trauma.
vascular clot and bleeding in the spinal cord are rare. Damage to the corticospinal tracts is usually caused by spinal deformity. Bone and joint diseases, fractures and dislocations are common causes. Spinal cord tumors, multiple sclerosis and stroke also play a role. Inflammatory diseases associated with pernicious anemia may also be the cause. In middle-aged and older people, progressive spastic paraplegia is usually caused by degenerative arthritis of the spine. This is where the herniated disc enters the lower cervical spinal canal and compresses the nerve.
Problems with muscle tissue and lower motor neurons
Attacks on lower motor neurons often result in paralysis and muscle atrophy. Polio is the main cause. Targets cell bodies or motor neurons in the medulla oblongata and spinal cord regions. Polyneuritis is another peripheral process that affects these neurons. Bell’s palsy is a different beast. This is an unknown form of peripheral neuritis that attacks the facial nerve. As a result, all the muscles on the other side of the face become paralyzed.
Diseases that directly damage muscle tissue are rare. Muscular dystrophy is particularly noticeable. This is hereditary. Large changes in the muscles themselves cause paralysis. Symptoms include progressive symmetrical weakness and wasting.
Pseudohypertrophic muscular dystrophy is a rare variant. It starts before puberty. It is more common in men and often causes serious disability within a few years. Other types usually start in adolescence or early adulthood. They affect men and women equally and progress much more slowly.
Metabolic disorders and neuromuscular function
In some cases, the muscles may weaken, but there is no structural damage to the nerves or muscle tissue. This is a sign of a metabolic disorder. Endocrine diseases, certain poisonings and various metabolic disorders can cause this symptom. Myasthenia gravis is the most common example. Its cause remains unknown.
This condition causes muscle weakness, but not atrophy. It can be mild or severe. It can affect the whole body or only certain muscle groups. It usually involves muscles controlled by cranial nerves. This weakness is caused by a defect in the chemical process that transmits impulses from motor nerve endings to muscle fibers. Some medications, such as neostigmine, can help control symptoms.
The line between structural damage and metabolic dysfunction can become blurred. Blockage of blood flow can cause structural problems. A chemical imbalance can cause a metabolic imbalance. Both can cause paralysis. The difference is in the mechanism. Understanding which mechanisms are at work will determine treatment. Is it a blood clot? A virus? A genetic abnormality? Or maybe the signal is wrong?
Diagnosis often requires combining these clues. History is important. Onset speed is important. Location is important. There is no unequivocal answer. The body is complex. This especially applies to the nervous system. Understanding where you failed is the first step in managing what happens next.
