The human body consists of a plethora of nerves that make up a complex nervous system. One of the principal functions of the nervous system is mobility.

The nervous system is responsible for the movement of the body’s muscles. This includes both the movement you can control (voluntary) and the movement you cannot control (involuntary).

When a section of this complex system becomes damaged, it can hamper the communication between the brain and muscles, leading to muscle weakness or paralysis in the affected area.

This damage may include trauma to the brain, spinal cord, or a number of nerves. It can affect a limb in the upper or lower regions of the body.

Monoplegia is a type of paralysis that is restricted to a single limb – usually and arm. The paralysis may sometimes be limited to a single muscle.

Although this condition can hinder functions, people with monoplegia are generally able to perform daily tasks, work around their symptoms, and take care of their general well being.

Most people living with monoplegia typically experience a gradual deterioration in the functioning of the limbs, which begins with weakness or limpness of the affected limb. As time passes, the effects of the condition exacerbate, leading to partial or full paralysis.

Although monoplegia and hemiplegia are both types of paralysis, they are very different. Monoplegia affects only one limb on the upper or lower part of the body. This means that if you have monoplegia in your left arm, you would not be able to move it; you can, however, still move your left leg.

Hemiplegia, on the other hand, is a type of paralysis that affects one side of the body. It could be either the right side or the left side.

Hemiplegia on one side of the body would hinder you from moving the limbs on that side of the body. The muscles on that side of the face could also be affected.

The two conditions are different; they, however, share many of the same potential causes. These causes include stroke, injury to the brain or spinal cord, or cerebral palsy.

Causes of Monoplegia

Monoplegia occurs as a result of damage to the part of the brain that controls the affected area. Many conditions that cause quadriplegia and paraplegia usually begin as monoplegia.

One of the major causes of monoplegia is cerebral palsy. Monoplegia is, to a great extent, associated with cerebral palsy; some medical practitioners even consider it a sign of cerebral palsy. Cerebral palsy is a group of neurological disorders that is very common in children, affecting about 0.2% of all births.

Cerebral palsy can be caused by a number of conditions and infections such as toxoplasmosis, rubella, oxygen deprivation at or immediately following birth, and exposure to high levels of heavy metals like lead and cadmium.

Symptoms of cerebral palsy include difficulty with speech, difficulty seeing or hearing, and curling of hands and toes.

Other disorders that can cause monoplegia include:

  • Head trauma
  • Spinal cord trauma
  • Epilepsy
  • Strokes and aneurysms
  • Vaccine-associated paralytic poliomyelitis
  • Monomeric spinal muscular atrophy.
  • Infections of the brain or spinal cord.
  • Physical trauma to the affected limb
  • Neuropathy
  • Complicated migraines
  • Plexopathy
  • Traumatic peroneal neuropathy
  • Lesions in the brain and spinal cord, including hematoma, tumors, or abscess.
  • Hereditary brachial neuritis
  • Hereditary neuropathy
  • Hemiparetic seizures
  • Neonatal brachial plexus paralysis

Signs and Symptoms of Monoplegia

The symptoms of monoplegia manifest suddenly, as in the case of an injury or stroke. Gradually, symptoms may also progress over time due to the progression of the underlying such as a motor neuron disease or cerebral palsy.

The primary symptom of the condition is the inability to move one of your arms or legs. The following symptoms can be observed in the affected limb:

  • Decreased sensation in a single limb. Some people with monoplegia can also experience an unusual and uncomfortable electrical sensation like pins and needles in the affected limb.
  • Weakness or limpness of the affected limb that does not appear to be related to another injury, such as a broken bone, strain, or sprain.
  • Curling of the toes or fingers of the affected limb.
  • Limited movement of the limb, which eventually leads to full paralysis.
  • Pain and discomfort in the region around the limb due to the muscles being stiff and the loss of muscle control.
  • Headaches, shoulder pain, and other associated conditions.

Treatment of Monoplegia

Monoplegia, as with all types of paralysis, has no cure. However, there are treatment options available to manage the symptoms and improve the quality of life and well being. Also, treatment of the underlying cause of the disorder is essential.

The following are treatment options for monoplegia. They include:

  • Physical therapy: This is used to help build strength and maintain flexibility and mobility in the affected limb. Physical activities like stretches and exercise can help prevent the limb from atrophy. Massages are also essential to stimulate the muscles and nerves and improve the flow of blood.
  • Medications: These may help to reduce some of the symptoms associated with monoplegia and improve well being. Examples of drugs include pain medications like ibuprofen and paracetamol and to alleviate discomfort and muscle relaxers to relieve muscle stiffness or spasms.
  • Occupational therapy: This teaches different skills and techniques to make it easier to perform everyday tasks such as getting dressed, bathing, or cooking.
  • Assistive Technology: These are devices that can make daily activities easier. Examples of assistive technology include wheelchairs, walkers, specialized grips and handles, and voice-activated devices.
  • Surgery: This may be necessary if the monoplegia is due to nerve compression or a tumor.