What Is Monoplegia in Medical Terminology?

In medical terminology, monoplegia (or monoparesis) is paralysis in a single limb, muscle or muscle group -- typically an arm. It is a rare type of cerebral palsy that is caused by numerous different factors. Monoplegia is treated differently, and its effective management depends on the accurate assessment of its root cause. Monoplegia caused by an abscess will be treated differently than that caused by multiple sclerosis.

Causes

• The most common cause of monoplegia is cerebral palsy -- the abnormal development in one or more parts of the brain that affects motor activity or movement. Monoplegia may be due to an abscess (or tumor) and thrombosis. Other causes include injuries (including neonatal injuries and sports-related postnatal injuries), stroke, nerve trauma, nerve impairment, nerve inflammation and multiple sclerosis.

Symptoms

• Symptoms of monoplegia include stiffness in a muscle group or limb, problems with lifting, pulling and other basic functions. Signs of functional weaknesses include co-contraction (when a doctor is able to isolate the culprit muscle or muscle group by feeling it with his/her hands), the arm-drop (dropping a paralyzed arm over a patient's face to see whether he/she will protect their faces from the fall) and pseudo-waxy flexibility (when a patient is unable to change the position of the affected limb).

Diagnostic Tests

• Monoplegia associated with cerebral palsy or some other cause -- such as multiple sclerosis -- will require months, even years of diagnostic tests and close observation. Electroencephalography, cerebrospinal fluid (CSF) analysis, evoked potential studies, computed tomography scan, magnetic resonance imagining (MRI) and electrophoresis are used to detect abnormalities in the brain and/or lesions, which manifest as monoplegia. Other neuropsychological tests are performed to rule out associated brain disorders, if any.

Treatment

• The main aim of the treatment is to reduce and relieve all neurological deficiencies, so the patient is able to regain proper functioning of his/her affected limb. A full neurological assessment is performed after a patient is diagnosed with monoplegia. This is to rule out any underlying conditions (like brain tumor) that could be causing the symptoms of monoplegia. An occupational therapist determines and sets an achievable set of expectations for the patient, which detail limb and other forms of weight and muscle-building exercises. The purpose of these exercises is to encourage the patient to use his or her affected limb.

Important Considerations

• Monoplegia affects children and adults. In children, it is often misdiagnosed as hemiplegia, which is paralysis on one side of the body.