Hemiplegia is a form of paralysis that affects one side of the body, often one arm and leg, although the paralysis sometimes can be experienced in the torso as well. Most commonly associated with cerebral palsy, this weakness or lack of sensation that leads to paralysis indicates an issue with one side of the brain, which is unable to produce, send or interpret signals as the result of disease or a traumatic injury, such as a traumatic brain injury (TBI).

In the early stages, patients frequently report experiencing the sensation of pins and needles before the situation progresses to muscle weakness and full paralysis.