Hemiplegia is total paralysis of the arm, leg, and trunk on the same side of the body. Hemiplegia is more severe than hemiparesis, wherein one half of the body has less marked weakness. Hemiplegia may be congenital or acquired from an illness or stroke.
Hemiplegia is not an uncommon medical disorder. In elderly individuals, strokes are the most common cause of hemiplegia. In children, the majority of cases of hemiplegia have no identifiable cause and occur with a frequency of about one in every thousand births. Experts indicate that the majority of cases of hemiplegia that occur up to the age of two should be considered to be cerebral palsy until proven otherwise.