The most common cause of paroxysmal paresis of one side of the body with or without other associated symptoms is transient cerebral ischemia. The majority of patients with a paroxysmal paresis need a cerebral imaging. In the initial phase of encephalitis, transient focal neurological symptoms occur including paresis which poses like transient ischemic attacks (TIA). Acute paraparesis or paraplegia consists in most cases in incomplete or complete paresis of the legs. The rare paresis of both arms is called diplegia brachialis. In patients with acute teraparesis or tetraplegia, the first differential diagnosis is a spinal lesion in the upper part of the cervical spine. Associated are commonly sensory symptoms and bladder or bowel function disturbance. In cases of an acute paresis of one extremity or even only singular muscle groups of one extremity, a monoparesis or monoplegia is present depending on the fact if the paresis is incomplete or complete.