Injuries at the lower medulla, spinal cord, and peripheral nerves result in ipsilateral hemiparesis.In a few cases, lesions above the medulla have resulted in ipsilateral hemiparesis:

In several reported cases, patients with hemiparesis from an old contralateral brain injury subsequently experienced worsening of their hemiparesis when hit with a second stroke in the ipsilateral brain. The authors hypothesize that brain reorganization after the initial injury led to more reliance on uncrossed motor pathways, and when these compensatory pathways were damaged by a second stroke, motor function worsened further. A case report describes a patient with a congenitally uncrossed pyramidal tract, who developed right-sided hemiparesis after a hemorrhage in the right brain. Diagnosis
Hemiplegia is identified by clinical examination by a health professional, such as a physiotherapist or doctor. Radiological studies like a CT scan or magnetic resonance imaging of the brain should be used to confirm injury in the brain and spinal cord, but alone cannot be used to identify movement disorders. Individuals who develop seizures may undergo tests to determine where the focus of excess electrical activity is.Hemiplegia patients usually show a characteristic gait. The leg on the affected side is extended and internally rotated and is swung in a wide, lateral arc rather than lifted in order to move it forward. The upper limb on the same side is also adducted at the shoulder, flexed at the elbow, and pronated at the wrist with the thumb tucked into the palm and the fingers curled around it.
The three scales examined were the Clinical Scale of Contraversive Pushing, Modified Scale of Contraversive Pushing, and the Burke Lateropulsion Scale. The results of the study show that reliability for each scale is good; moreover, the Scale of Contraversive Pushing was determined to have acceptable clinimetric properties, and the other two scales addressed more functional positions that will help therapists with clinical decisions and research. Causes
The most common cause of hemiparesis and hemiplegia is stroke. Strokes can cause a variety of movement disorders, depending on the location and severity of the lesion. Hemiplegia is common when the stroke affects the corticospinal tract. Other causes of hemiplegia include spinal cord injury, specifically Brown-Séquard syndrome, traumatic brain injury, or disease affecting the brain. A permanent brain injury that occurs during the intrauterine life, during delivery or early in life can lead to hemiplegic cerebral palsy. As a lesion that results in hemiplegia occurs in the brain or spinal cord, hemiplegic muscles display features of the upper motor neuron syndrome. Features other than weakness include decreased movement control, clonus (a series of involuntary rapid muscle contractions), spasticity, exaggerated deep tendon reflexes and decreased endurance.The incidence of hemiplegia is much higher in premature babies than term babies. There is also a high incidence of hemiplegia during pregnancy and experts believe that this may be related to either a traumatic delivery, use of forceps or some event which causes brain injury.