Hemiparesis is unilateral paresis, that is, weakness of the entire left or right side of the body (hemi- means half). Hemiplegia is, in its most severe form, complete paralysis of half of the body. Hemiparesis and hemiplegia can be caused by different medical conditions, including congenital causes, trauma, tumors, or stroke. Signs and symptoms Depending on the type of hemiparesis diagnosed, different bodily functions can be affected. Some effects are expected (e.g., partial paralysis of a limb on the affected side). Other impairments, though, can at first seem completely non-related to the limb weakness but are, in fact, a direct result of the damage to the affected side of the brain. Loss of motor skills People with hemiparesis often have difficulties maintaining their balance due to limb weaknesses leading to an inability to properly shift body weight. This makes performing everyday activities such as dressing, eating, grabbing objects, or using the bathroom more difficult. Hemiparesis with origin in the lower section of the brain creates a condition known as ataxia, a loss of both gross and fine motor skills, often manifesting as staggering and stumbling. Pure Motor Hemiparesis, a form of hemiparesis characterized by sided weakness in the leg, arm, and face, is the most commonly diagnosed form of hemiparesis. Pusher syndrome “Pusher syndrome” is a clinical disorder following left or right brain damage in which patients actively push their weight away from the nonhemiparetic side to the hemiparetic side. In contrast to most stroke patients, who typically prefer more weight-bearing on their nonhemiparetic side, this abnormal condition can vary in severity and leads to a loss of postural balance. The lesion involved in this syndrome is thought to be in the posterior thalamus on either side, or multiple areas of the right cerebral hemisphere. With a diagnosis of pusher behaviour, three important variables should be seen. The most obvious of which is spontaneous body posture of a longitudinal tilt of the torso toward the paretic side of the body occurring on a regular basis and not only on occasion. The use of the nonparetic extremities to create the pathological lateral tilt of the body axis is another sign to be noted when diagnosing for pusher behaviour. This includes abduction and extension of the extremities of the non-affected side, to help in the push toward the affected (paretic) side. The third variable that is seen is that attempts of the therapist to correct the pusher posture by aiming to realign them to upright posture are resisted by the patient. In patients with acute stroke and hemiparesis, the disorder is present in 10.4% of patients. Rehabilitation may take longer in patients that display pusher behaviour. The Copenhagen Stroke Study found that patients that presented with ipsilateral pushing used 3.6 weeks more to reach the same functional outcome level on the Barthel Index, than did patients without ipsilateral pushing. Pushing behavior has shown that perception of body posture in relation to gravity is altered. Patients experience their body as oriented upright when the body is actually tilted to the side of the brain lesion. In addition, patients seem to show no disturbed processing of visual and vestibular inputs when determining subjective visual vertical. In sitting, the push presents as a strong lateral lean toward the affected side and in standing, creates a highly unstable situation as the patient is unable to support their body weight on the weakened lower extremity. The increased risk of falls must be addressed with therapy to correct their altered perception of vertical. Pusher syndrome is sometimes confused with and used interchangeably as the term hemispatial neglect, and some previous theories suggest that neglect leads to pusher syndrome. However, another study had observed that pusher syndrome is also present in patients with left hemisphere lesions, leading to aphasia, providing a stark contrast to what was previously believed regarding hemispatial neglect, which mostly occurs with a right hemisphere lesion. Karnath summarizes these two conflicting views, as they conclude that both neglect and aphasia are highly correlated with pusher syndrome possibly due to the close proximity of relevant brain structures associated with these two respective syndromes. However, the article goes on to state that it is imperative to note that both neglect and aphasia are not the underlying causes of pusher syndrome. Physical therapists focus on motor learning strategies when treating these patients. Verbal cues, consistent feedback, practicing correct orientation and weight shifting are all effective strategies used to reduce the effects of this disorder.Having a patient sit with their stronger side next to a wall and instructing them to lean towards the wall is an example of a possible treatment for pusher behaviour. A new physical therapy approach for patients with pusher syndrome suggests that the visual control of vertical upright orientation, which is undisturbed in these patients, is the central element of intervention in treatment. In sequential order, treatment is designed for patients to realize their altered perception of vertical, use visual aids for feedback about body orientation, learn the movements necessary to reach proper vertical position, and maintain vertical body position while performing other activities. Classification of pusher syndrome Individuals who present with pusher syndrome or lateropulsion, as defined by Davies, vary in their degree and severity of this condition and therefore appropriate measures need to be implemented in order to evaluate the level of pushing. There has been a shift towards early diagnosis and evaluation of functional status for individuals who have suffered from a stroke and presenting with pusher syndrome in order to decrease the time spent as an in-patient at hospitals and promote the return to function as early as possible.Moreover, in order to assist therapists in the classification of pusher syndrome, specific scales have been developed with validity that coincides with the criteria set out by Davies’ definition of pusher syndrome.In a study by Babyar et al., an examination of such scales helped determine the relevance, practical aspects and clinimetric properties of three specific scales existing today for lateropulsion.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. 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. Other causes of hemiplegia in adults include trauma, bleeding, brain infections and cancers. Individuals who have uncontrolled diabetes, hypertension or those who smoke have a higher chance of developing a stroke. Weakness on one side of the face may occur and may be due to a viral infection, stroke or a cancer. Common Vascular: cerebral hemorrhage Infective: encephalitis, meningitis, brain abscess Neoplastic: glioma-meningioma Demyelination: disseminated sclerosis, lesions to the internal capsule Traumatic: cerebral lacerations, subdural hematoma rare cause of hemiplegia is due to local anaesthetic injections given intra-arterially rapidly, instead of given in a nerve branch. Congenital: cerebral palsy, Neonatal-Onset Multisystem Inflammatory Disease (NOMID) Disseminated: multiple sclerosis Psychological: parasomnia (nocturnal hemiplegia) Mechanism Movement of the body is primarily controlled by the pyramidal (or corticospinal) tract, a pathway of neurons that begins in the motor areas of the brain, projects down through the internal capsule, continues through the brainstem, decussates (or cross midline) at the LOWER medulla, then travels down the spinal cord into the motor neurons that control each muscle. In addition to this main pathway, there are smaller contributing pathways (including the anterior corticospinal tract), some portions of which do not cross the midline.