Hemiparesis

Hemiparesis, or unilateral paresis, is weakness of one entire 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. Hemiparesis, or unilateral paresis, is weakness of one entire 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. 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. 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 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.