Vol. 17 Issue 26
Sharing treatment ideas for 'Pusher Syndrome'
Perhaps many therapists who have treated patients with cerebrovascular accidents in their careers might have experienced "pusher syndrome." Depending on the severity of the push, it can be both physically and mentally challenging for therapists to treat these patients.
Therapists must be able to identify the clinical signs of the syndrome, and most importantly, be able to come up with effective treatment strategy to stop the push and assist patients in restoring midline orientation.
What is 'Pusher Syndrome?'
The "pusher syndrome," more formally known as "contraversive pushing," is a neurological deficit present in a group of stroke patients characterized by distorted postural orientation. These patients tend to use their less-affected limbs to actively push toward the more-affected side, and are very reluctant and resistant to accept weight on the less-affected side with any passive attempts to correct the push.
It was found that patients with contraversive pushing usually experienced a 20-degree tilt to the ipsilesional side when they are actually upright, despite normal visual and vestibular input.1 The posterior thalamus appears to be the fundamental brain structure that controls body upright posture; thus, lesion in this area is thought to be the cause of "pusher syndrome."2 Recently, it has been suggested that lesion in part of the insular cortex and the postcentral gyrus also contributed to contraversive pushing at the cortical level.3
Karnath and Broetz4 suggested three striking clinical signs with "pusher syndrome": 1) spontaneous body tilting toward the more-affected side; 2) abduction and extension of the less-affected extremities, and 3) resistance to passive correction of the tilted posture. From clinical observation, both signs 2 and 3 are important behaviors that distinguish patients with only balance impairment versus contraversive pushing, because many stroke patients exhibit loss of balance but yet able to accept correction. It appears that contraversive pushing rarely exists six months post-stroke,5 but it takes an average of 3.6 weeks longer to achieve similar functional outcomes compared to "non-pushers."6 Hence, the aim of physical therapy is to shorten the time it takes to reach that level.4
To date, there are limited research studies on physical therapy treatment approach for "pusher syndrome." Broetz, Johannsen and Karnath developed a treatment strategy using visual feedback to train patients' awareness of body orientation.7 They found significant improvement in the severity of pushing (measured with the Scale of Contraversive Pushing) between day 4 and 24 post-stroke. It is, however, a case report with eight subjects and without a control group, hence, further research is needed to examine the effect of the specific intervention approach.
It is surprising to note the limited number of research on this fairly common syndrome. It could be because of the difficulty measuring treatment variables and the fact that contraversive pushing would improve with time. Nevertheless, therapists need to establish the best possible treatment strategy when they encounter the syndrome in day-to-day clinical life. Below is a sharing of clinical experience, to give additional insights on developing treatment ideas for the "pusher syndrome":
Always use a mirror for visual feedback during treatment, either in sitting, standing or walking if possible.
Avoid elbow extension on the less-affected arm by supporting it on a surface. In both sitting and standing a chair, or an adjustable bedside table placed on the less-affected side, the height of the surface has to be high enough for the elbow to stay relaxed and flexed. Once the active push of the upper limb is minimized, it takes much less effort to regain midline orientation.
When the patient is able to maintain midline in static standing, therapists can start a dynamic standing activity, with a focus on weight shifting to the less-affected side initially, then slowly progress to multi-directions. Also, have the patient practice coming back to midline after weight shifting activity. It is not uncommon to see patients with difficulty finding the midline who have increased pushing after weight shifting activity. Repetition is the key.
Begin gait training with the patient's less-affected side against a wall or a raised mat. Patients tend to be less fearful of falling and tend to reduce pushing when there is a sturdy surface or environment on the less-affected side. They also appear to be less resistive to accept correction of the push because of the perceptual benefit of the stable environment.
More often, patients respond well to a verbal cue of "lean toward the wall" to correct the active push. Once the patient is able to obtain and maintain midline orientation, gradual transition to an assistive device is needed to progress to functional ambulation.
Therapists can also consider using body- weight support therapy as it provides a safe environment for patients and thus decrease fall risk. In addition, decreasing the weight on the affected side initially may help to decrease the active pushing.
Again, repetition is the key. A problem solving strategy is also beneficial, but the key is to involve patients both verbally and visually identify their push and how they can reduce the push and return to midline. This problem solving strategy should assist the internalization of their motor learning experience.
I found the above treatment ideas successful for most patients. They are at least helpful for therapists to identify where to begin when working with patients with "pusher syndrome." Again, these are treatment ideas from clinical experience; further research is needed to identify effective treatment strategy on improving functional outcomes.
Karnath, H-O., Ferber, S., & Dichgans, J. (2000). The origin of contraversive pushing: evidence for a second graviceptive system in humans. Neurology, 55, 1298-1304.
Karnath, H-O., Johannsen, L., Broetz, D., & KŸker, W. (2005). Posterior thalamic hemorrhage induces "pusher syndrome." Neurology, 64, 1014-1019.
Johannsen, L., Brotez, D., Naegele, T., & Karnath, H-O. (2006). "Pusher syndrome" following cortical lesions that spare the thalamus. Journal of Neurology, 253, 455-463.
Karnath, H-O., & Broetz, D. (2003). Understanding and treating "pusher syndrome." Physical Therapy, 83, 1119-1125.
Karnath, H-O., Johannsen, L., Broetz, D., et al. (2002). Prognosis of contraversive pushing. Journal of Neurology, 249, 1250-1253.
Pedersen, P., Wandel, A., Jorgensen, H., et al. (1996). Ipsilateral pushing in stroke: Incidence, relation to neuropsychological symptoms and impact on rehabilitation–the Copenhagen stroke study. Archives of Physical and Medical Rehabilitation, 77, 25-28.
Broetz, D., Johannsen, L., & Karnath, H-O. (2004). Time course of "pusher syndrome" under visual feedback treatment. Physiotherapy Research International, 9, 138-143.
Doris Chong is a physical therapist working in the Comprehensive Inpatient Rehabilitation Unit at Stanford University Medical Center in Palo Alto, CA. Her clinical expertise and interest is stroke rehabilitation.