**6. Prognosis and rehabilitation**

There are few studies that address the resolution of PB (Karnath et al., 2002; Broetz et al., 2004; Danells et al., 2004; Santos-Pontelli et al., 2004; Lafosse et al., 2005). Until now, the PB is described as having good prognosis with a maximum recovery time of 6 months (Karnath et al., 2002). Dannels and coworkers showed that the recovery of PB is neither strongly associated with age nor with the recovery of motor control evaluated by Fugl-Meyer motor scale (Danells et al., 2004). However, patients with neglect and those who presented higher initial SCP scores had longer PB recovery times (Danells et al., 2004; Lafosse et al., 2005). Recently, Babyar and coworkers demonstrated that pusher patients following stroke have a lower Functional Independence Measure efficiency and more dependency at discharge when compared with matched controls with equal functional limitations (Babyar et al., 2009). In addition, stroke patients seem to have worse PB prognosis than patients with brain trauma (Santos-Pontelli et al., 2004); this difference in recovery time may be related to etiology, extension, or inherent resolution mechanisms of the causative lesion.

Based on the Bobath concept, Davies described several activities using manual guidance (somesthetic information) to induce the midline body position in the pusher patients (Davies, 1985). Later, Broetz and Karnath suggested a visual feedback approach for PB based on their findings in 5 patients who presented with tilted SPV with unaffected SVV, as discussed above (Broetz et al., 2004; Broetz &Karnath, 2005). According to the authors,

vestibular dysfunction from the vertical misperceptions of pusher patients because SVV is essentially driven by this system (Anastasopoulos et al., 1997; Mittelstaedt, 1998; Trousselard et al., 2004). Other aspects to be considered for the evaluation of verticality perception are the learning effect and the number of trials performed. Therefore, in order to state which vertical perception is disturbed in pusher patients, the studies' designs require a meticulous methodology and a large sample of pusher patients. The underlying

Mean (SD)

+4,8 º (5,1°)

(1,86)\*\*

et al. (2009) 3 RBD 100% NA NA NA -8,7º (2,4°) SD: Standard Deviation; RBD: Right Brain Damage; LBD: Left Brain Damage; \*(with haptic component) \*\* Mean and standard deviation calculated from the data available in the reference (Perennou, D. A. et

Table 3. Summarized available data about the subjective perceptions of pusher patients.

etiology, extension, or inherent resolution mechanisms of the causative lesion.

There are few studies that address the resolution of PB (Karnath et al., 2002; Broetz et al., 2004; Danells et al., 2004; Santos-Pontelli et al., 2004; Lafosse et al., 2005). Until now, the PB is described as having good prognosis with a maximum recovery time of 6 months (Karnath et al., 2002). Dannels and coworkers showed that the recovery of PB is neither strongly associated with age nor with the recovery of motor control evaluated by Fugl-Meyer motor scale (Danells et al., 2004). However, patients with neglect and those who presented higher initial SCP scores had longer PB recovery times (Danells et al., 2004; Lafosse et al., 2005). Recently, Babyar and coworkers demonstrated that pusher patients following stroke have a lower Functional Independence Measure efficiency and more dependency at discharge when compared with matched controls with equal functional limitations (Babyar et al., 2009). In addition, stroke patients seem to have worse PB prognosis than patients with brain trauma (Santos-Pontelli et al., 2004); this difference in recovery time may be related to

Based on the Bobath concept, Davies described several activities using manual guidance (somesthetic information) to induce the midline body position in the pusher patients (Davies, 1985). Later, Broetz and Karnath suggested a visual feedback approach for PB based on their findings in 5 patients who presented with tilted SPV with unaffected SVV, as discussed above (Broetz et al., 2004; Broetz &Karnath, 2005). According to the authors,

et al. (2000) 5 RBD 100% -0,4 º (2,5°) +17,9 º (4,7°) NA NA

SPV Mean (SD)

2 LBD 73% -3,2º (4,8°) NA NA NA


+2,2° NA NA NA

SHV Mean (SD)


(1,71º)\*\* NA

SSA Mean (SD)

mechanisms of PB still remain unclear.

Number of patients

4

et al. (2006) 15 13 RBD

et al. (2008) 6 5RBD

**6. Prognosis and rehabilitation** 

Lesion

1 RBD 100%

side Neglect SVV

0%

1LBD NA -6,53º

Author (year)

Karnath

Saj et al (2005)

Johannsen

Pérennou

Honnoré

al., 2008).

because the orientation perception of visual cues in pusher patients is not impaired, they can be trained to use conscious strategies to realign their body.

However, the contralesional tilts of SPV, SVV and SHV recently described in patients with PB raise the question about the utility of visual feedback treatment in all pusher patients (Pedersen et al., 1996). Some findings with healthy subjects have shown a difference in performance if the learner directs attention toward the effect of the movement (an external focus) instead of to the movement itself (an internal focus) (Wulf et al., 1998). It is possible that in pusher patients with multimodal misperception, we could induce the patient to perceive that their body position is tilted by showing the difference between the effect of the movement using their perceived (wrong) vertical reference and using the (somesthetic or verbal) reference given by the therapist. Broetz and Karnath recommended this demonstration of the ineffective result of the pathological pushing in patients with unimodal misperception (Broetz et al., 2004).

Recently, Shepherd and Carr suggested that the behavioral development may be a natural adaptive response to rehabilitation methods that have the potential to increase the fear of falling and provoke defensive pushing (Shepherd &Carr, 2005). The fact that PB has been identified early after the encephalic lesion argues against this possibility. Additionally, we performed a systematic screening of PB in an acute neurological unit (Santos-Pontelli et al., 2004), and we often identified the PB while the patients were positioned sitting on the edge of the bed for the first time after the onset. Nevertheless, as pointed out by the authors, it is imperative to take the fear of falling into account and to be careful to perform the exercises without evoking fear.

Other general evidence-based methods of intervention are naturally applied for pusher patients because other neurological deficits are present. So far, several studies suggest the following: task-oriented exercises, patients' focus on the actual activity, strength and skill training, specific strategies for spatial neglect (when present), patients' awareness of their deficits, attention to the intensity of skill practice and the extent of cardiovascular stress, proper rehabilitation environment, and the use of a treadmill with and without body weight support [for review see (Carr & Shepherd, 2006)].

A consensus on neurological rehabilitation is that intervention requires specificity and that the postural balance is essential in regaining independence in the activities of daily living. Thus, exercises must be individualized, and the best therapeutic strategy for PB should be chosen based on the vertical misperception of each pusher patient as soon as possible. The absence of controlled trials that investigate the treatment of PB supports the need for further research. Moreover, we should be careful about making statements about the PB based on few samples. Multicenter researches could help PB investigative groups to perform more representative studies in order to clarify all the underlying aspects of this still largely unknown neurological disorder.
