Validation of a standardized assessment of postural control in stroke patients: the Postural Assessment Scale for Stroke Patients (PASS).

Few clinical tools available for assessment of postural abilities are specifically designed for stroke patients. Most have major floor or ceiling effects, and their metrological properties are not always completely known. The Postural Assessment Scale for Stroke patients (PASS), adapted from the BL Motor Assessment, was elaborated in concordance with 3 main ideas: (1) the ability to maintain a given posture and to ensure equilibrium in changing position both must be assessed; (2) the scale should be applicable for all patients, even those with very poor postural performance; and (3) it should contain items with increasing difficulty. This new scale has been validated in 70 patients tested on the 30th and 90th days after stroke onset. Normative data obtained in 30 age-matched healthy subjects are presented. The PASS meets the following requirements: (1) good construct validity: high correlation with concomitant Functional Independence Measure (FIM) scores (r=0.73, P=10(-6)), with lower-limb motricity scores (r=0.78, P<10(-6)), and with an instrumental measure of postural stabilization (r=0.48, P<10(-2)); (2) excellent predictive validity: high correlation between PASS scores on the 30th day and FIM scores on the 90th day (r=0.75, P<10(-6)); (3) high internal consistency (Cronbach alpha-coefficient=0.95); and (4) high interrater and test-retest reliabilities (average kappa=0.88 and 0.72). Our results confirm that the PASS is one of the most valid and reliable clinical assessments of postural control in stroke patients during the first 3 months after stroke

Understanding the pusher behavior of some stroke patients with spatial deficits: a pilot study.

To investigate whether pusher behavior (ie, a tendency among stroke patients with spatial deficits to actively push away from the nonparalyzed side and to resist any attempt to hold a more upright posture) affects only the trunk, for which gravitational feedback is given by somesthetic information, or the head as well, whose gravitational information is mainly given by the vestibular system (without vision). Description and measurement of clinical features. Rehabilitation center research laboratory. Eight healthy subjects age matched to 14 patients with left hemiplegia resulting from right-hemisphere stroke (3 pushers showing a severe spatial neglect, 11 without pusher behavior). All participants were asked to actively maintain an erect posture while sitting for 8 seconds on a rocking, laterally unstable platform. The task was performed with (in light) and without (in darkness) vision. The number of trials needed to succeed in the task was monitored. In successful trials, head, shoulders, thoracolumbar spine, and pelvis orientation in roll were measured by means of an automated, optical television image processor. Compared with other patients and healthy subjects, the 3 pushers missed many more trials and displayed a contralesional tilt of the pelvis but kept a correct head orientation. This tilt was especially pronounced without vision. Spatial neglect was a key factor, explaining 56% of patients' misorientation behavior with vision and 61% without vision. This pilot kinematic analysis shows that pusher behavior does not result from disrupted processing of vestibular information (eg, caused by a lesion involving the vestibular cortex); rather, it results from a high-order disruption in the processing of somesthetic information originating in the left hemibody, which could be graviceptive neglect (extinction). This disruption leads pushers to actively adjust their body posture to a subjective vertical biased to the side opposite the cerebral lesion