A new bedside test of gestures in stroke: The apraxia screen of TULIA (AST)

Background: Apraxia in patients with stroke may be overlooked, as clumsiness and deficient gestural communication are often attributed to frequently coexisting sensorimotor deficits and aphasia. Early and reliable detection of apraxia by a bedside test is relevant for functional outcome in patients with stroke. The present study was aimed at constructing a new bedside screening test for apraxia, called the Apraxia Screen of TULIA (AST), based on the comprehensive standardised Test for Upper-Limb Apraxia (TULIA). Methods: First, an item-reduction analysis of the TULIA (48 gestures) was performed, based on the methods of classical test theory and on a larger sample of patients with stroke (n=133) and matched healthy controls (n=50). Stepwise elimination of items resulted in a set of 12 items, demonstrating high internal consistency (Cronbach alpha=0.92). The six-point scoring method of the TULIA was dichotomised to the score levels pass and fail. In the second part of this study the validity of the AST was assessed prospectively in a new cohort of patients with stroke (n=31) by using the Pearson correlation analysis and binary classification display with the TULIA. Results and discussion: Validation of the 12-item AST with the TULIA showed a remarkable diagnostic reliability with high specificity, sensitivity and positive predictive value, for the presence and severity of apraxia. The AST is shown to be a reliable and valid bedside test in patients with stroke, allowing a straightforward assessment of apraxia within a few minutes.