[A New Diagnostic Tool for Apraxia in Patients with Right-Hemisphere Stroke: The Revised Cologne Apraxia Screening (KAS-R)].

The Cologne Apraxia Screening (KAS) was developed to diagnose apraxia following left-hemisphere (LH) stroke. The present study aims at developing a diagnostic tool for patients with right-hemisphere (RH) stroke (KAS-R) by modifying the test material of the KAS and reducing the test items based on psychometric analyses.A total of 100 patients with RH stroke and 77 healthy control participants were tested. Psychometric analyses led to the exclusion of 8 KAS items. The final KAS-R, consisting of 12 items, shows good internal consistency (α = 0.795) as well as high sensitivity (79.4 %) and specificity (84.4 %). Applying a cut-off value of ≤ 46 (out of 48) points, 39 RH stroke patients were diagnosed with apraxia. Significant correlations were found between the KAS-R and an imitation test as well as expert ratings, indicating high construct validity. The results suggest that the KAS-R is a reliable and valid diagnostic tool for apraxic deficits after RH stroke.