The measure of apraxia used in this study was the Test of Oral and Limb Apraxia (TOLA).31 In the TOLA, each subject was asked to perform each gesture first to verbal command (eg, “show me how you would wave ‘goodbye’”) and then to imitation (eg, “I want you to imitate the following gesture”). The gestures were all meaningful (ie, nonsense gestures were not evaluated). The TOLA31 consists of 6 categories of tasks performed to both command and imitation: proximal intransitive (eg, salute), proximal transitive (eg, stir a gallon of paint), distal intransitive (eg, make an “OK” sign), distal transitive (eg, dial a telephone), oral nonrespiratory (eg, bite an apple), and oral respiratory (eg, blow out a candle). In addition, subjects were shown pictures of an object and told, “Now I’m going to show you some pictures. Each picture shows an object that can be represented with a gesture. For example, here is a picture of a pen. If I were to represent it with a gesture without talking, I would do this.” (Make an appropriate gesture.) “Now, you make a gesture to represent this picture.”31 For this “gestured pictures” task, 3 categories were tested: proximal (eg, a meat grinder), distal (eg, tweezers), and oral (eg, toothbrush). Patients were instructed to use the nondominant hand to perform the actions. If this hand was too impaired to perform the task, the dominant hand was used. Table 1 shows the distribution of hands tested. On all transitive oral gestures (eg, licking an ice cream cone), the patient was restrained from cueing himself or herself by pretending to hold the object. The TOLA was administered and scored by trained bachelor’s- to master’s-level research assistants (including A.C.). All subject gestures were given a score of 0 to 3, where 3 represents normal performance; 2 represents noticeable errors, hesitancy, or self-correction; 1 represents a movement that retains some basic elements but is largely disordered; and 0 represents a movement that lacks all crucial elements of the gesture. The TOLA has been tested on healthy controls and patients with apraxia and has been demonstrated to have content, predictive, concurrent, and construct validity for the measurement of IMA.31 Patients who did not appear to understand the TOLA instructions were not included in the analysis, although this excluded only 1 subject.