Poster Session F, Tuesday, March 26, 8:00 – 10:00 am, Pacific Concourse
Behavioral and Neuroanatomical Characteristics of Stimulation-Induced Speech Arrest
Garret Kurteff1,2, Neal Fox1, Maansi Desai1,2, Alia Shafi1, Edward Chang1; 1University of California, San Francisco, 2University of Texas, Austin
For over a century, neurosurgeons performing awake cortical stimulation mapping have described the phenomenon of Speech Arrest, the temporary discontinuation of speech without simultaneous sensorimotor involvement. Despite its clinical and theoretical importance for the neuroanatomical localization of language function, Speech Arrest remains poorly characterized in the scientific literature. This study provides a comprehensive report of Speech Arrest in 34 patients who participated in clinical mapping tasks (e.g., counting to thirty) while undergoing awake language mapping during left hemisphere neurosurgery. We analyzed 291 speech disruptions using video and audio recordings acquired simultaneously with stimulation mapping, which were behaviorally classified as either instances of Speech Arrest or as Motor Errors. We found that Speech Arrest is characterized by a stimulation-induced delay in the onset of articulation until the termination of stimulation. Once initiated, the quality and duration of pronunciation is unaffected, and patients typically report subjectively feeling “unable to talk.” In contrast, stimulation-induced Motor Errors often begin while stimulation is still ongoing, and the resulting utterances are less intelligible and longer in duration than non-errors. A neuroanatomical dissociation between Speech Arrest and Motor Errors was also found. Most instances of Speech Arrest resulted from stimulation to pars opercularis and ventral/rostral precentral gyrus, while Motor Errors were the dominant error-type in dorsal/caudal quadrants of precentral gyrus. Interestingly, stimulation to pars triangularis (a region often considered part of anatomical Broca’s area) rarely elicited speech errors of either type. This study represents the first comprehensive quantitative characterization of Speech Arrest for neuroscientists and clinicians.
Topic Area: LANGUAGE: Other