P01.12.B Analysis of semi-spontaneous speech before, during and after awake craniotomy: a case study
Authors: Gommers E C , Collée K E , Vincent A J P E , Bos E M , Dirven C M F , Koekkoek S K , Kruizinga P , Satoer D D 
Published: September 2022

Abstract

Background
The standard treatment for patients with eloquent gliomas is awake craniotomy (AC) with direct electrical stimulation, which results in a larger extent of resection while maintaining language function. Intraoperative language monitoring includes different standardized tasks and spontaneous speech elicitation. Despite careful monitoring, it was found that spontaneous speech deteriorated long-term after surgery. However, intraoperative spontaneous speech has not been investigated before. Detailed analyses may reveal possible predictors for language outcome. For the first time, we present a case study in which we investigate and quantify semi-spontaneous speech before, during and after AC.

Material and Methods
A left-handed 50-year old male with a glioblastoma (WHO grade 4) in the left parietal lobe underwent AC. Semi-spontaneous speech was collected (audio/video recording) using the Sabadel story retelling task at: 1 day before (T1), during (T2), 2 days (T3) and 2 months (T4) after surgery. Recordings were manually transcribed and language errors were quantified. A preliminary acoustic analysis with simple automatic peak detection was performed. Comparisons between test moments were made.

Results
Manual transcription showed 1) notable changes in the number of paraphasias (T1: 1% - T2: 1% - T3: 9% - T4: 5%), interjections (T1: 9% - T2: 9% - T3: 15% - T4: 10%), minimal utterances (T1: 4% - T2: 4% - T3: 6% - T4: 1%), false starts (T1: 3% - T2: 5% - T3: 6% - T4: 8%), self-corrections (T1: 3% - T2: 2% - T3: 4% - T4: 7%) and 2) small changes in repetitions (T1: 1% - T2: 0% - T3: 2% - T4: 3%), hesitations (T1: 1% - T2: 0% - T3: 2% - T4: 0%), incomplete sentences (T1: 1% - T2: 0% - T3: 0% - T4: 1%), grammatical errors (T1: 2% - T2: 1% - T3: 2% - T4: 2%). The total number of words (T1: 273 - T2: 283 - T3: 249 - T4: 287) and utterances (T1: 39 - T2: 41 - T3: 36 - T4: 34) varied slightly. Acoustic analysis showed a slight increase in word length during and directly after surgery but it recovered to preoperative level on the long-term (T1: .66 s - T2: .75 s - T3: .87 s - T4: .69 s).

Conclusion
The semi-spontaneous speech task in this case study was sensitive to capture changes in perioperative language status. Paraphasias, interjections, minimal utterances, hesitations and word length increased directly after surgery followed by a decrease 2 months later. This is a frequently reported pattern of transient language deficits. However, other errors (false starts, repetitions, self-corrections, incomplete sentences) increased at 2 months after surgery, indicating longer term language deficits. Future exploration of both the acoustic analysis, which shows potential for real-time feedback, and the manual transcriptions, could possibly lead to a better understanding of intra- and postoperative language performance as a prognostic factor for long-term language outcome, with possible implications for language therapy.