The Importance of Material Used in Speech Therapy: Two Case Studies in Minimally Conscious State Patients

Abstract

Speech therapy can be part of the care pathway for patients recovering from comas and presenting a disorder of consciousness (DOC). Although there are no official recommendations for speech therapy follow-up, neuroscientific studies suggest that relevant stimuli may have beneficial effects on the behavioral assessment of patients with a DOC. In two case studies, we longitudinally measured (from 4 to 6 weeks) the behavior (observed in a speech therapy session or using items from the Coma Recovery Scale-Revised) of two patients in a minimally conscious state (MCS) when presenting music and/or autobiographical materials. The results highlight the importance of using relevant material during a speech therapy session and suggest that a musical context with a fast tempo could improve behavior evaluation compared to noise. This work supports the importance of adapted speech therapy for MCS patients and encourages larger studies to confirm these initial observations.

Keywords: autobiographical memory; minimally conscious state; music; speech therapy; tempo.

Figure 1

Experimental design for case study one. The four types of blocks (a preferred music context followed by an autobiographical speech therapy session, mC/aSP, a preferred music context followed by a neutral speech therapy session, mC/nSP, a silent context followed by an autobiographical speech therapy session, sC/aSP, and a silent context followed by a neutral speech therapy session, sC/nSP) were pseudo-randomly presented 3 times each throughout 4 weeks. The first four blocks are illustrated, corresponding to days 1, 3, 5 and 8.

Figure 2

Behavioral scores to mC/aSP (musical context/autobiographical speech therapy session, blue), mC/nSP (musical context/neutral session, red), sC/aSP (silent context/autobiographical session, green), and sC/nSP (silent context/neutral session, purple). (a) The average scores were expressed according to the 4 conditions (“/max, in %” means percentage of the maximum possible score, * means p < 0.05). (b) The average scores were expressed according to the 4 conditions and to each of the 8 behaviors (percentage of the maximum possible score).

Figure 3

Time course of the average weekly behavioral score in the two case studies. The average score of several blocks performed in the same week is presented chronologically from week 1 to week 4 (case study 1) or week 6 (case study 2).

Figure 4

Experimental design for case study two. A block consisted of a 15 min period of silence, followed by 3 triplets, each of which consisted of one of the three types of sound (white noise, fast music, or slow music), the question “are you okay?” (ok), and one of the three selected CRS items (it). The three types of sounds and the three items (Movement to command, Object manipulation, and Communication) were used in one block, their combinations being mixed in a homogeneous and pseudo-random way between the blocks. Twelve blocks were presented throughout 6 weeks. The first two blocks are illustrated, corresponding to days 1 and 3.

Figure 5

Number of successful responses to a question (“are you okay?”, in green) and to the CRS-R items (“Movement to command”, in blue, “Communication”, in red, and “Object manipulation” was never successfully completed), according to the experimental conditions (white noise, fast music, and slow music). * means p < 0.05.