Speech Therapy for Children With Rare Genetic Conditions and Childhood Apraxia of Speech

This study uses a single case experimental design (SCED) approach with a multiple baseline design.

Participants will be allocated to either speech movement therapy approach (Dynamic Temporal and Tactile Cueing [DTTC] or Rapid Syllable Transition Treatment [ReST]) (based on clinical and speech characteristics). Each participant is allocated to one treatment only. Each participant will follow an A-B-F pattern as follows.

A: Baseline: Within each group, participants will be randomly allocated to baseline lengths of 3, 4 or 5 probes (i.e., providing experimental control). Baseline probes will be collected twice per week (i.e., baseline duration will run from 1.5 to 2.5 weeks)

B: Treatment: All participants will complete a 4-week treatment block (3 sessions per week) with a qualified speech pathologist.

F: Follow-up: Maintenance probes will be completed at 1 week, 4 weeks and 8 weeks post-treatment.

Speech outcomes are measured repeatedly during baseline, treatment and follow-up to examine level, trend and maintenance of change over time.

The primary objective is to examine the efficacy of currently utilised speech treatments (i.e., DTTC, ReST) on accuracy of trained speech targets in children with CAS and rare genetic conditions.

Secondary objectives:

• To measure change in accuracy of untrained speech targets (generalisation)
• To measure change in connected speech intelligibility
• To measure change in functional communication (e.g., parent-reported communication and intelligibility)
• To explore parent satisfaction with the intervention and perceived impact on participation and quality of life

This trial anticipates n=20 participants, approximately n=10 per treatment group (DTTC, ReST) each contributing to a multiple baseline SCED.

Once consented, the individual estimated duration is 4 months:

• < 3 weeks for multiple baseline probes
• 4 weeks of treatment (incl. weekly probes)
• 8 weeks for follow-up/maintenance probes

Treatment:

• Intensive speech movement treatment delivered 3x/week for 4 weeks (12x 45-60 minute sessions).
• Established DTTC or ReST protocols will be followed. These treatments are manualised. Fidelity will be monitored via checklists and session recordings, with oversight from the CI
• Individualised target word sets will be based on each child's phonetic/phonotactic profile (i.e., the sounds and syllable structures they can and cannot produce)
• Speech probe assessments collected at each baseline, weekly during treatment, and at 1-, 4- and 8- weeks post-treatment

Inclusion criteria

• Children aged between 3 and 16 years, with a confirmed genetic condition and a diagnosis of childhood apraxia of speech; English as the primary language at home; able to participate in speech therapy 3 times per week for 4 weeks

Exclusion criteria

• Diagnosis of an acquired brain or movement condition likely to affect speech; currently receiving motor speech therapy in the community; diagnosis of a behavioural condition likely to impact engagement (i.e., unable to participate for 45 minutes, unable to focus attention at the speech therapist's face for a few minutes at a time, unable to say any sounds and/or use gesture, unable to try to copy speech therapist; intolerant to touch (if touch cues are needed for DTTC)