Journal of Speech Pathology & Therapy
Open Access

Apraxia, brain stimulation, Neuromodulator, Conventional therapy

Introduction

Apraxia of speech results from disrupted motor planning, leading to inconsistent speech errors and slowed speech rate. Stroke is a common cause, and effective rehabilitation is crucial for restoring communication. Traditional therapies focus on repetitive practice and cueing; however, recovery can be slow and incomplete. Recent advances suggest that combining speech therapy with neuromodulator techniques like tDCS may boost neuroplasticity and functional gains [1-5].

Case Presentation

The patient, Mr. J., a 58-year-old right-handed male, experienced a left-hemisphere ischemic stroke resulting in moderate aphasia and severe apraxia of speech. Initial evaluation showed impaired articulation, frequent phoneme substitutions, and disrupted prosody. Standardized assessments included the Apraxia Battery for Adults-2 (ABA-2) and the Frenchay Dysarthria Assessment.

Intervention

Mr. J. underwent a combined treatment protocol over eight weeks:

• Speech Therapy: Targeted articulatory placement, phoneme sequencing, and rhythm exercises delivered in 45-minute sessions, 3 times per week.
• tDCS: Anodal stimulation was applied over the left inferior frontal gyrus for 20 minutes prior to therapy sessions, aiming to enhance cortical excitability.

Caregivers were trained to support daily home practice.

Outcomes

Post-treatment assessments revealed:

• 40% improvement in speech intelligibility rated by blinded listeners.
• Reduction in articulatory errors from an average of 15 errors per 50 utterances to 7 errors.
• Increased verbal initiation and fluency during conversational speech.
• Patient-reported improvements in communication confidence and social participation [6, 7].

No adverse effects from tDCS were noted.

Discussion

This case illustrates that adjunctive transcranial direct current stimulation (tDCS) may enhance the effects of conventional speech therapy in adults with apraxia of speech (AOS), potentially by modulating neuroplasticity in perilesional or compensatory brain regions. The observed improvements in speech production suggest that tDCS, when paired with targeted Behavioral intervention, may facilitate greater gains than therapy alone. This aligns with emerging evidence supporting the role of non-invasive brain stimulation in promoting cortical reorganization and functional recovery in acquired speech and language disorders [8-10].

However, while the outcomes in this case are promising, they must be interpreted with caution due to the limitations inherent in a single-subject design. Individual variability in lesion site, severity of impairment, and responsiveness to both therapy and stimulation complicate generalization. Additionally, placebo effects and spontaneous recovery cannot be fully ruled out without a control condition.

To better understand the therapeutic potential of tDCS for AOS, further research is required. Well-designed, randomized controlled trials with larger sample sizes are necessary to establish efficacy, identify optimal stimulation parameters (e.g., site, intensity, duration), and determine which patient populations are most likely to benefit. Long-term follow-up studies would also help assess the durability of treatment effects. Despite current limitations, this case adds to the growing body of literature suggesting that neuromodulator techniques may offer valuable adjuncts to traditional speech therapy in neurogenic communication disorders.

Conclusion

Integrating non-invasive brain stimulation techniques, such as transcranial direct current stimulation (tDCS), with conventional speech therapy may offer new hope for individuals with persistent apraxia of speech (AOS) following stroke. By potentially enhancing neuroplasticity and supporting functional reorganization in affected brain regions, such combined approaches could accelerate and amplify speech recovery in select patients.

However, the effectiveness of these interventions depends on careful individualization, taking into account each patient’s neurological profile, severity of impairment, and responsiveness to treatment. A multidisciplinary model--incorporating neurologists, speech-language pathologists, neuropsychologists, and rehabilitation specialists-is essential to developing and delivering comprehensive, patient-centered care.

While early findings are encouraging, further research is needed to establish standardized protocols, determine long-term benefits, and identify optimal candidates. Nonetheless, the integration of neuromodulator into speech-language rehabilitation represents a promising direction in the ongoing effort to improve outcomes and quality of life for stroke survivors with AOS.