Introduction: Dysarthria, a neurological motor speech disorder, is regarded as a common sequala of traumatic brain injury (TBI). Palilalia is a speech disorder characterized by involuntary repetition of words, phrases, or sentences. Based on the evidence supporting the effectiveness of transcranial direct current stimulation (tDCS) in some speech disorders, we hypothesized that using tDCS would enhance the expected speech therapy outcome in a case of TBI with dysarthria and palilalia. Method: The "Be Clear" protocol, a relatively new approach in speech therapy in dysarthria, together with tDCS were employed in this single case investigation. With respect to the tDCS montage, regions of interest (ROIs) were identified based on the comparative analysis of resting-state vs. speech task-concurrent qEEG results. Results: Measures of intelligibility, an important index in the assessment of dysarthria, were superior to the primary protocol results immediately and 4 months after intervention. We did not find any factor other than the use of tDCS to justify this superiority. Palilalia showed a remarkable improvement immediately after intervention but fell somewhat after 4 months. This might have been justified owing to the subcortical origin of palilalia. Conclusion: Our present findings suggested that applying tDCS together with speech therapy might be more effective in similar case profiles as compared to traditional speech therapy. This notion needs to be systematically investigated in well-designed parallel arm clinical trials.

Purpose: Dysarthria, a neurological injury of the motor component of the speech circuitry, is of common consequences of traumatic brain injury (TBI). Palilalia is a speech disorder characterized by involuntary repetition of words, phrases, or sentences. Based on the evidence supporting the effectiveness of transcranial direct current stimulation (tDCS) in some speech and language disorders, we hypothesized that using tDCS would enhances the effectiveness of speech therapy in a client with chronic dysarthria following TBI. Method: We applied the constructs of the “Be Clear” protocol, a relatively new approach in speech therapy in dysarthria, together with tDCS on a chronic subject who affected by dysarthria and palilalia after TBI. Since there was no research on the use of tDCS in such cases, regions of interest (ROIs) were identified based on deviant brain electrophysiological patterns in speech tasks and resting state compared with normal expected patterns using the Quantitative Electroencephalography (QEEG) analysis. Results: Measures of perceptual assessments of intelligibility, an important index in the assessment of dysarthria, ​​were superior to the primary protocol results immediately and 4 months after intervention. We did not find any factor other than the use of tDCS to justify this superiority. The percentage of repeated words, an index in palilalia assessment, had a remarkable improvement immediately after intervention but fell somewhat after 4 months. We justified this case with subcortical origins of palilalia. Conclusion: Our present case-based findings suggested that applying tDCS together with speech therapy may improve intelligibility in similar case profiles as compared to traditional speech therapy. To reconfirm the effectiveness of the above approach in cases with dysarthria following TBI, more investigation need to be pursued.