Towards a core outcome set for dysarthria after stroke: What should we measure?

OBJECTIVE: To identify and agree on what outcome domains should be measured in research and clinical practice when working with stroke survivors who have dysarthria. DESIGN: Delphi process, two rounds of an online survey followed by two online consensus meetings. SETTING: UK and Australia. PARTICIPANTS: Stroke survivors with experience of dysarthria, speech and language therapists/pathologists working in stroke and communication researchers. METHODS: Initial list of outcome domains generated from existing literature and with our patient and public involvement group to develop the survey. Participants completed two rounds of this survey to rate importance. Outcomes were identified as 'in', 'unclear' or 'out' from the second survey. All participants were invited to two consensus meetings to discuss these results followed by voting to identify critically important outcome domains for a future Core Outcome Set. All outcomes were voted on in the consensus meetings and included if 70% of meeting participants voted 'yes' for critically important. RESULTS: In total, 148 surveys were fully completed, and 28 participants attended the consensus meetings. A core outcome set for dysarthria after stroke should include four outcome domains: (a) intelligibility of speech, (b) ability to participate in conversations, (c) living well with dysarthria, (d) skills and knowledge of communication partners (where relevant). CONCLUSIONS: We describe the consensus of 'what' speech outcomes after stroke are valued by all stakeholders including those with lived experience. We share these findings to encourage the measurement of these domains in clinical practice and research and for future research to identify 'how' best to measure these outcomes.

The complexity of multidisciplinary respiratory care in amyotrophic lateral sclerosis.

Motor neurone disease/amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder with no known cure, where death is usually secondary to progressive respiratory failure. Assisting people with ALS through their disease journey is complex and supported by clinics that provide comprehensive multidisciplinary care (MDC). This review aims to apply both a respiratory and a complexity lens to the key roles and areas of practice within the MDC model in ALS. Models of noninvasive ventilation care, and considerations in the provision of palliative therapy, respiratory support, and speech and language therapy are discussed. The impact on people living with ALS of both inequitable funding models and the complexity of clinical care decisions are illustrated using case vignettes. Considerations of the impact of emerging antisense and gene modifying therapies on MDC challenges are also highlighted. The review seeks to illustrate how MDC members contribute to collective decision-making in ALS, how the sum of the parts is greater than any individual care component or health professional, and that the MDC per se adds value to the person living with ALS. Through this approach we hope to support clinicians to navigate the space between what are minimum, guideline-driven, standards of care and what excellent, person-centred ALS care that fully embraces complexity could be. Educational aims: To highlight the complexities surrounding respiratory care in ALS.To alert clinicians to the risk that complexity of ALS care may modify the effectiveness of any specific, evidence-based therapy for ALS.To describe the importance of person-centred care and shared decision-making in optimising care in ALS.

Examining the occurrence and outcomes of concussion and mTBI in mixed martial arts athletes: a systematic review.

INTRODUCTION: Mixed martial arts (MMA) is a sport growing in popularity around the world. However, many individuals participate in the sport with little understanding of the potential short- and long-term consequences of injuries sustained while participating. Specifically, individuals are placed at a high risk of minor traumatic brain injury (mTBI) and concussive episodes as a result of head injuries incurred during training and competition. AIMS: The current review aimed to examine the literature surrounding the occurrence and outcomes of mTBI in MMA athletes to gain a better understanding of these consequences. METHODS: Twenty-five studies were identified within the current review, of which 14 examined occurrence of mTBI within the sport setting, and elevenidentified outcomes of injury. RESULTS: Overall, studies found that MMA athletes experienced mTBI and concussion to a greater extent than athletes in other sports. Deficits in memory, reaction time and processing speed were identified following occurrence of mTBI; however, several gaps in outcome measurement were identified within the current literature, including a lack of focus on speech and language outcomes. CONCLUSION: Future research should examine a wider variety of outcomes to provide a clearer understanding of the consequences of participating in the sport.

Feasibility of a Telerehabilitation Adaptation of the Be Clear Speech Treatment Program for Non-Progressive Dysarthria.

This study evaluated the feasibility and outcomes of a telerehabilitation adaptation of the Be Clear speech treatment program for adults with non-progressive dysarthria to determine clinical delivery viability and future research directions. Treatment effects on speech clarity, intelligibility, communication effectiveness, and participation, as well as psychosocial outcomes in 15 participants with non-progressive dysarthria, were explored. Intervention involved daily 1-h online sessions (4 days per week for 4 weeks, totalling 16 sessions) and daily home practice. Outcome measures were obtained at baseline (PRE), post-treatment (POST), and 12 weeks following treatment (FUP). Feasibility measures targeting participant satisfaction, treatment adherence and fidelity, and technical viability were also employed. The programme was feasible concerning technical viability and implementation, treatment adherence and fidelity. High levels of participant satisfaction were reported. Increases in overall ratings of communication participation and effectiveness were identified at POST and FUP. Reductions in speech rate were identified at FUP. Improvements in aspects of lingual and laryngeal function were also noted after treatment. Over time, improvements relating to the negative impact of dysarthria were identified. Naïve listeners perceived negligible changes in speech clarity following treatment. Online delivery of the Be Clear speech treatment program was feasible, and some positive speech benefits were observed. Due to the small sample size included in this research, statistically significant findings related to speech outcomes must be interpreted with caution. An adequately powered randomised controlled trial of Be Clear online is warranted to evaluate treatment efficacy.

Substrates of speech treatment-induced neuroplasticity in adults and children with motor speech disorders: A systematic scoping review of neuroimaging evidence.

Purpose: Neuroimaging may provide clinical evidence for speech treatment-induced neuroplasticity. This review aimed to report the current scope of evidence relating to brain changes identified using neuroimaging techniques, following effective speech intervention in adults and children with motor speech disorders (MSD).Method: Studies were retrieved from five electronic databases (PubMed, CINAHL, EMBASE (Medline), SCOPUS, and Web of Science) and a general internet search.Result: Seven studies met the inclusion criteria. Using structural or functional neuroimaging techniques, five studies reported on the effects of the Lee Silverman Voice Treatment for dysarthria in adults and children, one study on the outcome of rhythmic-melodic voice training in adults with apraxia of speech, and one study on the effects of Prompts for Restructuring Oral Muscular Phonetic Targets therapy in children with idiopathic apraxia of speech. Identified brain changes included: enhanced white matter tract integrity; normalisation of baseline cortical activity; right-hemisphere shifts in re-organisation; perilesional activations; and cortical thinning.Conclusion: The current review identified preliminary evidence for treatment-dependent brain changes in adults and children with MSD. Although important to interpret within the context of Phase I research, the identification of therapeutic effects across seven heterogeneous studies suggests that treatment-induced improvements in speech performance are underpinned by demonstrable alterations in brain structure and/or function. Future research is required to better define these mechanisms of neuronal re-organisation in individuals receiving treatment for MSD, including their prognostic potential.

Conversational trouble and repair in dementia: Revision of an existing coding framework.

A decline in the effectiveness of everyday conversation is often observed for people with dementia. This study explored conversational trouble and repair between people with dementia residing in residential care and professional care staff. The aim was to examine the utility of an existing conversational trouble and repair framework by Watson, Carter and Chenery (1999) in a comparatively larger sample. Twenty conversations were coded for dementia-specific trouble and repair; however, the original framework could not adequately accommodate the variety of trouble and repair within the dataset. The data was subsequently used to inform a revised framework, which captures a wide spectrum of trouble and repair in dementia and offers more precise codes to researchers and clinicians working with this clinical population. Examples of divergent coding strategies between the original and revised framework are provided as well as examples of trouble and repair patterns observed in both carers and people with dementia.

Acceptance of Rehabilitation Technology in Adults With Moderate to Severe Traumatic Brain Injury, Their Caregivers, and Healthcare Professionals: A Systematic Review.

BACKGROUND: Moderate to severe traumatic brain injuries (TBIs) commonly result in persistent physical, cognitive, and/or emotional deficits that require long-term rehabilitation. Technology-enabled rehabilitation provides an innovative alternative to traditional intervention models. End-user acceptance of these interventions, however, is a critical factor in determining the effective implementation and acceptance of these technologies. OBJECTIVE: To systematically review the literature to identify methods and measures used to evaluate user acceptance relating to rehabilitation technologies for adults with moderate to severe TBI, their caregivers, and healthcare professionals. METHODS: Six key databases including Medline, Embase, CINAHL, Cochrane, Scopus, and Web of Science were searched using the relevant search terms. RESULTS: From a yield of 2059 studies, 13 studies met the eligibility criteria. The review revealed limited research that formally evaluated user acceptance in relation to rehabilitation technologies designed for adults with TBI. Furthermore, where such evaluations were conducted, comprehensive research designs incorporating theoretical frameworks of technology acceptance were sparse. Importantly, a range of technologies and recommendations that positively influenced user acceptance were identified. Future directions for research in this area include the use of theory-driven research designs to enhance our understanding of technology acceptance, to support the development of rehabilitation technologies that maximize functional outcomes for individuals with TBI.

Toward the Development of SMART Communication Technology: Automating the Analysis of Communicative Trouble and Repair in Dementia.

BACKGROUND AND OBJECTIVES: Communication difficulties have been reported as one of the most stress-inducing aspects of caring for people with dementia. Notably, with disease progression comes an increase in the frequency of communication difficulty and a reduction in the effectiveness of attempts to remedy breakdowns in communication. The aim of the current research was to evaluate the utility of an automated discourse analysis tool (i.e., Discursis) in distinguishing between different types of trouble and repair signaling behaviors, demonstrated within conversations between people with dementia and their professional care staff. RESEARCH DESIGN AND METHODS: Twenty conversations between people with dementia and their professional care staff were human-coded for instances of interactive/noninteractive trouble and typical/facilitative repair behaviors. Associations were then examined between these behaviors and recurrence metrics generated by Discursis. RESULTS: Significant associations were identified between Discursis metrics, trouble-indicating, and repair behaviors. DISCUSSION AND IMPLICATIONS: These results suggest that discourse analysis software is capable of discriminating between different types of trouble and repair signaling behavior, on the basis of term recurrence calculated across speaker turns. The subsequent recurrence metrics generated by Discursis offer a means of automating the analysis of episodes of conversational trouble and repair. This achievement represents the first step toward the future development of an intelligent assistant that can analyze conversations in real time and offers support to people with dementia and their carers during periods of communicative trouble.

Lingual kinematics during rapid syllable repetition in Parkinson's disease.

BACKGROUND: Rapid syllable repetition tasks are commonly used in the assessment of motor speech disorders. However, little is known about the articulatory kinematics during rapid syllable repetition in individuals with Parkinson's disease (PD). AIMS: To investigate and compare lingual kinematics during rapid syllable repetition in dysarthric speakers with PD (DPD), non-dysarthric speakers with PD (NDPD) and a group of healthy controls. METHODS & PROCEDURES: Electromagnetic articulography was used to record tongue-tip and tongue-back movement in five DPD and five NDPD participants during rapid repetition of /ta/and /ka/syllables, and matched with six healthy controls. OUTCOMES & RESULTS: Results revealed significant between-group differences for most of the kinematic parameters measured but comparable rapid syllable repetition rates. Post-hoc analyses indicated that the DPD participants, when compared with the NDPD participants, had similar range but prolonged duration of lingual movement. The DPD and NDPD participants had primarily increased range and prolonged duration of lingual movement accompanied by increased speed parameters, when compared with healthy controls. CONCLUSIONS & IMPLICATIONS: The findings of the present study contradict theories that suggest that the clinical features of hypokinetic dysarthria, including articulatory imprecision, are the outcome of restrictions in the range of movement of the muscles of the articulators. The observed prolonged duration of lingual movement in PD may plausibly be due to the observed increased range of lingual movement rather than slowness of lingual movement.

Improved receptive and expressive language abilities in nonfluent aphasic stroke patients after application of rTMS: an open protocol case series.

BACKGROUND: Repetitive transcranial magnetic stimulation (rTMS) has been identified as a potentially valuable tool for the rehabilitation of language impairment after left hemisphere (LH) stroke, in populations of persons with chronic aphasia. Applied to a homologue to Broca's area, rTMS is posited to modulate bilateral language networks, promoting measurable behavioral language change, in accordance with theories of transcallosal disinhibition arising from the damaged LH. OBJECTIVE/HYPOTHESIS: The current investigation is an open-label study, presenting detailed case and group presentations on a population of seven nonfluent aphasic participants. Behavioral language performance is presented on expressive and receptive language measures up to 8 months after a 10-day protocol of 1 Hz stimulation. This research aims to provide longitudinal behavioral language outcomes for persons with aphasia, subsequent to rTMS and supplement previous studies to inform the clinical efficacy of rTMS. RESULTS: In accordance with previous investigations, significant improvements in picture naming, spontaneous elicited speech and auditory comprehension were found. Time of testing was identified as a significant main effect. Significant improvements in picture naming accuracy and decreases in picture naming latency were also identified. The results demonstrate sustained language improvements up to 8 months subsequent to TMS application. CONCLUSIONS: The results of this investigation are consistent with the findings of previous research studies, reporting behavioral language changes after rTMS in nonfluent aphasia. Additional evidence is provided to demonstrate that rTMS may facilitate retrieval mechanisms involved in picture naming.

Lingual kinematics in dysarthric and nondysarthric speakers with Parkinson's disease.

Articulatory dysfunction is recognised as a major contributor to the speech disturbances seen in Parkinson's disease (PD). The present study aimed to compare lingual kinematics during consonant production within a sentence in eight dysarthric (DPD) and seven nondysarthric (NDPD) speakers with PD with those of eleven nonneurologically impaired normal participants. The tongue tip and tongue back movements of the participants during sentence production were recorded using electromagnetic articulography (EMA). Results showed that both the DPD and NDPD had deviant articulatory movement during consonant production that resulted in longer duration of consonant production. When compared with the NDPD group, the DPD group primarily exhibited increased range of lingual movement and compatible duration of production with an accompanying increase in maximum velocity, maximum acceleration, and maximum deceleration. These findings are contrary to proposed theories that suggest articulatory imprecision in dysarthric speakers with PD is the outcome of reduced range of articulatory movement.

The effects of low frequency Repetitive Transcranial Magnetic Stimulation (rTMS) and sham condition rTMS on behavioural language in chronic non-fluent aphasia: Short term outcomes.

INTRODUCTION: The application of low frequency (1 Hz) Repetitive Transcranial Magnetic Stimulation (rTMS) to right hemisphere (RH) language homologues in non-fluent aphasic populations has yielded improvements in behavioural language function, up to 43 months post stimulation. Functional imaging studies have demonstrated RH language homologue "overactivation" post left inferior frontal gyrus (IFG) damage, in chronic non-fluent aphasia. The effects of low frequency (inhibitory) rTMS are postulated to be as a result of a reduction of overactivation in RH language homologues, facilitating the reorganisation of neural language networks. METHODS: Low frequency (1 Hz) rTMS was applied to the anterior portion of a Broca's area homologue (pars triangularis), for 20 minutes per day for 10 days, using a stereotactic neuronavigational system. Twelve non-fluent aphasic patients (six real stimulation and six sham), 2-10 years post stroke were stimulated. Behavioural language outcome measures were taken at baseline and 1 week post rTMS. RESULTS: Comparisons between the real stimulation and sham conditions indicated significant main effects between the stimulation and sham groups to 1 week post stimulation for naming accuracy, latency and repetition. CONCLUSIONS: This study indicates that rTMS has the capacity to modulate neural language networks, to facilitate improvements in behavioural language function, 1 week post TMS.

Modulation of N400 in chronic non-fluent aphasia using low frequency Repetitive Transcranial Magnetic Stimulation (rTMS).

Low frequency Repetitive Transcranial Magnetic Stimulation (rTMS) has previously been applied to language homologues in non-fluent populations of persons with aphasia yielding significant improvements in behavioral language function up to 43 months post stimulation. The present study aimed to investigate the electrophysiological correlates associated with the application of rTMS through measurement of the semantic based N400 Event-related brain potentials (ERP) component. Low frequency (1 Hz) rTMS was applied to the anterior portion of the homologue to Broca's area (pars triangularis), for 20 min per day for 10 days, using a stereotactic neuronavigational system. Twelve non-fluent persons with aphasia, 2-6 years post stroke were stimulated. Six participants were randomly assigned to receive real stimulation and six participants were randomly assigned to receive a blind sham control condition. ERP measures were recorded at baseline, 1 week and 2 months subsequent to stimulation. The findings demonstrate treatment related changes observed in the stimulation group when compared to the placebo control group at 2 months post stimulation indicating neuromodulation of N400 as a result of rTMS. No treatment related changes were identified in the stimulation group, when compared to the sham group from baseline to 1 week post stimulation. The electrophysiological results represent the capacity of rTMS to modulate neural language networks and measures of lexical-semantic function in participants with non-fluent aphasia and suggest that time may be an important factor in brain reorganization subsequent to rTMS.

Kinematic analysis of lingual function in dysarthric speakers with Parkinson's disease: An electromagnetic articulograph study.

Dysarthria in people with Parkinson's disease (PD) has been widely studied. However, a limited number of studies have investigated lingual function during speech production in this population. This study aimed to investigate lingual kinematics during speech production using electromagnetic articulography (AG-200 EMA). The PD group consisted of eight dysarthric speakers with PD and was matched with a group of eight controls. The tongue tip and tongue back movements of all participants during sentence production were recorded by EMA. Results showed that, perceptually, the participants with PD were mildly dysarthric. Kinematic results documented comparable (for alveolar sentence production) and increased (for velar sentence production) range of lingual movement in the PD group when compared to the control group. Lingual movement velocity, acceleration, and deceleration were also increased in the PD group, predominantly for the release phase of consonant production during sentence utterances. The PD group had longer duration in the production of alveolar consonant and comparable duration in the production of velar consonant. The results of the present study suggest the presence of impaired lingual control in individuals with PD. Increased range of articulatory movement, primarily in the release phase of consonant production, may account for articulatory imprecision in this population.

Language disorders subsequent to left cerebellar lesions: a case for bilateral cerebellar involvement in language?

BACKGROUND: Crossed cerebello-cerebral diaschisis, reflecting a functional depression of supratentorial language areas due to reduced input via cerebello-cortical pathways, may represent the neuropathological mechanism responsible for language deficits associated with cerebellar pathology. Although it has been proposed that language is lateralized to the right cerebellar hemisphere, recent clinical and neuroimaging studies suggest that the cerebellum may bilaterally influence the regulation of language, with the left cerebellar hemisphere also contributing to the mediation of language via ipsilateral cerebello-cortical pathways. AIMS: The aim of the study was to determine the effect of left primary cerebellar lesions on general as well as higher-level language function. METHODS AND PROCEDURES: Linguistic profiles of a group of ten individuals with left primary cerebellar lesions were compared with those of a group of non-neurologically impaired controls matched for age, gender and level of education. OUTCOMES AND RESULTS: The findings confirmed that higher-level language deficits may result from left primary cerebellar lesions possibly as a consequence of ipsilateral cerebral diaschisis. CONCLUSIONS: The results challenge the notion of a right lateralized cerebellum and support a role for the left as well as the right cerebellar hemisphere in the regulation of language function.

Delineating communication impairments associated with mild traumatic brain injury: a case report.

BACKGROUND: Mild traumatic brain injury (mTBI) without frank neurological disturbance has been linked to persistent physical, cognitive, and affective disturbances in some cases. The cognitive sequelae of this syndrome represent the most frequently studied symptoms, yet the legacy of such injuries on communicative functions remains largely undetermined. METHODS: A detailed language profile of a 19-year-old woman, 1 year 10 months following mTBI is compared with a matched normative cohort of 10 participants with nonneurological impairment. RESULTS: Deficits in attention, lexical access, complex lexical-semantic manipulation, response monitoring, and organization were revealed as a consequence of mTBI. CONCLUSIONS: This profile provides support for hypotheses pertaining to neuronal fallout mechanisms within the frontal lobes as a consequence of mild neurological insult.

Beyond verbal fluency: investigating the long-term effects of bilateral subthalamic (STN) deep brain stimulation (DBS) on language function in two cases.

Cognitive functioning has been described as largely impervious to chronic STN-DBS administered over 12-month periods. In relation to the domain of language, however, the effects of STN-DBS are yet to be thoroughly delineated. Verbal fluency tasks represent an almost exclusively applied index of linguistic proficiency relative to neuropsychological research within this population. Comprehensive investigations of the impact of STN-DBS on language function, however, have never been undertaken. The more precise elucidation of the role of the STN in the mediation of language processes, by way of assessments which probe language comprehension and production mechanisms, served as the primary focus of this research. Longitudinal analysis also afforded consideration of the way in which cognitive-linguistic circuits respond to STN-DBS over time. Bilateral STN-DBS primarily effected clinically reliable fluctuations (i.e., both improvements and declines) in performance in both subjects on tasks demanding cognitive-linguistic flexibility in the formulation and comprehension of complex language. Of particular note, both subjects demonstrated a cumulative increase in the proportion of reliable post-operative improvements achieved over time. The findings of this research lend support to models of subcortical participation in language which endorse a role for the STN, and suggest that bilateral STN-DBS may serve to enhance the proficiency of basal ganglia-thalamocortical linguistic circuits over time.

Redefining functional models of basal ganglia organization: role for the posteroventral pallidum in linguistic processing?

Traditionally the basal ganglia have been implicated in motor behavior, as they are involved in both the execution of automatic actions and the modification of ongoing actions in novel contexts. Corresponding to cognition, the role of the basal ganglia has not been defined as explicitly. Relative to linguistic processes, contemporary theories of subcortical participation in language have endorsed a role for the globus pallidus internus (GPi) in the control of lexical-semantic operations. However, attempts to empirically validate these postulates have been largely limited to neuropsychological investigations of verbal fluency abilities subsequent to pallidotomy. We evaluated the impact of bilateral posteroventral pallidotomy (BPVP) on language function across a range of general and high-level linguistic abilities, and validated/extended working theories of pallidal participation in language. Comprehensive linguistic profiles were compiled up to 1 month before and 3 months after BPVP in 6 subjects with Parkinson's disease (PD). Commensurate linguistic profiles were also gathered over a 3-month period for a nonsurgical control cohort of 16 subjects with PD and a group of 16 non-neurologically impaired controls (NC). Nonparametric between-groups comparisons were conducted and reliable change indices calculated, relative to baseline/3-month follow-up difference scores. Group-wise statistical comparisons between the three groups failed to reveal significant postoperative changes in language performance. Case-by-case data analysis relative to clinically consequential change indices revealed reliable alterations in performance across several language variables as a consequence of BPVP. These findings lend support to models of subcortical participation in language, which promote a role for the GPi in lexical-semantic manipulation mechanisms. Concomitant improvements and decrements in postoperative performance were interpreted within the context of additive and subtractive postlesional effects. Relative to parkinsonian cohorts, clinically reliable versus statistically significant changes on a case by case basis may provide the most accurate method of characterizing the way in which pathophysiologically divergent basal ganglia linguistic circuits respond to BPVP.

Re-appraising contemporary theories of subcortical participation in language: proposing an interhemispheric regulatory function for the subthalamic nucleus (STN) in the mediation of high-level linguistic processes.

Apropos the basal ganglia, the dominant striatum and globus pallidus internus (GPi) have been hypothesized to represent integral components of subcortical language circuitry. Working subcortical language theories, however, have failed thus far to consider a role for the STN in the mediation of linguistic processes, a structure recently defined as the driving force of basal ganglia output. The aim of this research was to investigate the impact of surgically induced functional inhibition of the STN upon linguistic abilities, within the context of established models of basal ganglia participation in language. Two males with surgically induced'lesions'of the dominant and non-dominant dorsolateral STN, aimed at relieving Parkinsonian motor symptoms, served as experimental subjects. General and high-level language profiles were compiled for each subject up to 1 month prior to and 3 months following neurosurgery, within the drug-on state (i.e., when optimally medicated). Comparable post-operative alterations in linguistic performance were observed subsequent to surgically induced functional inhibition of the left and right STN. More specifically, higher proportions of reliable decline as opposed to improvement in post-operative performance were demonstrated by both subjects on complex language tasks, hypothesised to entail the interplay of cognitive-linguistic processes. The outcomes of the current research challenge unilateralised models of functional basal ganglia organisation with the proposal of a potential interhemispheric regulatory function for the STN in the mediation of high-level linguistic processes.

Reappraising contemporary theories of subcortical participation in language: proposing an interhemispheric regulatory function for the subthalamic nucleus (STN) in the mediation of high-level linguistic processes.

Apropos the basal ganglia, the dominant striatum and globus pallidus internus (GPi) have been hypothesised to represent integral components of subcortical language circuitry. Working subcortical language theories, however, have failed thus far to consider a role for the STN in the mediation of linguistic processes, a structure recently defined as the driving force of basal ganglia output. The aim of this research was to investigate the impact of surgically induced functional inhibition of the STN upon linguistic abilities, within the context of established models of basal ganglia participation in language. Two males with surgically induced 'lesions' of the dominant and non-dominant dorsolateral STN, aimed at relieving Parkinsonian motor symptoms, served as experimental subjects. General and high-level language profiles were compiled for each subject up to 1 month prior to and 3 months following neurosurgery, within the drug-on state (i.e., when optimally medicated). Comparable post-operative alterations in linguistic performance were observed subsequent to surgically induced functional inhibition of the left and right STN. More specifically, higher proportions of reliable decline as opposed to improvement in post-operative performance were demonstrated by both subjects on complex language tasks, hypothesised to entail the interplay of cognitive-linguistic processes. The outcomes of the current research challenge unilateralised models of functional basal ganglia organisation with the proposal of a potential interhemispheric regulatory function for the STN in the mediation of high-level linguistic processes.