Oral Word Association Task Research Articles

The Relationship Between Cognitive-Linguistic Performance and Sleep Problems In Adults With Mild Traumatic Brain Injury

<h3>Research Objectives</h3> To determine the relationship between cognitive-linguistic performance and self-reported sleep problems. Hypothesis: Sleep problems, as assessed by global Pittsburgh Sleep Quality Assessment (PSQI) and measures of cognition (processing speed, memory, verbal fluency) will be significantly correlated and those with mTBI history will have reduced cognitive-linguistic performance compared to healthy controls. <h3>Design</h3> Retrospective, cross-sectional study. <h3>Setting</h3> Academic medical center. <h3>Participants</h3> Community-dwelling adults with (n=16) and without mTBI (n=23) were included in the sample. Inclusion criteria: age 18-55, native English speaker, normal to corrected vision and hearing. Exclusion criteria: history of neurological diseases (except mTBI), diagnosed speech or language disorder, presence of sleep disorders, and medications that may affect the brain. Individuals with mTBI were included if they met established clinical criteria for mTBI. <h3>Interventions</h3> N/A. <h3>Main Outcome Measures</h3> Measures included the Pittsburgh Sleep Quality Index (PSQI), WAIS-IV Symbol Search/Coding Tasks, Control Oral Word Association Task (COWAT) and NIH Toolbox Cognition Battery. Demographic and injury information was collected via an intake form. Neurobehavioral symptoms were measured using the Neurobehavioral Symptom Inventory (NSI). <h3>Results</h3> An independent samples t-test revealed significantly different PQSI, t(37) = 2.011, p = 0.026. and NSI, t(20.665) = 2.634, p = 0.008 group differences. No significant differences in verbal fluency, processing speed, or NIH cognitive scores were observed. Sleep quality (global PSQI score) and processing speed performance were found to be moderately negatively correlated, r(39)= -.357, p< 0.05 (1-tailed). <h3>Conclusions</h3> Results of this study indicate that sleep quality is an important measure to consider in the clinical assessment and management of mTBI-related cognitive-communication disorders. Future research should include objective measures of sleep when examining cognitive-linguistic performance in individuals with mTBI. <h3>Author(s) Disclosures</h3> There are no conflicts of interest to disclose.

Cognitive performance of patients with opioid use disorder transitioned to extended-release injectable naltrexone from buprenorphine: Post hoc analysis of exploratory results of a phase 3 randomized controlled trial

BackgroundOpioid use disorder (OUD) is associated with cognitive dysfunction. Understanding how pharmacotherapy may affect cognition is an important treatment consideration. MethodsThis was a hybrid residential-outpatient, randomized trial assessing transition regimens (naltrexone/buprenorphine [NTX/BUP] vs placebo-NTX/buprenorphine [PBO-N]/BUP) to extended-release naltrexone (XR-NTX) in patients with OUD seeking BUP discontinuation. Cognition was assessed at baseline, Day 22 (XR-NTX Day 14), and Day 36 (XR-NTX Day 28) using a range of measures (Brief Assessment of Cognition Symbol Coding test, Controlled Oral Word Association Task, Wechsler Memory Scale-III Spatial Span test, Continuous Performance Test, and Test of Attentional Performance). Pre-specified exploratory analyses compared treatment groups. Post hoc analyses were treatment-arm–independent analyses overall and by baseline BUP dose (<8 mg/day [low-dose] or 8 mg/day [higher-dose]). ResultsBaseline cognitive measures were similar between NTX/BUP and PBO-N/BUP groups and between BUP low-dose and higher-dose groups. There were improvements in several cognitive outcomes at Day 22 and Day 36 relative to baseline for the overall population, but no differences between NTX/BUP and PBO-N/BUP treatment groups were observed. Participants entering the study on low-dose BUP showed improvements at Day 36 relative to baseline in 5 of 7 cognitive outcomes; participants entering the study on higher-dose BUP generally did not show improvements in cognitive outcomes. ConclusionsImprovements in most cognitive domains were associated with the transition from BUP to XR-NTX, particularly in participants entering the study on low-dose (<8 mg/day) BUP. These improvements may be due to the discontinuation of BUP, the treatment with XR-NTX, or both.

Association Between Polygenic Risk Score for Schizophrenia and Neurocognitive Measures in the Western Australian Family Study of Schizophrenia (Wafss)

Background Schizophrenia (SZ) is a clinically heterogeneous disorder with multifactorial causes including a significant genetic contribution. Recent, large scale GWAS have described a polygenic risk score (PRS) for SZ which accounts for ~ 7% of variation on the liability scale (Bulik-Sullivan et al, 2015). The aim of this study was to ascertain whether the PRS also contributed to a range of psychological measures which are associated with SZ. Methods Our cohort comprised a set of 127 multiplex families recruited through a proband with SZ (n=536 including 161 SZ cases) and a control group of 30 unaffected families (n=121). We examined neurocognitive measures across 6 domains: General cognitive ability (National Adult Reading Test & Shipley Institute of Living Scale IQ); verbal learning and memory (Rey Auditory Verbal Learning Test); sustained attention (Continuous Performance Task, degraded stimulus and identical pairs); speed of information processing (inspection time); executive function (Controlled Oral Word Association Task) and personality factors (Schizotypal Personality Questionnaire & Temperament and Character Inventory) (Hallmayer et al, 2005). Whole genome sequence (WGS) data (Illumina 10X platform, 15X coverage) were available for a subset of the multiplex families (n=320). We mapped all 102,636 PRS SNPs to the called WGS data by rsID; 97,507 passed QC and were used to calculate a PRS for each individual (Purcell et al, 2009). Correlation between PRS and each neurocognitive measure was conducted in SOLAR adjusting for the relationship matrix, age, sex and educational attainment. Results In the multiplex families, all psychological measures were associated with SZ in the expected direction (FDR corrected at α 0.05). Comparison with the control families showed that the Shipley measure of current IQ, and the identical pairs measure of sustained attention were significantly impaired in unaffected relatives of those with SZ compared the healthy control cohort (FDR-corrected at α 0.05) indicating a shared genetic component with SZ. PRS was significantly correlated with the identical pairs task, both inspection time tasks, and personality measures after FDR correction with the expected direction of effect. Discussion Recent studies have shown associations between PRS and neurocognitive measures in healthy populations, including IQ measures in a population based sample of children (Hubbard et al 2016) and working memory in young adults (Hatzimanolis et al 2015). Our findings add to these data and support the presence of shared common genetic factors between SZ and measures of sustained attention, speed of information processing and personality factors in a familial cohort with SZ. This information may help to inform the selection of endophenotypes for SZ.

Dopamine pathway gene variants may modulate cognitive performance in the DHS - Mind Study.

BackgroundThere is an established association between type 2 diabetes and accelerated cognitive decline. The exact mechanism linking type 2 diabetes and reduced cognitive function is less clear. The monoamine system, which is extensively involved in cognition, can be altered by type 2 diabetes status. Thus, this study hypothesized that sequence variants in genes linked to dopamine metabolism and associated pathways are associated with cognitive function as assessed by the Digit Symbol Substitution Task, the Modified Mini‐Mental State Examination, the Stroop Task, the Rey Auditory‐Verbal Learning Task, and the Controlled Oral Word Association Task for Phonemic and Semantic Fluency in the Diabetes Heart Study, a type 2 diabetes‐enriched familial cohort (n = 893).MethodsTo determine the effects of candidate variants on cognitive performance, genetic association analyses were performed on the well‐documented variable number tandem repeat located in the 3' untranslated region of the dopamine transporter, as well as on single‐nucleotide polymorphisms covering genes in the dopaminergic pathway, the insulin signaling pathway, and the convergence of both. Next, polymorphisms in loci of interest with strong evidence for involvement in dopamine processing were extracted from genetic datasets available in a subset of the cohort (n = 572) derived from Affymetrix® Genome‐Wide Human SNP Array 5.0 and 1000 Genomes imputation from this array.ResultsThe candidate gene analysis revealed one variant from the DOPA decarboxylase gene, rs10499695, to be associated with poorer performance on a subset of Rey Auditory‐Verbal Learning Task measuring retroactive interference (P = 0.001, β = −0.45). Secondary analysis of genome‐wide and imputed data uncovered another DOPA decarboxylase variant, rs62445903, also associated with retroactive interference (P = 7.21 × 10−7, β = 0.3). These data suggest a role for dopaminergic genes, specifically a gene involved in regulation of dopamine synthesis, in cognitive performance in type 2 diabetes.

The relationship between habitual physical activity status and executive function in individuals with Alzheimer’s disease: a longitudinal, cross-lagged panel analysis

To determine whether habitual physical activity status specifically influences executive function change in Alzheimer’s disease (AD) over 1 year. In this longitudinal cohort study, 45 participants with AD were recruited and provided follow-up data approximately 1 year later. Executive function measures (map search task, digit symbol substitution task, controlled oral word association task, verbal fluency task) and habitual physical activity measures (Physical Activity Scale for the Elderly (PASE) and handgrip strength) were taken at baseline and follow-up. Individual composites were subsequently created. Additional demographic, lifestyle, and neuropsychiatric measures were also taken. In a structural equation model (χ2(26) = 9.84, p = .998, comparative fit index = 1.00, root mean square error of approximation = .00), a significant association was found between habitual physical activity and executive function change (β = .27, p = .04). In a cross-lagged panel analysis, a significant path was found between the PASE score and executive change (β = .22, p = .01). As higher habitual physical activity levels were associated with reduced executive function change, the promotion of low-intensity habitual physical activities in individuals with a diagnosis of AD may be warranted. Further research is needed, however, to explore the impact of habitual physical activity on the trajectory of change across cognitive domains, and how this relates to the progression of the underlying pathology associated with this disease.

Neurocognition and Duration of Psychosis: A 10-year Follow-up of First-Episode Patients.

A substantial proportion of schizophrenia-spectrum patients exhibit a cognitive impairment at illness onset. However, the long-term course of neurocognition and a possible neurotoxic effect of time spent in active psychosis, is a topic of controversy. Furthermore, it is of importance to find out what predicts the long-term course of neurocognition. Duration of untreated psychosis (DUP), accumulated time in psychosis the first year after start of treatment, relapse rates and symptoms are potential predictors of the long-term course. In this study, 261 first-episode psychosis patients were assessed neuropsychologically on one or more occasions. Patients were tested after remission of psychotic symptoms and reassessed 1, 2, 5, and 10 years after inclusion. The neurocognitive battery consisted of California Verbal Learning Test, Wisconsin Card Sorting Test, Controlled Oral Word Association Task, Trail Making A and B, and Finger Tapping. We calculated a composite score by adding the z-scores of 4 tests that were only moderately inter-correlated, not including Finger Tapping. Data were analyzed by a linear mixed model. The composite score was stable over 10 years. No significant relationship between psychosis before (DUP) or after start of treatment and the composite score was found, providing no support for the neurotoxicity hypothesis, and indicating that psychosis before start of treatment has no significant impact on the course and outcome in psychosis. We found no association between symptoms and the neurocognitive trajectory. Stable remission during the first year predicted neurocognitive functioning, suggesting that the early clinical course is a good predictor for the long-term course.

Neuroprotection in the Aftermath of a First Episode of Mania.

Objectives Despite cognition being normal or even superior tocontrols prior to a first episode of mania, there is a decline in cognitivecapacity that is arguably steepest in the interval after a first episode ofmania. What is unclear, is the extent to which this can be prevented and whichagents might be most useful for doing so. Methods This study reports the outcomes of a single-blind, randomised control trial of maintenance therapy with lithium compared toquetiapine after a first episode of mania. Cognition and structural imagingwere the primary endpoints. Results This study examined a number of paper and pencil tests ofneurocognition as well as a computerised battery including Cogstate andPresentation. Tests used include the Wechsler Test of Adult Reading, the WechslerAbbreviated Scale of Intelligence, Digit Span and Digit Symbol sub-tests of the Wechsler Adult Intelligence Scale – III, Trail Making Test, Rey Auditory VerbalLearning Test, Controlled Oral Word Association Task, Attention Network Test, Go-Nogoand Stroop Tasks. Results of this study will be presented. Conclusions Given that cognition is a major symptomatic domain ofbipolar disorder and has substantive effects on quality of life, functioningand symptomatic outcomes, the ability to influence the trajectory of cognitivechange is of considerable clinical importance.

Validity of a screening tool for detecting subtle cognitive impairment in the middle-aged and elderly.

The present study tested 121 middle-aged and elderly community-dwelling individuals on the computer-based Subtle Cognitive Impairment Test (SCIT) and compared their performance with that on several neuropsychological tests. The SCIT had excellent internal consistency, as demonstrated by a high split-half reliability measure (0.88–0.93). Performance on the SCIT was unaffected by the confounding factors of sex, education level, and mood state. Many participants demonstrated impaired performance on one or more of the neuropsychological tests (Controlled Oral Word Association Task, Rey Auditory and Verbal Learning Task, Grooved Pegboard [GP], Complex Figures). Performance on SCIT subtests correlated significantly with performance on many of the neuropsychological subtests, and the best and worst performing quartiles on the SCIT subtest discriminated between good and poor performers on other subtests, collectively indicating concurrent validity of the SCIT. Principal components analysis indicated that SCIT performance does not cluster with performance on most of the other cognitive tests, and instead is associated with decision-making efficacy, and processing speed and efficiency. Thus, the SCIT is responsive to the processes that underpin multiple cognitive domains, rather than being specific for a single domain. Since the SCIT is quick and easy to administer, and is well tolerated by the elderly, it may have utility as a screening tool for detecting cognitive impairment in middle-aged and elderly populations.

Placebo sleep affects cognitive functioning.

The placebo effect is any outcome that is not attributed to a specific treatment but rather to an individual's mindset (Benson & Friedman, 1996). This phenomenon can extend beyond its typical use in pharmaceutical drugs to involve aspects of everyday life, such as the effect of sleep on cognitive functioning. In 2 studies examining whether perceived sleep quality affects cognitive functioning, 164 participants reported their previous night's sleep quality. They were then randomly assigned to 1 of 2 sleep quality conditions or 2 control conditions. Those in the "above average" sleep quality condition were informed that they had spent 28.7% of their total sleep time in REM, whereas those in the "below average" sleep quality condition were informed that they had only spent 16.2% of their time in REM sleep. Assigned sleep quality but not self-reported sleep quality significantly predicted participants' scores on the Paced Auditory Serial Addition Test and Controlled Oral Word Association Task. Assigned sleep quality did not predict participants' scores on the Digit Span task, as expected, nor did it predict scores on the Symbol Digit Modalities Test, which was unexpected. The control conditions showed that the findings were not due to demand characteristics from the experimental protocol. These findings supported the hypothesis that mindset can influence cognitive states in both positive and negative directions, suggesting a means of controlling one's health and cognition.

Heritability and genetic association analysis of cognition in the Diabetes Heart Study

Cognitive performance is an important component of healthy aging. Type 2 diabetes (T2D) is associated with negative outcomes for the brain and cognition, although causal mechanisms have not been definitely determined. Genetic risk factors warrant further consideration in this context. This study examined the heritability of cognitive function as assessed by (1) the Digit Symbol Substitution Task; (2) the Modified Mini-Mental State Examination; (3) the Stroop Task; (4) the Rey Auditory-Verbal Learning Task; and (5) the Controlled Oral Word Association Task for Phonemic and Semantic Fluency, in the family-based, T2D-enriched, Diabetes Heart Study sample (n = 550 participants from 257 families). The genetic basis of these cognitive measures was further evaluated by association analysis with candidate single-nucleotide polymorphisms (SNPs) and genome-wide SNP data. Measures of cognitive function were significantly heritable (hˆ2 = 0.28–0.62) following adjustment for age, gender, and education. A total of 31 SNPs (from 26 genes/regions) selected to form an a priori set of candidate SNPs showed limited evidence of association with cognitive function when applying conservative metrics of significance. Genome-wide assessment of both noncoding and coding variants revealed suggestive evidence of association for several coding variants including rs139509083 in CNST (p = 4.9 × 10−9), rs199968569 in PLAA (p = 4.9 × 10−9) and rs138487371 in PCDH8 (p = 3.7 × 10−8). The identification of a heritable component to cognitive performance in T2D suggests a role for genetic contributors to cognitive performance even in the presence of metabolic disease and other associated comorbidities and is supported by the identification of genetic association signals in functionally plausible candidates.

Grey Matter Correlates of Three Language Tests in Non-demented Older Adults

Language has been extensively investigated by functional neuroimaging studies. However, only a limited number of structural neuroimaging studies have examined the relationship between language performance and brain structure in healthy adults, and the number is even less in older adults. The present study sought to investigate correlations between grey matter volumes and three standardized language tests in late life. The participants were 344 non-demented, community-dwelling adults aged 70-90 years, who were drawn from the population-based Sydney Memory and Ageing Study. The three language tests included the Controlled Oral Word Association Task (COWAT), Category Fluency (CF), and Boston Naming Test (BNT). Correlation analyses between voxel-wise GM volumes and language tests showed distinctive GM correlation patterns for each language test. The GM correlates were located in the right frontal and left temporal lobes for COWAT, in the left frontal and temporal lobes for CF, and in bilateral temporal lobes for BNT. Our findings largely corresponded to the neural substrates of language tasks revealed in fMRI studies, and we also observed a less hemispheric asymmetry in the GM correlates of the language tests. Furthermore, we divided the participants into two age groups (70-79 and 80-90 years old), and then examined the correlations between structural laterality indices and language performance for each group. A trend toward significant difference in the correlations was found between the two age groups, with stronger correlations in the group of 70-79 years old than those in the group of 80-90 years old. This difference might suggest a further decline of language lateralization in different stages of late life.

A comparison of the anticipated and pharmacological effects of alcohol on cognitive bias, executive function, craving and ad-lib drinking

Acute alcohol administration alters automatic processing of alcohol-related cues, impairs executive functions and increases alcohol seeking. Few studies have investigated the effects of expecting to receive alcohol on these measures. Thirty-one social drinkers completed three experimental sessions receiving either 0.65 g/kg alcohol, a placebo and a control beverage (which they knew was not alcoholic) before reporting craving and completing a test battery including a measure of automatic alcohol-approach tendencies (stimulus response compatibility task), a measure of executive function (Controlled Oral Word Association Task (COWAT)) and a taste test assessing ad-lib drinking. Results indicated that alcohol administration impaired performance on the COWAT and increased ad-lib drinking; however, there were no significant differences on these measures after administration of placebo versus control beverages. Craving was increased after alcohol and (to a lesser extent) after placebo. Automatic alcohol-approach tendencies were pronounced after both alcohol and placebo compared to the control beverage, with no difference between alcohol and placebo. Results suggest craving is sensitive to the anticipated and pharmacological effects of alcohol, alcohol-approach tendencies are particularly sensitive to the anticipated effects of alcohol, and measures of executive function and ad-lib drinking are affected by the pharmacological, but not the anticipated, effects of alcohol.

Cognitive and behavioral effects of lamotrigine and carbamazepine monotherapy in patients with newly diagnosed or untreated partial epilepsy

Purpose In this prospective study, we compared the long-term cognitive and behavioral effects of lamotrigine (LTG) and carbamazepine (CBZ) in patients with newly diagnosed or untreated partial epilepsy. Methods This was a multicenter, open-label, randomized study that compared monotherapy with LTG and CBZ in newly diagnosed or untreated patients with partial epilepsy. We employed an 8-week titration period and a 40-week maintenance period. Neuropsychological tests, Symptom Check List-90, and QOLIE-31 were assessed at baseline, 16 weeks, and 48 weeks after drug treatment. A group-by-time interaction was the primary outcome measure and was analyzed by use of the linear mixed model. Results A total of 110 patients were eligible and 73 completed the 48-week study (LTG, n = 39; CBZ, n = 34). Among the cognitive tests, significant group-by-time interaction was identified only in phonemic fluency of Controlled Oral Word Association Task ( p = 0.0032) and Stroop Color–Word Interference ( p = 0.0283), with a significant better performance for LTG group. All other neuropsychological tests included did not show significant group-by-time interactions. Among the subscales of Symptom Check List-90, significant group-by-time interactions were identified in Obsessive-Compulsive ( p = 0.0005), Paranoid Ideation ( p = 0.0454), Global Severity Index ( p = 0.0194), and Positive Symptom Total ( p = 0.0197), with a significant improvement for CBZ group. QOLIE-31 did not show significant group-by-time interactions. Conclusion Our data suggest that epilepsy patients on LTG have better performance on phonemic fluency and the task of Stroop Color–Word Interference than do patients on CBZ, whereas patients on CBZ had more favorable behavioral effects on two subscales and two global scores of Symptom Check List-90 than did patients on LTG.

The effects of perceived emotional distress on language performance in intractable epilepsy

We evaluated the potential moderating effect of emotional distress (Minnesota Multiphasic Personality Inventory 2, scales D and Pt) on language functioning (i.e., Boston Naming Test, phonemic paraphasic error production on the Boston Naming Test, Controlled Oral Word Association Task, Animal Naming, Token Test) in patients with left ( N = 43) and right ( N = 34) mesial temporal lobe epilepsy (MTLE) and frontal lobe epilepsy (FLE) ( N = 30). Video/EEG and brain imaging results confirmed localization. Logistic regression models revealed that perceived emotional distress moderated language performance. Performance of patients with left MTLE and that of patients with FLE were equally poor across language measures. Performance of patients with right MTLE was intact. Depression and anxiety differentially moderated performance. Anxiety was associated with better performance in patients with FLE on classically temporal lobe-mediated tasks (Boston Naming Test). Depression was associated with worse language performance on measures for which impaired performance was traditionally intrinsic to the underlying epileptogenic lesion (word fluency in FLE) . Emotional distress influences language performance. Adequate treatment of mood should be considered when managing pharmacoresistant epilepsy.

Age-Related Differences in Performance of Phonemic Verbal Fluency Measured by Controlled Oral Word Association Task (COWAT): A Meta-Analytic Study

Meta-analytical procedures were used to examine the research findings on age-related changes in phonemic verbal fluency measured by the Controlled Oral Word Association Task (COWAT). Data from 26 studies comparing adults from different age ranges were analyzed. An effect of aging was found in almost all age comparisons especially after 40 years of age. Results revealed a decline of this verbal ability after 60 years, which accelerates through the late 80s. Gender may influence COWAT performance after the sixth decade, favoring women over men. These results may be important in clinical situations where COWAT is used to assert pathological changes.

Cognitive effects of lamotrigine compared with topiramate in patients with epilepsy

To compare the cognitive effects of lamotrigine vs topiramate as adjunctive therapy in adults with epilepsy. A multicenter, double-blind, randomized, prospective study was conducted in adults with partial seizures. Lamotrigine or topiramate was introduced as an adjunctive therapy to carbamazepine or phenytoin and titrated over 8 weeks to target doses. These drugs were maintained another 8 weeks (maintenance phase) without dosage changes. The primary endpoint was change from screening to the end of the maintenance phase in a combined analysis of standardized measures of cognition (Controlled Oral Word Association Task [COWA]; Stroop Color-Word Interference; Digit Cancellation; Lafayette Grooved Pegboard, dominant hand; Rey Auditory Verbal Learning Test, delayed recall; and Symbol-Digit Modalities test). For the primary endpoint, cognitive performance at the end of the maintenance phase was better with lamotrigine than with topiramate (415.3 vs 315.1; p < 0.001). On the individual cognitive tests, performance was better with lamotrigine than with topiramate in mean changes from screening on the COWA (p < 0.001), Stroop Color-Word Interference (p = 0.038), and Symbol-Digit Modalities tests (p < 0.001). The treatment effect exceeded the minimum clinically important difference for the COWA and the Symbol-Digit Modalities test. Mean changes from screening in the Performance-On-Line test simulating driving skills reflected better performance with lamotrigine than with topiramate (p = 0.021). The median percentage change from baseline in seizure frequency was lower with lamotrigine than with topiramate during the escalation phase (-80% vs -100%; p = 0.028) but not during the maintenance phase (-75% vs -100%; p = 0.062). The frequencies of cognitive adverse events and of premature withdrawals related to cognitive decline were higher with topiramate than with lamotrigine (6% vs 0%; p = 0.013). Lamotrigine had significantly less impact than topiramate on measures of cognition when used as adjunctive therapy for partial seizures.

Executive Functions in Persons with Sleep Apnea.

Seventeen patients with sleep apnea syndrome [SAS, Respiratory Disturbance Index (RDI) = 12-85] were compared with 16 normal controls (RDI < 7) on neuropsychological tests of executive functions, a domain in which SAS patients have been suggested to have deficits. SAS patients demonstrated greater deficits in the retrieval of information from semantic memory (Controlled Oral Word Association task) and in shifting responses in the face of error (Wisconsin Card Sort Test), but differences in working memory were not observed. Eliciting deficits in cognitive executive functions in SAS may require more sensitive measures than are typically used in neuropsychiatric research.

Tapping, talking and the thalamus: Possible influence of the intralaminar nuclei on basal ganglia function

A patient with a discrete lesion of the left, intralaminar thalamic, nuclei exhibited a paradoxical finding with regard to finger-tapping. Normal subjects typically reduce their tapping rate when performing simultaneous verbal activity. Tapping was impaired in our patient's contralesional hand on baseline trials; however, performing the controlled oral word association (COWA) task, while finger-tapping, normalized her deficit. Subsequent experiments showed that motoric tasks rather than cognitive aspects of the COWA task were critical in potentiating finger-tapping performance. A SPECT study performed at rest revealed focal perfusion asymmetries in motor and premotor cortices. Because the caudal intralaminar nuclei project heavily to the striatum, striatal deafferentiation may account for these asymmetries. These observations provide some insight into the influences of the caudal intralaminar thalamic nuclei on basal ganglia function and the basal ganglia's influence on motor gating.