Simultaneous Damage of the Cingulate Cortex Zone II and Fronto-Striatal Circuit Causes Prolonged Selective Attentional Deficits

White matter tracts and executive functions: a review of causal and correlation evidence

Executive functions are high-level cognitive processes involving abilities such as working memory/updating, set-shifting and inhibition. These complex cognitive functions are enabled by interactions among widely distributed cognitive networks, supported by white matter tracts. Executive impairment is frequent in neurological conditions affecting white matter; however, whether specific tracts are crucial for normal executive functions is unclear. We review causal and correlation evidence from studies that used direct electrical stimulation during awake surgery for gliomas, voxel-based and tract-based lesion-symptom mapping, and diffusion tensor imaging to explore associations between the integrity of white matter tracts and executive functions in healthy and impaired adults. The corpus callosum was consistently associated with all executive processes, notably its anterior segments. Both causal and correlation evidence showed prominent support of the superior longitudinal fasciculus to executive functions, notably to working memory. More specifically, strong evidence suggested that the second branch of the superior longitudinal fasciculus is crucial for all executive functions, especially for flexibility. Global results showed left lateralization for verbal tasks and right lateralization for executive tasks with visual demands. The frontal aslant tract potentially supports executive functions, however, additional evidence is needed to clarify whether its involvement in executive tasks goes beyond the control of language. Converging evidence indicates that a right-lateralized network of tracts connecting cortical and subcortical grey matter regions supports the performance of tasks assessing response inhibition, some suggesting a role for the right anterior thalamic radiation. Finally, correlation evidence suggests a role for the cingulum bundle in executive functions, especially in tasks assessing inhibition. We discuss these findings in light of current knowledge about the functional role of these tracts, descriptions of the brain networks supporting executive functions and clinical implications for individuals with brain tumours.

An exploration of neural predictors of treatment compliance in cognitive-behavioral group therapy for hoarding disorder

A persistent and influential barrier to effective cognitive-behavioral therapy (CBT) for patients with hoarding disorder (HD) is treatment retention and compliance. Recent research has suggested that HD patients have abnormal brain activity identified by functional magnetic resonance (fMRI) in regions often engaged for executive functioning (e.g., right superior frontal gyrus, anterior insula, and anterior cingulate), which raises questions about whether these abnormalities could relate to patients' ability to attend, understand, and engage in HD treatment. We examined data from 74 HD-diagnosed adults who completed fMRI-measured brain activity during a discarding task designed to elicit symptom-related brain dysfunction, exploring which regions' activity might predict treatment compliance variables, including treatment engagement (within-session compliance), homework completion (between-session compliance), and treatment attendance. Brain activity that was significantly related to within- and between-session compliance was found largely in insula, parietal, and premotor areas. No brain regions were associated with treatment attendance. The results add to findings from prior research that have found prefrontal, cingulate, and insula activity abnormalities in HD by suggesting that some aspects of HD brain dysfunction might play a role in preventing the engagement needed for therapeutic benefit.

Is the deficit in attention-deficit/hyperactivity disorder a concentration deficit?

Attention-deficit/hyperactivity disorder (ADHD) is comprised of two behavioral clusters of symptoms, inattention and hyperactivity/impulsivity. Numerous studies have attempted to address the underlying neuropsychological mechanism of ADHD. However, there is still no uniform mechanism that can fully explain both inattention and hyperactivity/impulsivity symptoms. This review describes the research findings that have shifted the focus from cognitive selective attention to executive function deficits and notes that the prominence of the attention deficit remains unclear. As ADHD is not consistently explained by cognitive selective attention but rather with cognitive sustained attention/vigilance and executive function deficits, this review suggests that concentration deficit is likely the cause of inattention symptoms. Indeed, considering concentration deficit as the cause of inattention symptoms may better describe the underlying difficulties of maintaining and controlling attention in ADHD. In addition, as concentration, impulsivity, and hyperactivity may share a common cognitive deficit, this shift in focus may help in identifying a single mechanism for all ADHD symptoms.

Glioblastomas at the white matter of temporo-parietal junction cause a poor postoperative independence level

INTRODUCTION

Right cerebral hemispheric glioblastomas (GBMs) often decrease the Karnofsky performance status (KPS) score postoperatively, despite the patient having sufficient patient function while performing daily living. This study aimed to evaluate the factors that could cause poor KPS scores during the postoperative chronic phase in patients with right cerebral hemispheric GBMs.

METHODS

Data of 47 patients with newly diagnosed right cerebral hemispheric GBMs were analyzed. All patients were assessed preoperatively and 3 months postoperatively to determine KPS and brain function. To determine tumor location related to the postoperative KPS scores, we used voxel-based lesion symptom mapping (VLSM). The patients were divided into two groups (involvement and non-involvement groups) based on whether their lesion involved a significant region identified by VLSM. We then compared functional factors and prognosis between the groups using the chi-squared and log-rank tests, respectively.

RESULTS

The KPS score significantly decreased after surgery compared to that preoperatively measured (p = 0.023). VLSM revealed that tumors in the white matter of temporo-parietal junction (WM-TPJ) caused a significant decline in the KPS score at three months postoperatively. The patients in the involvement group had a higher probability of impaired attention, visuospatial cognition, emotion recognition, and visual field than did those in the non-involvement group. In addition, tumor in the WM-TPJ were associated with shorter progression-free survival and overall survival (p = 0.039 and 0.023, respectively).

CONCLUSIONS

GBMs involving the right WM-TPJ are more likely to result in poor postoperative KPS scores and prognoses. Impairments of several kinds of brain functions caused by tumor invasion to the WM-TPJ may be associated with lower KPS scores.

Surgical techniques and function outcome for cingulate gyrus glioma, how we do it

Objective

Cingulate cortex and cingulum both play crucial roles in limbic system. The aim of study is to observe and analyze surgical outcomes of cingulate gyrus glioma through extents of resection (EORs), overall survival (OS), and postsurgical neurological outcome.

Method

The authors retrospectively studied 95 consecutive adult cases of primary cingulate gliomas that all underwent craniotomies and tumor resection. The patients were classified into unitary sub-region based on the four-division model. The information of clinical symptoms, pathology, EOR, postoperative neurological outcome and survival were analyzed through group comparison.

Result

Low-grade gliomas (LGGs) were more prevalent (69.47%) for cingulate gyrus. Diffuse astrocytoma (40.00%) was most common histopathological diagnosis in total. Regarding sub-regions tumor involved in, midcingulate cortex (MCC) glioma was most prevalent (54.74%) followed by anterior cingulate cortex (ACC) glioma. Among all patients, 83 patients (87.37%) received EOR ≥ 90%. In LGG group, 58 patients (87.88%) received EOR ≥ 90%. The achievement of EOR significantly correlated with survival (P = 0.006). MCC cases were significantly associated with short-term morbidity in either language or motor function (P = 0.02). Majority of ACC cases (80.65%) escaped from any short-term deficits and nearly 90% free for permanent morbidity. Tumors in the dominant hemisphere were significantly associated with language dysfunction or cognition dysfunction, either short-term (P=0.0006) or long-term morbidity (P=0.0111). Age was the only postoperative susceptible predictor for all types of transient (P=0.021) and permanent (P=0.02) neurological deficit.

Conclusion

Regarding cingulate gyrus glioma, the management of surgical plans could be carried out into four sub-region level. In spite of short-term neurological dysfunction caused by surgical procedure, majority of transient dysfunction could be relieved or recovered in long-term. The necessary effort to prolong overall survival is still to achieve advisable EOR.