Topological Aberrance of Structural Brain Network Provides Quantitative Substrates of Post-Traumatic Brain Injury Attention Deficits in Children

Background: Traumatic brain injury (TBI)-induced attention deficits are among the most common long-term cognitive consequences in children. Most of the existing studies attempting to understand the neuropathological underpinnings of cognitive and behavioral impairments in TBI have utilized heterogeneous samples and resulted in inconsistent findings. The current research proposed to investigate topological properties of the structural brain network in children with TBI and their relationship with post-TBI attention problems in a more homogeneous subgroup of children who had severe post-TBI attention deficits (TBI-A). Materials and Methods: A total of 31 children with TBI-A and 35 group-matched controls were involved in the study. Diffusion tensor imaging-based probabilistic tractography and graph theoretical techniques were used to construct the structural brain network in each subject. Network topological properties were calculated in both global level and regional (nodal) level. Between-group comparisons among the topological network measures and analyses for searching brain-behavioral were all corrected for multiple comparisons using Bonferroni method. Results: Compared with controls, the TBI-A group showed significantly higher nodal local efficiency and nodal clustering coefficient in left inferior frontal gyrus and right transverse temporal gyrus, whereas significantly lower nodal clustering coefficient in left supramarginal gyrus and lower nodal local efficiency in left parahippocampal gyrus. The temporal lobe topological alterations were significantly associated with the post-TBI inattentive and hyperactive symptoms in the TBI-A group. Conclusion: The results suggest that TBI-related structural re-modularity in the white matter subnetworks associated with temporal lobe may play a critical role in the onset of severe post-TBI attention deficits in children. These findings provide valuable input for understanding the neurobiological substrates of post-TBI attention deficits, and have the potential to serve as quantitatively measurable criteria guiding the development of more timely and tailored strategies for diagnoses and treatments to the affected individuals. Impact statement This study provides a new insight into the neurobiological substrates associated with post-traumatic brain injury attention deficits (TBI-A) in children, by evaluating topological alterations of the structural brain network. The results demonstrated that relative to group-matched controls, the children with TBI-A had significantly altered nodal local efficiency and nodal clustering coefficient in temporal lobe, which strongly linked to elevated inattentive and hyperactive symptoms in the TBI-A group. These findings suggested that white matter structural re-modularity in subnetworks associated with temporal lobe may serve as quantitatively measurable biomarkers for early prediction and diagnosis of post-TBI attention deficits in children.

Altered cortical activation and connectivity patterns for visual attention processing in young adults post-traumatic brain injury: A functional near infrared spectroscopy study

AIMS

This study aimed at understanding the neurobiological mechanisms associated with inattention induced by traumatic brain injury (TBI). To eliminate the potential confounding caused by the heterogeneity of TBI, we focused on young adults postsports-related concussion (SRC).

METHODS

Functional near-infrared spectroscopy (fNIRS) data were collected from 27 young adults post-SRC and 27 group-matched normal controls (NCs), while performing a visual sustained attention task. Task responsive cortical activation maps and pairwise functional connectivity among six regions of interest were constructed for each subject. Correlations among the brain imaging measures and clinical measures of attention were calculated in each group.

RESULTS

Compared to the NCs, the SRC group showed significantly increased brain activation in left middle frontal gyrus (MFG) and increased functional connectivity between right inferior occipital cortex (IOC) bilateral calcarine gyri (CG). The left MFG activation magnitude was significantly negatively correlated with the hyperactive/impulsive symptom severity measure in the NCs, but not in the patients. The right hemisphere CG-IOC functional connectivity showed a significant positive correlation with the hyperactive/impulsive symptom severity measure in patients, but not in NCs.

CONCLUSION

The current data suggest that abnormal left MFG activation and hyper-communications between right IOC and bilateral CG during visual attention processing may significantly contribute to behavioral manifestations of attention deficits in patients with TBI.

Neuropsychological outcomes of standard risk and high risk patients treated for acute lymphoblastic leukemia on Dana-Farber ALL consortium protocol 95-01 at 5 years post-diagnosis

BACKGROUND

Children treated for acute lymphoblastic leukemia (ALL) as High Risk (HR) patients may be more vulnerable to neurocognitive late effects because of the greater intensity of their therapy. We compared neuropsychological outcomes in children treated for Standard Risk (SR) or HR ALL on Dana-Farber Cancer Institute (DFCI) Consortium ALL Protocol 95-01. We also evaluated their performance relative to normative expectations.

PROCEDURE

Between 1996 and 2000, 498 children with newly diagnosed ALL were treated on Protocol 95-01, 298 of whom were eligible for neuropsychological follow-up. A feature of this protocol was modification of risk group criteria to treat more children as SR rather than HR patients, intended to minimize toxicities. Testing was completed at a median of 5.3 years post-diagnosis for 211 patients (70.8%; ages 6-25 years; 45.5% male; 40% HR), all of whom were in continuous complete remission.

RESULTS

Test scores for both groups were generally at or above normative expectation, with the exception of verbal working memory, processing complex visual information, and parent ratings of metacognitive skills. After adjusting for covariates, the SR group performed better on measures of IQ and academic achievement, working memory and visual learning. Effect sizes, however, were only in the small to moderate range.

CONCLUSIONS

HR patients exhibited neuropsychological deficits relative to SR patients, though the differences were modest in degree. Modification of the risk group criteria to treat more children on the SR protocol therefore likely afforded some benefit in terms of neurocognitive late effects.

Neuropsychological outcomes from a randomized trial of triple intrathecal chemotherapy compared with 18 Gy cranial radiation as CNS treatment in acute lymphoblastic leukemia: findings from Dana-Farber Cancer Institute ALL Consortium Protocol 95-01

PURPOSE

We evaluated late neuropsychological toxicity in children treated for standard-risk acute lymphoblastic leukemia (ALL) who were randomly assigned to receive either cranial radiation therapy (CRT) with double intrathecal (IT) chemotherapy or intensive triple IT chemotherapy (no CRT) as CNS-directed therapy.

PATIENTS AND METHODS

Between 1996 and 2000, 164 children with standard-risk ALL treated on Dana-Farber Cancer Institute Consortium Protocol 95-01 were randomly assigned to receive either 18 Gy CRT delivered in twice daily fractions (0.9 [DOSAGE ERROR CORRECTED] Gy) with double IT therapy (methotrexate and cytarabine) or intensive triple IT drug (methotrexate, cytarabine and hydrocortisone) without CRT. Neuropsychological testing was completed at a median 6 years postdiagnosis for 79 children (CRT, n = 39; triple IT, n = 40), all of whom were in continuous complete remission.

RESULTS

Cognitive function for both groups was solidly in the average range, with no consistent group differences in basic cognitive skills. Children treated on the CRT plus double IT arm did, however, exhibit less fluent output and were less effective at modulating their behavior by parent report.

CONCLUSION

This randomized trial revealed only subtle differences 6 years after diagnosis between children who received CNS therapy as CRT plus double IT drug or as intensive triple IT drug. In most situations where comparable therapeutic efficacy can be achieved without CRT, it is preferable to do so. Where therapeutically necessary, however, CRT at lower doses may not add risk for significant neurotoxicity.

Outcomes of a Randomized Trial of Hyperfractionated Cranial Radiation Therapy for Treatment of High-Risk Acute Lymphoblastic Leukemia: Therapeutic Efficacy and Neurotoxicity

Purpose

We evaluated 8-year survival and late neuropsychologic toxicity in children with acute lymphoblastic leukemia treated in a randomized clinical trial to test whether hyperfractionated (twice daily) cranial radiation therapy (CRT) can reduce incidence and severity of late toxicities associated with 18 Gy of CRT.

Patients and Methods

Between 1987 and 1995, 369 children treated on two consecutive Dana-Farber Cancer Institute Consortium protocols for high-risk acute lymphoblastic leukemia were randomly assigned to conventionally fractionated CRT (CFX) or hyperfractionated CRT (HFX) to a total dose of 18 Gy. Neuropsychologic testing was completed for 125 of 287 children in continuous complete remission. Event-free and overall survival, as well as neuropsychologic function, were compared for the two arms of the protocol.

Results

Eight-year event-free survival (± SE) was 80% ± 3% for children randomly assigned to CFX and 72% ± 3% for HFX (P = .06). Overall survival was 85% ± 3% for CFX and 78% ± 3% for HFX (P = .06). CNS relapses occurred in 2.8% of patients receiving CFX and 2.7% receiving HFX (P = .99). Cognitive function for both groups was solidly in the average range, with no group differences in intelligence, academic achievement, visuospatial reasoning, or verbal learning. Children on the HFX arm exhibited a modest advantage for visual memory (P < .05).

Conclusion

HFX provides no benefit in terms of cognitive late effects and may compromise antileukemic efficacy. HFX should not be substituted for conventionally dosed CRT in children who require radiation therapy for treatment of acute lymphoblastic leukemia.

Parental distress during pediatric leukemia and posttraumatic stress symptoms (PTSS) after treatment ends

OBJECTIVE

To evaluate prospectively the association between parental anxiety during treatment for childhood leukemia and posttraumatic stress symptoms (PTSS) after treatment ends. A secondary goal is to explore concurrent variables associated with parental avoidance after treatment ends.

METHODS

This is a longitudinal follow-up study of 113 parents of children treated for leukemia who previously participated in a study of procedural distress during treatment. Data included parental self-report questionnaires completed during treatment and after treatment.

RESULTS

Using hierarchical multiple regression, we found anxiety during treatment to be a significant predictor of later PTSS for mothers, but not fathers. Anxiety, self-efficacy, posttraumatic growth and length of time since treatment ended were associated with parental avoidance.

CONCLUSIONS

Highly anxious parents are at risk for PTSS and may benefit from approaches that decrease anxiety during treatment and afterward. Enhancing self-efficacy related to follow-up care and identifying positive aspects of the traumatic experiences are suggested as treatment approaches for families after cancer treatment.

[Intestinal hemorrhage as cause of late death in a patient with abdominal aortic prosthesis]

Intestinal bleeding from abdominal aortic aneurysm is a rare complication; it represents an exceptional occurrence in patients with abdominal aortic prosthesis. The Authors report one case of intestinal hemorrhage caused by interruption in the posterior suture-line between prosthesis and aorta. The hemorrhage has been the cause of death in this patient 4 months after the operation; the exact diagnosis has been recognized only at autopsy, after a gastroduodenal resection performed for a suspected bleeding peptic ulcer. Pathology, ethiology and diagnosis of this case are commented and discussed.