Changes in neurocognitive functioning and quality of life in adult patients with brain tumors treated with radiotherapy

Lomustine overdose in a patient with diffuse glioma: symptoms, management and outcome

A male patient started PCV chemotherapy (a combination of procarbazine, lomustine and vincristine) for a recurrent oligodendroglioma grade 2. Unfortunately, our patient took an unintended overdose of lomustine during the first PCV course: instead of 160 mg absolute dose of lomustine on day 1 only, he consumed 160 mg absolute dose of lomustine for seven consecutive days to a total dose of 1120 mg. Pancytopenia became evident after 24 days, and several months of severe myelosuppression, infections, reduced general condition, and nutrition difficulties followed. Fortunately, our patient with time recovered his bone marrow function. However, the patient's quality of life was reduced for a long time and several lessons were learnt: oral and written information on chemotherapy is essential, but not always sufficient to ensure the correct dosing of patient-administered chemotherapy. Oral chemotherapeutics should be delivered as a single-dose supply or be administered by experienced health personnel.

CACNA1B protects naked mole-rat hippocampal neuron from apoptosis via altering the subcellular localization of Nrf2 after 60Co irradiation

Although radiotherapy is the most effective treatment modality for brain tumors, it always injures the central nervous system, leading to potential sequelae such as cognitive dysfunction. Radiation induces molecular, cellular, and functional changes in neuronal and glial cells. The hippocampus plays a critical role in learning and memory; therefore, concerns about radiation-induced injury are widespread. Multiple studies have focused on this complex problem, but the results have not been fully elucidated. Naked mole rat brains were irradiated with 60Co at a dose of 10 Gy. On 7 days, 14 days, and 28 days after irradiation, hippocampi in the control groups were obtained for next-generation sequencing. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were subsequently performed. Venn diagrams revealed 580 differentially expressed genes (DEGs) that were common at different times after irradiation. GO and KEGG analyses revealed that the 580 common DEGs were enriched in molecular transducer activity. In particular, CACNA1B mediated regulatory effects after irradiation. CACNA1B expression increased significantly after irradiation. Downregulation of CACNA1B led to a reduction in apoptosis and reactive oxygen species levels in hippocampal neurons. This was due to the interaction between CACNA1B and Nrf2, which disturbed the normal nuclear localization of Nrf2. In addition, CACNA1B downregulation led to a decrease in the cognitive functions of naked mole rats. These findings reveal the pivotal role of CACNA1B in regulating radiation-induced brain injury and will lead to the development of a novel strategy to prevent brain injury after irradiation.

The role of particle radiotherapy in the treatment of skull base tumors

The skull base is an anatomically and functionally critical area surrounded by vital structures such as the brainstem, the spinal cord, blood vessels, and cranial nerves. Due to this complexity, management of skull base tumors requires a multidisciplinary approach involving a team of specialists such as neurosurgeons, otorhinolaryngologists, radiation oncologists, endocrinologists, and medical oncologists. In the case of pediatric patients, cancer management should be performed by a team of pediatric-trained specialists. Radiation therapy may be used alone or in combination with surgery to treat skull base tumors. There are two main types of radiation therapy: photon therapy and particle therapy. Particle radiotherapy uses charged particles (protons or carbon ions) that, due to their peculiar physical properties, permit precise targeting of the tumor with minimal healthy tissue exposure. These characteristics allow for minimizing the potential long-term effects of radiation exposure in terms of neurocognitive impairments, preserving quality of life, and reducing the risk of radio-induced cancer. For these reasons, in children, adolescents, and young adults, proton therapy should be an elective option when available. In radioresistant tumors such as chordomas and sarcomas and previously irradiated recurrent tumors, particle therapy permits the delivery of high biologically effective doses with low, or however acceptable, toxicity. Carbon ion therapy has peculiar and favorable radiobiological characteristics to overcome radioresistance features. In low-grade tumors, proton therapy should be considered in challenging cases due to tumor volume and involvement of critical neural structures. However, particle radiotherapy is still relatively new, and more research is needed to fully understand its effects. Additionally, the availability of particle therapy is limited as it requires specialized equipment and expertise. The purpose of this manuscript is to review the available literature regarding the role of particle radiotherapy in the treatment of skull base tumors.

Radiation-Induced Brain Injury: Age Dependency of Neurocognitive Dysfunction Following Radiotherapy

Cranial radiotherapy is a known risk factor for neurocognitive impairment in cancer survivors. Although radiation-induced cognitive dysfunction is observed in patients of all ages, children seem to be more vulnerable than adults to suffering age-related deficits in neurocognitive skills. So far, the underlying mechanisms by which IR negatively influences brain functions as well as the reasons for the profound age dependency are still insufficiently known. We performed a comprehensive Pubmed-based literature search to identify original research articles that reported on age dependency of neurocognitive dysfunction following cranial IR exposure. Numerous clinical trials in childhood cancer survivors indicate that the severity of radiation-induced cognitive dysfunction is clearly dependent on age at IR exposure. These clinical findings were related to the current state of experimental research providing important insights into the age dependency of radiation-induced brain injury and the development of neurocognitive impairment. Research in pre-clinical rodent models demonstrates age-dependent effects of IR exposure on hippocampal neurogenesis, radiation-induced neurovascular damage and neuroinflammation.

Investigating survival, quality of life and cognition in PROton versus photon therapy for IDH-mutated diffuse grade 2 and 3 GLIOmas (PRO-GLIO): a randomised controlled trial in Norway and Sweden

INTRODUCTION

The use of proton therapy increases globally despite a lack of randomised controlled trials demonstrating its efficacy and safety. Proton therapy enables sparing of non-neoplastic tissue from radiation. This is principally beneficial and holds promise of reduced long-term side effects. However, the sparing of seemingly non-cancerous tissue is not necessarily positive for isocitrate dehydrogenase (IDH)-mutated diffuse gliomas grade 2-3, which have a diffuse growth pattern. With their relatively good prognosis, yet incurable nature, therapy needs to be delicately balanced to achieve a maximal survival benefit combined with an optimised quality of life.

METHODS AND ANALYSIS

PRO-GLIO (PROton versus photon therapy in IDH-mutated diffuse grade 2 and 3 GLIOmas) is an open-label, multicentre, randomised phase III non-inferiority study. 224 patients aged 18-65 years with IDH-mutated diffuse gliomas grade 2-3 from Norway and Sweden will be randomised 1:1 to radiotherapy delivered with protons (experimental arm) or photons (standard arm). First intervention-free survival at 2 years is the primary endpoint. Key secondary endpoints are fatigue and cognitive impairment, both at 2 years. Additional secondary outcomes include several survival measures, health-related quality of life parameters and health economy endpoints.

ETHICS AND DISSEMINATION

To implement proton therapy as part of standard of care for patients with IDH-mutated diffuse gliomas grade 2-3, it should be deemed safe. With its randomised controlled design testing proton versus photon therapy, PRO-GLIO will provide important information for this patient population concerning safety, cognition, fatigue and other quality of life parameters. As proton therapy is considerably more costly than its photon counterpart, cost-effectiveness will also be evaluated. PRO-GLIO is approved by ethical committees in Norway (Regional Committee for Medical & Health Research Ethics) and Sweden (The Swedish Ethical Review Authority) and patient inclusion has commenced. Trial results will be published in international peer-reviewed journals, relevant conferences, national and international meetings and expert forums.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT05190172).

Financial toxicity among adolescent and young adult cancer survivors: A systematic review of educational attainment, employment, and income

PURPOSE

To identify, evaluate and summarize the evidence on educational attainment, employment status and income of AYAs surviving cancer.

METHODS

A search of six databases for articles published between 01/01/2010 and 03/31/2022 was performed. Articles with an AYA survivorship population, quantitative design and a cancer-free comparator group were included. Data extraction was conducted, and quality appraisal was completed using ROBINS-I. Results were summarized using a narrative synthesis.

RESULTS

A total of 2801 articles were identified, of which 12 were included. Among the limited evidence, educational attainment did not differ from cancer-free peers. Survivors were more likely to be unemployed, have lower incomes and require social security for income supplementation. Evidence suggested that females, diagnosis of brain cancer and the presence of late-effects were among the risk factors for severe outcomes.

CONCLUSIONS

Limited socioeconomic evidence exists for AYAs surviving cancer. Long-lasting financial toxicities occur and highlights a need for further investigation.

Clinical Outcomes and Prognostic Analysis of 101 Patients of Central Neurocytoma: A 10-Year Treatment Experience at a Single Institution

Objective

Central neurocytoma (CN) is a rare type of tumor that currently lacks an optimal treatment protocol. This study aimed to explore the clinical outcomes of CN in a cohort of 101 patients and identify prognostic factors associated with multiple treatment modalities.

Methods

This monocentric study retrospectively analyzed the clinical data of 101 CN patients who underwent surgical resection. The patients were followed up, and their overall survival (OS) and progression-free survival (PFS) were calculated.

Results

For the entire cohort, the 5- and 10-year OS rates were 88.7% and 82.8%, respectively, and the 5- and 10-year PFS rates were 86.5% and 64.9%, respectively. Of the 82 (81.19%) patients with CN who underwent gross total resection (GTR), 28 (28/82, 34.1%) also received radiotherapy (RT). Of the 19 (18.81%) patients with CN who underwent subtotal resection (STR), 11 (11/19, 57.9%) also received RT or stereotactic radiosurgery (SRS). Compared to STR, GTR significantly improved the 5-year OS (92.4% vs. 72.4%, P=0.011) and PFS (92.4% vs. 60.4%, P=0.009) rates. Radiotherapy did not affect OS in the GTR group (p=0.602), but it had a statistically significant effect on OS in the STR group (P<0.001). However, the OS (P=0.842) and PFS (P=0.915) in the STR plus radiotherapy group were comparable to those in the GTR alone group. Compared to STR alone, STR plus radiotherapy improved the 5-year PFS rate from 25% to 75% in patients with atypical CN (P=0.004). Cox regression models and a competing risk model showed that the removal degree and radiotherapy were independent prognostic factors for survival. With improvements in modern radiotherapy techniques, severe radiotherapy toxicity was not observed.

Conclusion

Our findings support the use of GTR whenever possible. Radiotherapy can improve the prognosis of patients who undergo STR, especially in atypical CNs having a higher tendency to relapse. Close imaging follow-up is necessary. Our findings will help clinicians to select optimal, individualized treatment strategies to improve OS and PFS for patients with CN.

Prediction Models for Radiation-Induced Neurocognitive Decline in Adult Patients With Primary or Secondary Brain Tumors: A Systematic Review

Purpose

Although an increasing body of literature suggests a relationship between brain irradiation and deterioration of neurocognitive function, it remains as the standard therapeutic and prophylactic modality in patients with brain tumors. This review was aimed to abstract and evaluate the prediction models for radiation-induced neurocognitive decline in patients with primary or secondary brain tumors.

Methods

MEDLINE was searched on October 31, 2021 for publications containing relevant truncation and MeSH terms related to “radiotherapy,” “brain,” “prediction model,” and “neurocognitive impairments.” Risk of bias was assessed using the Prediction model Risk Of Bias ASsessment Tool.

Results

Of 3,580 studies reviewed, 23 prediction models were identified. Age, tumor location, education level, baseline neurocognitive score, and radiation dose to the hippocampus were the most common predictors in the models. The Hopkins verbal learning (n = 7) and the trail making tests (n = 4) were the most frequent outcome assessment tools. All studies used regression (n = 14 linear, n = 8 logistic, and n = 4 Cox) as machine learning method. All models were judged to have a high risk of bias mainly due to issues in the analysis.

Conclusion

Existing models have limited quality and are at high risk of bias. Following recommendations are outlined in this review to improve future models: developing cognitive assessment instruments taking into account the peculiar traits of the different brain tumors and radiation modalities; adherence to model development and validation guidelines; careful choice of candidate predictors according to the literature and domain expert consensus; and considering radiation dose to brain substructures as they can provide important information on specific neurocognitive impairments.

Irradiated microvascular endothelial cells may induce bystander effects in neural stem cells leading to neurogenesis inhibition

Radiation-induced neurocognitive dysfunction (RIND) has attracted a lot of attention lately due to the significant improvement of the survival of cancer patients after receiving cranial radiotherapy. The detailed mechanisms are not completely understood, but extensive evidence supports an involvement of the inhibition of hippocampal neurogenesis, which may result from radiation-induced depletion of neural stem cells (NSCs) as well as the damage to neurogenic niches. As an important component of neurogenic niches, vascular cells interact with NSCs through different signaling mechanisms, which is similar to the characteristics of radiation-induced bystander effect (RIBE). But whether RIBE is involved in neurogenesis inhibition contributed by the damaged vascular cells is unknown. Thus, the purpose of the present study was to investigate the occurrence of RIBEs in non-irradiated bystander NSCs induced by irradiated bEnd.3 vascular endothelial cells in a co-culture system. The results show that compared with the NSCs cultured alone, the properties of NSCs were significantly affected after co-culture with bEnd.3 cells, and further change was induced without obvious oxidative stress and apoptosis when bEnd.3 cells were irradiated, manifesting as a reduction in the proliferation, neurosphere-forming capability and differentiation potential of NSCs. All these results suggest that the damaged vascular endothelial cells may contribute to neurogenesis inhibition via inducing RIBEs in NSCs, thus leading to RIND.

Neuroanatomical changes seen in MRI in patients with cerebral metastasized breast cancer after radiotherapy

Purpose:

To quantify neuroanatomical changes using magnetic resonance imaging (MRI) in patients with cerebral metastasized breast cancer after brain radiotherapy (RT).

Methods:

Fifteen patients with breast cancer with brain metastases who underwent whole brain RT (WBR), radiosurgery (RS), and/or hypofractionated stereotactic treatment (STX) were examined at four time points (TPs). A total of 48 MRIs were available: prior to RT (TP1), 5–8 months after RT (TP2), 9–11 months after RT (TP3), and >20 months after RT (TP4). Using automatic segmentation, 25 subcortical structures were analyzed. Patients were split into three groups: STX (receiving STX and RS), RS (receiving RS only), and WBR (receiving WBR at least once). After testing for a normal distribution for all values using the Kolmogorov-Smirnov test, a two-sided paired t test was used to analyze volumetric changes. For those values that were not normally distributed, the nonparametric Mann-Whitney test was employed.

Results:

The left cerebellum white matter (p = 0.028), the right pallidum (p = 0.038), and the left thalamus (p = 0.039) significantly increased at TP2 compared to TP1. The third ventricle increased at all TPs (p = 0.034–0.046). The left choroid plexus increased at TP3 (p = 0.037) compared to TP1. The left lateral ventricle increased at TP3 (p = 0.012) and TP4 (p = 0.027). Total gray matter showed a trend of volume decline in STX and WBR groups.

Conclusions:

These findings indicate that alterations in the volume of subcortical structures may act as a sensitive parameter when evaluating neuroanatomical changes and brain atrophy due to radiotherapy. Differences observed for patients who received STX and WBR, but not those treated with RS, need to be validated further.

Graph Theoretical Analysis of Brain Network Characteristics in Brain Tumor Patients: A Systematic Review

Graph theory is a branch of mathematics that allows for the characterization of complex networks, and has rapidly grown in popularity in network neuroscience in recent years. Researchers have begun to use graph theory to describe the brain networks of individuals with brain tumors to shed light on disrupted networks. This systematic review summarizes the current literature on graph theoretical analysis of magnetic resonance imaging data in the brain tumor population with particular attention paid to treatment effects and other clinical factors. Included papers were published through June 24^th, 2020. Searches were conducted on Pubmed, PsycInfo, and Web of Science using the search terms (graph theory OR graph analysis) AND (brain tumor OR brain tumour OR brain neoplasm) AND (MRI OR EEG OR MEG). Studies were eligible for inclusion if they: evaluated participants with a primary brain tumor, used graph theoretical analyses on structural or functional MRI data, MEG, or EEG, were in English, and were an empirical research study. Seventeen papers met criteria for inclusion. Results suggest alterations in network properties are often found in people with brain tumors, although the directions of differences are inconsistent and few studies reported effect sizes. The most consistent finding suggests increased network segregation. Changes are most prominent with more intense treatment, in hub regions, and with factors such as faster tumor growth. The use of graph theory to study brain tumor patients is in its infancy, though some conclusions can be drawn. Future studies should focus on treatment factors, changes over time, and correlations with functional outcomes to better identify those in need of early intervention.

Health-related quality of life in patients with primary brain tumors during and three months after treatment with proton beam therapy

Background

Proton beam therapy (PBT) is increasingly administered to patients with primary brain tumors. Benefits of new treatments must be weighed against side effects and possible deterioration in health-related quality of life (HRQoL). The aim of this study was to describe and compare HRQoL, including acute symptom experiences and associated factors, in patients with malignant and benign brain tumors treated with PBT.

Materials and Methods

Adult PBT-treated patients with primary brain tumors (n = 266) were studied. HRQoL was assessed with EORTC QLQ-C30, QLQ-BN20, HADS, ISI and MFI before, during and three months after treatment. Associations with demographic and medical factors were explored.

Results

Between baseline and three months post-treatment: HRQoL decreased significantly in the global health/QOL domains physical functioning, role functioning and cognitive functioning in the malignant group, global health/QOL and physical functioning decreased significantly in the benign group, more comorbidity was significantly associated with increased motor dysfunction, leg weakness, headache and future uncertainty. Fatigue and depression were the most frequent symptoms in both groups. Independent predictors of risk factor recognition were age, sex, chemotherapy, comorbidity and education level.

Discussion

Global health/QOL in patient with brain tumors is very complex and multidimensional. Symptoms are interrelated and related to patient, tumor and treatment factors. It is important to identify aspects of HRQoL that may be affected by treatment. These include both benefits, expected to improve HRQoL, and negative changes such as symptom experience and influencing factors. Evidence-based guidelines are needed for symptom management, and for high quality of care for patients experiencing low PBT-related HRQoL.

Reduction of pTau and APP levels in mammalian brain after low-dose radiation

Brain radiation can occur from treatment of brain tumors or accidental exposures. Brain radiation has been rarely considered, though, as a possible tool to alter protein levels involved in neurodegenerative disorders. We analyzed possible molecular and neuropathology changes of phosphorylated-Tau (pTau), all-Tau forms, β-tubulin, amyloid precursor protein (APP), glial fibrillary acidic protein (GFAP), ionized calcium binding adaptor molecule 1 (IBA-1), myelin basic protein (MBP), and GAP43 in Frontal Cortex (FC), Hippocampus (H) and Cerebellum (CRB) of swine brains following total-body low-dose radiation (1.79 Gy). Our data show that radiated-animals had lower levels of pTau in FC and H, APP in H and CRB, GAP43 in CRB, and higher level of GFAP in H versus sham-animals. These molecular changes were not accompanied by obvious neurohistological changes, except for astrogliosis in the H. These findings are novel, and might open new perspectives on brain radiation as a potential tool to interfere with the accumulation of specific proteins linked to the pathogenesis of various neurodegenerative disorders.

Radiation-induced bystander effects may contribute to radiation-induced cognitive impairment

PURPOSE

Despite being a major treatment modality for brain cancer due to its efficiency in achieving cancer control, radiotherapy has long been known to cause long-term side effects, including radiation-induced cognitive impairment (RICI). Neurogenesis inhibition due to radiation-induced damage in neural stem cells (NSCs) has been demonstrated to be an important mechanism underlying RICI. Radiation-induced bystander effects (RIBEs) denote the biological responses in non-targeted cells after their neighboring cells are irradiated. We have previously demonstrated that RIBEs could play an important role in the skin wound healing process. Therefore, we aimed to investigate whether RIBEs contribute to RICI in this study.

MATERIALS AND METHODS

The transwell co-culture method was used to investigate bystander effects in mouse NSCs induced by irradiated GL261 mouse glioma cells in vitro. The proliferation, neurosphere-forming capacity and differentiation potential of NSCs were determined as the bystander endpoints. The exosomes were extracted from the media used to culture GL261 cells and were injected into the hippocampus of C57BL/6 mice. Two months later, the neurogenesis of mice was assessed using BrdU incorporation and immunofluorescence microscopy, and cognitive function was evaluated by the Morris Water Maze.

RESULTS

After co-culture with GL261 glioma cells, mouse NSCs displayed inhibited proliferation and reduced neurosphere-forming capacity and differentiation potential. The irradiated GL261 cells caused greater inhibition and reduction in NSCs than unirradiated GL261 cells. Moreover, adding the exosomes secreted by GL261 cells into the culture of NSCs inhibited NSC proliferation, suggesting that the cancer cell-derived exosomes may be critical intercellular signals. Furthermore, injection of the exosomes from GL261 cells into the hippocampus of mice caused significant neurogenesis inhibition and cognitive impairment two month later, and the exosomes from irradiated GL261 cells induced greater inhibitory effects.

CONCLUSION

RIBEs mediated by the exosomes from irradiated cancer cells could contribute to RICI and, therefore, could be a novel mechanism underlying RICI.

The Art of Living With Symptoms: A Qualitative Study Among Patients With Primary Brain Tumors Receiving Proton Beam Therapy

Symptom management in conjunction with proton beam therapy (PBT) from patient's perspective has not been explored. Such knowledge is essential to optimize the care in this relatively new treatment modality.

Brain irradiation leads to persistent neuroinflammation and long-term neurocognitive dysfunction in a region-specific manner

Long-term cognitive deficits are observed after treatment of brain tumors or metastases by radiotherapy. Treatment optimization thus requires a better understanding of the effects of radiotherapy on specific brain regions, according to their sensitivity and interconnectivity. In the present study, behavioral tests supported by immunohistology and magnetic resonance imaging provided a consistent picture of the persistent neurocognitive decline and neuroinflammation after the onset of irradiation-induced necrosis in the right primary somatosensory cortex of Fischer rats. Necrosis surrounded by neovascularization was first detected 54 days after irradiation and then spread to 110 days in the primary motor cortex, primary somatosensory region, striatum and right ventricle, resulting in fiber bundle disruption and demyelination in the corpus callosum of the right hemisphere. These structural damages translated into selective behavioral changes including spatial memory loss, disinhibition of anxiety-like behaviors, hyperactivity and pain hypersensitivity, but no significant alteration in motor coordination and grip strength abilities. Concomitantly, activated microglia and reactive astrocytes, accompanied by infiltration of leukocytes (CD45+) and T-cells (CD3+) cooperated to shape the neuroinflammation response. Overall, our study suggests that the slow and gradual onset of cellular damage would allow adaptation in brain regions that are susceptible to neuronal plasticity; while other cerebral structures that do not have this capacity would be more affected. The planning of radiotherapy, adjusted to the sensitivity and adaptability of brain structures, could therefore preserve certain neurocognitive functions; while higher doses of radiation could be delivered to brain areas that can better adapt to this treatment. In addition, strategies to block early post-radiation events need to be explored to prevent the development of long-term cognitive dysfunction.

Development and initial psychometric evaluation of a radiotherapy-related symptom assessment tool, based on data from patients with brain tumours undergoing proton beam therapy

BACKGROUND

Currently, no available tool easily and effectively measures both the frequency, intensity and distress of symptoms among patients receiving radiotherapy. A core symptom set (fatigue, insomnia, pain, appetite loss, cognitive problems, anxiety, nausea, depression, constipation, diarrhoea and skin reaction) has been identified and assessed across oncology research to better understand the pattern of symptoms and treatment side effects.

AIM

The aim was to develop a tool measuring the multiple-symptom experience in patients undergoing radiotherapy and evaluate its psychometric properties (validity, reliability and responsiveness).

DESIGN

This study has a prospective, longitudinal and quantitative design.

METHODS

We developed a patient-reported outcome questionnaire, the Radiotherapy-Related Symptoms Assessment Scale to assess the frequency, intensity and distress associated with symptoms. Patients (n = 175) with brain tumours undergoing proton beam therapy completed the Radiotherapy-Related Symptoms Assessment Scale and the health-related quality of life questionnaire (EORTC QLQ-C30) during treatment. We assessed the validity, reliability and responsiveness of the Radiotherapy-Related Symptoms Assessment Scale and evaluated the validity against QLQ-C30.

RESULTS

There were significant questionnaire-questionnaire correlations regarding selected items, primarily fatigue, insomnia and pain, indicating satisfactory criterion-related validity. The Radiotherapy-Related Symptoms Assessment Scale had fair to good retest reliability.

CONCLUSION

The Radiotherapy-Related Symptoms Assessment Scale is a valid instrument for assessing symptom intensity and distress in patients with brain tumour undergoing PBT, with psychometric properties within the expected range. The Radiotherapy-Related Symptoms Assessment Scale provides nurses with substantial information on symptom experience but requires little effort from the patient. Additional studies are required to further assess the psychometric properties in patients with different cancer diagnoses receiving conventional radiotherapy.

A comparison of systematic instruction, error-based learning and trial and error to train the use of smartphone memory apps after acquired brain injury: A three-armed phase II randomised controlled trial study protocol

Background:

The uptake of smartphones as external compensatory memory aids following an acquired brain injury (ABI) in rehabilitation settings is low. Potential reasons for this include professionals not having evidence-based guidelines regarding the best methods to train smartphone use and prospective users not being familiar with technology and/or having memory and learning difficulties. This paper describes the protocol of a study that aims to compare the efficacy of three training methods (Systematic Instruction, Error-based Learning and Trial-and-Error) for training the use of a smartphone reminder app, in people with ABI presenting with memory complaints.

Methods/Design:

This is a three-armed, assessor-blinded, Phase II randomised controlled trial. The estimated sample size is 51 participants aged >18 years, who are equally randomised to one of the three training groups. They are seen across four sessions: one to conduct baseline measures; one for training the use of an app and two for follow-up assessments (1- and 6-weeks post-training). The main outcome measure is proficiency of performance in tasks with the trained app. Secondary outcomes include generalisation of skills to other apps, number of errors committed while attempting the tasks, frequency of smartphone usage in general and as a memory aid and confidence in smartphone use and memory self-efficacy. Outcome measures are collected by an independent blinded assessor. Proficiency of performance, generalisation of skills and error commission are measured immediately post-training and at the two follow-up sessions. The other secondary measures are taken pre-intervention and at the two follow-up sessions.

Discussion:

This study will provide initial evidence regarding the efficacy of three different methods to train ABI survivors with memory difficulties in how to use smartphone apps as compensatory memory aids. The results could inform a larger Phase III trial and advance knowledge concerning the advantages or disadvantages of using error-reducing and trial-and-error techniques. Further, the findings could determine the potential of error-based learning as an emerging training method for people with memory impairment within rehabilitation.

Evaluation of quality of care in relation to health-related quality of life of patients diagnosed with brain tumor: a novel clinic for proton beam therapy

Purpose

Patients with brain tumors constitute a vulnerable group, and it is important that they receive the highest quality of care (QoC). The study aim was to describe the perceptions of QoC and its association with health-related quality of life in brain tumor patients undergoing proton beam therapy in a newly established clinic.

Method

Data were collected at the start of treatment and after 3 and 6 weeks. Adult patients (≥ 18 years old) with brain tumors (n = 186) completed two self-administered questionnaires: a modified Quality from the Patients’ Perspective, which measures perceived reality and subjective importance of care, and the EORTC QLQ-C30. Data were analyzed using parametric and non-parametric statistical tests.

Results

The perceived QoC was highest for treatment information and lowest for dietician and smoking information, whereas interaction with doctors and nurses was rated as the most important aspect of quality of care. Subjective importance ratings were significantly higher than perceived reality ratings for 60% of items. A better global health was moderately correlated with a higher perceived support for fatigue.

Conclusions

A need for quality improvement was identified for several aspects of patient care. Greater symptom distress during the treatment period led to greater perceived importance of symptom support. Ensuring QoC is complex and collaboration with other health care professionals is essential.

Relevance to clinical practice

The clinic could improve QoC regarding information about possible symptoms, adjust care according to patient perceptions of importance, and involve patients in care decisions.

Electronic supplementary material

The online version of this article (10.1007/s00520-018-4557-7) contains supplementary material, which is available to authorized users.

The Feasibility of Integrating Resting-State fMRI Networks into Radiotherapy Treatment Planning

BACKGROUND

Functional magnetic resonance imaging (fMRI) presents the ability to selectively protect functionally significant regions of the brain when primary brain tumors are treated with radiation therapy. Previous research has focused on task-based fMRI of language and sensory networks; however, there has been limited investigation on the inclusion of resting-state fMRI into the design of radiation treatment plans.

METHODS AND MATERIALS

In this pilot study of 9 patients with primary brain tumors, functional data from the default mode network (DMN), a network supporting cognitive functioning, was obtained from resting-state fMRI and retrospectively incorporated into the design of radiation treatment plans. We compared the dosimetry of these fMRI DMN avoidance treatment plans with standard of care treatment plans to demonstrate feasibility. In addition, we used normal tissue complication probability models to estimate the relative benefit of fMRI DMN avoidance treatment plans over standard of care treatment plans in potentially reducing memory loss, a surrogate for cognitive function.

RESULTS

On average, we achieved 20% (P = 0.002) and 12% (P = 0.002) reductions in the mean and maximum doses, respectively, to the DMN without compromising the dose coverage to the planning tumor volume or the dose-volume constraints to organs at risk. Normal tissue complication probability models revealed that when the fMRI DMN was considered during radiation treatment planning, the probability of developing memory loss was lowered by more than 20%.

CONCLUSION

In this pilot study, we demonstrated the feasibility of including rs-MRI data into the design of radiation treatment plans to spare cognitively relevant brain regions during radiation therapy. These results lay the groundwork for future clinical trials that incorporate such treatment planning methods to investigate the long-term behavioral impact of this reduction in dose to the cognitive areas and their neural networks that support cognitive performance.

Cognitive impairment and morphological changes after radiation therapy in brain tumors: A review

Life expectancy of patients treated for brain tumors has lengthened due to the therapeutic improvements. Cognitive impairment has been described following brain radiotherapy, but the mechanisms leading to this adverse event remain mostly unknown. Technical evolutions aim at enhancing the therapeutic ratio. Sparing of the healthy tissues has been improved using various approaches; however, few dose constraints have been established regarding brain structures associated with cognitive functions. The aims of this literature review are to report the main brain areas involved in cognitive adverse effects induced by radiotherapy as described in literature, to better understand brain radiosensitivity and to describe potential future improvements.

Neuropsychological profiles of breast cancer and brain tumor cohorts in Northeast Ontario, Canada

PURPOSE

As developments in cancer treatment have improved outcomes, research has increasingly focused on the role of cancer-related cognitive impairment (CRCI) in quality of life for cancer survivors. Impairment profiles have been heterogeneous across studies, necessitating the study of these effects across different cohorts. The purpose of this preliminary study is to compare the memory profiles of Northeast Ontario breast and CNS cancer patients, as there is no literature which exists for profiling CRCI within this largely rural region.

METHODS

Sixty-three outpatients with breast cancer (n = 32) or CNS tumors (n = 30) at the Northeast Cancer Centre in Sudbury, Canada, were administered a neuropsychological test battery as part of their clinical examination. Domains measured within this study included attention and concentration, processing speed, motor function, language skills, verbal and visual memory, and executive functioning.

RESULTS

Participants with brain tumors scored poorer on most neuropsychological measures than participants with breast cancer. Initial verbal memory for individuals with breast cancer was lower than delayed recall and recognition trials. Trial 1 performance for this group was also negatively correlated with self-reported anxiety scores.

CONCLUSIONS

Consistent with the literature, participants with breast cancer obtained higher scores on most test measures than participants with CNC tumors. Breast cancer participants had lower verbal memory scores on initial trials compared to delayed recall, potentially due to relationships with anxiety and attention. Further research into this cohort will strive to gain greater understanding of the patterns of deficits experienced and how these may inform individuals with cancer in other regions.

[Cognitive deficits following brain tumor radiation therapy]

Brain radiation is an important treatment option for malignant and benign brain diseases. The possible acute or chronic impact of radiation therapy on cognitive performance is important for daily functioning and quality of life. A detailed evaluation of cognitive impairment is important in the context of how to control disease progression. The susceptibility of the hippocampus to radiation-induced neuronal damage and its important role in memory highlight that therapeutic strategies require precision medicine.

Neuroinflammation-Induced Memory Deficits Are Amenable to Treatment with D-Cycloserine

Cognitive deficits, especially memory loss, are common following many types of brain insults which are associated with neuroinflammation, although the underlying mechanisms are not entirely clear. The present study aimed to characterize the long-term cognitive and behavioral impairments in a mouse model of neuroinflammation in the absence of other insults and to evaluate the therapeutic potential of D-cycloserine (DCS). DCS is a co-agonist of the NMDA receptor that ameliorates cognitive deficits in models of TBI and stroke. Using a mouse model of global neuroinflammation induced by intracisternal (i.c.) administration of endotoxin (LPS), we found long-lasting microgliosis, memory deficits, impaired LTP, and reduced levels of the obligatory NR1 subunit of the NMDA receptor. A single administration of DCS, 1 day after i.c. LPS reduced microgliosis, reversed the cognitive deficits and restored LTP and NR1 levels. These results demonstrate that neuroinflammation alone, in the absence of trauma or ischemia, can cause persistent (>6 months) memory deficits linked to deranged NNMDA receptor function and suggest a possible role for NMDA co-agonists in reducing the cognitive sequelae of neuroinflammation.

Cognitive outcome after radiotherapy in brain tumor

PURPOSE OF REVIEW

Survival of brain tumor patients has increased with improvements in cancer treatments. However, treatments like radiotherapy can be neurotoxic and thus new end-points in clinical trials, as well as in individual management, have appeared. This article reviews the cognitive outcomes after radiotherapy in brain tumor patients, focusing on radiation-induced impairments, and then discusses actual cognitive assessment limitations.

RECENT FINDINGS

Although physiopathology of radiation-induced cognitive impairments remains elusive, a general course can be described as acute, early-delayed, and late-delayed effects corresponding to different processes. The last is of high interest because the related impairments are irreversible. In this context, a cognitive assessment should be performed as often as possible, but actual tools are unfortunately not developed. Nevertheless, with respect to neuro-oncologic specificities, new cognitive tools could be developed to overcome these limitations.

SUMMARY

Improvements in neuropsychologic assessment for brain tumor patients are urgently needed. A dynamic vision of radiation-induced cognitive impairments appears inevitable and should lead to a change in actual considerations about neurotoxicity follow-up.

Upfront bevacizumab may extend survival for glioblastoma patients who do not receive second-line therapy: an exploratory analysis of AVAglio

BACKGROUND

In this post-hoc, exploratory analysis, we examined outcomes for patients enrolled in the AVAglio trial of front-line bevacizumab or placebo plus radiotherapy/temozolomide who received only a single line of therapy.

METHODS

Patients with newly diagnosed glioblastoma received protocol-defined treatment until progressive disease (PD). Co-primary endpoints were investigator-assessed progression-free survival (PFS) and overall survival (OS). After confirmed PD, patients were treated at the investigators' discretion. PFS/OS were assessed in patients with a PFS event who did not receive post-PD therapy (Group 1) and patients with a PFS event who received post-PD therapy plus patients who did not have a PFS event at the final data cutoff (Group 2). Kaplan-Meier methodology was used. A multivariate Cox proportional hazards model for known prognostic variables was generated.

RESULTS

Baseline characteristics were balanced. In patients with a PFS event who did not receive post-PD therapy (Group 1; n = 225 [24.4% of the intent-to-treat population]), the addition of bevacizumab to radiotherapy/temozolomide resulted in a 3.6-month extension in both median PFS (hazard ratio [HR]: 0.62, P = .0016) and median OS (HR: 0.67, P = .0102). Multivariate analyses supported this OS benefit (HR: 0.66). In the remaining patients (Group 2; n = 696), a 5.2-month PFS extension was observed in bevacizumab-treated patients (HR: 0.61, P < .0001); OS was comparable between the treatment arms (HR: 0.88, P = .1502). No significant differences in safety were observed between the 2 groups.

CONCLUSION

This exploratory analysis suggests that the addition of bevacizumab to standard glioblastoma treatment prolongs PFS and OS for patients with PD who receive only one line of therapy.

EpiBrainRad: an epidemiologic study of the neurotoxicity induced by radiotherapy in high grade glioma patients

Background

Radiotherapy is one of the most important treatments of primary and metastatic brain tumors. Unfortunately, it can involve moderate to severe complications among which leukoencephalopathy is very frequent and implies cognitive deficits such as memory, attention and executive dysfunctions. However, the incidence of this complication is not well established and the risk factors and process are poorly understood. The main objective of the study is to improve knowledge on radio-induced leukoencephalopathy based on pluridisciplinar approaches combining cognitive, biologic, imagery and dosimetric investigations.

Method/Design

The EpiBrainRad study is a prospective cohort study including newly diagnosed high grade gliomas patients treated by radiotherapy and concomitant-adjuvant temozolomide chemotherapy. Patients are included between their surgery and first day of radio-chemotherapy, and the follow-up lasts for 3 years after treatment. Cognitive functioning assessments, specific blood biomarkers measures and magnetic resonance imagery are performed at different moment during the follow-up, and a specific dosimetric assessment of organs involved in the beam fields is performed. Firstly, leukoencephalopathy incidence rate will be estimated in this population. Secondly, correlations between cognitive impairments and dosimetry, biomarkers ranges and anomalies on imagery will be analyzed in order to better understand the onset and evolution of cognitive decrement associated with radiotherapy. Furthermore, a new cognitive test, quickly and easily performed, will be studied to determine its sensibility to detect leukoencephalopathy decrement.

Discussion

With an original multidisciplinary approach, the EpiBrainRad study aims to improve knowledge on radio-induced leukoencephalopathy in order to improve its early diagnosis and prevention. The main challenge is to preserve quality-of-life after cancer treatments which imply to study the incidence of radiation-induced complications and their associated risk factors.

Trial Registration

NCT02544178

Survivorship: cognitive function, version 1.2014

Cognitive impairment is a common complaint among cancer survivors and may be a consequence of the tumors themselves or direct effects of cancer-related treatment (eg, chemotherapy, endocrine therapy, radiation). For some survivors, symptoms persist over the long term and, when more severe, can impact quality of life and function. This section of the NCCN Guidelines for Survivorship provides assessment, evaluation, and management recommendations for cognitive dysfunction in survivors. Nonpharmacologic interventions (eg, instruction in coping strategies; management of distress, pain, sleep disturbances, and fatigue; occupational therapy) are recommended, with pharmacologic interventions as a last line of therapy in survivors for whom other interventions have been insufficient.

Volumetric modulated arc therapy for hippocampal-sparing radiotherapy in transformed low-grade glioma: A treatment planning case report

Timing of radiotherapy for low-grade gliomas is still controversial due to concerns of possible adverse late effects. Prevention of possible late cognitive sequelae by hippocampal avoidance has shown promise in phase II trials. A patient with progressive low-grade glioma with gradual dedifferentiation into anaplastic astrocytoma is presented along with description of radiotherapy planning process attempting to spare the hippocampus. To our knowledge, this is the first described case using volumetric modulated arc technique to spare hippocampus during transformed low-grade glioma radiotherapy. Using modern intensity-modulated radiotherapy systems it is possible to selectively spare hippocampus together with other standard organs at risk. For selected patients, an attempt to spare hippocampus can be considered as long as other dose characteristics are not significantly compromised compared to standard treatment plan created without any effort to avoid hippocampus.

Health-Related Quality of Life of Adolescent and Young Adult Survivors of Central Nervous System Tumors

This article uses qualitative methods to describe the domains of health-related quality of life (HRQoL) that adolescent and young adult (AYA) survivors of central nervous system (CNS) tumors identify as important. Survivors clearly attributed aspects of their current HRQoL to their disease or its treatment. We identified 7 key domains of AYA CNS tumor survivorship: physical health, social well-being, mental health, cognitive functioning, health behaviors, sexual and reproductive health, and support systems. Although most aspects of HRQoL that survivors discussed represented new challenges, there were several areas where survivors pointed out positive outcomes. There is a need for a HRQoL tool designed for this population of survivors, given their unique treatment and survivorship experience. Aspects of HRQoL related to cognition, sexual and reproductive health, health behaviors, and support systems are not typically included in generic HRQoL tools but should be assessed for this population. Developing HRQoL measurement instruments that capture the most significant aspects of HRQoL will improve the ability to track HRQoL in AYA CNS tumor survivors and in the long-term management of common sequelae from CNS tumors and their treatments.

Long-term outcomes of adjuvant radiotherapy after surgical resection of central neurocytoma

Background and purpose

The role of adjuvant radiotherapy for central neurocytomas (CNs) is not clear. Therefore, we aimed to examine the clinical outcomes of treating histologically confirmed CNs with adjuvant RT after surgical resection.

Material and methods

Sixty-three CN patients were retrospectively evaluated: 24 patients underwent gross total resection (GTR); 28, subtotal resection (STR); 9, partial resection (PR), and 2, biopsy (Bx). They underwent adjuvant RT after surgery (median dose, 54 Gy).

Results

The median follow-up was 69 months (15–129 months). The 5-year overall survival (OS) and 5-year progression-free survival (PFS) were 94.4% and 95% after GTR + RT, 96.4% and 100% after STR + RT, and 100% and 90.9% after PR + RT. Only three patients had tumor recurrence: at the primary site at 30 and 24 months in two GTR + PR patients, and dissemination to the spinal cord at 75 months in one STR + RT patient. Thirty-eight (63.3%) patients experienced late neurotoxicity (28, grade 1; 7, grade 2; 3, grade 3). Short-term memory impairment was the most common toxicity.

Conclusions

RT after incomplete resection (IR) led to OS and PFS comparable to those for GTR. Considering the excellent outcomes and limited late toxicity, adjuvant RT maybe a good option for CN patients who undergo IR.

Stereotactic radiosurgery for treatment of brain metastases. A report of the DEGRO Working Group on Stereotactic Radiotherapy

BACKGROUND

This report from the Working Group on Stereotaktische Radiotherapie of the German Society of Radiation Oncology (Deutsche Gesellschaft für Radioonkologie, DEGRO) provides recommendations for the use of stereotactic radiosurgery (SRS) on patients with brain metastases. It considers existing international guidelines and details them where appropriate.

RESULTS AND DISCUSSION

The main recommendations are: Patients with solid tumors except germ cell tumors and small-cell lung cancer with a life expectancy of more than 3 months suffering from a single brain metastasis of less than 3 cm in diameter should be considered for SRS. Especially when metastases are not amenable to surgery, are located in the brain stem, and have no mass effect, SRS should be offered to the patient. For multiple (two to four) metastases--all less than 2.5 cm in diameter--in patients with a life expectancy of more than 3 months, SRS should be used rather than whole-brain radiotherapy (WBRT). Adjuvant WBRT after SRS for both single and multiple (two to four) metastases increases local control and reduces the frequency of distant brain metastases, but does not prolong survival when compared with SRS and salvage treatment. As WBRT carries the risk of inducing neurocognitive damage, it seems reasonable to withhold WBRT for as long as possible.

CONCLUSION

A single (marginal) dose of 20 Gy is a reasonable choice that balances the effect on the treated lesion (local control, partial remission) against the risk of late side effects (radionecrosis). Higher doses (22-25 Gy) may be used for smaller (< 1 cm) lesions, while a dose reduction to 18 Gy may be necessary for lesions greater than 2.5-3 cm. As the infiltration zone of the brain metastases is usually small, the GTV-CTV (gross tumor volume-clinical target volume) margin should be in the range of 0-1 mm. The CTV-PTV (planning target volume) margin depends on the treatment technique and should lie in the range of 0-2 mm. Distant brain recurrences fulfilling the aforementioned criteria can be treated with SRS irrespective of previous WBRT.

Hippocampus sparing in whole-brain radiotherapy. A review

Radiation treatment techniques for whole-brain radiation therapy (WBRT) have not changed significantly since development of the procedure. However, the recent development of novel techniques such as intensity-modulated radiation therapy (IMRT), volumetric-modulated arc therapy (VMAT) and helical tomotherapy, as well as an increasing body of evidence concerning neural stem cells (NSCs) have altered the conventional WBRT treatment paradigm. In this regard, hippocampus-sparing WBRT is a novel technique that aims to spare critical hippocampus regions without compromising tumour control. Published data on this new technique are limited to planning and feasibility studies; data on patient outcome are still lacking. However, several prospective trials to analyse the feasibility of this technique and to document clinical outcome in terms of reduced neurotoxicity are ongoing.

Management of low-grade gliomas: a review of patient-perceived quality of life and neurocognitive outcome

Low-grade glioma (LGG) comprises nearly 20% of all central nervous system glial tumors, with approximately 2000-3000 patients diagnosed annually in the United States. Because of their infiltrative ability and aggressive nature, the average 10-year survival is 30% when <90% of the tumor is resected. Since the 1970s, prognosis for LGGs has improved significantly. This improvement is primarily attributable to earlier diagnoses via magnetic resonance imaging scanning, increased awareness of the more favorable oligo component, technical advances in intraoperative neurosurgery, and stratification for young age. Using a number of prognostic factors, LGGs have been classified into low-risk and high-risk subgroups. Optimal therapy for patients with low-risk, supratentorial grade II glioma remains a highly controversial issue in the neuro-oncology community. The concerns regarding the toxicity of therapy often outweigh the benefits of delaying tumor progression. The recommendation for observation is made without full prospective understanding of the impact of radiologic tumor progression on the quality of life (QOL), neurocognitive function (NCF), seizure control, and functional status of these patients. We present a review of the current knowledge of the management of LGG with emphasis upon patient-reported outcomes of QOL, NCF, and seizure control. We also discuss current clinical trials with proposals to evaluate QOL, NCF, and seizure control in patients undergoing observation alone after newly diagnosed low-risk LGG or treatment options for those patients in the high-risk group.

Long-term evaluation of cognition after glioma surgery in eloquent areas

Preservation of cognition is an important outcome measure in eloquent area glioma surgery. Glioma patients may have pre-operative deficits in one or more cognitive domains which could deteriorate post-operatively. It is assumed that these impairments recover within 3 months; some studies however, still detected cognitive decline. Longer follow-up is necessary to elucidate the conclusive effects of surgery. 45 patients with gliomas (low- and high-grade, but without contrast enhancement at diagnosis) in eloquent areas were assessed pre-operatively, 3 months and 1 year post-operatively with a neuropsychological test-protocol. Patients' performance was compared to normal population and between test-moments. Univariate analyses were performed between cognitive change and tumor-characteristics (localization, grade, volume, extent of resection [EOR]) and treatment-related factors (radio-/chemotherapy). Pre- and post-operatively, impairments were found in all cognitive domains; language, memory, attention and executive functions (p < 0.05). Post-operatively, permanent improvement was observed on a memory test (verbal recall: t = -1.931, p = 0.034), whereas deterioration was found on a language test (category fluency: t = 2.517, p = 0.030). Between 3 months and 1 year, patients improved on 2 language tests (naming: t = -2.781, p = 0.026 and letter fluency: t = -1.975, p = 0.047). There was no influence of tumor- or treatment-related factors on cognitive change. The findings underline the importance of cognitive testing at longer term post-operatively, as cognitive recovery took longer than 3 months, especially within the language domain. However, this longitudinal follow-up study showed that glioma surgery is possible without major long-term damage of cognitive functions. Tumor characteristics and EOR are no additional risk factors for cognitive outcome.

Whole brain radiotherapy: Consequences for personalized medicine

Several studies focusing on brain irradiation are in progress. Reflecting updates of relevant outcomes in palliative treatment of patients suffering from brain metastases, the primary objective of these studies is the evaluation of neurocognitive function and quality of life. Improvements of technology in radiation oncology allows us to spare the hippocampal region while appropriately irradiating other parts of brain tissue. Irradiation of the hippocampus region is likely to lead to manifestations of adverse events with a subsequent impact on patient's quality of life, which is in fact an improper approach in palliative medicine. Ongoing studies evaluate results of hippocampus avoiding radiotherapy compared to standard whole brain radiotherapy. Incorporation of neurocognitive function assessment may result in the confirmation of superiority of sparing the region of hippocampus and thus change current style of providing brain irradiation.

Cranial irradiation alters dendritic spine density and morphology in the hippocampus

Therapeutic irradiation of the brain is a common treatment modality for brain tumors, but can lead to impairment of cognitive function. Dendritic spines are sites of excitatory synaptic transmission and changes in spine structure and number are thought to represent a morphological correlate of altered brain functions associated with hippocampal dependent learning and memory. To gain some insight into the temporal and sub region specific cellular changes in the hippocampus following brain irradiation, we investigated the effects of 10 Gy cranial irradiation on dendritic spines in young adult mice. One week or 1 month post irradiation, changes in spine density and morphology in dentate gyrus (DG) granule and CA1 pyramidal neurons were quantified using Golgi staining. Our results showed that in the DG, there were significant reductions in spine density at both 1 week (11.9%) and 1 month (26.9%) after irradiation. In contrast, in the basal dendrites of CA1 pyramidal neurons, irradiation resulted in a significant reduction (18.7%) in spine density only at 1 week post irradiation. Analysis of spine morphology showed that irradiation led to significant decreases in the proportion of mushroom spines at both time points in the DG as well as CA1 basal dendrites. The proportions of stubby spines were significantly increased in both the areas at 1 month post irradiation. Irradiation did not alter spine density in the CA1 apical dendrites, but there were significant changes in the proportion of thin and mushroom spines at both time points post irradiation. Although the mechanisms involved are not clear, these findings are the first to show that brain irradiation of young adult animals leads to alterations in dendritic spine density and morphology in the hippocampus in a time dependent and region specific manner.