Brain White Matter Microstructure as a Risk Factor for Cognitive Decline After Chemotherapy for Breast Cancer.

PURPOSE: Cognitive decline is frequently observed after chemotherapy. As chemotherapy is associated with changes in brain white matter microstructure, we investigated whether white matter microstructure before chemotherapy is a risk factor for cognitive decline after chemotherapy. METHODS: Neuropsychologic tests were administered before and 6 months (n = 49), 2 years (n = 32), and 3 years (n = 32) after chemotherapy in patients with breast cancer receiving anthracycline-based chemotherapy (BC + CT group), at matched intervals to patients with BC who did not receive systemic therapy (BC - CT group: n = 39, 23, and 19, respectively) and to no-cancer controls (NC group: n = 37, 29, and 28, respectively). Using multivariate normative comparison, we evaluated to what extent the cognitive profiles of patients deviated from those of controls. Fractional anisotropy (FA), derived from magnetic resonance diffusion tensor imaging, was used to measure white matter microstructure before treatment. FA was evaluated as a risk factor for cognitive decline, in addition to baseline age, fatigue, cognitive complaints, and premorbid intelligence quotient. We subsequently ran voxel-wise diffusion tensor imaging analyses to investigate white matter microstructure in specific nerve tracts. RESULTS: Low FA independently predicted cognitive decline early (6 months, P = .013) and late (3 years, P < .001) after chemotherapy. FA did not predict cognitive decline in the BC - CT and NC groups. Voxel-wise analysis indicated involvement of white matter tracts essential for cognitive functioning. CONCLUSION: Low FA may reflect low white matter reserve. This may be a risk factor for cognitive decline after chemotherapy for BC. If validated in future trials, identification of patients with low white matter reserve could improve patient care, for example, by facilitating targeted, early interventions or even by influencing choices of patients and doctors for receiving chemotherapy.

Measuring decline in white matter integrity after systemic treatment for breast cancer: omitting skeletonization enhances sensitivity.

Chemotherapy for non-central nervous system cancers is associated with abnormalities in brain structure and function. Diffusion tensor imaging (DTI) allows for studying in vivo microstructural changes in brain white matter. Tract-based spatial statistics (TBSS) is a widely used processing pipeline in which DTI data are typically normalized to a generic DTI template and then 'skeletonized' to compensate for misregistration effects. However, this approach greatly reduces the overall white matter volume that is subjected to statistical analysis, leading to information loss. Here, we present a re-analysis of longitudinal data previously analyzed with standard TBSS (Menning et al., BIB 2018, 324-334). For our current approach, we constructed a pipeline with an optimized registration method in Advanced Normalization Tools (ANTs) where DTI data are registered to a study-specific, high-resolution T1 template and the skeletonization step is omitted. In a head to head comparison, we show that with our novel approach breast cancer survivors who had received chemotherapy plus or minus endocrine therapy (BC + SYST, n = 26) showed a global decline in overall FA that was not present in breast cancer survivors who did not receive systemic therapy (BC-SYST, n = 23) or women without a cancer diagnosis (no cancer controls, NC, n = 30). With the standard TBSS approach we did not find any group differences. Moreover, voxel-based analysis for our novel pipeline showed a widespread decline in FA in the BC + SYST compared to the NC group. Interestingly, the BC-SYST group also showed a decline in FA compared to the NC group, although in much less voxels. These results were not found with the standard TBSS approach. We demonstrate that a modified processing pipeline makes DTI data more sensitive to detecting changes in white matter integrity in non-CNS cancer patients after treatment, particularly chemotherapy.

Subcortical surface morphometry in substance dependence: An ENIGMA addiction working group study.

While imaging studies have demonstrated volumetric differences in subcortical structures associated with dependence on various abused substances, findings to date have not been wholly consistent. Moreover, most studies have not compared brain morphology across those dependent on different substances of abuse to identify substance-specific and substance-general dependence effects. By pooling large multinational datasets from 33 imaging sites, this study examined subcortical surface morphology in 1628 nondependent controls and 2277 individuals with dependence on alcohol, nicotine, cocaine, methamphetamine, and/or cannabis. Subcortical structures were defined by FreeSurfer segmentation and converted to a mesh surface to extract two vertex-level metrics-the radial distance (RD) of the structure surface from a medial curve and the log of the Jacobian determinant (JD)-that, respectively, describe local thickness and surface area dilation/contraction. Mega-analyses were performed on measures of RD and JD to test for the main effect of substance dependence, controlling for age, sex, intracranial volume, and imaging site. Widespread differences between dependent users and nondependent controls were found across subcortical structures, driven primarily by users dependent on alcohol. Alcohol dependence was associated with localized lower RD and JD across most structures, with the strongest effects in the hippocampus, thalamus, putamen, and amygdala. Meanwhile, nicotine use was associated with greater RD and JD relative to nonsmokers in multiple regions, with the strongest effects in the bilateral hippocampus and right nucleus accumbens. By demonstrating subcortical morphological differences unique to alcohol and nicotine use, rather than dependence across all substances, results suggest substance-specific relationships with subcortical brain structures.

Brain Hyperconnectivity >10 Years After Cisplatin-Based Chemotherapy for Testicular Cancer.

Chemotherapy for testicular cancer (TC) has been associated with neurotoxic effects shortly post-treatment. Late effects of chemotherapy on brain function in this patient group are still unknown. In this study, we investigated differences between patients with and without chemotherapy in functional brain networks at rest and during an affective processing functional magnetic resonance imaging (fMRI) task on average >14 years post-treatment. In addition, we report on changes in cognitive functioning during survivorship by comparing present and previous performance on a neuropsychological test battery on average 11 years earlier (3 years post-treatment). Twenty-eight chemotherapy (43.1 ± 7.5 years) and 23 surgery-only (48.2 ± 9.5 years) TC survivors were examined using neurocognitive tests and 3T-fMRI >10 years after treatment end. Brain functional networks were identified using dual regression independent component analysis. Task fMRI was analyzed using a block design. Standardized domain change scores were calculated for each individual to assess cognitive change. TC patients in the chemotherapy group showed functional hyperconnectivity at rest in the precuneus network, sensory and motor function network, executive control network, and the ventral stream network when compared with surgery-only patients. Furthermore, hypoactivation was found when performing the affective processing task. Cognitive data revealed that both groups showed comparable patterns of change from 3 to 14 years after initial treatment. This study provides novel insights on the possible underlying neurobiological mechanisms of late neurotoxic effects of cisplatin-based chemotherapy. Present findings reveal that functional hyperconnectivity is widespread, possibly to compensate for the pathophysiological disturbances. This concurs with our previous findings of structural hyperconnectivity in white matter. Longitudinal multimodal imaging studies are warranted to further investigate the association between long-term structural and functional network connectivity data, as well as its relationship with cognitive changes.

The development of hypothalamic obesity in craniopharyngioma patients: A risk factor analysis in a well-defined cohort.

BACKGROUND: Hypothalamic obesity (HO) is a major concern in patients treated for craniopharyngioma (CP). The influence of degree of resection on development of HO, event-free survival (EFS), and neuroendocrine sequelae is an issue of debate. PROCEDURE: A retrospective cohort consisting of all CP patients treated between 2002 and 2012 in two university hospitals was identified. Multivariable logistic regression was used to study the associations between preoperative BMI, age at diagnosis, tumor volume, performed surgical resection, and presence of HO at follow-up. RESULTS: Thirty-five patients (21 children and 14 adults) were included. Median follow-up time was 35.6 months (4.1-114.7). Four patients were obese at diagnosis. HO was present in 19 (54.3%) patients at last follow-up of whom eight were morbidly obese. Thirteen (37.1%) patients underwent partial resection (PR) and 22 (62.9%) gross total resection (GTR). GTR was related to HO (OR 9.19, 95% CI 1.43-59.01), but for morbid HO, obesity at diagnosis was the only risk factor (OR 12.92, 95% CI 1.05-158.73). EFS in patients after GTR was 86%, compared to 42% after PR (log-rank 9.2, P = 0.003). Adjuvant radiotherapy after PR improved EFS (log-rank 8.2, P = 0.004). Panhypopituitarism, present in 15 patients, was mainly seen after GTR. CONCLUSIONS: HO is less frequent after PR than after GTR, but PR cannot always prevent the development of morbid obesity in patients with obesity at diagnosis. PR reduces the occurrence of panhypopituitarism. When developing a treatment algorithm, all these factors should be considered.

Changes in brain white matter integrity after systemic treatment for breast cancer: a prospective longitudinal study.

An increasing number of studies suggest chemotherapy for breast cancer may be neurotoxic. Cross-sectional MRI diffusion tensor imaging (DTI) studies suggest a vulnerability of brain white matter to various chemotherapeutic regimens. Up till now, this was confirmed in one prospective DTI study: Deprez et al. (2012) showed a widespread decline in fractional anisotropy (FA) of breast cancer patients after chemotherapy consisting of 5-fluorouracil (5-FU), epirubicin and cyclophosphamide (FEC) +/- taxanes +/- endocrine treatment. Our aim was to evaluate whether similar detrimental effects on white matter integrity would be observed with the currently widely prescribed anthracycline-based chemotherapy for breast cancer (predominantly doxorubicin and cyclophosphamide +/- taxanes +/- endocrine treatment (=BC + SYST; n = 26) compared to no systemic treatment (BC; n = 23) and no-cancer controls (NC; n = 30). Assessment took place before and six months after chemotherapy, and matched intervals for the unexposed groups. DTI data were analyzed using voxel-based tract-based spatial statistics and region of interest (ROI) analysis. Voxel-based analysis did not show an effect of chemotherapy +/- endocrine treatment on white matter integrity. ROI analysis however indicated subtle detrimental effects of chemotherapy +/- endocrine treatment by showing a larger decline in WM integrity in the superior longitudinal fasciculus and corticospinal tract in BC + SYST than BC. Indications for relatively mild neurotoxicity in our study might be explained by patient characteristics and specific aspects of data analysis. The omission of 5-FU in current treatment regimens or the administration of doxorubicin instead of epirubicin is also discussed as an explanation for the observed effects.

Mitochondrial Encephalopathy and Transient 3-Methylglutaconic Aciduria in ECHS1 Deficiency: Long-Term Follow-Up.

We report the major diagnostic challenge in a female patient with signs and symptoms suggestive of an early-onset mitochondrial encephalopathy. Motor and cognitive development was severely delayed and brain MRI showed signal abnormalities in the putamen and caudate nuclei. Metabolic abnormalities included 3-methylglutaconic aciduria and elevated lactate levels in plasma and cerebrospinal fluid, but were transient. Whole exome sequencing at the age of 25 years finally revealed compound heterozygous mutations c.[229G>C];[563C>T], p.[Glu77Gln];[Ala188Val] in the ECHS1 gene. Activity of short-chain enoyl-CoA hydratase, a mitochondrial enzyme encoded by the ECHS1 gene, was markedly decreased in lymphocytes. Retrospective urine analysis confirms that elevated levels of S-(2-carboxypropyl)cysteamine, S-(2-carboxypropyl)cysteine, and N-acetyl-S-(2-carboxypropyl)cysteine can be a diagnostic clue in the disease spectrum of ECHS1 mutations.

d-Cycloserine enhanced extinction of cocaine-induced conditioned place preference is attenuated in serotonin transporter knockout rats.

d-Cycloserine (DCS), a partial NMDA receptor agonist, has been proposed as a cognitive enhancer to facilitate the extinction of drug-related memories. However, it is unknown whether there are individual differences in the efficacy of DCS. Here, we set out to investigate the influence of serotonin transporter (5-HTT) genotype on DCS treatment outcome and the underlying neural mechanism. To that end, we first determined the mRNA levels of several NMDA receptor subunits and observed a reduction in NR1/NR2C receptors in the ventromedial prefrontal cortex and nucleus accumbens of 5-HTT-/- compared with 5-HTT+/+ rats. Based on this finding, we hypothesized a lower sensitivity to DCS in the 5-HTT-/- rats. To test this, rats were trained in a cocaine-induced conditioned place preference (CPP) paradigm. A significant extinction of CPP was observed in 5-HTT+/+ rats receiving 1 mg/kg i.v. DCS, while a similar effect was found in the 5-HTT-/- rats only after 5 mg/kg. Following CPP, we tested if DCS were able to reduce FosB/∆FosB protein expression, a molecular switch for cocaine-seeking behaviour. We observed an overall lower number of FosB/∆FosB positive cells in 5-HTT-/- ventromedial prefrontal cortex and amygdala and an overall effect of DCS treatment on the number of positive cells in the nucleus accumbens. In conclusion, in this study, we show that the dosing of DCS to facilitate the extinction of cocaine-seeking behaviour is, at least partially, determined by 5-HTT genotype.

Prefrontal Glx and GABA concentrations and impulsivity in cigarette smokers and smoking polysubstance users.

Glutamate and GABA play an important role in substance dependence. However, it remains unclear whether this holds true for different substance use disorders and how this is related to risk-related traits such as impulsivity. We, therefore, compared Glx (as a proxy measure for glutamate) and GABA concentrations in the dorsal anterior cingulate cortex (dACC) of 48 male cigarette smokers, 61 male smoking polysubstance users, and 90 male healthy controls, and investigated the relationship with self-reported impulsivity and substance use. Glx and GABA concentrations were measured using proton Magnetic Resonance Spectroscopy. Impulsivity, smoking, alcohol and cocaine use severity and cannabis use were measured using self-report instruments. Results indicate a trend towards group differences in Glx. Post-hoc analyses showed a difference between smokers and healthy controls (p=0.04) and a trend towards higher concentrations in smoking polysubstance users and healthy controls (p=0.09), but no differences between smokers and smoking polysubstance users. dACC GABA concentrations were not significantly different between groups. Smoking polysubstance users were more impulsive than smokers, and both groups were more impulsive than controls. No significant associations were observed between dACC neurotransmitter concentrations and impulsivity and level and severity of smoking, alcohol or cocaine use or the presence of cannabis use. The results indicate that differences in dACC Glx are unrelated to type and level of substance use. No final conclusion can be drawn on the lack of GABA differences due to assessment difficulties. The relationship between dACC neurotransmitter concentrations and cognitive impairments other than self-reported impulsivity should be further investigated.

Changes in brain activation in breast cancer patients depend on cognitive domain and treatment type.

BACKGROUND: Cognitive problems in breast cancer patients are common after systemic treatment, particularly chemotherapy. An increasing number of fMRI studies show altered brain activation in breast cancer patients after treatment, suggestive of neurotoxicity. Previous prospective fMRI studies administered a single cognitive task. The current study employed two task paradigms to evaluate whether treatment-induced changes depend on the probed cognitive domain. METHODS: Participants were breast cancer patients scheduled to receive systemic treatment (anthracycline-based chemotherapy +/- endocrine treatment, n = 28), or no systemic treatment (n = 24) and no-cancer controls (n = 31). Assessment took place before adjuvant treatment and six months after chemotherapy, or at similar intervals. Blood oxygen level dependent (BOLD) activation and performance were measured during an executive functioning task and an episodic memory task. Group-by-time interactions were analyzed using a flexible factorial design. RESULTS: Task performance did not differ between patient groups and did not change over time. Breast cancer patients who received systemic treatment, however, showed increased parietal activation compared to baseline with increasing executive functioning task load compared to breast cancer patients who did not receive systemic treatment. This hyperactivation was accompanied by worse physical functioning, higher levels of fatigue and more cognitive complaints. In contrast, in breast cancer patients who did not receive systemic treatment, parietal activation normalized over time compared to the other two groups. CONCLUSIONS: Parietal hyperactivation after systemic treatment in the context of stable levels of executive task performance is compatible with a compensatory processing account of hyperactivation or maintain adequate performance levels. This over-recruitment of brain regions depends on the probed cognitive domain and may represent a response to decreased neural integrity after systemic treatment. Overall these results suggest different neurobehavioral trajectories in breast cancer patients depending on treatment type.

Cognitive Impairment in a Subset of Breast Cancer Patients After Systemic Therapy-Results From a Longitudinal Study.

CONTEXT: Studies indicate adverse effects of breast cancer (BC) and cancer treatment on cognitive function. OBJECTIVES: To investigate the effects of systemic treatment on cognitive performance in BC patients. METHODS: Participants were BC patients scheduled to receive systemic treatment (BC + SYST; n = 31), or no systemic treatment (BC; n = 24) and no-cancer (NC) controls (n = 33). Neuropsychological examinations were used to study cognitive performance on 18 tests grouped into eight cognitive domains, before adjuvant treatment (T1) and six months after chemotherapy (T2), or at similar intervals. We also assessed health-related quality of life, anxiety and depression, mood, stress, and cognitive problems. Analysis of variance was used to assess group differences of cognitive performance and multivariate normative comparison to classify impairment, comparing scores of each participant against the distribution of the scores of NC controls. RESULTS: Of BC + SYST, 16% were cognitively impaired at T2, compared to 4% in BC and 6% in NC. Although not significant, we observed moderate effect sizes for worse performance in the BC + SYST group compared to NC (Flanker congruent [effect size {ES} = 0.44] and stimulus incongruent [ES = 0.44]) and compared to BC (Controlled Oral Word Association Test [ES = 0.47], digit span [ES = 0.41], and Hopkins Verbal Learning Test immediate [ES = 0.71] and delayed recall [ES = 0.65]). Cognitively impaired patients had a significantly lower estimated premorbid intelligence, worse physical and social functioning, and more distress at T2 compared to unimpaired patients. CONCLUSION: Our findings indicate that cognitive impairment after systemic treatment occurs in a subset of BC patients. The predictive value of demographic and psychosocial factors in cognitive impairment should be further investigated in a larger sample of impaired patients.

Cognitive impairment and associated loss in brain white microstructure in aircrew members exposed to engine oil fumes.

Cabin air in airplanes can be contaminated with engine oil contaminants. These contaminations may contain organophosphates (OPs) which are known neurotoxins to brain white matter. However, it is currently unknown if brain white matter in aircrew is affected. We investigated whether we could objectify cognitive complaints in aircrew and whether we could find a neurobiological substrate for their complaints. After medical ethical approval from the local institutional review board, informed consent was obtained from 12 aircrew (2 females, on average aged 44.4 years, 8,130 flying hours) with cognitive complaints and 11 well matched control subjects (2 females, 43.4 years, 233 flying hours). Depressive symptoms and self-reported cognitive symptoms were assessed, in addition to a neuropsychological test battery. State of the art Magnetic Resonance Imaging (MRI) techniques were administered that assess structural and functional changes, with a focus on white matter integrity. In aircrew we found significantly more self-reported cognitive complaints and depressive symptoms, and a higher number of tests scored in the impaired range compared to the control group. We observed small clusters in the brain in which white matter microstructure was affected. Also, we observed higher cerebral perfusion values in the left occipital cortex, and reduced brain activation on a functional MRI executive function task. The extent of cognitive impairment was strongly associated with white matter integrity, but extent of estimated number of flight hours was not associated with cognitive impairment nor with reductions in white matter microstructure. Defects in brain white matter microstructure and cerebral perfusion are potential neurobiological substrates for cognitive impairments and mood deficits reported in aircrew.

Lower cognitive performance and white matter changes in testicular cancer survivors 10 years after chemotherapy.

OBJECTIVE: Chemotherapy (CT) is associated with adverse effects on cognition. Only few studies have investigated cognition in testicular cancer (TC) patients and studies on very late effects of CT on cognition are absent. Further, brain changes in relation to treatment have not been investigated in TC. The objective of the present study is to compare psychosocial functioning, cognitive performance and brain (micro)structure following surgery and CT for TC, against surgery (S)-only. METHODS: Twenty-eight CT (43.1±7.5 y) and 23 S-only (48.2±9.5y) TC survivors on average 14 yr post-treatment were examined using questionnaires, neurocognitive tests, and 3T-MRI [Diffusion Kurtosis Imaging (DKI), T1-weighted and Fluid Attenuated Inversion Recovery]. A multivariate cognitive performance score (Mahalanobis distance) was calculated to indicate the grade of cognitive performance. Kurtosis parameters, gray matter, and white matter (WM) volume were calculated from MRI data. RESULTS: Overall, the CT group showed lower cognitive performance (5.35±1.7) compared with the S-only group (4.4±0.9; P=0.03; d=0.70). Further, TC patients reported more memory problems after CT. DKI revealed a significantly higher radial kurtosis after CT in several anterior and posterior brain areas (P<0.05, corrected), but this was unrelated to cognitive performance. CONCLUSIONS: This cross-sectional study suggests that men receiving CT for TC are at risk for long-term lower cognitive performance. Although CT affected WM microstructure, this was unrelated to cognitive performance. More extensive, preferably prospective studies are warranted to confirm these results and to provide more insight into the possible mechanisms behind the observed cognitive sequelae after treatment for TC.

Multimodal MRI and cognitive function in patients with breast cancer prior to adjuvant treatment--the role of fatigue.

An increasing body of literature indicates that chemotherapy (ChT) for breast cancer (BC) is associated with adverse effects on the brain. Recent research suggests that cognitive and brain function in patients with BC may already be compromised before the start of chemotherapy. This is the first study combining neuropsychological testing, patient-reported outcomes, and multimodal magnetic resonance imaging (MRI) to examine pretreatment cognition and various aspects of brain function and structure in a large sample. Thirty-two patients with BC scheduled to receive ChT (pre-ChT+), 33 patients with BC not indicated to undergo ChT (pre-ChT-), and 38 no-cancer controls (NCs) were included. The examination consisted of a neuropsychological test battery, self-reported aspects of psychosocial functioning, and multimodal MRI. Patients with BC reported worse scores on several aspects of quality of life, such as higher levels of fatigue and stress. However, cortisol levels were not elevated in the patient groups compared to the control group. Overall cognitive performance was lower in the pre-ChT+ and the pre-ChT- groups compared to NC. Further, patients demonstrated prefrontal hyperactivation with increasing task difficulty on a planning task compared to NC, but not during a memory task. White matter integrity was lower in both patient groups. No differences in regional brain volume and brain metabolites were found. The cognitive and imaging data converged to show that symptoms of fatigue were associated with the observed abnormalities; the observed differences were no longer significant when fatigue was accounted for. This study suggests that cancer-related psychological or biological processes may adversely impact cognitive functioning and associated aspects of brain structure and function before the start of adjuvant treatment. Our findings stress the importance to further explore the processes underlying the expression of fatigue and to study whether it has a contributory role in subsequent treatment-related cognitive decline.

Very Late Treatment-Related Alterations in Brain Function of Breast Cancer Survivors.

Although adjuvant chemotherapy (CT) for breast cancer (BC) is associated with very late side-effects on cognition and brain function, studies on adverse effects of specific treatment regimens are scarce. Here, neurotoxicity profiles after different treatment strategies were compared in BC survivors randomized to high-dose (HI) or conventional-dose (CON-) CT, in women treated with radiotherapy (RT) -only and a healthy control (HC) group. We administered a neurocognitive test battery, a planning fMRI task (Tower of London) and episodic memory fMRI task (Paired Associates paradigm) in BC survivors who received CON-CT (n=24) and HC (n=27). Data were compared to BC survivors who received HI-CT (n=17) and RT-only (n=15) and who were previously assessed. Testing took place ±11.5 years post-CT. Furthermore, neurocognitive data were compared to neurocognitive data acquired ≤2 years post-treatment. Cognitive assessment revealed sustained cognitive decline in 10.5% of HI-CT, 8.3% of CON-CT, 6.7% of RT-only patients and 0% in the HC. Hypoactivation was found in task-related prefrontal and parietal areas for both CT-groups versus RT-only, with HI-CT showing more pronounced hypoactivation than CON-CT, combined with worse task performance. RT-only survivors performed at a similar level to HC while showing hyperactivation in task-related brain areas. Long after treatment, CT is associated with cognitive problems and task-related hypoactivation that depend on the specific cytotoxic regimen. This worse performance in patients who received CT could be explained by impaired brain functioning that is more severe with more intense CT.

Neurotoxicity in breast cancer survivors ≥10 years post-treatment is dependent on treatment type.

Adjuvant chemotherapy (CT) for breast cancer (BC) is associated with very late side-effects on brain function and structure. However, little is known about neurotoxicity of specific treatment regimens. To compare neurotoxicity profiles after different treatment strategies, we used neurocognitive testing and multimodality MRI in BC survivors randomized to high-dose (HI), conventional-dose (CON-) CT or radiotherapy (RT) only and a healthy control (HC) group. BC survivors who received CON-CT (n = 20) and HC (n = 20) were assessed using a neurocognitive test battery and multimodality MRI including 3D-T1, Diffusion Tensor Imaging (DTI) and 1H-MR spectroscopy (1H-MRS) to measure various aspects of cerebral white (WM) and gray matter (GM). Data were compared to previously assessed groups of BC survivors who received HI-CT (n = 17) and RT-only (n = 15). Testing took place on average 11.5 years post-CT. 3D-T1 showed focal GM volume reductions both for HI-CT and CON-CT compared to RT-only (p < .004). DTI-derived mean diffusivity and 1H-MRS derived N-acetyl aspartate showed WM injury specific to HI-CT but not CON-CT (p < .05). Residual effects were revealed in the RT-only group compared to HC on MRI and neurocognitive measurements (p < .05). Ten years after adjuvant CT for BC lower cerebral GM volume was found in HI as well as CON-CT BC survivors whereas injury to WM is restricted to HI-CT. This might indicate that WM brain changes after BC treatment may show more pronounced (partial) recovery than GM. Furthermore, our results suggest residual neurotoxicity in the RT-only group, which warrants further investigation.

Reduced frontal brain volume in non-treatment-seeking cocaine-dependent individuals: exploring the role of impulsivity, depression, and smoking.

In cocaine-dependent patients, gray matter (GM) volume reductions have been observed in the frontal lobes that are associated with the duration of cocaine use. Studies are mostly restricted to treatment-seekers and studies in non-treatment-seeking cocaine abusers are sparse. Here, we assessed GM volume differences between 30 non-treatment-seeking cocaine-dependent individuals and 33 non-drug using controls using voxel-based morphometry. Additionally, within the group of non-treatment-seeking cocaine-dependent individuals, we explored the role of frequently co-occurring features such as trait impulsivity (Barratt Impulsivity Scale, BIS), smoking, and depressive symptoms (Beck Depression Inventory), as well as the role of cocaine use duration, on frontal GM volume. Smaller GM volumes in non-treatment-seeking cocaine-dependent individuals were observed in the left middle frontal gyrus. Moreover, within the group of cocaine users, trait impulsivity was associated with reduced GM volume in the right orbitofrontal cortex, the left precentral gyrus, and the right superior frontal gyrus, whereas no effect of smoking severity, depressive symptoms, or duration of cocaine use was observed on regional GM volumes. Our data show an important association between trait impulsivity and frontal GM volumes in cocaine-dependent individuals. In contrast to previous studies with treatment-seeking cocaine-dependent patients, no significant effects of smoking severity, depressive symptoms, or duration of cocaine use on frontal GM volume were observed. Reduced frontal GM volumes in non-treatment-seeking cocaine-dependent subjects are associated with trait impulsivity and are not associated with co-occurring nicotine dependence or depression.

Increase in central striatal dopamine transporters in patients with Shwachman-Diamond syndrome: additional evidence of a brain phenotype.

Patients with Shwachman-Diamond syndrome (SDS) do not only experience well-described physical features like skeletal abnormalities and hematological dysfunctions, but recent studies also suggested attention and working memory deficits in SDS. Indeed, a recent structural magnetic resonance imaging (MRI) study demonstrated smaller brain regions in SDS. Regarding attention and working memory, however, an important role for the neurotransmitter dopamine is well established. Therefore, in this study we assessed in vivo dopamine transporters (DATs; a specific marker of dopaminergic cells expressed in nerve terminals) and performed structural MRI in SDS. In 6 and 5 young SDS patients, respectively, we were able to acquire DAT single photon emission computed tomography (SPECT) and MRI examinations, and the data were compared to age-matched control data. Striatal DAT binding was significantly increased in SDS patients as compared to controls. In addition, we observed significantly smaller volumes particularly posteriorly and caudally located in the brain: the corpus callosum, brainstem, and cerebellum. Also the thalamus was smaller in SDS patients than in controls. In conclusion, our data replicate earlier findings on smaller brain regions in SDS. In addition, our novel molecular imaging data suggest that SDS patients may have a dysregulated dopaminergic system. These findings may be of relevance to increase our understanding of behavioral and cognitive deficits in SDS.

[Children with obesity and declining linear growth curve: Cushing's disease?]. / Kinderen met obesitas en afbuigende lengtegroeicurve: ziekte van Cushing?

We describe two children who presented with extreme weight gain and failure to grow in height, and who were both diagnosed with Cushing's disease. Following preoperative metyrapone treatment, both children successfully underwent curative transsphenoidal surgery. While obesity is a common and increasing problem in childhood, Cushing's disease is rare. The combination of weight gain and growth failure in a child is an alarming sign in which underlying endocrine disease must be ruled out.

Late effects of high-dose adjuvant chemotherapy on white and gray matter in breast cancer survivors: converging results from multimodal magnetic resonance imaging.

The neural substrate underlying cognitive impairments after chemotherapy is largely unknown. Here, we investigated very late (>9 years) effects of adjuvant high-dose chemotherapy on brain white and gray matter in primary breast cancer survivors (n = 17) with multimodal magnetic resonance imaging (MRI). A group of breast cancer survivors who did not receive chemotherapy was scanned for comparison (n = 15). Neuropsychological tests demonstrated cognitive impairments in the chemotherapy group. Diffusion tensor imaging (DTI) with tract-based spatial statistics showed that chemotherapy was associated with focal changes in DTI values indicative for reduced white matter integrity. Single voxel proton MR spectroscopy (1H-MRS) in the left centrum semiovale (white matter) showed a reduction of N-acetylasparate/creatine indicative of axonal injury. Voxel-based morphometry demonstrated a reduction of gray matter volume that overlapped with fMRI hypoactivation (as reported in a previous publication) in posterior parietal areas and colocalized with DTI abnormalities. Also, DTI correlated with 1H-MRS only in the chemotherapy group. These results converge to suggest that high-dose adjuvant chemotherapy for breast cancer is associated with long-term injury to white matter, presumably reflecting a combination of axonal degeneration and demyelination, and damage to gray matter with associated functional deficits. Hormonal treatment with tamoxifen may also have contributed to the observed effects, although results from other studies indicate that it is unlikely that tamoxifen is solely or largely responsible. Using this multimodality approach we provide for the first time insight into the neural substrate underlying cognitive impairments following systemic administration of cytotoxic agents many years after treatment.