Effects of Adjuvant Chemotherapy on Cognitive Function of Patients With Early-stage Colorectal Cancer.

PURPOSE: Chemotherapy-related cognitive impairment can occur in cancer survivors after treatment, especially those patients who have undergone chemotherapy for breast cancer. The frequency and to what extent such toxicity develops in colorectal cancer (CRC) survivors is unknown. The present prospective study evaluated the effects of adjuvant chemotherapy on the cognitive performance of patients with localized CRC compared with a control group who had not undergone chemotherapy. PATIENTS AND METHODS: Consecutive patients with localized stage II and III CRC completed neuropsychological assessments, self-reported cognitive complaint questionnaires, and depressive symptom evaluations before starting fluoropyrimidine-based adjuvant chemotherapy and after 12 months. Blood was collected for apolipoprotein E genotyping. Diffusion tensor imaging data were acquired from a subset of participants at both evaluation points. RESULTS: From December 2012 to December 2014, 137 patients were approached and 85 were included. Of these 85 patients, 49 had undergone chemotherapy and 26 had not, in accordance with the standard recommendations for adjuvant therapy for CRC. The mean age was 62.5 ± 9.4 years, 60% were men, and the mean educational attainment was 7.6 ± 3.7 years. No difference was found in the global composite score (P = .38), attention (P = .84), or memory (P = .97) between the 2 groups during the follow-up period (mean ± standard deviation, 375 ± 29 days). However, a statistically significant difference was found for executive function after adjustment for age, sex, education, and depressive symptoms at baseline (ß -1.80; 95% confidence interval, -3.50 to -0.11; P = .04), suggesting worse performance for the chemotherapy group. For the 32 patients who had undergone magnetic resonance imaging, tract-based spatial statistics did not show voxelwise significant differences in structural brain connectivity at baseline or during follow-up. Apolipoprotein E polymorphisms were not predictive of cognitive dysfunction. CONCLUSION: Patients with CRC who received adjuvant 5-fluorouracil with or without oxaliplatin presented with a decline in executive function after 12 months compared with patients with localized disease who had not received chemotherapy.

Corpus callosum diffusion abnormalities in refractory epilepsy associated with hippocampal sclerosis.

OBJECTIVES: To detect by diffusion tensor imaging (DTI) the extent of microstructural integrity changes of the corpus callosum (CC) in patients with hippocampal sclerosis (HS) and to evaluate possible association with clinical characteristics. METHODS: Fourty-two patients with temporal lobe epilepsy (TLE) and HS and 30 control subjects were studied with DTI. We grouped patients according to lesion side (left or right) HS. Mean diffusivity (MD), fractional anisotropy (FA), radial (RD) and axial diffusivity (AD) were extracted from five segments in CC midsagittal section obtained by automatic segmentation. CC DTI findings were compared between groups. We also evaluated association of DTI changes and clinical characteristics. RESULTS: HS patients displayed decreased FA and increased MD and RD in the anterior, mid-posterior and posterior CC segments, compared to controls. No differences were observed in AD. Patients reporting febrile seizure as the initial precipitating event presented more intense diffusion changes. No differences were seen comparing left and right HS. Age at epilepsy onset, disease duration and seizure frequency were not associated with DTI findings. CONCLUSIONS: This is one of the largest series of TLE-HS patients evaluating CC white matter fiber integrity by DTI, which allowed us to study how some clinical characteristics, such as seizure frequency, disease duration and lesion side, are related to CC integrity. Occurrence of febrile seizure was the only factor that had significant impact on tract integrity. Diffusion changes were not restricted to the posterior part of the CC; we observed the same changes for the anterior part of the CC. Diffusion changes were characterized by an increase in RD, while the AD remained intact for all regions of the CC.

DTI-based tractography of the arcuate fasciculus in patients with polymicrogyria and language disorders.

OBJECTIVES: To assess the integrity of the arcuate fasciculus (AF) with diffusion tensor imaging (DTI) and tractography in patients with congenital polymicrogyria (PMG) and language disorders. METHODS: Twelve patients with PMG and 12 matched controls were prospectively evaluated with DTI (32 gradient encoding directions, b-value=1000 s/mm(2)) at 3.0T. The AF was virtually dissected with a deterministic streamline approach. DTI metrics included FA (fractional anisotropy), mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD). A subset of patients (n=4) was evaluated to assess cognitive performance and language skills. RESULTS: Qualitative evaluation revealed several abnormalities in tracts size and architecture in nearly all PMG patients. Remarkably, in 3 patients with bilateral PMG, the AF was not delineated on both hemispheres. In comparison to controls, patients exhibited significant decrease of FA (p=0.003) in addition to increase of RD (p=0.03) in the right AF, whereas there was significant increase of MD in the left AF (p=0.04). All 4 patients with language evaluation had suboptimal performance on lexical fluency and prosodic linguistic. CONCLUSIONS: DTI and tractography suggest that the AF is severely disrupted in patients with PMG, providing an anatomical in vivo substrate for the language disorders commonly associated with these cortical malformations.

Diffusion abnormalities of the corpus callosum in patients with malformations of cortical development and epilepsy.

PURPOSE: Diffusion tensor imaging (DTI) is a magnetic resonance imaging (MRI) technique that can characterize white matter (WM) architecture and microstructure. DTI has demonstrated extensive WM changes in patients with several epileptic syndromes, but few studies have focused on patients with malformations of cortical development (MCD). Our aim was to investigate the quantitative diffusion properties of the corpus callosum (CC), a major commissural bundle critical in inter-hemispheric connectivity, in a large group of patients with MCD. METHODS: Thirty-two MCD patients and 32 age and sex-matched control subjects were evaluated with DTI at 3.0 T. We analyzed the three major subdivisions of the CC (genu, body, and splenium) with deterministic tractography to yield fractional anisotropy (FA), mean diffusivity (MD), parallel diffusivity (λ||) and perpendicular diffusivity (λ⊥). We further assessed the CC with region of interest (ROI)-based analyses and evaluated different subgroups of MCD (polymicrogyria/schizencephaly, heterotopia, and cortical dysplasia). Partial correlations between diffusion changes and clinical parameters (epilepsy duration and age at disease onset) were also queried. RESULTS: There were significant reductions of FA, accompanied by increases in MD and λ⊥ in all segments of the CC in the patients group with both analytical methods. The absolute differences in FA were greater on ROI-analyses. There were no significant differences between the MCD subgroups, and no correlations between clinical parameters of epilepsy and FA. CONCLUSIONS: Our study indicates DTI abnormalities consistent with microstructural changes in the corpus callosum of MCD patients. The findings support the idea that patients with epilepsy secondary to cortical malformations present widespread WM changes that extend beyond the macroscopic MRI-visible lesions.

Phosphorus magnetic resonance spectroscopy in malformations of cortical development.

PURPOSE: The aim of this study was to evaluate phospholipid metabolism in patients with malformations of cortical development (MCDs). METHODS: Thirty-seven patients with MCDs and 31 control subjects were studied using three-dimensional phosphorus magnetic resonance spectroscopy ((31)P-MRS) at 3.0 T. The voxels in the lesions and in the frontoparietal cortex of the control subjects were compared (the effective volumes were 12.5 cm(3)). Robust quantification methods were applied to fit the time-domain data to the following resonances: phosphoethanolamine (PE); phosphocholine (PC); inorganic phosphate (Pi); glycerophosphoethanolamine (GPE); glycerophosphocholine (GPC); phosphocreatine (PCr); and α-, ß-, and γ-adenosine triphosphate (ATP). We also estimated the total ATP (ATP(t) = α-+ß-+γ-ATP), phosphodiesters (PDE = GPC+GPE), phosphomonoesters (PME = PE+PC), and the PME/PDE, PCr/ATP(t) and PCr/Pi ratios. The magnesium (Mg(2+)) levels and pH values were calculated based on PCr, Pi, and ß-ATP chemical shifts. KEY FINDINGS: Compared to controls and assuming that a p-value < 0.05 indicates statistical significance, the patients with MCDs exhibited significantly lower pH values and higher Mg(2+) levels. In addition, the patients with MCDs had lower GPC and PDE and an increased PME/PDE ratio. SIGNIFICANCE: Mg(2+) and pH are important in the regulation of bioenergetics and are involved in many electrical activity pathways in the brain. Our data support the idea that neurometabolic impairments occur during seizure onset and propagation. The GPC, PDE, and PME/PDE abnormalities also demonstrate that there are membrane turnover disturbances in patients with MCDs.