A pilot study of neuropsychological functions, APOE and amyloid imaging in patients with gliomas.

Brain tumor patients treated with radiotherapy (RT) often develop cognitive dysfunction, and recent studies suggest that the APOE ε-4 allele may influence cognitive outcome. The ε-4 allele is known to promote beta (ß) amyloid deposition in the cortex, and preliminary evidence suggests that RT may be associated with this process. However, it is unknown whether ß-amyloid accumulation contributes to treatment neurotoxicity. In this pilot study, we assessed neuropsychological functions and ß-amyloid retention using 18F-florbetaben (FBB) PET in a subset of brain tumor patients who participated in our study of APOE polymorphisms and cognitive functions. Twenty glioma patients treated with conformal RT ± chemotherapy participated in the study: 6 were APOE ε-4 carriers and 14 were non-ε-4 carriers. Patients completed a neuropsychological re-evaluation (mean time interval = 5 years, SD = 0.83) and brain MRI and FBB PET scans. Wilcoxon signed-rank test comparisons between prior and current neuropsychological assessments showed a significant decline in attention (Brief Test of Attention, p = 0.018), and a near significant decline in verbal learning (Hopkins Verbal learning Test-Learning, p = 0.07). Comparisons by APOE status showed significant differences over time in attention/working memory (WAIS-III digits forward, p = 0.028 and digits backward, p = 0.032), with a decline among APOE ε-4 carriers. There were no significant differences in any of the FBB PET analyses between APOE ε-4 carriers and non-ε-4 carriers. The findings suggest that glioma patients may experience worsening in attention and executive functions several years after treatment, and that the APOE ε-4 allele may modulate cognitive decline, but independent of increased ß-amyloid deposition.

Brain structure and function in patients with ovarian cancer treated with first-line chemotherapy: a pilot study.

Women with ovarian cancer often undergo chemotherapy involving multiple agents. However, little is known about treatment-related central neurotoxicity in this population. The goal of this cross-sectional study was to assess brain structure and function and neurocognitive abilities in patients with ovarian cancer following first-line chemotherapy. Eighteen patients with ovarian, peritoneal and fallopian tube cancer and eighteen healthy controls matched for gender, age and education participated in the study. The patients were evaluated 1-4 months following completion of first-line taxane/platinum chemotherapy. All participants underwent structural and functional magnetic resonance imaging (MRI), and completed neuropsychological tests of attention, memory and executive functions. Neuroimaging assessments included voxel-based morphometry (VBM) for measuring gray matter (GM) volume, and functional MRI (fMRI) during the N-back working memory task. The results of VBM showed that patients had significantly reduced GM volume compared to healthy controls in the right middle/superior frontal gyrus, and in the left supramarginal gyrus and left inferior parietal lobule. fMRI results indicated significantly decreased activation in patients relative to healthy controls in the left middle frontal gyrus and left inferior parietal lobule during the N-back task (1/2/3-back >0-back). There were no statistically significant differences between the two groups on the neuropsychological tests. This is the first study showing structural and functional alterations involving frontal and parietal regions in patients with ovarian cancer treated with first-line chemotherapy. These findings are congruent with studies involving women with breast cancer, and provide additional supporting evidence for central neurotoxicity associated with taxane/platinum chemotherapy.

Prospective assessment of white matter integrity in adult stem cell transplant recipients.

Hematopoietic stem cell transplantation (HSCT) is often used in the treatment of hematologic disorders. Although it can be curative, the pre-transplant conditioning regimen can be associated with neurotoxicity. In this prospective study, we examined white matter (WM) integrity with diffusion tensor imaging (DTI) and neuropsychological functioning before and one year after HSCT in twenty-two patients with hematologic disorders and ten healthy controls evaluated at similar intervals. Eighteen patients received conditioning treatment with high-dose (HD) chemotherapy, and four had full dose total body irradiation (fTBI) and HD chemotherapy prior to undergoing an allogeneic or autologous HSCT. The results showed a significant decrease in mean diffusivity (MD) and axial diffusivity (AD) in diffuse WM regions one year after HSCT (p-corrected <0.05) in the patient group compared to healthy controls. At baseline, patients treated with allogeneic HSCT had higher MD and AD in the left hemisphere WM than autologous HSCT patients (p-corrected <0.05). One year post-transplant, patients treated with allogeneic HSCT had lower fractional anisotropy (FA) and higher radial diffusivity (RD) in the right hemisphere and left frontal WM compared to patients treated with autologous HSCT (p-corrected <0.05).There were modest but significant correlations between MD values and cognitive test scores, and these were greatest for timed tests and in projection tracts. Patients showed a trend toward a decline in working memory, and had lower cognitive test scores than healthy controls at the one-year assessment. The findings suggest a relatively diffuse pattern of alterations in WM integrity in adult survivors of HSCT.

A prospective evaluation of changes in brain structure and cognitive functions in adult stem cell transplant recipients.

Hematopoietic stem cell transplantation (HSCT) is an efficacious treatment for many hematologic malignancies. However, the conditioning regimen of high-dose (HD) chemotherapy with or without total body irradiation (TBI) can be associated with neurotoxicity. In this prospective study, we used quantitative neuroimaging techniques to examine regional gray matter and ventricular volumes, and standardized neuropsychological tests to assess cognitive function before and 1 year after HSCT in 28 patients with hematologic malignancies and in ten healthy controls evaluated at similar intervals. Nineteen patients received conditioning treatment with HD chemotherapy alone and nine had both TBI and HD chemotherapy. There was a significant reduction in gray matter volume in the middle frontal gyrus bilaterally and in the left caudate nucleus in the patient group (all patients combined) but not among healthy controls over the 1-year follow-up period. There was a significant increase in left lateral ventricle volume and in total ventricle volume in the patient group, relative to healthy controls. Similar brain structural changes were seen for patients treated with HD chemotherapy alone. The neuropsychological results showed that 21% of patients could be classified as impaired at baseline. The Reliable Change Index suggested no significantly different rates of cognitive decline between patients and healthy controls. The findings suggest that HSCT patients may be at an increased risk for developing regional brain volume loss, and that subgroups may experience cognitive dysfunction prior to and 1 year following the transplant.

Cognitive functions in primary central nervous system lymphoma: literature review and assessment guidelines.

BACKGROUND: Treatment-related neurotoxicity has been recognized as a significant problem in patients with primary central nervous system lymphoma (PCNSL) as effective treatment has increased survival rates. There is, however, a paucity of research on cognitive functions in this population. DESIGN: In a review of the literature, a total of 17 articles that described cognitive outcome in adult PCNSL patients were identified. RESULTS: The studies that assessed cognitive functions after whole-brain radiotherapy combined with chemotherapy reported cognitive impairment in most patients. Patients treated with chemotherapy alone had either stable or improved cognitive performance in most studies. Methodological problems, however, limited the ability to ascertain the specific contribution of disease and various treatment interventions to cognitive outcome. On the basis of the literature review, a battery of cognitive and quality-of-life (QoL) measures to be used in prospective clinical trials was proposed. The battery is composed of five standardized neuropsychological tests, covering four domains sensitive to disease and treatment effects (attention, executive functions, memory, psychomotor speed), and QoL questionnaires, and meets criteria for use in collaborative trials. CONCLUSION: The incorporation of formal and systematic cognitive evaluations in PCNSL studies will improve our understanding of treatment-related neurotoxicity in this population.

Cognitive functions in survivors of primary central nervous system lymphoma.

BACKGROUND: The standard treatment for primary CNS lymphoma (PCNSL) involves high-dose methotrexate-based (MTX) chemotherapy and whole brain radiotherapy (WBRT). This combined regimen prolongs patient survival, but also carries a substantial risk for delayed neurotoxicity particularly in the elderly. However, cognitive outcome evaluations have not been included in most clinical trials. OBJECTIVE: To assess cognitive functioning and quality of life in PCNSL survivors treated either with WBRT +/- MTX-based chemotherapy or chemotherapy alone. METHODS: Twenty-eight PCNSL patients in disease remission received a post-treatment baseline neuropsychological evaluation, and a subset of patients were available for an 8-month follow-up evaluation. Assessment of quality of life and extent of white matter disease on MRI were also performed. RESULTS: Patients displayed mild to moderate impairments across several cognitive domains. These were of sufficient severity to reduce quality of life in half of the patient sample. Comparisons according to treatment type revealed more pronounced cognitive impairment, particularly in the memory and attention/executive domains, among patients treated with WBRT +/- chemotherapy. Extent of white matter disease correlated with attention/executive, memory, and language impairment. CONCLUSIONS: PCNSL survivors treated with WBRT +/- chemotherapy displayed more pronounced cognitive dysfunction than patients treated with MTX-based chemotherapy alone.

An integrated functional magnetic resonance imaging procedure for preoperative mapping of cortical areas associated with tactile, motor, language, and visual functions.

OBJECTIVE: To evaluate an integrated battery of preoperative functional magnetic resonance imaging (fMRI) tasks developed to identify cortical areas associated with tactile, motor, language, and visual functions. METHODS: Sensitivity of each task was determined by the probability that a targeted region was activated for both healthy volunteers (n = 63) and surgical patients with lesions in these critical areas (n = 125). Accuracy of each task was determined by the correspondence between the fMRI maps and intraoperative electrophysiological measurements, including somatosensory evoked potentials (n = 16), direct cortical stimulation (n = 9), and language mapping (n = 5), and by preoperative Wada tests (n = 13) and visual field examinations (n = 6). RESULTS: For healthy volunteers, the overall sensitivity was 100% for identification of the central sulcus, visual cortex, and putative Wernicke's area, and 93% for the putative Broca's area (dominant hemisphere). For patients with tumors affecting these regions of interest, task sensitivity was 97% for identification of the central sulcus, 100% for the visual cortex, 91% for the putative Wernicke's area, and 77% for the putative Broca's area. These sensitivities were enhanced by the use of multiple tasks to target related functions. Concordance of the fMRI maps and intraoperative electrophysiological measurements was observed whenever both techniques yielded maps and Wada and visual field examinations were consistent with fMRI results. CONCLUSION: This integrated fMRI task battery offers standardized and noninvasive preoperative maps of multiple critical functions to facilitate assessment of surgical risk, planning of surgical routes, and direction of conventional, intraoperative electrophysiological procedures. Thus, a greater range of structural and functional relationships is brought to bear in the service of optimal outcomes for neurosurgery.

Concordance between functional magnetic resonance imaging and intraoperative language mapping.

Although the correspondence between functional-magnetic resonance imaging (fMRI) representations of the sensorimotor cortex and intraoperative electrophysiology (including somatosensory evoked potential, SSEP, recordings and direct cortical stimulation) has been reported, a similar correspondence between fMRI and intraoperative localization of the language-sensitive cortex is not as well established. The aim of the present study was to evaluate the concordance between fMRI and intraoperative electrophysiology with respect to the localization of the language-sensitive and sensorimotor cortices. We present the results of 21 patients who underwent language and sensorimotor mapping by fMRI and intraoperative electrophysiology including SSEP recordings (n = 21), direct cortical stimulation of motor cortex (n = 15) and direct cortical stimulation of Broca's and Wernicke's area (n = 5). When responses were obtained with both methods, localization of function concurred in all cases. These observations suggest that fMRI represents a reliable preoperative tool for the identification of language-sensitive areas.

Bismuth subsalicylate toxicity as a cause of prolonged encephalopathy with myoclonus.

Bismuth subsalicylate preparations are over-the-counter products for gastrointestinal complaints. Bismuth toxicity causes delirium, psychosis, ataxia, myoclonus, and seizures and is reversible over several weeks or months, when bismuth intake is stopped. We report a 54-year-old man with a 6-week history of progressive confusion and memory difficulty and a 2-3-week history of involuntary movements and gait impairment. His encephalopathy was further characterized by marked multifocal myoclonic jerks, coarse postural tremors, postural instability, and gait ataxia. He gradually improved. Extensive toxic, metabolic, and infectious workup demonstrated bismuth toxicity. Spinal tap and brain magnetic resonance scan were normal. Electroencephalography showed bihemispheric slowing. As his encephalopathy cleared, he reported using bismuth subsalicylate long term (daily intake of 8 oz). Bismuth levels 5 weeks after cessation of bismuth were elevated and normalized after 12 weeks. He followed a typical course for bismuth toxicity with subacute progressive encephalopathy and gradual recovery. Creutzfeldt-Jakob was strongly considered due to his rapidly progressive encephalopathy, multifocal myoclonus, and ataxia. Due to its rarity, bismuth toxicity is often overlooked. We hope this presentation will increase recognition of bismuth toxicity. We believe more detailed labeling of bismuth products is needed to avoid similar toxicity from this readily available product.