Identifying neuroanatomical signatures of anorexia nervosa: a multivariate machine learning approach.

BACKGROUND: There are currently no neuroanatomical biomarkers of anorexia nervosa (AN) available to make clinical inferences at an individual subject level. We present results of a multivariate machine learning (ML) approach utilizing structural neuroanatomical scan data to differentiate AN patients from matched healthy controls at an individual subject level. METHOD: Structural neuroimaging scans were acquired from 15 female patients with AN (age = 20, s.d. = 4 years) and 15 demographically matched female controls (age = 22, s.d. = 3 years). Neuroanatomical volumes were extracted using the FreeSurfer software and input into the Least Absolute Shrinkage and Selection Operator (LASSO) multivariate ML algorithm. LASSO was 'trained' to identify 'novel' individual subjects as either AN patients or healthy controls. Furthermore, the model estimated the probability that an individual subject belonged to the AN group based on an individual scan. RESULTS: The model correctly predicted 25 out of 30 subjects, translating into 83.3% accuracy (sensitivity 86.7%, specificity 80.0%) (p < 0.001; χ 2 test). Six neuroanatomical regions (cerebellum white matter, choroid plexus, putamen, accumbens, the diencephalon and the third ventricle) were found to be relevant in distinguishing individual AN patients from healthy controls. The predicted probabilities showed a linear relationship with drive for thinness clinical scores (r = 0.52, p < 0.005) and with body mass index (BMI) (r = -0.45, p = 0.01). CONCLUSIONS: The model achieved a good predictive accuracy and drive for thinness showed a strong neuroanatomical signature. These results indicate that neuroimaging scans coupled with ML techniques have the potential to provide information at an individual subject level that might be relevant to clinical outcomes.

Intrinsic connectivity networks within cerebellum and beyond in eating disorders.

Cerebellum seems to have a role both in feeding behavior and emotion regulation; therefore, it is a region that warrants further neuroimaging studies in eating disorders, severe conditions that determine a significant impairment in the physical and psychological domain. The aim of this study was to examine the cerebellum intrinsic connectivity during functional magnetic resonance imaging resting state in anorexia nervosa (AN), bulimia nervosa (BN), and healthy controls (CN). Resting state brain activity was decomposed into intrinsic connectivity networks (ICNs) using group spatial independent component analysis on the resting blood oxygenation level dependent time courses of 12 AN, 12 BN, and 10 CN. We extracted the cerebellar ICN and compared it between groups. Intrinsic connectivity within the cerebellar network showed some common alterations in eating disordered compared to healthy subjects (e.g., a greater connectivity with insulae, vermis, and paravermis and a lesser connectivity with parietal lobe); AN and BN patients were characterized by some peculiar alterations in connectivity patterns (e.g., greater connectivity with the insulae in AN compared to BN, greater connectivity with anterior cingulate cortex in BN compared to AN). Our data are consistent with the presence of different alterations in the cerebellar network in AN and BN patients that could be related to psychopathologic dimensions of eating disorders.

An atypical case of sporadic fatal insomnia.

Fatal insomnia is a rare human prion disease characterised by sleep-wake disturbances, thalamic degeneration and deposition of type 2 disease-specific prion protein (PrP(Sc)). This report details a patient with sporadic fatal insomnia who exhibited cerebral deposition of type 1 PrP(Sc) and neuropathological changes largely in the basal ganglia. Previous damage of this brain region by a surgically removed colloid cyst and the insertion of two intracerebral shunts may have influenced the distribution of PrP(Sc) through a chronic inflammatory process. These findings add to our knowledge of the phenotypic variability of human prion diseases with prominent sleep disturbances.

Chemotherapy-Induced Neurotoxicity: Evidence of a Protective Role of CC Homozygosis in the Interleukin-1ß Gene-511 C>T Polymorphism.

We hypothesized that the IL-1ß-511 C>T polymorphism could be associated with the development of neurotoxicity and that it could be a possible biomarker to rate the risk of occurrence of neurotoxicity in cancer patients. Genomic DNA was extracted from 85 cancer patients: 49 received systemic chemotherapeutic treatment (CHT) and 36 patients did not receive it (No-CHT). All subjects were genotyped for the functionally active polymorphisms of IL-1ß-511 C>T. We estimated neurotoxicity with the evaluation of neurological deficits. CHT patients showed erythrocytopenia, neurological deficit and a slight lowering of cognitive performance. The subgroup of patients carrying the CC genotype of the IL-1ß-511 C>T gene showed lesser neurological deficits. In the context of cancer treatment, we suggested the potential value of IL-1ß-511 C>T as genetic biomarkers to identify patients with higher risk to develop neurological deficits.

The Neurobiological Basis of the Distress Thermometer: A PET Study in Cancer Patients.

The objective of this study was to investigate the possible associations between the Distress Thermometer (DT) scores and the brain metabolism of structures involved in stress response. Twenty-one cancer patients were assessed using the DT, Problem Checklist and Hospital Anxiety and Depression Scale (HADS). The psychological measures were correlated with [18 F]PET-FDG brain glucose metabolism. Multiple and linear regression and binary logistic regression were run to analyse data. The DT and HADS scores illustrated that 48% of patients were distressed, 19% were depressed and 48% were anxious. Results showed that some subcortical areas activity, such as part of midbrain and of hypothalamus, was correlated with the DT scores. The Problem Checklist scores correlated with the activity of the same areas and included more regions in the limbic forebrain and brainstem. Compared with the DT and Problem Checklist, HADS-Depression scores showed a more extensive pattern of correlation with brain activity, including limbic and cortical areas. The results highlighted that the DT scores correlated with the activity of brain areas typically involved in stress response. Indeed, hypothalamus metabolism was found to be the best predictor of distressed patients.

Distribution of activated caspase-3 in relation with apoptosis in human malignant gliomas.

Activated caspase-3has been immunohistochemically studied in 30glioblastomas. Its distribution has been compared with that of apoptotic nuclei demonstrated by terminal dUTP nick-end labeling (TUNEL) and morphology. The best procedure for the demonstration of caspase-3 requires formalin fixation, followed by Carnoy fixation, with microwave irradiation. The number of positive cells is lower than that of apoptotic nuclei shown by TUNEL technique, especially in perinecrotic pseudo-palisadings, and there are also qualitative variations. Positive staining occurs in nuclei, cytoplasms or in both cell compartments. The interpretation of Caspase-3 positive staining is based on its crucial position in the final pathway to apoptosis and on the mechanisms by which it cleaves cytoplasmic and nuclear proteins among which inhibitory/caspase-activated DNase system is included.

Motor neuron disease in the province of Turin, Italy, 1966-1980. Survival analysis in an unselected population.

We performed a population based survival analysis of all incident cases (220) of motor neuron disease (MND) in the province of Turin, Italy, during the period 1966-1980. 175 cases were diagnosed as amyotrophic lateral sclerosis (ALS), 43 as progressive muscular atrophy (PMA) and 2 as progressive bulbar palsy (PBP). The life-tables of MND, adjusted as to the "expected" mortality, showed a survival rate of 27.8% and 22.0% at 5 and 10 years, respectively. The course of PMA and ALS cases was different, with a 5-year survival rate of 66.8% and 17.7%, respectively. Nevertheless both life-tables showed a similar pattern with a rapidly fatal outcome in the first 3 years after diagnosis and a slower death rate in the following years. In each curve, the slopes suggested the presence of 2 subgroups with different prognosis. It is to be stressed that a percentage of PMA patients (25.7%) showed a rapidly fatal outcome and that a subgroup of ALS patients (26.6%) showed a relatively benign course. This might suggest a different individual susceptibility to the disease.

The chemotherapy long-term effect on cognitive functions and brain metabolism in lymphoma patients.

AIM: A growing number of neuropsychological studies reported that chemotherapy may impair brain functions, inducing persistent cognitive changes in a subset of cancer survivors. The aim of this paper was to investigate the neural basis of the chemotherapy induced neurobehavioral changes by means of metabolic imaging and neuropsychological testing. METHODS: We studied the resting brain [¹8F]FDG-PET/CT images of 50 adult cancer patients with diagnosis of lymphoma: 18 patients were studied prior and 32 after to chemotherapy. All patients underwent to a neuropsychological examination assessing cognitive impairment (tests for shifting attention, verbal memory, phonemic fluency), depression, anxiety and distress. RESULTS: Compared to no chemotherapy patients, the treated group showed significant bilateral lower rate of glucose metabolism in prefrontal cortices, cerebellum, medial cortices and limbic brain areas. The metabolism of these regions negatively correlated with number of cycles and positively with post-chemotherapy time. The treated group showed a poorer performance in many frontal functions, but similar level of depression, anxiety and distress. CONCLUSIONS: Chemotherapy induced significant long-term changes in metabolism of multiple regions with a prevailing involvement of the prefrontal cortex. The observed cognitive dysfunctions could be explained by these changes. The recovery from chemotherapy is probably affected by treatment duration and by the time elapsed after its end. We speculated that the mechanism could be an accelerating ageing / oxidative stress that, in some patients at risk, could result in an early and persistent cognitive impairment.

Functional MR study of a motor task and the tower of London task at 1.0 T.

INTRODUCTION: The use of functional magnetic resonance imaging (fMRI) for clinical applications and basic neuroscience is constantly increasing. The discussion about minimum performance requirement for a correct implementation of fMRI is still open, and one of the critical points is the magnetic field strength. We tested the feasibility of fMRI at 1.0 T during motor and cognitive tasks. METHODS: Fourteen healthy subjects were scanned during a motor task and 12 while performing the Tower of London task. In the activated areas, the percentage signal change due to BOLD (blood oxygenation level dependent) contrast was analysed. To check basic image quality of the acquisition system we measured quality indices in a temporal series of images of a phantom. RESULTS: Motor and cognitive brain activations matched previous results obtained at higher field strengths. The mean percentage change over subjects in the motor task was in the range 1.3-2.6% for the primary motor area and 0.8-6.7% for the cerebellum. In the cognitive task, the mean percentage change over subjects was 0.7-1.2% for a frontal area and 0.6-2.8% for a parietal area. The percentage noise of the phantom temporal series was less than 0.4%. Percentage changes and signal to noise ratio, although lower than that obtained with high-field systems, allowed activation maps to be obtained in all subjects. CONCLUSION: Our results replicate previous fMRI results demonstrating reproducible motor-related brain activations and extend the field to a complex cognitive task, thus providing evidence of the safety for routine clinical use of 1-T equipment.

The effect of gender on planning: An fMRI study using the Tower of London task.

Since the introduction of brain mapping, evidences of functional gender differences have been corroborating previous behavioral and neuropsychological results showing a sex-specific brain organization. We investigated gender differences in brain activation during the performance of the Tower of London (TOL) task which is a standardized test to assess executive functions. Eighteen healthy subjects (9 females and 9 males) underwent fMRI scanning while solving a series of TOL problems with different levels of difficulty. Data were analyzed by modeling both genders and difficulty task load. Task-elicited brain activations comprised a bilateral fronto-parietal network, common to both genders; within this network, females activated more than males in dorsolateral prefrontal cortex (DLPFC) and right parietal cortex, whereas males showed higher activity in precuneus. A prominent parietal activity was found at low level of difficulty while, with heavier task demand, several frontal regions and subcortical structures were recruited. Our results suggest peculiar gender strategies, with males relying more on visuospatial abilities and females on executive processing.

Early onset cerebellar ataxia with retained tendon reflexes: prevalence and gene frequency in an Italian population.

A genetic epidemiologic analysis of early onset cerebellar ataxias (EOCA) with retained tendon reflexes was performed in a defined area of Northwestern Italy. Forty cases diagnosed from 1940 to 1990 were ascertained. The ascertainment probability was 85.7%. The segregation analysis (Weinberg's proband method and 'singles' method under incomplete ascertainment) is compatible with autosomal recessive inheritance. The point prevalence ratio was 1.0/100,000 population. The birth incidence rate was 1/48,000 live births. Gene frequency was estimated to be 1/218. The ratio of first-cousin marriages among parents of EOCA (4.5%) was lower than expected using Dahlberg's formula (8.9%).

Reduced life expectancy in 40 cases of early onset cerebellar ataxia with retained tendon reflexes: a population-based study.

A survival analysis of 40 cases of early onset cerebellar ataxia (EOCA) with retained tendon reflexes was performed. They represent all cases of EOCA diagnosed between 1945 and 1990 among residents of a defined area of Northwestern Italy, followed up to December 31, 1990. The survival rates were respectively 92%, 87% and 77% at 10, 20 and 30-years, worse than expected in a disease which is usually considered benign. The relative death rate was 4 times higher than expected for the general population. Prognosis was significantly worse for males than for females, whereas the age of onset and the calendar year of onset did not affect survival.

Prognosis and clinical varieties of ALS disease.

210 cases of ALS disease in the period 1955-1979 are considered. Different parameters such as sex, age, duration and clinical course have been correlated with four clinical types: conventional, pseudopolyneuritic, pyramidal and bulbar. The age distribution shows a peak in the fifth decade of life. The sex ratio is 2.08:1. Considering together all the clinical types, the mean duration of the disease is 27.05 months. The bulbar variety has the poorest prognosis (19.6 months) and the pyramidal variety the best (37.59 months). Familiarity is evidenced in only 3 cases. All our data are discussed and compared with those of the literature.

Cerebellar syndrome in adult celiac disease with vitamin E deficiency.

We studied a woman with adult onset celiac disease complicated by a cerebellar syndrome that progressed despite the resolution of the malabsorption symptoms with a gluten free diet. The patient presented vitamin E deficiency and the cerebellar symptoms improved with vitamin E therapy. This case supports the possible role of this deficiency in the development of the neurological complications of celiac disease.

Primary progressive cerebellar ataxia.

Thirty-two patients with primary progressive cerebellar ataxia were studied using MRI. This technique is better than CT in demonstrating atrophy of cerebellar structures as well as of brainstem and spinal cord. The differential diagnosis from other diseases particularly with multiple sclerosis is easier. The degree of ataxia correlated well with the degree of atrophy of cerebellum. However we could not see any correlation between the degree of atrophy and the onset and duration of the disease and no certain specific aspects could be demonstrated in the different groups examined.

Motor neuron disease in the Province of Turin, Italy, 1971-1980.

The incidence and prevalence of motor neuron disease (MND) in the Province of Turin, North-West Italy, were investigated for the period 1971-1980. The crude incidence rate of MND was 0.67/100,000/year. The annual incidence rate, age and sex adjusted to the Italian population in 1971 was 0.69 cases per 100,000 inhabitants, 0.94 for men and 0.45 for women, with a male to female incidence ratio of 2.09:1. The prevalence of MND was 2.62/100,000, 3.57 for males and 1.71 for females. The mean age at the time of diagnosis was 55.6 years. Annual incidence rates increased with advancing age. Amyotrophic lateral sclerosis was found to be 4 times more frequent than progressive muscular atrophy (0.53/100,000/year v. 0.14/100,000/year). The distribution of MND was uneven in the Province suggesting a proportional relationship to the distribution of population density. Possible explanations of this finding are discussed.

Glutamate dehydrogenase (GDH) deficiency in different types of progressive hereditary cerebellar ataxia.

Leukocyte glutamate dehydrogenase (GDH) was studied in 29 patients affected by progressive cerebellar ataxia (PCA) and in 20 healthy controls. Eight GDH-deficient patients, with GDH activity 2 SD below mean value of controls, were identified. GDH deficiency did not identify a subgroup of PCA by characteristic pattern of inheritance and/or age of onset of disease. However, the GDH-deficient patients presented more neurological signs than non-GDH-deficient patients. A significant correlation was observed between GDH deficiency and the presence of extrapyramidal signs, supranuclear palsy, absence of osteotendineal reflexes and neurogenic electromyographical findings.

A survival analysis of 155 cases of progressive muscular atrophy.

We performed a survival analysis of 155 cases of progressive muscular atrophy (PMA). In about half the cases, hands were involved first, the lower limbs in 30% and the shoulder girdle in 23%. The lifetables of PMA, adjusted to the expected mortality, showed a survival rate of 61.3% and 56.4% at three and five years, respectively. The location of onset symptoms did not modify the life expectancy, whereas the age of the patients at the moment of first diagnosis had a great influence on the course of the disease. The patients were further subdivided in two groups on the basis of the diffusion of the neuromuscular damage at the moment of the diagnosis. The course of the patients with a localized disease was markedly better than that of subjects with widespread disease. Some hypotheses are made about the latter group of cases.