Optimisation of statistical methodologies for a better diagnosis of neurological and psychiatric disorders by means of SPECT

In the last years there has been a wide consensus on the importance of brain imaging in assessing neurodegenerative and psychiatric disorders. Different techniques for functional and anatomical examination are currently clinically implemented in neurology and psychiatry to improve sensitivity, specificity and accuracy of the diagnosis of various diseases. In addition, the increasing life expectancy in the Western world raises the social importance and the economical impact of age-related neurodegenerative disorders since the incidence of Alzheimer disease and Parkinson disease is higher in the elderly. An early diagnosis of neuro-psychiatric diseases and the assessment of "natural" changes of regional cerebral blood flow (rCBF) distribution during normal aging are hence of utmost importance. In the recent past brain disorders have extensively been investigated by means of optimised nuclear medicine techniques, instruments and algorithms. Diagnosis can be better achieved by identifying those structures in which CBF or metabolism deviate from normality resulting in significant changes as compared to a reference database. In the present paper we present some studies investigating, by means of recently implemented diagnostic tools, patients bearer of various neuro-psychiatric disorders. The improved nuclear medicine techniques and instrumentation, the state-of-the-art software for brain imaging standardisation and the use of sophisticated multivariate data analysis are extensively reviewed

Patients' and caregivers' perspectives: assessing an intensive rehabilitation programme and outcomes in Huntington's disease

Aim: To investigate the subjective evaluation of an intensive rehabilitation programme and outcomes by people with Huntington’s disease (HD) and their caregivers. Subjects and methods: A written questionnaire was mailed to people with mild-moderate HD (n = 40) who had completed at least one course of the intensive, inpatient rehabilitation protocol carried out at a facility of the Italian National Welfare System in the previous 3 years (on average 8.6 months before). Descriptive and inferential statistics were used. Thematic analyses were also conducted on written texts. Results: The response rate was 93%. A general improvement after discharge was perceived by all of the respondents. Improvements were reported on gait, balance, motor control, and fall reduction. Duration of benefits was estimated to last from 1 to 3 months by 71% of informants with no carry over to the next admission, which occurred on average 5.7 months later. Ameliorations were also reported in speech and swallowing, and several psychosocial aspects: mood, apathy, familiar and social relationships (binomial test, p < 0.05). As far as organisational aspects of structure and programme are concerned, all respondents expressed a positive evaluation (binomial test, p < 0.05). The mean vote given to the whole rehabilitation experience by patients on a 10-point scale was 7.3, confirmed by caregivers’ mean vote of 7.4. Additional free comments were added by the majority of respondents (n = 35). From caregivers’ and patient’s perspectives, relevant themes emerged. Conclusion: An intensive rehabilitation programme in people with HD is perceived to produce relevant improvements beyond bodily motor and functional performance. Patients’ and caregivers’ evaluations are relevant in health-care research in order to assess the worth of a programme and to define new ones

Optimisation of statistical methodologies for a better diagnosis of neurological and psychiatric disorders by means of SPECT

Abstract In the last years there has been a wide consensus on the importance of brain imaging in assessing neurodegenerative and psychiatric disorders. Different techniques for functional and anatomical examination are currently clinically implemented in neurology and psychiatry to improve sensitivity, specificity and accuracy of the diagnosis of various diseases. In addition, the increasing life expectancy in the Western world raises the social importance and the economical impact of age-related neurodegenerative disorders since the incidence of Alzheimer disease and Parkinson disease is higher in the elderly. An early diagnosis of neuro-psychiatric diseases and the assessment of &quot;natural&quot; changes of regional cerebral blood flow (rCBF) distribution during normal aging are hence of utmost importance. In the recent past brain disorders have extensively been investigated by means of optimised nuclear medicine techniques, instruments and algorithms. Diagnosis can be better achieved by identifying those structures in which CBF or metabolism deviate from normality resulting in significant changes as compared to a reference database. In the present paper we present some studies investigating, by means of recently implemented diagnostic tools, patients bearer of various neuro-psychiatric disorders. The improved nuclear medicine techniques and instrumentation, the state-of-the-art software for brain imaging standardisation and the use of sophisticated multivariate data analysis are extensively reviewed

Differences at brain SPECT between depressed females with and without adult ADHD and healthy controls: etiological considerations

<p>Abstract</p> <p>Background</p> <p>Comorbidity between Attention Deficit Hyperactivity Disorder (ADHD) and mood disorders is common. Alterations of the cerebellum and frontal regions have been reported in neuro-imaging studies of ADHD and major depression.</p> <p>Methods</p> <p>Thirty chronically depressed adult females of whom 16 had scores below, and 14 scores above, cut-offs on the 25-items Wender Utah Retrospective Scale (WURS-25) and the Wender-Reimherr Adult Attention Deficit Disorder Scale (WRAADDS) were divided into subgroups designated "Depression" and "Depression + ADHD", respectively. Twenty-one of the patients had some audiological symptom, tinnitus and/or hearing impairment. The patients were investigated with other rating scales and ^99mTc-HMPAO SPECT. Controls for ^99mTc-HMPAO SPECT were 16 healthy females. SPECT was analyzed by both statistical parametric mapping (SPM2) and the computerized brain atlas (CBA). Discriminant analysis was performed on the volumes of interest generated by the CBA, and on the scores from rating scales with the highest group differences.</p> <p>Results</p> <p>The mean score of a depression rating scale (MADRS-S) was significantly lower in the "Depression" subgroup compared to in the "Depression + ADHD" subgroup. There was significantly decreased tracer uptake within the bilateral cerebellum at both SPM and CBA in the "Depression + ADHD" subgroup compared to in the controls. No decrease of cerebellar tracer uptake was observed in "Depression". Significantly increased tracer uptake was found at SPM within some bilateral frontal regions (Brodmann areas 8, 9, 10, 32) in the "Depression + ADHD" subgroup compared to in "Depression". An accuracy of 100% was obtained for the discrimination between the patient groups when thalamic uptake was used in the analysis along with scores from Socialization and Impulsivity scales.</p> <p>Conclusion</p> <p>The findings confirm the previous observation of a cerebellar involvement in ADHD. Higher bilateral frontal ^99mTc-HMPAO uptake in "Depression + ADHD" compared to in "Depression" indicate a difference between these subgroups. ^99mTc-HMPAO uptake mechanisms are discussed.</p

Brain hypermetabolism in amyotrophic lateral sclerosis: a FDG PET study in ALS of spinal and bulbar onset

Specific biological markers for Autism Spectrum Disorder (ASD) have not yet been established. Functional studies have shown abnormalities in the anatomo-functional connectivity of the limbic-striatal "social" brain. This study aimed to investigate regional cerebral blood flow (rCBF) at rest. Thirteen patients with ASD of normal intelligence and ten IQ-, sex- and age-matched healthy controls (HC) underwent PET/CT using [1- 11 C]butanol, a perfusion tracer. As compared to HC, ASD showed significant CBF increases in the right parahippocampal, posterior cingulate, primary visual and temporal cortex, putamen, caudatus, substantia nigra and cerebellum. No statistically significant correlation between CBF and IQ was found. The limbic, posterior associative and cerebellar cortices showed increased blood flow in ASD, confirming previous findings about the neurobiology of ASD

Brain hypermetabolism in amyotrophic lateral sclerosis: A FDG PET study in ALS of spinal and bulbar onset.

Abstract Purpose To identify the neurobiological traits of amyotrophic lateral sclerosis (ALS) and to elucidate functional differences between ALS of spinal and bulbar onset. We hypothesized that glucose metabolism distribution might vary between groups. Methods The study groups comprised 32 patients with ALS of either bulbar (n=13) or spinal (n=19) onset and 22 subjects as controls. They were investigated by [ 18 F]fluorodeoxyglucose (FDG) positron emission tomography (FDG PET), comparing the patient groups with each other and with the controls by statistical parametric mapping. Results Highly significant relative increases in glucose metabolism distribution were found in the group comprising all 32 ALS patients as compared with the controls in the bilateral amygdalae, midbrain, pons and cerebellum. Relative hypermetabolism was also found in patients with spinal onset as compared with the controls in the right midbrain. In patients with bulbar onset compared with the controls and with patients with spinal onset, large relatively hypometabolic areas were found in the bilateral frontal cortex, right insula, anterior cingulate, precuneus and inferior parietal lobe. Patients with spinal onset had significantly higher scores in a neuropsychological test assessing verbal fluency compared with patients with bulbar onset. Conclusion This large FDG PET investigation provided unprecedented evidence of relatively increased metabolism in the amygdalae, midbrain and pons in ALS patients as compared with control subjects, possibly due to local activation of astrocytes and microglia. Highly significant relative decreases in metabolism were found in large frontal and parietal regions in the bulbar onset patients as compared with the spinal onset patients and the controls, suggesting a differential metabolic and neuropsychological state between the two conditions

A discussion on multi-way ANOVA using a permutation approach

We deal with permutation testing for balanced and unbalanced repeated measures designs and we consider a replicated homoscedastic (balanced or unbalanced) factorial design with fixed effects (Milliken et al., 1984) as the basic experimental plan. The design responses are measured in L time occasions. The usual linear model for responses is: y = {y ij(l) r = ...........................................................................................  so that, the null hypothesis H0 is true if all partial sub hypotheses are true. In order to test separately the overall null hypotheses, we jointly consider  the L measures, then the permutation solution is based on the nonparametric combination methodology (Pesarin, 2001). It is worth noting that the new permutation approach, presented here, is exact and, being conditional to the sufficient statistic represented by the data matrix it does not require normality of error terms in the linear model for responses.