Clinical and radiological features of posterior cortical atrophy (PCA) in a GRN mutation carrier: a case report.

BACKGROUND AND PURPOSE: Posterior cortical atrophy (PCA) is a rare neurodegenerative syndrome, defined by a distinctive clinical-radiological profile, with Alzheimer's disease (AD) pathology accounting for the majority of cases. The aim of this report was to present the case of a patient with impairment of visual and constructional abilities as initial manifestations. METHOD: The patient underwent a multidimensional assessment, including neuropsychological evaluation, structural and functional imaging and genetic screening. RESULTS: Neurological and neuropsychological assessment showed an impairment of constructive and visuo-spatial skills, associated with dyscalculia, simultanagnosia, optic ataxia and oculomotor apraxia. In accordance with the latest consensus criteria, a diagnosis of PCA was made. Consistent with the clinical findings, structural and functional imaging showed a peculiar pattern of atrophy with primary involvement of right parieto-occipital cortices, whereas cerebrospinal fluid biochemical analysis did not reveal a profile compatible with AD pathology. Genetic screening identified a known pathogenic GRN mutation. CONCLUSION: We present a case of PCA in a GRN mutation carrier in whom a concomitant AD pathological process was excluded. Consequently, although lacking histological data, our case suggests GRN-related pathology causative of PCA. Through this report we provide further evidence for a new neurodegenerative pathway leading to PCA, extending the clinical spectrum of GRN-associated phenotypes.

A kinetics-based approach to amyloid PET semi-quantification.

PURPOSE: To develop and validate a semi-quantification method (time-delayed ratio, TDr) applied to amyloid PET scans, based on tracer kinetics information. METHODS: The TDr method requires two static scans per subject: one early (~ 0-10 min after the injection) and one late (typically 50-70 min or 90-100 min after the injection, depending on the tracer). High perfusion regions are delineated on the early scan and applied onto the late scan. A SUVr-like ratio is calculated between the average intensities in the high perfusion regions and the late scan hotspot. TDr was applied to a naturalistic multicenter dataset of 143 subjects acquired with [18F]florbetapir. TDr values are compared to visual evaluation, cortical-cerebellar SUVr, and to the geometrical semi-quantification method ELBA. All three methods are gauged versus the heterogeneity of the dataset. RESULTS: TDr shows excellent agreement with respect to the binary visual assessment (AUC = 0.99) and significantly correlates with both validated semi-quantification methods, reaching a Pearson correlation coefficient of 0.86 with respect to ELBA. CONCLUSIONS: TDr is an alternative approach to previously validated ones (SUVr and ELBA). It requires minimal image processing; it is independent on predefined regions of interest and does not require MR registration. Besides, it takes advantage on the availability of early scans which are becoming common practice while imposing a negligible added patient discomfort.

Source-Based Morphometry Multivariate Approach to Analyze [123I]FP-CIT SPECT Imaging.

PURPOSE: [123I]FP-CIT (DaTSCAN®) single-photon emission computed tomography (SPECT) imaging is widely used to study neurodegenerative parkinsonism, by measuring presynaptic dopamine transporter (DAT) in striatal regions. Beyond DAT, [123I]FP-CIT may be considered for other monoaminergic systems, in particular the serotonin transporter (SERT). Independent component analysis (ICA) implemented in source-based morphometry (SBM) could represent an alternative method to explore monoaminergic pathways, studying the relationship among voxels and grouping them into "neurotransmission" networks. PROCEDURES: One hundred forty-three subjects [84 with Parkinson's disease (PD) and 59 control individuals (CG)] underwent DATSCAN® imaging. The [123I]FP-CIT binding was evaluated by multivariate SBM approach, as well as by a whole-brain voxel-wise univariate (statistical parametric mapping, SPM) approach. RESULTS: As compared to the univariate whole-brain approach (SPM) (only demonstrating striatal [123I]FP-CIT binding reduction in PD group), SBM identified six sources of non-artefactual origin, including basal ganglia and cortical regions as well as brainstem. Among them, three sources (basal ganglia and cortical regions) presented loading scores (as index of [123I]FP-CIT binding) significantly different between PD and CG. Notably, even if not significantly different between PD and CG, the remaining three non-artefactual sources were characterized by a predominant frontal, brainstem, and occipito-temporal involvement. CONCLUSION: The concept of source blind separation by the application of ICA (as implemented in SBM) represents a feasible approach to be considered in [123I]FP-CIT (DaTSCAN®) SPECT imaging. Taking advantage of this multivariate analysis, specific patterns of variance can be identified (involving either striatal than extrastriatal regions) that could be useful in differentiating neurodegenerative parkinsonisms.

Impulse control disorder in PD: A lateralized monoaminergic frontostriatal disconnection syndrome?

BACKGROUND: Impulse Control Disorder symptoms (ICD) in Parkinson's disease (PD) has been recently associated by magnetic Resonance imaging with impaired cortico-striatal connectivity, especially between left putamen and frontal associative areas. METHODS: 84 patients entered the study (21 PD-ICD+ and 64 PD-ICD-) and underwent DATSCAN imaging. The striatal tracer uptake was evaluated using BRASS software (Hermes, Sweden). The whole-brain analysis was performed with Statistical Parametric Mapping (SPM). RESULTS: PD-ICD+ showed a significant reduction of left putaminal and left inferior frontal gyrus tracer uptake compared to PD-ICD-. Functional covariance analysis using left putamen as the seed point showed that, in contrast to ICD-patients, ICD+ patients had no functional covariance with contralateral basal ganglia and ipsilateral cingulate cortex, as index of an impaired inter- and intra-hemispheric dopamine binding in PD-ICD+. DISCUSSION: the results support and expand the concept of a functional disconnection syndrome linked to ICD symptoms in PD patients through an asymmetric molecular frontostriatal network breakdown with left basal ganglia as central hub.

Evaluation of patients with coronary artery disease. IQ-SPECT protocol in myocardial perfusion imaging: Preliminary results.

UNLABELLED: Quantification of myocardial perfusion scintigraphy is often performed to assist physicians in detecting coronary artery disease (CAD). Modern software and hardware packages provide improvements able to shorten scan time and/or reduce administered activity, without compromising image quality in radionuclide myocardial perfusion imaging (MPI). Recently, multifocal collimators were introduced with dedicated reconstruction software, named IQ-SPECT, able to shorten considerably scan time. The aim of our study was to compare this new protocol to the already validated standard ones. PATIENTS, METHODS: We enrolled 43 patients with suspected or diagnosed CAD. All patients underwent a two-days protocol radionuclide myocardial perfusion scan at rest and after a standard stress test (exercise or dipyridamole) after administering 99mTc-tetrofosmin. Images were acquired on a 2-head gamma camera and reconstructed with attenuation correction. All the images were scored using a 17-segments model by three experienced physicians, blind to clinical data and to acquisition and processing modality. RESULTS, CONCLUSION: No significant differences were recorded in perfusion scores on paired t-test and Wilcoxon among the full-time images reconstructed with standard protocol or IQ-SPECT, both overall on a 17-segments evaluation and when considering different territories of distribution. MPI with IQ-SPECT protocol can be acquired at about a quarter scan time without disagreement compared to full time scan acquisition performed with standard protocols.

Neuroanatomical correlates of behavioural phenotypes in behavioural variant of frontotemporal dementia.

BACKGROUND: Behavioural variant of frontotemporal dementia (bvFTD) frequently presents complex behavioural changes, that rarely occur in isolation. Targeting behavioural phenotypes instead of single behavioural symptoms may potentially provide a disease model in which to investigate brain substrates of behavioural abnormalities. OBJECTIVE: To identify behavioural phenotypes and to assess the associated brain correlates in a cohort of patients with bvFTD. METHODS: Two hundred and seven consecutive individuals fulfilling clinical criteria for bvFTD were enrolled. Each participant's caregiver completed frontal behavioural inventory on 24 key behavioural disturbances. Confirmatory factor analysis (CFA) models were applied, and behavioural phenotypes identified. For each phenotype, a score was derived based on the "best" CFA model (Bifactor CFA). One hundred two participants underwent SPECT scan. A regression analysis between scores for each factor and regional cerebral blood flow was carried out (P<0.001). RESULTS: One "general" behavioural phenotype and four factors were identified, that were termed "disinhibited", "apathetic", "aggressive", and "language" phenotypes. The most robust brain correlate was identified for "disinhibited" phenotype, in the region of the anterior cingulated and anterior temporal cortex, bilaterally, and for apathetic phenotype in the left dorsolateral frontal cortex. As expected, language phenotype correlated with greater hypoperfusion in the left frontotemporal lobes. No significant correlation between aggressive phenotype and regional cerebral blood flow was found. Moreover, the "general" behavioural severity was associated with greater damage in the right frontal lobe. CONCLUSIONS: Behavioural phenotypes are associated with specific brain damage in bvFTD, involving distinct cerebral networks.

Nature versus nurture in frontotemporal lobar degeneration: the interaction of genetic background and education on brain damage.

BACKGROUND: Frontotemporal lobar degeneration (FTLD) is a progressive neurodegenerative disorder with a strong genetic background. It has been reported that modifiable factors, i.e. education (E), might act as proxies for reserve capacity. OBJECTIVE: To evaluate the impact of genetic background (positive family history, FH) on reserve mechanisms, by measuring regional cerebral blood flow (rCBF) correlates in FTLD patients. METHODS: 145 FTLD patients were recruited and underwent clinical, neuropsychological, behavioral assessment, and SPECT study. The main effect of E and FH on rCBF was evaluated. To test the potential interaction between the E and rCBF in FTLD patients with or without positive FH, a difference of slope analysis in the two groups was calculated. All the analyses were controlled for disease severity (Clinical Dementia Rating Scale, FTD-CDR). RESULTS: A main effect of education (E+ < E-) in frontal regions was reported, and high genetic loading (FH+ < FH-) was associated with a greater bilateral temporoparietal hypoperfusion. Evaluating the relationship between E and rCBF, a greater hypoperfusion of cingulate region in FH+ as compared to FH- was observed. DISCUSSION: Reserve mechanisms are available also in presence of an unfavorable genetic status. However, these compensatory mechanisms are modulated by the interaction with genetic factors.

The new Alzheimer's criteria in a naturalistic series of patients with mild cognitive impairment.

To test the validity of the new diagnostic criteria for Alzheimer's disease (AD) in a naturalistic series of patients with mild cognitive impairment (MCI). Ninety consecutive MCI patients were enrolled in a longitudinal study on the natural history of cognitive impairment. Medial temporal (MT) atrophy on MRI was defined as hippocampal volume below the fifth percentile of the distribution in healthy elders, abnormal CSF was based on Sjogren's cutoffs for Abeta42 and tau, and temporoparietal hypometabolism on 18F-FDG PET based on Herholz's t sum score. Patients were followed clinically to detect conversion to AD (MCI-AD), non-AD dementia (MCI-nAD), or no conversion (MCI-NC). The 24 MCI-AD and 15 MCI-nAD patients had sociodemographic, clinical, and neuropsychological baseline features similar to the 51 MCI-NC patients. All MCI patients with MT atrophy converted to AD, as did all those with abnormal CSF, but only 48 and 35% of those without MT atrophy or abnormal CSF converted (p on logrank test = 0.0007 and 0.001). Prediction of AD conversion was enhanced when positivity to either MT atrophy or abnormal CSF was considered, with only 15% of those MCI patients negative on both converting to AD (p < 0.0005). Markers were not predictive of non-AD dementia conversion. The accuracy of either MT atrophy or abnormal CSF in discriminating MCI-AD from MCI-NC was good (AUC 0.82, 95% CI 0.70-0.95). MT atrophy and abnormal CSF are the single most robust predictors of conversion to AD in MCI patients, and their combination enhances prediction. AD markers are not predictive of conversion to non-AD dementia.

¹³¹I treatment of toxic nodular goiter under combined thyrostatic-thyromimetic medication is at low risk of late hypothyroidism.

AIM: Treatment of toxic nodular goiter with ¹³¹I is a first-line therapy for hyperthyroidism. To avoid a thyrotoxic storm, ¹³¹I is usually administered after pretreatment with antithyroid drugs, with thyroid-stimulating hormone (TSH) increase and functional recruitment of inhibited normal tissue. Therefore, both autonomous nodule(s) and normal tissue are irradiated. This may be a reason for late hypothyroidism occurring in 15-25% of patients. This study aimed at assessing different pretreatment modalities with combined methymazole and triiodothyronine, achieving euthyroidism with suppressed TSH. METHODS: After diagnosis of autonomously functioning toxic nodule, patients were subjected to thyrostatic medication. Two months later, TSH was checked; if >0.5 mU/L triiodothyronine treatment was associated. After 2 more months, if the TSH level was suppressed, patients received ¹³¹I-therapy. A total of 149 patients were consecutively enrolled, 41 of whom with uninodular and 108 with multinodular goiter. They were evaluated at diagnosis, pretreatment, 3 and 6 months after therapy and at late follow-up (6.8+/-4.2 years; range: 1-22 years). RESULTS: Administered activity was calculated according to ¹³¹I uptake and gland weight. Methymazole was discontinued 6 days before treatment and T3 was maintained until administration of ¹³¹I-therapy. Euthyroidism was achieved in 88% of patients. At late follow-up, subclinical hypothyroidism was observed in 10 patients (6.7%) and overt hypothyroidism in 5 patients (3.3%). No pathological consequences or side effects of ¹³¹I-therapy were found during the 6.8+/-4.2 year follow-up period. CONCLUSION: Treatment of toxic nodular goiter with ¹³¹I-therapy, under combined thyrostatic-thyromimetic treatment is a simple, safe, well-tolerated, and effective procedure.

Metabolic compensation and depression in Alzheimer's disease.

BACKGROUND/AIMS: The aim of this study was to map metabolic compensation and depression in Alzheimer's disease (AD) on a voxel-by-voxel basis. METHODS: Twenty-one healthy elderly subjects and 25 AD patients underwent cerebral MR and FDG-PET imaging. All images were processed with SPM2, and whole-brain gray matter (GM) atrophy and hypometabolism maps were computed. Metabolic compensation and depression were assessed using Biological Parametric Mapping software. RESULTS: GM atrophy and hypometabolism mapped to similar regions, with varying degrees of severity. Significant metabolic compensation was found in the amygdala, while exceeding hypometabolism was mainly located in the posterior cingulate cortex. CONCLUSION: Metabolic depression can be due to both distant effects of atrophy and to additional hypometabolism-inducing factors, such as amyloid deposition. Conversely, metabolic compensation could reflect spared synaptic plasticity of the surviving neurons. The investigation of the metabolic compensation mechanism could help in the comprehension of the AD underlying pathology.

The FTLD-modified Clinical Dementia Rating scale is a reliable tool for defining disease severity in frontotemporal lobar degeneration: evidence from a brain SPECT study.

BACKGROUND: Frontotemporal Lobar Degeneration (FTLD) is a heterogeneous disorder characterized by impairment in executive functions, behavioural disturbance and language deficit. Reliable scales of global impairment are under evaluation. A consortium of Mayo Clinic and University of California FTLD Centers has recently developed the FTLD-modified Clinical Dementia Rating (CDR) scale to assess FTLD severity. OBJECTIVE: To evaluate whether FTLD-modified CDR scores correlate with the pattern and degree of brain SPECT hypoperfusion in patients with FTLD. METHODS: Ninety-nine patients with FTLD entered the study. Patients underwent a clinical evaluation and a wide standardized neuropsychological assessment, including mini-mental state examination (MMSE) and FTLD-modified CDR. A brain SPECT perfusion imaging study was carried out in each patient. A linear correlation analysis between frontotemporal dementia-modified CDR or neuropsychological tests scores and perfusion data was performed. RESULTS: There was a significant relationship between higher FTLD-modified CDR score and lower global regional cerebral blood flow in the frontal and temporal lobes, bilaterally. No significant correlation between MMSE and brain frontotemporal hypoperfusion was found. The correlation between brain hypoperfusion pattern and neuropsychological test scores tapping different cognitive domains fitted with previously published data. CONCLUSIONS: The recently introduced FTLD-modified CDR scale correlates with the degree of frontotemporal hypoperfusion in patients with FTLD. This study confirms and further supports the usefulness of FTLD-modified CDR in future clinical trials to monitor disease progression.

Revisiting brain reserve hypothesis in frontotemporal dementia: evidence from a brain perfusion study.

BACKGROUND: Literature data on Alzheimer's disease suggest that years of schooling and occupational level are associated with a reserve mechanism. No data on patients with behavioral variant frontotemporal dementia (bvFTD) are available yet. OBJECTIVE: To evaluate the impact of education, occupation, and midlife leisure activities on brain reserve in bvFTD. METHODS: Fifty-four bvFTD patients entered the study and underwent neuropsychological and behavioral assessment, including the FTD-modified Clinical Dementia Rating for FTD (FTD-modified CDR), and SPECT imaging. We tested for the linear correlation of educational and occupational level, and midlife leisure activities with regional cerebral blood flow (rCBF), controlling for demographic variables (age and gender) and for cognitive performance (FTD-modified CDR) (statistical parametric mapping). RESULTS: A significant relationship between higher educational and occupational attainments and lower rCBF in medial frontal cortex and dorsolateral frontal cortex, bilaterally, was found (p < 0.005). When midlife leisure activities were considered, no correlation was found. The correlation between a reserve index, accounting for both educational and occupational level, and rCBF showed the same pattern of hypoperfusion. CONCLUSIONS: This study suggests that education and occupation act as proxies for reserve capacity in bvFTD. These lifestyle attainments may counteract the onset of this genetic-based disease in at-risk individuals.

Survival in frontotemporal lobar degeneration and related disorders: latent class predictors and brain functional correlates.

BACKGROUND: Establishing survival rate in frontotemporal lobar degeneration (FTLD) is a clinical challenge for defining disease outcomes and monitoring therapeutic interventions. Using the latent profile analysis (LPA) approach, we have previously suggested that FTLD patients can be grouped into specific phenotypes- "pseudomanic behavior" (LC1), "cognitive" (LC2), and "pseudodepressed behavior" (LC3)-on the basis of neuropsychological, functional, and behavioral data. OBJECTIVE: The aim of this study was to evaluate the rate of survival in FTLD, to identify predictors of survival, and to determine the likely usefulness of LPA in defining prognosis. METHODS: A total of 252 FTLD patients entered the study. A clinical evaluation and standardized assessment were carried out, as well as a brain imaging study. LPA on neuropsychological, functional, and behavioral data was performed. Each patient was followed up over a 5-year period, and institutionalization or death was considered. RESULTS: The survival rate was associated neither with demographic characteristics, co-morbidities, family history for dementia, nor clinical diagnosis. The presence of the three LC phenotypes was confirmed by LPA. A different survival rate was predicted by LCs, the worse prognosis being found in LC1 (hazard ratio [HR] = 15.7, 95% confidence interval [CI] = 7.2-34.9, p < 0.001, reference LC3). LC2 had a worse prognosis compared to LC3 (HR = 2.07, 95% CI = 0.98-4.37, p = 0.06). Greater hypoperfusion in the orbitomesial frontal cortex was specifically associated with LC1 compared with the other LCs. CONCLUSIONS: A data-driven approach regarding neuropsychological and behavioral assessment might be useful in clinical practice for defining a FTLD prognosis and hopefully will lead to the possibility of identifying patient groups for the evaluation of treatment response in future trials.

Tau haplotype influences cerebral perfusion pattern in frontotemporal lobar degeneration and related disorders.

OBJECTIVE: The modulating factors on phenotypic expression of frontotemporal lobar degeneration (FTLD) remain still unknown. The aim of this study was to determine whether tau genetic variability modulates the brain functional and the clinical phenotypic expression of FTLD. MATERIALS AND METHODS: Clinical and neurological evaluations, a standardized neuropsychological assessments as well as a brain single photon emission tomography perfusion imaging studies were performed in 48 FTLD patients. Cerebral perfusion patterns were analysed according to H1 or H2 tau haplotypes by statistical parametric mapping and principal component analysis. RESULTS: Two different patterns of cerebral dysfunction characterized the haplotypes, as hypoperfusion of frontal medial and cingulated cortex in H2-carriers and a prevalent involvement of posterior parietal regions in H1-carriers. Further, a significant increase of cerebrospinal fluid total tau and phospho tau levels was found in H2-carriers. CONCLUSIONS: These findings support a role of tau haplotype in modulating disease phenotype by influencing the hypoperfusion pattern and cerebrospinal fluid tau levels in FTLD.

Combined 99mTc-ECD SPECT and neuropsychological studies in MCI for the assessment of conversion to AD.

Identifying pre-clinical Alzheimer's disease (AD) in subjects with mild cognitive impairment (MCI) is a major issue in clinical diagnosis. Establishing a combination of predictive markers from different fields of research might help in increasing the diagnostic accuracy. Aim of this study was to evaluate the potential role of 99mTc-ECD single photon emission computed tomography (SPECT) and memory scores in predicting conversion to AD in MCI subjects. Thirty-one MCI subjects underwent a clinical and neuropsychological examination, and a regional cerebral blood flow (rCBF) SPECT scan at baseline. Subjects had been followed periodically through 2 years in order to monitor the progression of cognitive symptoms. Canonical variate analysis of principal components was able to separate all subjects who converted to AD from those who remained stable, the former being characterized by a specific hypometabolic pattern, involving the parietal and temporal lobes, precuneus, and posterior cingulate cortex. Canonical correlation analysis of combined baseline memory deficits and rCBF SPECT images identified pre-clinical AD with a sensitivity and specificity of 77.8%. The pattern of hypoperfusion 99mTc-ECD SPECT and the severity of memory deficits predict the risk of progression to probable AD dementia in MCI subjects.

Crossed aphasia with left spatial neglect and visual imperception: a case report.

A 64-year-old right-handed woman with no left-handers in the family developed aphasia associated with moderate left hemiparesis and dense left homonymous hemianopia following rupture of a right middle cerebral artery aneurysm and subsequent selective surgery confined to the right hemisphere. Severe left spatial neglect and constructional apraxia were also present. The patient was an achondroplasic dwarf whose previous medical and neurological history was otherwise unremarkable. Computed tomography of the brain showed a large right temporo-insulofrontoparietal lesion. Language and nonverbal cognitive functions were assessed after 2 and 6 months, and then four years later. A reportedly overall language disruption in the acute period evolved into Wernicke's aphasia and then into a mild form of conduction aphasia. The associated left spatial neglect eventually shrank to a minimum. The patient never had clinically detectable visual agnosia, but on specific tests of visual recognition and perception some impairment was found four years after onset. The left hemiparesis disappeared in time while the left hemianopia persisted. This case is a convincing example of an entirely righthanded person in whom both linguistic and visuospatial functions are represented in the right hemisphere.