Paola Basilico

CIRCULATING AND INTRATHECAL MIRNAS AS POTENTIAL BIOMARKERS FOR ALZHEIMER'S DISEASE

(A) CVS resulted in no behavioral differences in the Open Field Test. (B) In the Novel Object Recognition Test, CVS resulted in impairment among aging mice only

CSF β-amyloid as a putative biomarker of disease progression in multiple sclerosis.

Background: Neurodegeneration plays a major role in determining disability in multiple sclerosis (MS) patients. Hence, there is increasing need to identify reliable biomarkers, which could serve as prognostic measure of disease progression. Objectives: To assess whether cerebrospinal fluid (CSF) tau and β-amyloid (Aβ) levels were altered in newly diagnosed MS patients and correlated with disability. Moreover, we investigated whether these CSF biomarkers associate with macroscopic brain tissue damage measures. Methods: CSF Aβ and tau levels were determined by enzyme-linked immunosorbent assay in CSF samples from 48 newly diagnosed MS patients, followed-up clinically for 3 years by recording their Expanded Disability Status Scale score at 6-month intervals, and 45 controls. All patients underwent magnetic resonance imaging at baseline and at the end of follow-up to quantify their lesion load (LL). Results: CSF Aβ levels were significantly reduced in patients compared to controls (p < 0.001). Lower CSF Aβ levels at baseline were a disability predictor at 3-year follow-up (p = 0.009). CSF tau levels correlated with T2- and T1-LL (p < 0.001). Conclusion: CSF Aβ reduction is a promising biomarker of neurodegeneration and may predict patients’ clinical outcome. Therefore, CSF Aβ should be considered as a potential biomarker of prognostic value.

Molecular Basis of Young Ischemic Stroke

Epidemiological and family studies have provided evidence on the role of genetic factors in stroke, particularly in stroke occurring at young age. However, despite its impact, young stroke continues to be understudied. This article reviews the existing literature on the most investigated monogenic disorders (CADASIL, Fabry disease, MELAS, RVCL, COL4A1, Marfan and Ehlers-Danlos syndromes) causing stroke in young and a number of candidate genes associated with stroke occurring in patients younger than 50 years. Although our study failed in identifying strong and reliable associations between specific genes and young stroke, our detailed literature revision on the field allowed us to compile a panel of genes possibly generating a susceptibility to stroke, which could be a starting point for future research. Since stroke is a potentially preventable disease, the identification of genes associated with young stroke may promote novel prevention strategies and allow the identification of therapeutic disease targets.

CSF β-amyloid and white matter damage: a new perspective on Alzheimer’s disease

Objective To assess the connection between amyloid pathology and white matter (WM) macrostructural and microstructural damage in demented patients compared with controls. Methods Eighty-five participants were recruited: 65 with newly diagnosed Alzheimer’s disease (AD), non-AD dementia or mild cognitive impairment and 20 age-matched and sex-matched healthy controls. β-amyloid1-42 (Aβ) levels were determined in cerebrospinal fluid (CSF) samples from all patients and five controls. Among patients, 42 had pathological CSF Aβ levels (Aβ(+)), while 23 had normal CSF Aβ levels (Aβ(−)). All participants underwent neurological examination, neuropsychological testing and brain MRI. We used T2-weighted scans to quantify WM lesion loads (LLs) and diffusion-weighted images to assess their microstructural substrate. Non-parametric statistical tests were used for between-group comparisons and multiple regression analyses. Results We found an increased WM-LL in Aβ(+) compared with both, healthy controls (p=0.003) and Aβ(−) patients (p=0.02). Interestingly, CSF Aβ concentration was the best predictor of patients’ WM-LL (r=−0.30, p<0.05) when using age as a covariate. Lesion apparent diffusion coefficient value was higher in all patients than in controls (p=0.0001) and correlated with WM-LL (r=0.41, p=0.001). In Aβ(+), WM-LL correlated with WM microstructural damage in the left peritrigonal WM (p<0.0001). Conclusions WM damage is crucial in AD pathogenesis. The correlation between CSF Aβ levels and WM-LL suggests a direct link between amyloid pathology and WM macrostructural and microstructural damage.

The loss of macular ganglion cells begins from the early stages of disease and correlates with brain atrophy in multiple sclerosis patients

Background: The importance of neurodegeneration in multiple sclerosis (MS) is increasingly well recognized. Objectives: To evaluate retinal pathology using optical coherence tomography (OCT) and to investigate possible associations between retinal layers’ thickness and specific patterns of gray matter volume in patients with a new diagnosis of MS. Methods: A total of 31 patients underwent OCT scans and brain magnetic resonance imaging. In total, 30 controls underwent the same OCT procedure. The association between focal cortical volume and OCT measurements was investigated with voxel-based morphometry (VBM). Results: Compared to controls, patients’ macular retinal nerve fiber layer (mRNFL), macular ganglion cell layer (mGCL), macular inner plexiform layer (mIPL), and macular ganglion cell-inner plexiform layer (mGCIPL) thickness were significantly reduced (p = 0.0009, p = 0.0003, p = 0.0049, and p = 0.0007, respectively). Peripapillary RNFL (pRNFL) and temporal sector pRNFL (T-pRNFL) did not show any significant changes, although there was a trend toward T-pRNFL thinning (p = 0.0254). VBM analysis showed that mGCIPL and pRNFL were significantly correlated with the volume reduction of occipital-parietal cortex (p < 0.005). Conclusion: mRNFL, mGCL, and mIPL are significantly reduced in MS patients without concomitant pRNFL thinning. These retinal changes show a significant association with cortical regions that are known to be important for visuospatial performance.

CSF β-amyloid predicts prognosis in patients with multiple sclerosis.

Background: The importance of predicting disease progression in multiple sclerosis (MS) has increasingly been recognized, and hence reliable biomarkers are needed. Objectives: To investigate the prognostic role of cerebrospinal fluid (CSF) amyloid beta1–42 (Aβ) levels by the determination of a cut-off value to classify patients in slow and fast progressors. To evaluate possible association with white matter (WM) and grey matter (GM) damage at early disease stages. Methods: Sixty patients were recruited and followed up for 3–5 years. Patients underwent clinical assessment, brain magnetic resonance imaging (MRI; at baseline and after 1 year), and CSF analysis to determine Aβ levels. T1-weighted volumes were calculated. T2-weighted scans were used to quantify WM lesion loads. Results: Lower CSF Aβ levels were observed in patients with a worse follow-up Expanded Disability Status Scale (EDSS; r = −0.65, p < 0.001). The multiple regression analysis confirmed CSF Aβ concentration as a predictor of patients’ EDSS increase (r = −0.59, p < 0.0001). Generating a receiver operating characteristic curve, a cut-off value of 813 pg/mL was determined as the threshold able to identify patients with worse prognosis (95% confidence interval (CI): 0.690–0.933, p = 0.0001). No differences in CSF tau and neurofilament light chain (NfL) levels were observed (p > 0.05). Conclusion: Low CSF Aβ levels may represent a predictive biomarker of disease progression in MS.

Distinct patterns of brain atrophy in Genetic Frontotemporal Dementia Initiative (GENFI) cohort revealed by visual rating scales

BackgroundIn patients with frontotemporal dementia, it has been shown that brain atrophy occurs earliest in the anterior cingulate, insula and frontal lobes. We used visual rating scales to investigate whether identifying atrophy in these areas may be helpful in distinguishing symptomatic patients carrying different causal mutations in the microtubule-associated protein tau (MAPT), progranulin (GRN) and chromosome 9 open reading frame (C9ORF72) genes. We also analysed asymptomatic carriers to see whether it was possible to visually identify brain atrophy before the appearance of symptoms.MethodsMagnetic resonance imaging of 343 subjects (63 symptomatic mutation carriers, 132 presymptomatic mutation carriers and 148 control subjects) from the Genetic Frontotemporal Dementia Initiative study were analysed by two trained raters using a protocol of six visual rating scales that identified atrophy in key regions of the brain (orbitofrontal, anterior cingulate, frontoinsula, anterior and medial temporal lobes and posterior cortical areas).ResultsIntra- and interrater agreement were greater than 0.73 for all the scales. Voxel-based morphometric analysis demonstrated a strong correlation between the visual rating scale scores and grey matter atrophy in the same region for each of the scales. Typical patterns of atrophy were identified: symmetric anterior and medial temporal lobe involvement for MAPT, asymmetric frontal and parietal loss for GRN, and a more widespread pattern for C9ORF72. Presymptomatic MAPT carriers showed greater atrophy in the medial temporal region than control subjects, but the visual rating scales could not identify presymptomatic atrophy in GRN or C9ORF72 carriers.ConclusionsThese simple-to-use and reproducible scales may be useful tools in the clinical setting for the discrimination of different mutations of frontotemporal dementia, and they may even help to identify atrophy prior to onset in those with MAPT mutations.

Word and Picture Version of the Free and Cued Selective Reminding Test (FCSRT): Is There Any Difference?

The Free and Cued Selective Reminding Test (FCSRT) is the most commonly used neuropsychological test to evaluate episodic memory. Two variants of FCSRT exist, using the recall of words (FCSRT-w) or pictures (FCSRT-p). Fourteen patients with mild cognitive impairment underwent neuropsychological evaluation and brain magnetic resonance. We found differences in FCSRT-w and FCSRT-p variants scores. FCSRT-p was correlated with atrophy in areas involved in visual stimuli processing while FCSRT-w was correlated to hippocampal atrophy. Our study suggests that FCSRT-w and FCSRT-p scores are not equivalent, but a larger cohort of patients is needed to validate these results.

The Neuroanatomy of Somatoform Disorders: A Magnetic Resonance Imaging Study

BACKGROUND Somatoform disorders (SDs) are a heterogeneous group of psychiatric syndromes characterized by common symptoms, which may mimic a physical condition but they are not explained by a medical condition. Although the biologic nature of this disorder has been widely accepted, the neuroanatomical correlates characterizing SDs are still inconclusive. OBJECTIVE This study aims to explore gray matter (GM) volume alterations in SD patients compared to healthy controls and their possible association with clinical and cognitive measures. METHOD We used voxel-based morphometry to examine regional GM volumes in 20 inpatients with SDs and 24-matched healthy controls. Only for SD patients, we employed multiple instruments to assess psychopathology and cognitive functioning, which were then used to explore their association with GM volume deficits. RESULTS Compared to healthy controls, SD patients showed GM volume reductions in the hypothalamus, left fusiform gyrus, right cuneus, left inferior frontal gyrus, left posterior cingulate, and right amygdala (p < 0.05, cluster Family Wise Error corrected). Additionally, in SD, Symptom Checklist-90-Phobia and Hamilton Depressive Rating Scale scores negatively correlated with specific fronto-temporoparietal regions whereas Symptom Checklist-90-Sleep scores positively correlated with anterior cingulate cortex. Lastly, the Boston Naming Test negatively correlated with fronto-temporoparietal and striatal volumes whereas Free and Cued Selective Reminding Test and Stroop scores positively correlated with superior temporal gyrus and cuneus, respectively (all p < 0.05, cluster Family Wise Error corrected). CONCLUSION Our results suggest that SDs might be characterized by selective impairments in specific cortico-limbic regions associated to two overlapping circuits, the neuromatrix of pain and the emotion regulation system.

Hallucinations in Neurological Disorders

Hallucinations are present in many nonpsychiatric subjects. Indeed, these false perceptions are frequently observed in degenerative and non-degenerative neurological disorders. In this chapter, we aim to describe the phenomenology, pathogenesis, and available therapies for hallucinations in these neurological conditions.