Bipolar disorders and deep grey matter in multiple sclerosis: A preliminary quantitative MRI study.

BACKGROUND: Bipolar disorder (BD) is frequently observed in patients affected by multiple sclerosis (MS), presenting a lifetime estimate of around 8%. However, uncertainty exists on the brain damage associated with this psychiatric comorbidity. This study aimed to investigate the effect of brain atrophy, particularly that of the subcortical grey matter (scGM) structures that notoriously regulate the affective functioning, on the co-occurrence of BD in patients with MS. METHODS: A group of patients with MS affected by BD and a control group of patients with MS without any mood/psychiatric disorder, as defined using standardised diagnostic tools (Advanced Neuropsychiatric Tools and Assessment Schedule), were recruited. The patients underwent brain MRI, and the volumes of the whole brain (WB), white matter (WM), and grey matter (GM) were estimated using SIENAX. Thus, the scGM volumes of the putamen, caudate, thalamus, hippocampus, amygdala, nucleus accumbens, and pallidus were estimated using the FIRST tool. RESULTS: The sample included 61 patients with MS, amongst whom 15 (24.6%) had BD. No differences in the WB, WM, and cortical GM volumes were observed between the patients with MS with and without BD. Conversely, the multiple regression analysis revealed a significant association of BD with lower volumes of the putamen (p = 0.032), nucleus accumbens (p = 0.029), and pallidus (p = 0.061; with a trend towards significance), independently from the demographic and MS clinical features. CONCLUSIONS: Our preliminary results indicated that the nucleus accumbens and putamen are smaller in MS patients with BD. Further investigations in larger cohorts of MS patients with affective disorders are necessary to confirm these data and understand the structural brain damage underlying this psychiatric comorbidity.

The impact of deep grey matter volume on cognition in multiple sclerosis.

BACKGROUND: Cognitive dysfunctions are very frequent in people living with multiple sclerosis (MS). Several studies have previously indicated grey matter (GM) atrophy as useful predictor of patients' cognitive impairment. However, considerable uncertainty exists about the possible impact of deep grey matter volumes on cognition. This study aimed to evaluate the relationship of the subcortical (sc) GM volumes with the presence and severity of global and selective cognitive impairment in MS. METHODS: A group of MS patients with relapsing remitting course were enrolled. Patients underwent a neuropsychological evaluation by using the Brief Repeatable Battery of Neuropsychological Tests (BRBN) and the Delis-Kaplan Executive Function System Sorting Test (D-KEFST); z scores were estimated and items with z score below 2 standard deviation were considered failed. Thus, brain MRIs images were acquired and measurements of whole brain (WB), white matter (WM), and cortical grey matter (GM) were obtained by SIENAX. After FIRST tool segmentation, volumes of subcortical GM structures were also estimated. RESULTS: The sample included 50 MS patients, of which 16/50 (32%) subjects were cognitively impaired. Multiple regression analyses found a significant association of severity of cognitive impairment, defined as number of failed neuropsychological tests, with lower volumes of cortex (p=0.003), thalamus (p=0.009), caudate (p=0.011), putamen (p=0.020), pallidus (p=0.012) and hippocampus (p=0.045), independently from other MS features. In addition, an association between accumbens volume and D-KEFS ST FSC and D-KEFS ST FSD z scores was observed (p<0.03). CONCLUSIONS: Our results indicated that volumes of several scGM structures, and in particular of thalamus, contribute to determine cognitive dysfunctions in MS, mainly influencing the executive functioning. Further investigations in larger MS cohorts with cognitive impairment are necessary to better understand the structural brain damage underlying this "invisible disability".

Assessing the burden of vascular risk factors on brain atrophy in multiple sclerosis: A case- control MRI study.

BACKGROUND: Some studies have indicated the importance of considering the presence of vascular comorbidities as negative prognostic factors for MRI outcomes in multiple sclerosis (MS). This study aimed to evaluate the possible influence of the most frequent vascular risk factors on brain volume in MS, also exploring the burden of their combined effects. METHODS: MS patients with at least one vascular risk factor and a control group of MS patients were enrolled. Patients underwent brain MRI and the volumes of the whole brain (WB), white matter (WM), grey matter (GM), and cortical GM were estimated by SIENAX. Longitudinal atrophy was assessed by SIENA. RESULTS: The sample included 326 MS patients, of these 49 (15%) had diabetes mellitus, 44 (13.4%) hypertension and 50 (15.3%) were active smokers. Multiple regression analyses revealed that diabetes mellitus was associated with significant reductions in WB (p = 0.03), GM and cortical GM (p = 0.01) volumes. Similarly, reduced cortical GM volume was associated with hypertension (p < 0.05). A strong relationship between the co-occurrence of multiple vascular risk factors and lower cortical GM volume (p = 0.007) was also identified. Ninety patients were included in the longitudinal study and a greater annualized brain volume loss was found in those with at least one vascular risk factor than in the control group (-1.05% vs. -0.58%, p = 0.005). CONCLUSIONS: Our results show that the vascular comorbidities affect brain atrophy, indicating that these conditions should be carefully monitored in patients with MS with a focus on limiting brain damage.

Adult brain volume in multiple sclerosis: The impact of paediatric onset.

BACKGROUND: Paediatric onset multiple sclerosis (POMS) is associated with reduced brain and deep grey matter volume in comparison with that in healthy controls and individuals with adult onset multiple sclerosis (AOMS). The aim of our study was to evaluate the impact of POMS on adult brain volume with adjustment for other parameters, such as disease duration. PATIENTS AND METHODS: We recruited 20 POMS and 40 AOMS patients and 20 healthy controls matched for age and sex. All study participants were adults at the time of inclusion in the study. All study subjects underwent brain magnetic resonance imaging (MRI) to evaluate whole brain, white matter, grey matter, cortical, and deep grey matter volumes. Clinical features, such as the Expanded Disability Status Scale (EDSS) score and disease duration, were also assessed. RESULTS: Brain (p = 0.01), grey matter (p = 0.01), and deep grey matter volume (p = 0.03) was significantly lower in POMS patients than in AOMS patients, while no differences were detected in the volume of white matter or cortical grey matter. A multiple linear regression analysis showed a relationship between brain volume (dependent variable) and the independent variables age (p < 0.000) and paediatric onset (p < 0.001), while other independent variables, including disease duration, sex, and disability, were not significantly different among groups. There were significant differences in thalamic volume among POMS and AOMS patients and healthy controls. CONCLUSION: Our data support the previous findings that POMS patients have reduced brain and deep grey matter volume, particularly thalamic volume, compared with sex- and age-matched AOMS patients and healthy controls. These findings appear to be independent of disease duration and other clinical features.

Cognition in multiple sclerosis: Between cognitive reserve and brain volume.

BACKGROUND: Several correlations between cognitive impairment (CI), radiologic markers and cognitive reserve (CR) have been documented in MS. OBIECTIVE: To evaluate correlation between CI and brain volume (BV) considering CR as possibile mitigating factor. METHODS: 195 relapsing MS patients underwent a neuropsychological assessment using BICAMS. BV was estimated using SIENAX to obtain normalized volume of brain (NBV), white matter (NWV), gray matter (NGV) and cortical gray matter (CGV). CR was estimated using a previously validated tool. RESULTS: Pearson test showed a correlation between the symbol digit modality test (SDMT) score and NBV (r=0.38; p<0.000) NGV(r=0.31; p<0.000), CGV (r=0.35; p<0.000) and CRI score(r=0.42; p<0.000). Linear regression (dependent variable:SDMT) showed a relationship with CR scores (p=0.000) and NGV(p<0.000). A difference was detected between cognitive impaired and preserved patients regarding mean of NBV(p=0.002), NGV(p=0.007), CGV(p=0.002) and CR Scores (p=0.007). Anova showed a association between the presence of CI (dependent variable) and the interaction term CRIQ × CGV (p=0.004) whit adjustment for age and disability evaluated by EDSS. CONCLUSIONS: Our study shows a correlation between cognition and BV, in particular gray matter volume. Cognitive reserve is also confirmed as an important element playing a role in the complex interaction to determine the cognitive functions in MS.

Brain volume in early MS patients with and without IgG oligoclonal bands in CSF.

BACKGROUND: Oligoclonal bands of IgG (OB) are proposed as an early prognostic factor of the disease. Growing attention is directed towards brain volume evaluation as a possible marker of the severity of MS. Previous studies found that MS patients lacking OB have less brain atrophy. AIM: to evaluate a possible relationship between OB and cerebral volume in a cohort of early MS patients. METHODS: Inclusion criteria were: diagnosis of relapsing-remitting MS; CSF analysis and MRI acquired simultaneously and within 12 months from clinical onset. A total of 15 healthy controls underwent MRI. RESULTS: In 20 MS patients, CSF analysis did not show OB synthesis (OB negative group). A control group of 25 MS patients in whom OB was detected was also randomly recruited (OB positive group). T test showed a significant difference in NWV between the OB positive and OB negative groups (P value = 0.01), and between the OB positive group and the healthy controls (P value = 0.001). No differences were detected between OB negative group and healthy controls. Multivariable linear regression showed a relationship between NWV and OB synthesis (P value = 0.02) controlling for age, gender, and EDSS. CONCLUSIONS: Our preliminary results suggest that OB positive patients show more atrophy of white matter since early phases of the disease, supporting the role of CSF analysis as a prognostic factor in MS.

Characterization of implant materials in fetal bovine serum and sodium sulfate by electrochemical impedance spectroscopy. II. Coarsely sandblasted samples.

Electrochemical impedance spectroscopy is used to investigate the corrosion resistance of coarsely sandblasted implant alloys, commercially pure titanium, Ti6Al4V, Ti6Al7Nb, and CoCrMo in 0.1M sodium sulfate and fetal bovine serum. Coarsely sandblasted samples have a heterogeneous surface constituted by a large number of protrusions and recessions. Impedance spectra collected in sodium sulfate present two time constants (maxima in the phase-angle of the bode plot) associated with the total surface and with the tips, respectively. In bovine serum, the two maxima in the impedance spectra cannot be distinguished because of the formation of an adsorption layer of organic molecules, which causes a decrease in the values of both the total and tips' capacitances as well as an increase in the polarization resistance. Ti6Al4V and Ti6Al7Nb show the highest corrosion rate both in serum and in sodium sulfate. Based on the capacitance values obtained in sodium sulfate, the real surface area of the coarsely sandblasted electrodes has been estimated relative to mechanically polished surfaces. The values of the effective electrode area correlate with the mechanical properties of the samples: in fact, the softest electrode (commercially pure titanium) shows the largest effective electrode area, whereas the hardest material (CoCrMo alloy) shows the smallest surface area.

Characterization of implant materials in fetal bovine serum and sodium sulfate by electrochemical impedance spectroscopy. I. Mechanically polished samples.

Electrochemical impedance spectroscopy is used to monitor the long-term stability (up to 150 days) of mechanically polished commercial pure titanium, Ti6Al4V, Ti6Al7Nb, and CoCrMo alloys in 0.1M sodium sulfate and fetal bovine serum. A capacitive spectrum in the frequency range from 10(-3) to 10(5) Hz is always found and the impedance spectra can be fitted by a simple parallel RC circuit with a constant phase element. The open circuit potential observed in serum is always more cathodic and the polarization resistance (R(p)) is higher than that recorded in sodium sulfate solutions. The observed variation of the equivalent capacitance in serum bovine suggests that an adsorption layer of organic molecules develops on the electrode surface and it is responsible for both the decrease in open circuit potential and the higher R(p), because it hinders the oxygen evolution reaction and the charge transfer responsible for the passive film dissolution (or growth). Among the alloys studied, Ti6Al4V displayed the highest steady-state values of R(p) both in serum and in sodium sulfate.