RESUMO
Calcium channels control the inflow of calcium ions into cells and are involved in diverse cellular functions. The CACNA1C gene polymorphism rs1006737 A allele has been strongly associated with increased risk for bipolar disorder (BD) and with modulation of brain morphology. The medial prefrontal cortex (mPFC) has been widely associated with mood regulation in BD, but the role of this CACNA1C polymorphism in mPFC morphology and brain aging has yet to be elucidated. One hundred seventeen euthymic BD type I subjects were genotyped for CACNA1C rs1006737 and underwent 3 T three-dimensional structural magnetic resonance imaging scans to determine cortical thickness of mPFC components (superior frontal cortex (sFC), medial orbitofrontal cortex (mOFC), caudal anterior cingulate cortex (cACC) and rostral anterior cingulate cortex (rACC)). Carriers of the CACNA1C allele A exhibited greater left mOFC thickness compared to non-carriers. Moreover, CACNA1C A carriers showed age-related cortical thinning of the left cACC, whereas among A non-carriers there was not an effect of age on left cACC cortical thinning. In the sFC, mOFC and rACC (left or right), a negative correlation was observed between age and cortical thickness, regardless of CACNA1C rs1006737 A status. Further studies investigating the direct link between cortical thickness, calcium channel function, apoptosis mechanism and their underlying relationship with aging-associated cognitive decline in BD are warranted.
Assuntos
Alelos , Transtorno Bipolar/genética , Transtorno Bipolar/patologia , Canais de Cálcio Tipo L/genética , Predisposição Genética para Doença/genética , Córtex Pré-Frontal/patologia , Adolescente , Adulto , Fatores Etários , Transtorno Bipolar/diagnóstico por imagem , Dominância Cerebral/genética , Dominância Cerebral/fisiologia , Feminino , Triagem de Portadores Genéticos , Humanos , Imageamento Tridimensional , Imageamento por Ressonância Magnética , Masculino , Polimorfismo Genético/genética , Córtex Pré-Frontal/diagnóstico por imagem , Estatística como Assunto , Adulto JovemRESUMO
OBJECTIVE: The objective of this study was to evaluate brain lithium levels using (7) Li magnetic resonance spectroscopy after 6 weeks of lithium therapy in bipolar depression to test the hypothesis that brain and plasma lithium are correlated. It was also tested whether responders and remitters have different pharmacokinetics, blood and brain lithium levels (ratio) compared with those presenting suboptimal antidepressant improvement. METHOD: Twenty-three patients with bipolar disorder (I and II) during depressive episodes were included and followed up for 6 weeks at the University of Sao Paulo using flexible dose of lithium (450-900 mg/day). Sixteen patients were drug-naïve. At endpoint, patients underwent a (7) Li-MRS scan and brain lithium concentrations were calculated. RESULTS: A significant association between central and peripheral lithium levels was found only in remitters (r = 0.7, P = 0.004) but not in non-remitters (r = -0.12, P = 0.76). Also, brain lithium (but not plasma) was inversely correlated with age (r = -0.46, P = 0.025). Plasma lithium did not correlate with any clinical outcome, lithium dosage or adverse effects. CONCLUSION: These findings suggest that non-remitters may not transport lithium properly to the brain, which may underlie treatment resistance to lithium in BD. Future studies with (7) Li-MRS integrated with the evaluation of blood-brain barrier transport mechanisms and longitudinal clinical outcomes in BD and aging are warranted.
Assuntos
Antimaníacos/farmacocinética , Transtorno Bipolar/metabolismo , Encéfalo/metabolismo , Depressão/metabolismo , Compostos de Lítio/farmacocinética , Adulto , Antimaníacos/uso terapêutico , Transtorno Bipolar/sangue , Transtorno Bipolar/tratamento farmacológico , Barreira Hematoencefálica/metabolismo , Encéfalo/efeitos dos fármacos , Depressão/sangue , Depressão/tratamento farmacológico , Feminino , Humanos , Compostos de Lítio/uso terapêutico , Espectroscopia de Ressonância Magnética/métodos , MasculinoRESUMO
BACKGROUND AND PURPOSE: (1)H-MR spectroscopy is a useful tool in brain tumor evaluation. A critical point in obtaining representative spectra is the correct voxel positioning, which can be more accurate after Gd administration. Some experimental data suggested that Gd could cause Cho signal loss. Our aim was to evaluate the effect of Gd in the Cho peak area and width in patients with GBM. MATERIALS AND METHODS: We performed multivoxel (1)H-MR spectroscopy before and after Gd administration in 18 patients with GBM. Quantification of Cho peak area and width in each voxel was completed, and the Cho mean and maximum values before and after Gd injection were calculated in the tumor and contralateral hemisphere. Choline peak area and width values obtained before and after contrast were compared, considering as separate entities enhancing and nonenhancing tumoral voxels and the contralateral hemisphere. RESULTS: No statistically significant differences were found for the Cho peak area mean values in the tumoral voxels or contralaterally (P > .05). A tendency for an increase in the Cho peak width mean value was found in the tumoral enhancing voxels (P = .055). A statistically significant decrease was found for the mean value of the maximum Cho peak area in enhancing tumoral voxels (P = .020). No significant differences were found in the nonenhancing tumoral voxels or contralaterally (P > .05). CONCLUSIONS: The injection of Gd before performing (1)H-MR spectroscopy might not significantly affect the Cho peak area in patients with GBM. The paramagnetic contrast seems to cause a different effect, depending on Gd enhancement.
Assuntos
Neoplasias Encefálicas/metabolismo , Encéfalo/metabolismo , Colina/análise , Meios de Contraste , Espectroscopia de Ressonância de Spin Eletrônica/métodos , Gadolínio , Glioblastoma/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Neoplasias Encefálicas/diagnóstico , Meios de Contraste/administração & dosagem , Feminino , Gadolínio/administração & dosagem , Glioblastoma/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
CTX is a rare lipid-storage disease. Novel MRS findings from 3 patients, using a short TE, were the presence of lipid peaks at 0.9 and 1.3 ppm in the depth of the cerebellar hemisphere; this might represent an additional marker of disease that is CNS-specific and noninvasive. A decrease in NAA concentration was also detected and attributed to neuroaxonal damage. One patient presented an increase in mIns concentration, pointing to gliosis and astrocytic proliferation.
Assuntos
Ácido Aspártico/análogos & derivados , Espectroscopia de Ressonância Magnética , Xantomatose Cerebrotendinosa/metabolismo , Xantomatose Cerebrotendinosa/patologia , Adulto , Ácido Aspártico/metabolismo , Cerebelo/metabolismo , Cerebelo/patologia , Colina/metabolismo , Humanos , Inositol/metabolismo , Ácido Láctico/metabolismo , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
BACKGROUND AND PURPOSE: Malformations of cortical development (MCD) are traditionally considered as a cause of epilepsy. Our aim was to study patients with focal MCD, by using multivoxel proton MR spectroscopy; we focused not only on the lesion but also on the normal-appearing contralateral side (NACS). Our hypothesis was that the metabolic abnormality extends to the NACS; therefore, it would be inadequate to consider NACS as an internal control. MATERIALS AND METHODS: We studied 16 patients with focal MCD. MR spectroscopy was performed by using a point-resolved spectroscopy sequence technique, including the MCD area and the NACS. In each volume of interest, a smaller volume of interest of 2.25 cm(3) centered on the MCD was selected to study the N-acetylaspartate/creatine (NAA/Cr) ratio. In NACS, this ratio was studied by placing a symmetric voxel in comparison with the smaller MCD volume of interest. A control group (n=30) was also studied to evaluate both white and gray matter by using the same MR spectroscopy protocol. RESULTS: From 16 analyzed volumes of interest with MCD, 9 were composed of gray matter heterotopia and 7 of cortical dysplasia. MR spectroscopy of both MCD lesions and NACS (n=10) showed decreased NAA/Cr compared with that of the control group. NACS in these patients did not present significant differences regarding NAA/Cr in comparison with the affected side. CONCLUSIONS: MR spectroscopy demonstrated abnormal NAA/Cr in both MCD lesions and NACS in patients harboring focal MCD, giving support to the hypothesis that in MCD metabolic abnormalities extend far away from the limits of the lesion, reaching the contralateral side.
Assuntos
Ácido Aspártico/análogos & derivados , Córtex Cerebral/anormalidades , Córtex Cerebral/metabolismo , Creatina/metabolismo , Epilepsia/metabolismo , Espectroscopia de Ressonância Magnética/métodos , Prótons , Adolescente , Adulto , Ácido Aspártico/metabolismo , Biomarcadores/metabolismo , Córtex Cerebral/crescimento & desenvolvimento , Criança , Epilepsia/diagnóstico , Feminino , Humanos , Masculino , Distribuição TecidualRESUMO
We describe how proton MR spectroscopy ((1)H-MR spectroscopy) was useful in elucidating the diagnosis of galactosemia in an undiagnosed 6-month-old infant. In vivo (1)H-MR spectroscopy of the brain showed a doublet at 3.7 parts per million, which was identified as galactitol (Gal-ol) by in vitro (1)H-MR spectroscopy of the urine. Galactosemia was subsequently confirmed by laboratory tests and treatment was initiated. A follow-up brain MR imaging and (1)H-MR spectroscopy study revealed resolution of white matter lesions and disappearance of Gal-ol peaks.
Assuntos
Química Encefálica , Galactitol/análise , Galactosemias/diagnóstico , Espectroscopia de Ressonância Magnética , Encéfalo/patologia , Feminino , Galactitol/urina , Galactosemias/dietoterapia , Humanos , Lactente , Imageamento por Ressonância MagnéticaRESUMO
The aim of this study was to correlate diffusion to magnetization transfer (MT) magnetic resonance imaging (MRI) results in multiple sclerosis (MS), in order to establish if the former technique provides complementary information. Magnetization transfer ratio (MTR) and apparent diffusion coefficient (ADC) were measured in 156 different regions of interest (ROIs) of 14 MS patients, where 84 corresponded to T1 hypointense lesions, 60 to T1 isointense lesions and 12 to regions of normal appearing white matter (NAWM). MTR mean value was higher for T1 isointense than for T1 hypointense lesions, and lower when compared to NAWM. ADC mean value for T1 isointense lesions was higher than for NAWM, but lower than for T1 hypointense lesions. A significant negative correlation was found between ADC and MTR for hypointense lesions (Pearson's r = -0.758, P < 0.001), whereas this correlation was much weaker for T1 isointense lesions (Pearson's r= -0.256, P = 0.049). There was no correlation between ADC and MTR for NAWM. The fact that ADC and MTR show a strong correlation only for T1 hypointense lesions indicates that, when tissue integrity is not severely compromised, as in the case of T1 isointense lesions or NAWM, ADC and MTR might be sensitive to different pathological processes.