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Abstract Objective: We aimed to evaluate whether human immunodeficiency virus (HIV)-positive patients with and without clinically significant memory deficits and healthy control participants differ on in vivo hydrogen-1 magnetic resonance spectroscopy (H-MRS) in the posterior cingulate gyri. Materials and Methods: In total, 21 HIV-positive patients with memory deficit (HIV+wMD) were compared with 15 HIV-positive patients without memory deficit (HIV+wOMD) and 22 sex-, age-, and education-matched control participants. Memory impairments were classified based on the participants' performance on the Rey Auditory Verbal Learning Test. Short echo time (30 ms), single-voxel H-MRS was performed using a 1.5-T magnetic resonance scanner. Results: The HIV+wMD and HIV+wOMD groups had higher choline/creatine ratio in the posterior cingulate gyri than the control group. There were no significant metabolite ratio differences between the HIV+wMD and HIV+wOMD groups. Conclusion: HIV-positive patients with and without memory deficits had significantly higher choline/creatine ratios than controls in the posterior cingulate gyri, which may reflect cerebral inflammation, altered cell membrane metabolism, microgliosis, and/or astrocytosis.
Resumo Objetivo: Nós avaliamos se os pacientes HIV-positivos com e sem déficits de memória clinicamente significativos e controles saudáveis diferem na espectroscopia de prótons do giro do cíngulo posterior, por ressonância magnética (RM) cerebral. Materiais e Métodos: Vinte e um pacientes HIV-positivos com déficit de memória foram comparados com 15 pacientes HIV-positivos sem déficit de memória e 22 controles, pareados por sexo, idade e escolaridade. As deficiências de memória foram classificadas por meio do desempenho no Teste de Aprendizagem Auditivo-Verbal de Rey. A espectroscopia de prótons foi realizada com tempo de eco curto (30 ms), por voxel único, no giro do cíngulo posterior, utilizando aparelho de RM de 1,5 T. Resultados: Os pacientes HIV-positivos com e sem déficit de memória apresentaram aumento da relação colina/creatina no giro do cíngulo posterior, comparados aos controles. Não houve diferenças significativas nas relações metabólicas no grupo HIV-positivo com déficit de memória, em relação ao grupo de pacientes HIV-positivo sem déficit. Conclusão: Pacientes HIV-positivos com e sem déficits de memória apresentaram relações colina/creatina significativamente aumentadas em relação aos controles, no giro do cíngulo posterior, o que pode refletir inflamação cerebral, alteração do metabolismo da membrana celular, microgliose e/ou astrocitose.
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Objective To investigate the value of 1H-MRS technology combined with linear combination model (LCmodel) software in diagnosis of Parkinson disease (PD) cognitive impairment.Methods Thirty-five PD patients (PD group) and 22 matched healthy subjects (control group) were collected.Patients in PD group were divided into PDN and PDMCI subgroups according to whether having cognitive impairment or not.The concentration of metabolites of posterior cingulate gyrus (PCG)was applied with 1H-MRS technology combined with LCmodel software.The differences of metabolites were compared between the two groups,and the correlations between metabolites level and cognitive status were analyzed.Results The absolute concentrations of metabolites in PDN subgroup were not significantly different from those in control group (all P＞0.05).The absolute concentrations of total creatine (tCr),N-acetyl aspartate (NAA),myo-inositol (mI) and glycerophosphocholine+ phosphocholine (tCho) in PDMCI subgroup were lower than those in control group (all P＜0.05).The absolute concentration of tCr in PDMCI subgroup was lower than that in PDN subgroup (P＜0.05).There was positive correlation among the absolute concentration of tCr (r=0.444,P=0.01),glutathione (GSH;r=0.393,P=0.024) and MMSE scores,as well as among the absolute concentration of tCr (r=0.367,P=0.035),GSH (r=0.376,P=0.031),tCho (r=0.375,P=0.031) and MoCA scores.Conclusion 1 H-MRS technology combined with LCmodel software can quantitatively analyze the changes of metabolites in PCG,therefore being helpful to evaluating PD cognitive impairment.
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Objective To explore the spatial distribution of abnormal brain areas and metabolic changes in Alzheimer's disease (AD),and provide a reference for early clinical diagnosis of AD.Methods Sixteen cases of AD patients and 1 6 healthy controls (HC)underwent multi-voxel 1H-MRS examination with semi-LASER sequence.The posterior cingulate gyrus section was localized as the volume of interest(VOI)level.The VOI consisted of bilateral posterior cingulate gyrus,occipital lobe cortex,lateral ventricle paratrigonal white matter and dorsal thalamus.N-acetylaspartate (NAA),creatine (Cr),choline (Cho),myo-inositol (MI)and glutamate-glutamine (Glx)concentration were measured.Differences in metabolite were compared between AD and HC groups.Relationships between metabolite and clinical mini-mental state examination(MMSE)score were analyzed.Results For metabolite index in VOI of right hemisphere:the AD group displayed significantly lower NAA,NAA/Cr,NAA/MI and higher MI,MI/Cr levels in posterior cingulate gyrus,lower NAA,Glx levels in occipital lobe cortex,lower NAA and higher Cho levels in dorsal thalamus.For metabolite index in VOI of left hemisphere:the AD group displayed significantly lower NAA,NAA/Cr,NAA/MI,Glx/Cr and higher MI/Cr levels in posterior cingulate gyrus,lower NAA and higher Cho/Cr levels in occipital lobe cortex,lower NAA and higher cho levels in lateral ventricle paratrigonal white matter,lower Glx and higher Cho levels in dorsal thalamus.NAA/Cr was positively correlated with Glx/Cr in left posterior cingulate gyrus in AD group.Conclusion NAA is decreased while MI is increased in posterior cingulate gyrus in AD patients.Cho is increased in both grey and white matter.Glx is decreased mainly within grey matter,involving both cortex and sub cortex structures.