Qualitative and quantitative evaluation by brain SPECT of the functional changes associated with Neuropsychiatric Systemic Lupus Erythematosus (NPSLE)

O Lúpus Eritematoso Sistêmico (LES) é uma doença autoimune que pode envolver o sistema nervoso central e periférico, caracterizando a forma neuropsiquiátrica da doença (LESNP). Pacientes com LESNP podem apresentar alterações perfusionais à tomografia computadorizada por emissão de fóton único (SPECT) cerebral, restando saber sua contribuição diagnóstica comparativamente à Ressonância Magnética, técnica de neuroimagem de escolha nas doenças neurológicas. A RM tem sido útil principalmente na avaliação da atrofia cerebral e lesões glióticas, enquanto o SPECT detecta alterações mais sutis na microvasculatura cerebral. Com o objetivo de aumentar a acurácia diagnóstica do SPECT cerebral na avaliação de pacientes com LESNP, o presente estudo avaliou (a) os achados qualitativos do SPECT e RM cerebral, (b) os achados quantitativos através do software Statistical Parametric Mapping (SPM), (c) e a evolução temporal das alterações perfusionais entre as avaliações pré e pós tratamento, através do software Subtraction Ictal Spect Co-registered to MRI (SISCOM). Foram analisados retrospectivamente 60 pacientes com LESNP. Além dos dados clínicos e laboratoriais, realizamos o SPM nos SPECTs pré tratamento e a subtração entre os SPECTs pós e pré tratamento e fusão com a RM. O SPM foi realizado na plataforma MATLAB©, e o SISCOM no software ANALYZE© 10.0. Somente 26 pacientes realizaram ambos os SPECTs pré e pós tratamento, permitindo a análise do SISCOM. Os resultados mostraram que a idade média dos pacientes (52 femininos, 8 masculinos) foi de 41,78 anos. Seis pacientes evoluíram para óbito e 4 apresentaram abortos prévios. A maioria eram brancos (68,30%) e a média de idade no início do LESNP foi de 33,13 anos. Os pacientes submeteram-se em média a 10,33 sessões de pulsoterapia. A média de pontuação para o índice SLICC/ACR-DI foi de 5,83 e, para o SLEDAI, de 37,63. A análise qualitativa dos SPECTs pré e pós tratamento revelaram áreas de hiper e hipoperfusão associadas a manifestações psiquiátricas e neurológicas . Na análise quantitativa, o SPM identificou áreas cerebrais significativamente acometidas pelo LESNP. A análise qualitativa concordou com o SPM em 56,67% das áreas de hiperperfusão e 53,33% das de hipoperfusão. O SPM modificou o laudo final qualitativo em 25 (41,67%) pacientes. Dos 26 pacientes submetidos ao SISCOM, 19 apresentaram sintomas psquiátricos e 7 apresentaram sintomas neurológicos. No SISCOM, 15 (57,69%) pacientes apresentaram melhora, 12 (46,15%) ativação, 8 (30,77%) desativação e 6 (23,07%) piora perfusional no seguimento. O sexo foi preditivo da ativação e da piora perfusional, a raça-não branca foi preditiva da piora perfusional e o resultado normal para o complemento 3 foi preditivo da melhora perfusional no SISCOM. Nós encontramos associação entre o SLEDAI e a quantidade de pulsoterapias, e entre a idade e o dano da doença ao SLICC. A análise qualitativa mostrou superioridade diagnóstica do SPECT cerebral sobre a RM, ao evidenciar áreas de hiperperfusão e hipoperfusão no parênquima cerebral associadas aos sintomas do LESNP. Nós concluímos que o SPM auxiliou nos laudos visuais no NPSLE, o SISCOM revelou a dinâmica fisiopatológica do envolvimento cerebral após as pulsoterapias, que o SISCOM foi associado com as pontuações no SLEDAI e SLICC, que o gênero, raça e complemento C3 foram associados à melhora ou piora perfusional no NPSLE após o tratamento.Systemic Lupus Erythematosus (SLE) is an autoimmune disease that may involve the central and peripheral nervous system, leading to neuropsychiatric manifestations of the disease (NPSLE). Patients with NPSLE may present perfusion changes on cerebral Single Photon Emission Computed Tomography (SPECT), but it remains to be seen its diagnostic contribution comparativelly to the Magnetic Resonance Imaging, the neuroimaging technique of choice in neurological diseases. The MRI has been useful mainly in evaluating cerebral atrophy and gliotic lesions, while SPECT detects more subtle changes in the cerebral microvasculature. In order to increase the diagnostic accuracy of brain SPECT in the assessment of patients with NPSLE, this study evaluated (a) the qualitative findings of cerebral SPECT and MRI, (b) the quantitative findings on the Statistical Parametric Mapping (SPM), (c) and the temporal evolution of perfusion changes between the pre and post-treatment assessments, using the Subtraction Ictal Spect Co-registered to MRI (SISCOM) software. Sixty NPSLE patients were retrospectively evaluated. In addition to clinical and laboratory data, we performed the SPM on pre-treatment SPECTs and the subtraction between the post and pre-treatment SPECTs coregistered to MRI. The SPM was carried out on the MATLAB© platform, and the SISCOM on the ANALYZE© 10.0 software. Only 26 patients performed both pre and post-treatment SPECT, enabling SISCOM analysis. The results showed that the mean age of patients (52 females, 8 males) was 41.78 years. Six patients died and 4 had previous abortions. Most were white (68.30%) and the mean age at the beginning of the NPSLE was 33.13 years. Patients underwent an average of 10.33 pulse therapy sessions. The average score for the SLICC/ACR-DI index was 5.83 and for the SLEDAI, 37.63. Qualitative analysis of pre and post-treatment SPECTs revealed areas of hyper and hypoperfusion associated with psychiatric and neurological manifestations. Quantitative analysis by SPM showed brain regions significantly affected by NPSLE. Qualitative analysis agreed with SPM in 56.67% of hyperperfusion and 53.33% of hypoperfusion areas. The SPM modified the final qualitative report in 25 (41.67%) patients. From 26 patients undergoing SISCOM, 19 had psychiatric manifestations and 7 had neurological symptoms. Fifteen (57.69%) patients showed improvement of perfusion on SISCOM, 12 (46.15%) activation, 8 (30.77%) deactivation and 6 (23.07%) worsened perfusion on follow-up. Gender was predictive of activation and perfusional worsening, non-white race was predictive of perfusional worsening, and the normal result for complement 3 was predictive of perfusional improvement on SISCOM. We found an association between SLEDAI and the amount of pulse therapies, and between age and disease damage to SLICC. Qualitative analysis showed diagnostic superiority of brain SPECT over MRI for NPSLE in identifying hyperperfusion and hypoperfusion areas on brain parenchyma associated with NPSLE manifestations. We concluded that the SPM helped the visual reports in NPSLE, SISCOM revealed the pathophysiological dynamics of brain involvement after pulse therapies, the SISCOM findings were associated to SLEDAI and SLICC scores, and that gender, race and C3 complement were associated with perfusion improvement or worsening in NPSLE after treatment