عوامل مؤثر پرفیوژن SPECT مغز و ارتباطات در افسردگی مقاوم به درمان
|کد مقاله||سال انتشار||مقاله انگلیسی||ترجمه فارسی||تعداد کلمات|
|29823||2015||7 صفحه PDF||سفارش دهید||5800 کلمه|
Publisher : Elsevier - Science Direct (الزویر - ساینس دایرکت)
Journal : Psychiatry Research: Neuroimaging, Volume 231, Issue 2, 28 February 2015, Pages 134–140
This study aims to characterize and compare functional brain single photon emission tomography (SPECT) perfusion and connectivity in treatment-resistant depression (TRD) according to distinct demographic or clinical profiles (male vs. female; old vs. young; unipolar vs. bipolar) and to study their relationship to the severity and the duration of episode/illness. We retrospectively included 127 consecutive patients who met DSM-IV criteria for a nonpsychotic major TRD episode. All patients were studied using 99mTc-ethyl cysteinate dimer SPECT. Whole-brain, voxel-based, between-groups analyses were performed according to demographic and clinical data and in comparison to 37 healthy subjects. Voxel-wise interregional correlation was also performed to compare functional SPECT connectivity. Finally, relationships were searched for regarding severity and duration of episode/illness. The whole group of patients exhibited significant hypoperfusion within bilateral fronto-temporal, insular, and anterior cingulate cortices, as well as within the left caudate. Functional connectivity between left frontal and left cerebellar regions was higher in patients than in healthy subjects. Gender, age, and type of mood disorder did not influence these SPECT patterns. A significant relationship was found between brain SPECT perfusion and either duration or global severity of illness in particular frontal areas. Our data support the hypothesis of a shared SPECT pattern, whatever the profile of TRD, involving fronto-temporal regions and the cerebellum.
Depression has many profiles. Even though the core symptoms are characterized by persistently depressed mood or anhedonia, demographic features are linked to varying patterns of symmptomatology. Among younger depressed patients, the predominant symptoms are loss of interest, feelings of guilt or of being a burden, suicidal thoughts, and depressed mood, whereas the elderly minimize or deny depressed mood, and present more cognitive impairment or hypochondriacal symptoms (Shahpesandy, 2005). Women report more distress, lack of energy, and bulimia associated to weight gain and anxiety, while men report more decreased appetite, psychomotor retardation, substance abuse, and suicidal ideation (Marcus et al., 2005). Moreover, the type of mood disorder may influence the course of depression. In this line, bipolar depression is related to higher rates of psychomotor retardation, cognitive difficulty, or early awakening while unipolar depression is characterized by vegetative and psychomotor symptoms and anxiety (Mitchell et al., 2008). Finally, treatment-resistant depression (TRD) is unfortunately common, afflicting 10–30% of treated-patients (Souery et al., 2006). Functional neuroimaging provides valuable information in psychiatric diseases. Single photon emission tomography (SPECT) is, for example, useful in the differential diagnosis of depression, particularly in distinguishing it from neurodegenerative diseases (Cho et al., 2002). Neuroimaging has also been used as a means to investigate the predictive/prognostic value of specific cortico-limbic patterns (Richieri et al., 2011 and Richieri et al., 2012) as well as to aid in the understanding of neural mechanisms underlying antidepressant effects (Richieri et al., 2012). More recently, neuroimaging studies have explored functional connectivity using magnetic resonance imaging (MRI), and have identified cortico-limbic abnormalities (Alalade et al., 2011 and Ma et al., 2013). Those different demographic/clinical profiles of depression may impact functional neuroimaging findings, as much as factors such as age and gender also cause variations in healthy subjects, within structural ( Leonard et al., 2008 and Gong et al., 2009) and functional brain networks (Luders et al., 2009, Tian et al., 2011 and Tomasi and Volkow, 2012). However, based on the clinical characteristics and course of TRD, and specific neurobiological profiles derived from neuroimaging or genetic studies, Fagiolini and Kupfer (2003) have suggested that TRD may be a unique subtype of depression. Functional neuroimaging could be used to understand the mechanisms of TRD, and especially to determine if there are functional brain abnormalities that are distinctive within the clinical profile of TRD. In the current retrospective study, we used 99mTc-ethyl cysteinate dimer SPECT to characterize and compare cerebral perfusion and functional connectivity in a wide range of TRD patients, taking into account several covariables, including demographic (age, gender) or clinical characteristics (type, severity, and episode/illness duration), in order to determine functional substrates of TRD.
نتیجه گیری انگلیسی
Clinical characteristics of the patient group are presented in Table 1. The 127 patients were predominantly women (58.3%). Mean age was 53.4 years (±12.8). They presented unipolar (n=83) or bipolar (n=44) TRD, with moderate to high severity (BDI=33.2; SD=11.4), and moderate to high level of anxiety (STAI=60.4; SD=11.6). The duration of the current episode and the duration of illness were variable, respectively, 17.2 months (SD=8.5) and 17.0 years (SD=13.0). There were no significant differences between men and women in terms of age (p=0.384), diagnosis (p=0.809), episode and illness duration (p=0.855 and p=0.763, respectively), and BDI score (p=0.968). A statistical difference was found for anxiety (p=0.010) and CGI (p=0.009), for which women had a more severe symptomatology. Only illness duration was related to age (< and≥65 years; p=0.012). Patients with bipolar depression differed from unipolar patients in terms of shorter episodes (p=0.004), longer illness (p=0.007), and lower anxiety severity (p=0.032).