Reduced NAA levels in the dorsolateral prefrontal cortex of young bipolar patients

OBJECTIVE: Converging evidence implicates prefrontal circuits in the pathophysiology of bipolar disorder. Proton spectroscopy studies performed in adult bipolar patients assessing prefrontal regions have suggested decreased levels of N-acetylaspartate (NAA), a putative marker of neuronal integrity. In order to examine whether such abnormalities would also be found in younger patients, a 1H spectroscopy study was conducted that focused on the dorsolateral prefrontal cortex of children and adolescents with bipolar disorder. METHOD: The authors examined the levels of NAA, creatine plus phosphocreatine, and choline-containing molecules in the left dorsolateral prefrontal cortex of 14 bipolar disorder patients (mean age=15.5 years, SD=3, eight female) and 18 healthy comparison subjects (mean age=17.3, SD=3.7, seven female) using short echo time, single-voxel in vivo 1H spectroscopy. Absolute metabolite levels were determined using the water signal as an internal reference. RESULTS: Bipolar patients presented significantly lower NAA levels and a significant inverse correlation between choline-containing molecules and number of previous affective episodes. No differences were found for other metabolites. CONCLUSIONS: These findings suggest that young bipolar patients have decreased NAA levels in the dorsolateral prefrontal cortex, similar to what was previously reported in adult patients. Such changes may reflect an underdevelopment of dendritic arborizations and synaptic connections. These neuronal abnormalities in the dorsolateral prefrontal cortex of bipolar disorder youth are unlikely to represent long-term degenerative processes, at least in the subgroup of patients where the illness had relatively early onset.     

Plasma concentrations of anxiolytic neuroactive steroids in men with panic disorder

Plasma concentrations of neuroactive steroids in men with panic disorder (PD) were measured to evaluate their relations to psychopathology both before and during treatment. Participants comprised 13 men with PD and 10 normal controls. Patients were evaluated while drug-free as well as after 1 and 2 months of paroxetine therapy. Psychopathology was assessed by the State-Trait Anxiety Inventory (STAI), the Panic-Associated Symptom Scale, and the Fear Questionnaire total score. Plasma concentrations of steroids were measured by radioimmunoassay. The plasma concentrations of progesterone and dehydroepiandrosterone were greater in drug-free patients than in controls, whereas those of allopregnanolone and tetrahydrodeoxycorticosterone did not differ between the two groups. Paroxetine treatment for 2 months significantly increased the plasma concentration of allopregnanolone but did not affect those of the other steroids. At 2 months of therapy, allopregnanolone concentrations in patients were significantly greater than those in controls. The plasma concentrations of progesterone and tetrahydrodeoxycorticosterone correlated with the STAI state score in patients before treatment. Our data suggest that neuroactive steroids may play a role in PD in men.     

Technical analysis of volume-rendering algorithms: application in low-contrast structures using liver vascularisation as a model

AIM: To assess the influence of pre-set volume-rendering opacity curves (OC) on image quality and to identify which absolute parameters (density of aorta, hepatic parenchyma and portal vein) affect visualization of portal vascular structures (low-contrast structures). MATERIALS AND METHODS: Twenty-two patients underwent a dual-phase spiral CT with the following parameters: collimation 3 mm, pitch 2, increment 1 mm. Three scans were performed: one without contrast medium and the latter two after the injection of contrast material (conventionally identified as 'arterial' and 'portal'). The images were sent to a workstation running on an NT platform equipped with post-processing software allowing three-dimensional (3D) reconstructions to generate volume-rendered images of the vascular supply to the liver. Correlation between the absolute values of aorta, liver and portal vein density, OC parameters, and image quality were assessed. RESULTS: 3D images generated using pre-set OC obtained a much lower overall quality score than those produced with OC set by the operator. High contrast between the liver and the portal vein, for example during the portal vascular phase, allows wider windows, thus improving image quality. Conversely, the OC in the parenchymal phase scans must have a high gradient in order to better differentiate between the vascular structures and the surrounding hepatic parenchyma. CONCLUSIONS: Image features considered to be of interest by the operator cannot be simplified by the mean of pre-set OC. Due to their strong individual variability automatic 3D algorithms cannot be universally applied: they should be adapted to both image and patient characteristics.     

Image assessment with multislice CT coronary angiography

AIM: To investigate the diagnostic accuracy of two different protocols for image evaluation used in multislice computed tomography coronary angiography (MSCT-CA). MATERIALS AND METHODS: Sixty patients with suspected coronary artery disease undergoing conventional coronary angiography (CA) were enrolled for MSCT-CA. All patients underwent 16-row MSCT (Sensation 16, Siemens, Germany) with the following parameters: detector rows 16, collimation 0.75 mm, gantry rotation time 375 ms. Two independent observers assessed the images for significant stenosis using a a protocol with standard projections and a three-dimensional protocol. The diagnostic accuracy for both methods was calculated using quantitative CA as a reference standard. RESULTS: The sensitivity, specificity, negative predictive value and positive predictive value obtained with the conventional projection protocol and with three-dimensional protocol were: 54% and 93%, 97% and 97%, 76% and 86%, 92% and 99%, respectively. CONCLUSIONS: Conventional projections in the assessment of MSCT-CA provide insufficient diagnostic accuracy compared with three-dimensional processing.     

Natural history, diagnosis, treatment and outcome of papillary thyroid microcarcinoma (PTMC): a mono-institutional 12-year experience

The clinical and histopathological records of 149 consecutive patients with papillary thyroid microcarcinoma (PTMC), homogeneously studied and operated on by the same surgeon in the period 1990 to 2001, were reviewed. After a mean 6.5-year follow-up, three cases of loco-regional recurrence (2%) were observed. These three patients had all undergone partial thyroidectomy only and tumour relapse occurred in the residual thyroid tissue. No recurrence was observed in patients treated by total thyroidectomy and I. At variance with other reported series, no lymph node recurrence was observed in our series, in particular in the group of 23 patients with evidence of nodal metastases at initial diagnosis (three of whom were revealed by I scan after surgery). Therefore, a preventive effect of I treatment in our patient population can be hypothesized. However, prolonged follow-up will be necessary to clarify this. Due to the inability of current imaging modalities to select pre-operatively PTMC patients at risk for recurrence (presence of thyroid capsular invasion, multifocality and microscopic lymph node metastases), it appears reasonable to offer the patient total thyroidectomy when a pre-operative diagnosis of PTMC is reached. Moreover, the policy of our thyroid cancer centre is that, in these patients, post-surgical I scan should be obtained in order to detect unknown metastatic deposits, and I treatment should also be considered in patients with poor clinical and histopathological prognostic factors. In contrast, in patients operated on for benign thyroid disease and with delayed diagnosis of PTMC at definitive histopathological examination, re-operation might be avoided in the presence of unifocal disease without thyroid capsular invasion and with ultrasound-'normal' residual thyroid tissue. Close clinical and ultrasound follow-up is recommended, especially in patients who have undergone conservative surgery only.     

Prevention of venous thromboembolism in spinal surgery

Deep vein thrombosis (DVT), and its most feared complication, pulmonary embolism (PE), still have a high incidence with high risk for patients health. Proven prophylactic measures are available but are generally underused, and DVT is still considered the most common cause of preventable death among hospitalized patients. The rationale for prophylaxis of venous thromboembolism is based on the clinically silent nature of the disease, the relatively high prevalence among hospitalized patients and the potentially tragic consequences of a missed diagnosis. During the last 15–20 years, spine surgery has changed radically, developing into a well-defined area of specialist surgery, and some attention is now being given to DVT events in spine surgery. The incidence of DVT during spine surgery is not documented in the literature, because only case reports or retrospective studies are reported. It would therefore be very helpful to initiate a multicenter study in order to understand this problem better and to develop, if possible, some guidelines on prophylactic measures in spine surgery. In doing so, we need to consider each patients pattern, any risk factors and every kind of surgical technique related to DVT, in order to improve the outcome of the patient and to reduce any medicolegal problems that could arise from a thrombotic complication or an epidural hematoma, with its high potential for irreversible consequences.     

Clinical trial of time-resolved scanning optical mammography at 4 wavelengths between 683 and 975 nm

The first time-resolved optical mammograph operating beyond 900 nm (683, 785, 913, and 975 nm) is presently being used in a clinical trial to test the diagnostic potential of the technique in detecting and characterizing breast lesions. Between November 2001 and October 2002, 101 patients with malignant and benign lesions were analyzed retrospectively. Scattering plots, as derived from a homogeneous model, and late gated intensity images, to monitor spatial changes in the absorption properties, are routinely used. The intensity images available at four wavelengths provide sensitivity to the main tissue constituents (oxy- and deoxyhemoglobin, water, and lipids), in agreement with expected tissue composition and physiology, while the scattering plots mirror structural changes. Briefly, tumors are usually identified due to the strong blood absorption at short wavelengths, cysts to the low scattering, and fibroadenomas to low absorption at 913 nm and high at 975 nm, even though the optical features of fibroadenomas seem not to be uniquely defined. The effectiveness of the technique in localizing and discriminating different lesion types is analyzed as a function of various parameters (lesion size, compressed breast thickness, and breast parenchymal pattern). .     

Anatomical MRI study of borderline personality disorder patients

Hippocampal volume reduction has been reported in patients with borderline personality disorder (BPD), and is hypothesized to be associated with traumatic childhood experiences. We extended this investigation to explore additional brain regions and other potential clinical correlates of structural brain changes in BPD. Ten unmedicated BPD subjects and 20 healthy controls were assessed for current and past Axis I and II comorbidities and histories of childhood abuse. All had magnetic resonance imaging (MRI) studies with a 1.5 T GE Signa Imaging System, performing three-dimensional-gradient echo imaging (SPGR) with the following parameters: TR=25 ms, TE=5 ms, and slice-thickness=1.5 mm. Compared with healthy controls, BPD subjects had significantly smaller right and left hippocampal volumes, most marked in subjects with childhood abuse, and significantly increased right and left putamen volumes, especially in subjects with substance use disorders. No significant differences between groups were found for caudate, amygdala, temporal lobes, dorsolateral prefrontal cortex and total brain volumes. This study replicated prior findings of diminished hippocampal volumes in subjects with BPD. Also, increased putamen volumes were found in BPD, a finding that has not been previously reported. Early traumatic experiences may play a role in hippocampal atrophy, whereas substance use disorders may contribute to putamen enlargement.     

"Wish bias" in antidepressant drug trials?

The present study investigated whether the outcome of randomized clinical trials studying fluoxetine favored fluoxetine, where this was the experimental agent, and favored comparator antidepressants in trials where fluoxetine was the reference agent. A systematic review of all double-blind, randomized clinical trials comparing fluoxetine with any other antidepressant drug in patients suffering from depression was carried out. Thirty-seven studies meeting the inclusion criteria were analyzed. A metaregression analysis indicated that, after adjusting for possible confounders, studies where fluoxetine was the experimental agent were positively associated with treatment effect, indicating a significant advantage for fluoxetine. The evidence that the outcome of fluoxetine trials varied according to whether this drug was used as a new compound or a reference one suggests the presence of bias.