Parenchymal abnormalities associated with cerebral venous sinus thrombosis: assessment with diffusion-weighted MR imaging

BACKGROUND AND PURPOSE: The common entity cerebral venous sinus thrombosis is associated with the poorly characterized imaging finding of parenchymal abnormalities; diffusion-weighted imaging has offered some insight into these manifestations. We assessed the relationship between the diffusion constant from apparent diffusion coefficient (ADC) maps in patients with cerebral venous thrombosis (CVT) with follow-up imaging findings and clinical outcome. METHODS: We evaluated the medical records and T2-weighted MR images of 13 patients with CVT complicated by intraparenchymal abnormality. Diffusion-weighted (DW) images and ADC maps were evaluated for increased, decreased, or unchanged signal intensity and were compared with signal intensity of contralateral, normal-appearing brain. In addition, ADCs were obtained in nine pixel regions of interest in abnormal regions in eight of the 13 patients. RESULTS: Eight patients had superficial CVT, and five had superficial and deep CVT. CVT of deep veins was associated with deep gray nucleus and deep white matter abnormalities, whereas superficial CVT was associated with cortical and subcortical abnormalities. Twenty-four nonhemorrhagic lesions were identified in 10 of 13 patients on the basis of follow-up imaging findings. Four patients without seizures had lesions with decreased diffusion that appeared hyperintense on follow-up T2-weighted images, three patients with seizures had lesions with decreased diffusion that resolved, and seven patients had lesions with increased diffusion that resolved. Three of 10 patients had more than one lesion type. No difference was noted in mean ADCs for lesions with decreased diffusion that resolved compared with lesions with decreased diffusion that persisted. CONCLUSION: DW imaging in these patients disclosed three lesion types: lesions with elevated diffusion that resolved, consistent with vasogenic edema; lesions with low diffusion that persisted, consistent with cytotoxic edema in patients without seizure activity; and lesions with low diffusion that resolved in patients with seizure activity. This information may be important in prospectively determining severity of irreversible injury and in patient treatment.     

Lymph Node Retrieval after Preoperative Chemoradiotherapy for Rectal Cancer

Background

Current guidelines recommend the assessment of at least 12 lymph nodes for rectal cancer staging. Preoperative chemoradiotherapy may affect lymph node yield in this malignancy. This study investigated the impact of neoadjuvant chemoradiotherapy on the number of lymph nodes retrieved from rectal cancer patients.

Methods

An analysis of 162 rectal cancer patients who underwent curative surgery between 2005 and 2010. Seventy-one patients with stage II or III tumors received preoperative chemoradiotherapy. Using multivariate analysis, we assessed the correlation between clinicopathologic variables and number of retrieved lymph nodes. We also evaluated the association between survival and number of lymph nodes obtained.

Results

On multivariate analysis, preoperative chemoradiotherapy was the only variable to independently affect the number of lymph nodes obtained. The mean number of lymph nodes was 14.2 in patients treated with preoperative chemoradiotherapy and 19.4 in those not treated (P?P?=?0.003). After chemoradiation, the number of retrieved lymph nodes was inversely correlated with tumor regression grade. Results showed that 5-year overall and disease-free survival were similar whether the patient had 12 or more nodes retrieved or not.

Conclusions

Preoperative chemoradiotherapy reduces the lymph node yield in rectal cancer. The number of retrieved lymph nodes is affected by degree of histopathologic response of the tumor to chemoradiation. Thus, number of lymph nodes should not be used as a surrogate for oncologic adequacy of resection after neoadjuvant chemoradiotherapy for rectal cancer.     

Leiomyosarcoma of the inferior vena cava--a case report

This paper presents a patient successfully treated for leiomyosarcoma of the vena cava, with no recurrence or symptoms on an 8-year follow-up. A 56-year-old woman presented with chronic and progressive periumbilical and right upper abdominal pain. Physical examination and laboratory tests revealed no abnormalities. Computed tomography showed a high-density image inside the vena cava. Cavography showed a filling defect with complete occlusion of the vena cava involving the renal veins and greatly developed collateral circulation through lumbar veins. Laparotomy was performed and a large caval mass involving the renal veins was dissected and resected. Venous reconstruction was undertaken using a 19-mm bovine pericardium prosthesis (Labcor, MG-Brazil) interposed as a substitute to the vena cava, and the renal veins were anastomosed to the side of the graft. Pathologic examination confirmed a leiomyosarcoma with free surgical margins. The postoperative course was uneventful and the patient was discharged on postoperative day 8. The venous flow through the inferior vena became normal, as confirmed by later cavography. This paper presents a case of successfully managed leiomyosarcoma of the vena cava with a thorough review of the literature. The treatment of such patients and the use of bovine pericardium are also discussed.     

Appendix interposition for total left ureteral reconstruction

IntroductionAppendix interposition has been described as an option for surgical reconstruction of partial and total ureteral defects both in children and adults. However, to our knowledge, appendix interposition for a total left ureteral reconstruction has never been described.Case reportWe report the first case of total left ureteral reconstruction with cecal appendix to connect the renal pelvis of a native kidney to the urinary bladder in a 3-month-old child with ureteral necrosis following pyeloplasty.ResultsPostoperative recovery was uneventful. Postoperative intravenous pyelogram showed good flow of dye from the pelvis past the appendicular graft into the bladder. After 6 months, the child was asymptomatic, within the normal growth curve for height and weight.ConclusionTotal ureteral reconstruction with cecal appendix is a feasible technique in young children. Surveillance for late operative complications is required, since this is the first case of total left ureteral reconstruction with appendix to connect the renal pelvis of a native kidney to the urinary bladder.     

Molecular epidemiology of spinocerebellar ataxias in Cuba: Insights into SCA2 founder effect in Holguin

The objective of this study was to determine the prevalence of hereditary ataxias in Cuba, with a special focus on the clinical and molecular features of SCA2. Clinical assessments were performed by neurological examinations and application of the SARA scale. Molecular analyses of genes SCA1–3, SCA6, SCA17 and DRPLA identified 753 patients with SCA and 7173 asymptomatic relatives, belonging to 200 unrelated families. 86.79% of all SCA patients were affected with SCA2. In the Holguin province, the average population prevalence of SCA2 is 40.18 × 10⁵ inhabitants, with the remarkable figure of 141.66 × 10⁵ in the Baguanos municipality. The high prevalence of the SCA2 mutation in Holguin reflects most likely a founder effect. The stabilization of the prevalence along time suggests the existence of premutated chromosomes with pure CAG, acting as reservoir for further expansions. CAG repeat length correlated inversely with age at onset, accounting for 80% of the variability. Genetic anticipation was observed in the 80% of transmissions. Repeat instability was greater in paternal transmissions whereas CAG expansions without anticipation was observed in 10.97% suggesting the effect of CAA interruptions in the CAG segment, which decrease the toxicity of the abnormal ataxin-2, and/or other protective factors.     

Trace amine metabolism in Parkinson's disease: Low circulating levels of octopamine in early disease stages

Recent evidence suggests that trace amines such as tyramine and octopamine, alternative products of tyrosine metabolism (an aminoacid parent of dopamine and noradrenaline), play a role in the homeostasis of the extrapyramidal system. However, the relevance of these trace amines in the pathogenesis of Parkinson's disease is still largely unknown. Here, we assessed the plasma levels of octopamine and noradrenaline in three sub-groups of PD patients, namely de novo, non-fluctuating and fluctuating patients, versus age-matched control subjects. We show that octopamine is detectable in plasma of all subjects, the mean levels of which are significantly lower in PD patients, including de novo patients, when compared to controls (p < 0.001). Unlike this, no changes in plasmatic noradrenaline levels were found in the de novo patients, but only in plasma of fluctuating and non-fluctuating PD patients. These findings raise the possibility that Parkinson's disease is firstly characterized by abnormalities of tyrosine decarboxylase, rather than tyrosine hydroxylase, enzyme activity. Given the role of this enzyme in the production of trace amines, circulating octopamine levels may hold promise as a biomarker of early Parkinson's disease.     

PDCD1 gene polymorphisms in different Mexican ethnic groups and their role in the susceptibility to hypersensitivity pneumonitis

ObjectiveHypersensitivity pneumonitis (HP) is an immunological disorder caused by antigen exposure in susceptible individuals. The PDCD1 polymorphisms, PD1.3 and PD1.5 have been associated with the susceptibility to inflammatory disorders. This study was conducted to test whether the PD1.3 and PD1.5 polymorphisms are associated with HP in Mexican patients and to explore the distribution of these polymorphisms in different Mexican ethnic groups.Design and methodsWe studied 98 Mexican patients with HP and 92 healthy Mexican controls. Also, 156 healthy Amerindian individuals from two ethnic groups were included (96 Mayans and 60 Mayos). Polymorphisms were determined by TaqMan 5′ nuclease assays.ResultsSignificant differences in the distribution of the PD1.3 and PD1.5 genotypes between HP patients and healthy Mestizo controls were not found. We observed a significantly different distribution of these polymorphisms in Mexican Mestizos when compared to the Amerindians.ConclusionsWe found no association between PD1 polymorphism and HP; however the distribution of these polymorphisms was different in Mexican Mestizos and Amerindians.     

Adequacy and Diagnostic Accuracy of Aspiration vs. Capillary Fine Needle Thyroid Biopsies

Thyroid nodules can be biopsied by fine needle aspiration (FNA) or fine needle capillary (FNC) biopsies. However, there is controversy on whether one technique is superior to another. In a randomized cytopathologist-blinded cross-sectional study, 260 patients (238 females, age 43.2 ± 12.6) with nodular (82.7%) and diffuse goiter (17.3%) underwent 520 FNAs and 520 FNCs (not guided by ultrasound). Smears were scored for sample adequacy, and diagnosed as malignant, benign, suspicious, or nondiagnostic. Diagnostic accuracy was calculated based on the histological findings of 58 patients submitted to surgery. Intra-technique diagnostic accuracy and sample adequacy was seen in all samples. FNA and FNC provided similar cytological diagnosis, respectively (benign: 75.8% vs. 74.2%, p = 0.600; malignant: 3.8% vs. 3.8%, p = 0.871; suspicious: 10.4% vs. 10.8%, p = 0.913; and nondiagnostic: 10.0% vs. 11.2%, p = 0.598). Adequacy scores were similar by FNA (7.94 ± 2.84) and FNC (7.96 ± 2.81, p = 0.909). The same proportion of adequate or superior samples was seen in both techniques (91.6%). Sensitivity was equal to 85.7% for FNA and 100% for FNC. Similarly, specificity was 100% for both techniques. FNA and FNC provide the similar sample adequacy and diagnostic accuracy. The choice of technique should be based on the operator’s personal preferences and experience.