Increased subcortical neural activity among HIV+ individuals during a lexical retrieval task.

BACKGROUND: Deficits in lexical retrieval, present in approximately 40% of HIV+ patients, are thought to reflect disruptions to frontal-striatal functions and may worsen with immunosuppression. Coupling frontal-striatal tasks such as lexical retrieval with functional neuroimaging may help delineate the pathophysiologic mechanisms underlying HIV-associated neurological dysfunction. OBJECTIVE: We examined whether HIV infection confers brain functional changes during lexical access and retrieval. It was expected that HIV+ individuals would demonstrate greater brain activity in frontal-subcortical regions despite minimal differences between groups on neuropsychological testing. Within the HIV+ sample, we examined associations between indices of immunosuppression (recent and nadir CD4+ count) and task-related signal change in frontostriatal structures. Method16 HIV+ participants and 12 HIV- controls underwent fMRI while engaged in phonemic/letter and semantic fluency tasks. Participants also completed standardized measures of verbal fluency RESULTS: HIV status groups performed similarly on phonemic and semantic fluency tasks prior to being scanned. fMRI results demonstrated activation differences during the phonemic fluency task as a function of HIV status, with HIV+ individuals demonstrating significantly greater activation in BG structures than HIV- individuals. There were no significant differences in frontal brain activation between HIV status groups during the phonemic fluency task, nor were there significant brain activation differences during the semantic fluency task. Within the HIV+ group, current CD4+ count, though not nadir, was positively correlated with increased activity in the inferior frontal gyrus and basal ganglia. CONCLUSION: During phonemic fluency performance, HIV+ patients recruit subcortical structures to a greater degree than HIV- controls despite similar task performances suggesting that fMRI may be sensitive to neurocompromise before overt cognitive declines can be detected. Among HIV+ individuals, reduced activity in the frontal-subcortical structures was associated with lower CD4+ count.

Brain network local interconnectivity loss in aging APOE-4 allele carriers.

Old age and possession of the APOE-4 allele are the two main risk factors for developing later onset Alzheimer's Disease (AD). Carriers of the APOE-4 allele have known differences in intrinsic functional brain network activity across the life span. These individuals also demonstrate specific regional differences in gray and white matter gross structure. However, the relationship of these variations to whole brain structural network connectivity remains unclear. We performed diffusion tensor imaging (DTI), T1 structural imaging, and cognitive testing on aging APOE-4 noncarriers (n = 30; mean age = 63.8±8.3) and APOE-4 carriers (n = 25; mean age = 60.8 ±9.7). Fiber tractography was used to derive whole brain structural graphs, and graph theory was applied to assess structural network properties. Network communication efficiency was determined for each network by quantifying local interconnectivity, global integration, and the balance between these, the small worldness. Relative to noncarriers, APOE-4 carriers demonstrated an accelerated age-related loss of mean local interconnectivity (r = -0.64, P ≤ 0.01) and regional local interconnectivity decreases in the precuneus (r = -0.64), medial orbitofrontal cortex (r = -0.5), and lateral parietal cortex (r = -0.54). APOE-4 carriers also showed significant age-related loss in mean cortical thickness (r = -0.52, P < 0.05). Cognitively, APOE-4 carriers had significant negative correlations of age and performance on two episodic memory tasks (P < 0.05). This genotype-specific pattern of structural connectivity change with age thus appears related to changes in gross cortical structure and cognition, potentially affecting the rate and/or spatial distribution of AD-related pathology.

Safety of percutaneous, image-guided biopsy of hepatocellular carcinoma with and without concurrent ablation.

PURPOSE: To determine the prevalence of adverse events after image-guided biopsy of histologically proven hepatocellular carcinomas (HCC) using a standardized, indirect access, coaxial biopsy technique. METHODS: In this IRB-approved, HIPAA compliant, and retrospective study, we evaluated all consecutive adult patients from 2011 to 2016 who underwent image-guided biopsy of HCC with and without concurrent ablation. Tumor seeding was defined as any new lesion along the needle tract on subsequent imaging. Adverse events were graded using both the Clavien-Dindo Complication Classification system and the most recently proposed Society of Interventional Radiology (SIR) Adverse Event Classification System. RESULTS: A total of 383 patients underwent 398 biopsies (64 ± 11 years; 112 women, 271 men). Most patients (282; 71%) underwent concurrent ablation. Adverse events occurred after 18 biopsies (4.5%): 13 were Grade I (Clavien-Dindo) or minor (SIR) and included hematoma (7), hepatic vein thrombus (2), portal vein thrombus (2), moderate pleural effusion (1), and small pneumothorax (1). The remaining 5 (1.3%) adverse events were classified as Grade II-IIIa (Clavien-Dindo) or moderate (SIR) and included hematoma requiring blood products (n = 1), arrhythmia (n = 1), and symptomatic pleural effusions requiring treatment (n = 3). Baseline age, sex, cause of liver disease, HCC diameter, and HCC grade were not associated with adverse events. There were no tumor seeding events after a median follow-up of 611 days (interquartile range of 211-1104). CONCLUSION: Percutaneous image-guided tissue sampling using a standardized, indirect access, coaxial technique can be performed safely with and without concurrent ablation by trained cross-sectional interventional radiologists at a tertiary liver transplant center.

Amyloid-ß-related angiitis: a report of 2 cases with unusual presentations.

Amyloid-ß-related angiitis (ABRA) is a rare complication of cerebral amyloid angiopathy in which amyloid-ß deposition in the leptomeningeal and cortical vessels is associated with vasculitis characterized by transmural lymphohistiocytic, often granulomatous, inflammation. Patients usually present with acute to subacute cognitive dysfunction, headaches, and focal neurologic deficits. We report 2 cases of ABRA with unusual clinical presentations, including one case with fatal cerebral edema leading to herniation and Duret hemorrhages, and another associated with both lobar and deep parenchymal hemorrhages with intraventricular extension as well as hypercoagulability. Both showed extensive vascular amyloid-ß deposition associated with granulomatous angiitis and foreign body-type multinucleated giant cells. One of our cases demonstrates the likely effects of ABRA on impairment of fluid regulation leading to severe cerebral edema, which is an uncommon manifestation of ABRA, and may be a result of impaired blood-brain barrier function or malfunction of the neurovascular unit.