Emerging Concepts in Vascular Dementia: A Review.

OBJECTIVE: Vascular dementia (VaD) is the second most common cause of dementia and a major health concern worldwide. A comprehensive review on VaD is warranted for better understanding and guidance for the practitioner. We provide an updated overview of the epidemiology, pathophysiological mechanisms, neuroimaging patterns as well as current diagnostic and therapeutic approaches. MATERIALS AND METHODS: A narrative review of current literature in VaD was performed based on publications from the database of PubMed, Scopus and Google Scholar up to January, 2021. RESULTS: VaD can be the result of ischemic or hemorrhagic tissue injury in a particular region of the brain which translates into clinically significant cognitive impairment. For example, a cerebral infarct in the speech area of the dominant hemisphere would translate into clinically significant impairment as would involvement of projection pathways such as the arcuate fasciculus. Specific involvement of the angular gyrus of the dominant hemisphere, with resultant Gerstman's syndrome, could have a pronounced effect on functional ability despite being termed a "minor stroke". Small vessel cerebrovascular disease can have a cumulate effect on cognitive function over time. It is unfortunately well recognized that "good" functional recovery in acute ischemic or haemorrhagic stroke, including subarachnoid haemorrhage, does not necessarily translate into good cognitive recovery. The victim may often be left unable to have gainful employment, drive a car safely or handle their affairs independently. CONCLUSIONS: This review should serve as a compendium of updated information on VaD and provide guidance in terms of newer diagnostic and potential therapeutic approaches.

Focal epilepsy caused by single cerebral cavernous malformation (CCM) is associated with regional and global resting state functional connectivity (FC) disruption.

Epilepsy, including the type with focal onset, is increasingly viewed as a disorder of the brain network. Here we employed the functional connectivity (FC) metrics estimated from the resting state functional MRI (rsfMRI) to investigate the changes of brain network associated with focal epilepsy caused by single cerebral cavernous malformation (CCM). Eight CCM subjects and 21 age and gender matched controls were enrolled in the study. Seven of 8 CCM subjects underwent surgical resection of the CCM and became seizure free and 4 of the surgical subjects underwent a repeat rsfMRI study. We showed that there was both regional and global disruption of the FC values among the CCM subjects including decreased in homotopic FC (HFC) and global FC (GFC) in the regions of interest (ROIs) where the CCMs were located. There was also the disruption of the default mode network (DMN) especially the FC between the middle prefrontal cortex (MPFC) and the right lateral parietal cortex (LPR) among these individuals. We observed the trend of alleviation of these disruptions after the individual has become seizure free from the surgical resection of the CCM. Using a voxel-based approach, we found the disruption of the HFC and GFC in the brain tissue immediately adjacent to the CCM and the severity of the disruption appeared inversely proportional to the distance of the brain tissue to the lesion. Our findings confirm the disruption of normal brain networks from focal epilepsy, a process that may be reversible with successful surgical treatments rendering patients seizure free. Some voxel-based metrics may help identify the epileptogenic zone and guide the surgical resection.

Comparing the volume of gliomas in the brain in FLAIR and post-contrast T1-weighted MRI sequences.

The imaging modality used to diagnose and monitor brain gliomas is magnetic resonance imaging (MRI), with standard protocols including contrast-enhanced T1-weighted and fluid-attenuated inversion recovery (FLAIR) image sequences. Many clinical trials are currently using contrast-enhanced T1-weighted MR image sequences to evaluate tumor response to treatment, but it is our hypothesis that FLAIR sequences will detect higher tumor volumes and, therefore, should be the preferred image sequence for this purpose. In this retrospective study, a volumetric analysis was conducted on the post-contrast T1-weighted and FLAIR MR image sequences of 38 patients with confirmed brain gliomas. The two volumes were subsequently found to have a statistically significant positive correlation. The FLAIR volume was also found to be greater than the post-contrast T1-weighted volume in all 38 patients. As a result, FLAIR image sequences provide a more complete characterization of gliomas and may be more beneficial when observing tumor response after treatment.

Carcinomatous meningitis secondary to transitional cell bladder cancer.

We report a patient with carcinomatous meningitis secondary to known transitional cell carcinoma of the bladder. The patient presented with multiple focal neurological signs and symptoms. Diagnosis was suggested by magnetic resonance imaging and confirmed by analysis of the cerebrospinal fluid. He received whole brain radiotherapy despite a poor prognosis. To our knowledge, this is only the fifth reported case of neoplastic meningitis due to bladder cancer with confirmatory imaging and cytology and only the fourth reported case that presented with cranial nerve involvement.

Hydatid disease of the central nervous system: a review of literature with an emphasis on Latin American countries.

OBJECTIVE: To provide an up to date review of the epidemiology, etiology, treatment and prevention of hydatid cyst of the central nervous system, with an emphasis in South American countries. METHODS: We searched the PubMed databases for articles containing the terms 'hydatid cyst' and 'nervous system'. RESULTS: We found and reviewed 303 articles and their related references. We provide the available information on the pathology, life cycle and diagnostic modalities (laboratory tests and imaging) along with possible complications of the disease. Current treatment methods of hydatid cyst in the brain and spine are also being discussed. DISCUSSION: Echinococcosis is a rare parasitic disease, endemic in some parts of South America. The epidemiology of echinococcosis is influenced by agricultural, educational, economic, medical and cultural factors. Human infestation occurs through the fecal-oral route. Infection of the central nervous system is rare, and the mainstay of treatment is surgical excision of the intracranial or spinal cyst, when present. Preventive programs should break the parasite life cycle and also educate the farmers in endemic areas.

Management of acute ischemic stroke: current status of pharmacological and mechanical endovascular methods.

OBJECTIVE: To provide the current strategies of acute stroke management using pharmacological and interventional endovascular modalities. METHODS: Review of the literature for publications in English language literature on endovascular pharmacological and mechanical thrombolysis and clot retrieval. RESULTS: Aggressive management protocols have yielded therapeutic windows for effective reperfusion of ischemic brain in acute cerebral hypoperfusion/stroke. Starting with intravenous infusion of thrombolytics, which still remains to be the best feasible treatment for acute stroke management, recent advances in neuron imaging made it possible to utilize emergency cerebral angiographic evaluation of intracranial vessels followed by therapeutic measure that could be pharmacological or mechanical intervention. Intra-arterial clot lysis under image guidance combined with intravenous administration of thrombolytic is rapidly evolving with encouraging results. Microcatheters and endovascular appliances tested very positively, yielding better outcomes in acute stroke. MERCI trial, Multi MERCI trial and Stroke trials [emergency management of stroke (EMS) and interventional management of stroke (IMS)] have shown that early recanalization and reperfusion constitute good prognostic indicators by reducing mortality and improving neurological outcomes. Further trials are expected to yield better evidence to form guidelines for aggressive management of acute cerebral ischemia. DISCUSSION: Intravenous fibrinolysis is, to date, the best possible intervention in acute stroke and has been shown to be a better alternative to aspirin, the only known effective, pharmacological treatment. Endovascular interventions have shown very promising results with intra-arterial administration of thrombolytics as well as mechanical clot retrieving methods.

Creating an IHE ATNA-based audit repository.

Compliance with the Health Insurance Portability and Accountability Act (HIPAA) requires gathering audit information from picture archiving and communications systems (PACS) regarding evidence trails of human interactions. Until recently, most PACS users have had limited access to auditing information. Access required resources to handle manual inspection of audit logs, and access to proprietary databases was not always available. Some vendors now produce eXtensible Markup Language (XML) audit logs based on certain events occurring in PACS. However, it is up to the user to convert this information into an easily mined data repository supporting compliance and quality control. This process can be handled in multiple ways, which could mean different audit mechanisms depending on the PACS (or other hospital system) used. It is apparent that an organized method of dealing with audit information is needed. This help may be provided within the Integrating the Healthcare Environment (IHE) framework. The IHE initiative defines a set of profiles, actors, and transactions that create common scenarios for particular workflow processes. The Integration Profiles depict security as a fundamental requirement of the framework. Specifically, the Audit Trail and Node Authentication (ATNA) profile defines standards based mechanisms for securely transmitting and storing audit records in a central repository. The data structure defined by the profile provides a number of record types that capture different audit events. A general feasibility study for storing currently available PACS audit information following the profile is defined, and steps to an automated solution are discussed.

Pathogenesis of brain and spinal cord atrophy in multiple sclerosis.

For more than a century, multiple sclerosis was viewed as a disease process characterized by oligodendrocyte and myelin loss, and research into the pathogenesis of multiple sclerosis was mainly focused on the mechanisms of inflammation. However, with development of more sophisticated neuroimaging and molecular biology techniques, attention has shifted to new aspects of pathogenesis of multiple sclerosis: axonal loss and neurodegeneration. Evidence is increasing that tissue destruction, primarily axonal loss and neurodegeneration, is a key element in the pathogenesis of multiple sclerosis. In addition, it is now known that brain and spinal cord atrophy begins early in the disease process of multiple sclerosis and advances relentlessly throughout the course of the disease. Cumulative data suggest that axonal loss is the major determinant of progressive neurologic disability in patients with multiple sclerosis. Magnetic resonance imaging and magnetic resonance spectroscopy in patients with multiple sclerosis for < 5 years indicate brain atrophy and loss of axonal integrity. Neurodegeneration and axonal loss in patients with multiple sclerosis are initially accompanied by a local response from oligodendrocyte progenitor cells and some remyelination. However, these repair mechanisms eventually fail, and patients typically develop generalized brain atrophy, cognitive decline, and permanent disability. Although the exact mechanisms underlying central nervous system atrophy in patients with multiple sclerosis are largely unknown, evidence exists that atrophy may represent an epiphenomenon related to the effects of dynamic inflammation within the central nervous system, including demyelination, axonal injury, neuronal loss, Wallerian degeneration, and possibly iron deposition. This article summarizes the potential mechanisms involved in central nervous system atrophy in patients with multiple sclerosis.