Blood-Brain Barrier Disruption and Perivascular Spaces in Small Vessel Disease and Neurodegenerative Diseases: A Review on MRI Methods and Insights

Perivascular spaces (PVS) and blood-brain barrier (BBB) disruption are two key features of cerebral small vessel disease (cSVD) and neurodegenerative diseases that have been linked to cognitive impairment and are involved in the cerebral waste clearance system. Magnetic resonance imaging (MRI) offers the possibility to study these pathophysiological processes noninvasively in vivo. This educational review provides an overview of the MRI techniques used to assess PVS functionality and BBB disruption. MRI-visible PVS can be scored on structural images by either (subjectively) counting or (automatically) delineating the PVS. We highlight emerging (diffusion) techniques to measure proxies of perivascular fluid and its movement, which may provide a more comprehensive understanding of the role of PVS in diseases. For the measurement of BBB disruption, we explain the most commonly used MRI technique, dynamic contrast-enhanced (DCE) MRI, as well as a more recently developed technique based on arterial spin labeling (ASL). DCE MRI and ASL are thought to measure complementary characteristics of the BBB. Furthermore, we describe clinical studies that have utilized these MRI techniques in cSVD and neurodegenerative diseases, particularly Alzheimer's disease (AD). These studies demonstrate the role of PVS and BBB dysfunction in these diseases and provide insight into the large overlap, but also into the differences between cSVD and AD. Overall, MRI techniques may provide valuable insights into the pathophysiological mechanisms underlying these diseases and have the potential to be used as markers for disease progression and treatment response. LEVEL OF EVIDENCE: 3 TECHNICAL EFFICACY: Stage 2.

Different blood-brain-barrier disruption profiles in multiple sclerosis, neuromyelitis optica spectrum disorders, and neuropsychiatric systemic lupus erythematosus

AIM OF THE STUDY

To assess differences in BBB damage profiles by measuring serum levels of soluble vascular cell adhesion molecule-1 (sVCAM-1), soluble platelet endothelial cell adhesion molecule-1 (sPECAM-1), soluble intercellular adhesion molecule-1 (sICAM-1), and S100 calcium-binding protein B (S100B) in relapsing-remitting multiple sclerosis (RRMS), neuromyelitis optica spectrum disorders (NMOsd), and neuropsychiatric systemic lupus erythematosus (NPSLE) patients.

CLINICAL RATIONALE FOR THE STUDY

Blood-brain-barrier (BBB) disruption is one of the key pathological processes involved in various demyelinating diseases of the central nervous system (CNS) and is associated with shedding of cell adhesion molecules and S100B into the serum compartment. Therefore, making an assessment of serum levels of the above-mentioned molecules could provide information about disease pathogenesis, severity of BBB disruption, and disease activity.

MATERIAL AND METHODS

We recruited 42 RRMS, 19 NMOsd and 35 NPSLE patients. Subjects were treated with beta-interferons or glatiramer acetate (RRMS), oral steroids and/or azathioprine (NMOsd, NPSLE), other immunosuppressants (NPSLE), or antimalarials (NPSLE). The clinical condition of the patients was assessed using the Kurtzke Expanded Disability Status Scale for MS and NMOsd, and the Systemic Lupus Erythematosus Disease Activity Index for NPSLE. Serum levels of sVCAM-1, sPECAM-1, sICAM-1 and S100B were determined using enzyme-linked immunosorbent assay (ELISA).

RESULTS

We found the lowest levels of sPECAM-1, sICAM-1 and S100B in sera from NMOsd patients. The highest levels of sPECAM-1 and sICAM-1 were observed in NPSLE, and in NPSLE and MS, respectively. There were no statistically significant differences in sVCAM-1 levels between the examined groups. In MS and NMOsd, there was a negative correlation between the EDSS score and the following molecules: sPECAM-1, sICAM-1 and S100B.

CONCLUSIONS AND CLINICAL IMPLICATIONS

We conclude that there is a different profile of blood-brain-barrier disruption reflected by cell adhesion molecules shedding in the spectrum of autoimmune CNS disorders with disseminated white matter lesions. These molecules could become new biomarkers to be used in CNS demyelinating diseases differential diagnoses and monitoring disease activity, but further studies on larger groups of patients are necessary.

Advances in the Potential Biomarkers of Epilepsy

Epilepsy is a group of chronic neurological disorders characterized by recurrent, spontaneous, and unpredictable seizures. It is one of the most common neurological disorders, affecting tens of millions of people worldwide. Comprehensive studies on epilepsy in recent decades have revealed the complexity of epileptogenesis, in which immunological processes, epigenetic modifications, and structural changes in neuronal tissues have been identified as playing a crucial role. This review discusses the recent advances in the biomarkers of epilepsy. We evaluate the possible molecular background underlying the clinical changes observed in recent studies, focusing on therapeutic investigations, and the evidence of their safety and efficacy in the human population. This article reviews the pathophysiology of epilepsy, including recent reports on the effects of oxidative stress and hypoxia, and focuses on specific biomarkers and their clinical implications, along with further perspectives in epilepsy research.

Osteopontin as a Potential Therapeutic Target for Ischemic Stroke

BACKGROUND

Ischemic stroke is the third leading cause of death and the most frequent cause of permanent disability in adults worldwide. Tremendous advances have been made in understanding of the pathophysiology of cerebral ischemia. Nevertheless, there is still no effective neuroprotectant available in the clinical work. Recently, osteopontin (OPN), a glycophosphoprotein, has attracted more attention due to its various effects in cardiovascular and nervous system diseases.

OBJECTIVE

The aim of present review was to summarize recent findings about neuroprotective effects of OPN on ischemic stroke, targeting to provide a novel therapeutic strategy.

METHODS

To prepare this review, a pathophysiological and pharmacological literature survey was performed using PubMed, and Web of Science. Also, some statistical and epidemiological literature sources were used.

RESULTS

Mounting evidence indicates that OPN attenuates cerebral damage and promotes neurogenesis in ischemic stroke by binding to its receptors to activate diverse signaling pathways.

CONCLUSION

The paper highlights the neuroprotective and pro-regenerative effects of OPN after cerebral ischemia, which would demonstrate its therapeutic potential in ischemic stroke and other informs of ischemic brain injury.