Quantifying subclinical central nervous lesions in primary antiphospholipid syndrome: the role of magnetization transfer imaging

Brain Parenchymal Fraction in Healthy Adults-A Systematic Review of the Literature

Brain atrophy is an important feature of many neurodegenerative disorders. It can be described in terms of change in the brain parenchymal fraction (BPF). In order to interpret the BPF in disease, knowledge on the BPF in healthy individuals is required. The aim of this study was to establish a normal range of values for the BPF of healthy individuals via a systematic review of the literature. The databases PubMed and Scopus were searched and 95 articles, including a total of 9269 individuals, were identified including the required data. We present values of BPF from healthy individuals stratified by age and post-processing method. The mean BPF correlated with mean age and there were significant differences in age-adjusted mean BPF between methods. This study contributes to increased knowledge about BPF in healthy individuals, which may assist in the interpretation of BPF in the setting of disease. We highlight the differences between post-processing methods and the need for a consensus gold standard.

Cerebral blood flow abnormalities in neurologically asymptomatic patients with primary antiphospholipid syndrome

Objective: To evaluate cerebral blood flow abnormalities in primary antiphospholipid syndrome (PAPS) patients without ongoing neurological manifestations. Patients and methods: We included 28 PAPS patients and 28 healthy controls. Carotid Doppler ultrasound, and echocardiographic evaluation were done. Transcranial Doppler ultrasonography measured mean flow velocity (MFV) in the carotid siphon, middle, anterior, posterior, intracranial vertebral arteries, and basilar artery (11 cerebral arteries). Results were considered abnormal when the MFV was out of the normal range according to age and/or flow asymmetry and/or more than four arterial segments affected. Results: The mean age of patients was 41.4 ± 11.2 and 39.3 ± 8.6 years in controls. Disease duration was 11 ± 2.7 years. A significant increase in MFV in 7/11 cerebral arteries in PAPS patients, mainly in the middle and anterior cerebral arteries was found compared with controls. A significant association between lupus anticoagulant, history of stroke and obesity with a greater number of affected arteries was found. We did not find an association between MFV and abnormal echocardiography, arterial hypertension and carotid intima-media thickness. Conclusions: Asymptomatic patients with PAPS can have significantly increased MFVs. These alterations may be the consequence of accelerated atherosclerosis, PAPS vasculopathy or both. Whatever the cause, these findings can represent a risk for stroke in PAPS patients that needs the trial of other therapeutic options.

Antiphospholipid syndrome and the brain in pediatric and adult patients

The most common neurological manifestations of antiphospholipid syndrome (APS) in all age-groups include stroke and transient ischemic attacks due to arterial thromboses and cerebral ischemia. Antiphospholipid antibodies may cause additional non-criteria neurological impairments through vascular, neuroinflammatory and direct neuronal effects. Anti-aggregant or anticoagulant therapies are indicated for APS-related ischemic strokes. Treatment regimens for asymptomatic antibody-positive patients and those with refractory or recurrent disease remain controversial. There is scant literature on the epidemiology and therapy of neurological APS manifestations in pediatric patients. Assessments of modifiable cardiovascular and inherited thrombophilia risk factors are essential in patients with APS. There may be a role for novel neuroimaging modalities in quantifying APS-related microstructural brain damage. The clinical utility of statins, antimalarials, angiotensin-converting enzyme inhibitors, and thrombin inhibitors warrant further research.

T2 detection of tumor invasion within segmented components of glioblastoma multiforme

PURPOSE

To use T2-weighted images to detect tumor invasion when comparing normal individuals to groups of gliomablastoma multiforme (GBM) patients with varying levels of CXCR4, a chemokine receptor that promotes tumor migration.

MATERIALS AND METHODS

T2-weighted images were acquired preoperatively in 22 treatment-naïve GBM patients. Two groups were formed based on the expression levels of CXCR4. A third group of normal volunteers was used for comparison. Each image was segmented to obtain four different clusters for tissue types identified as white matter, basal ganglia, gray matter/edema and cerebrospinal fluid (CSF)/tumor. Signal intensity histograms were formed for each cluster and compared between groups.

RESULTS

In every cluster the GBM groups displayed significantly higher standard deviations of intensity distributions when compared to normal subjects. Significant differences in skewness were found between normal subjects and GBM patients in the white matter, basal ganglia, and CSF/tumor. Further, when the two groups of GBM patients were compared the CXCR4-high group was found to have a significant shift in the median intensity values in the cluster containing gray matter and peritumoral edema.

CONCLUSION

T2 signal intensity histograms in normal subjects differ significantly from those obtained from GBM groups, suggesting widespread dissemination of disease.