Implications and limitations of magnetic resonance perfusion imaging with 1.5-Tesla pulsed arterial spin labeling in detecting ictal hyperperfusion during non-convulsive status epileptics.

Background: Recent our reports showed that 3-T pseudocontinuous arterial spin labeling (3-T pCASL) magnetic resonance perfusion imaging with dual post labeling delay (PLD) of 1.5 and 2.5 s clearly demonstrated the hemodynamics of ictal hyperperfusion associated with non-convulsive status epilepticus (NCSE). We aimed to examine the utility of 1.5-T pulsed arterial spin labeling (1.5-T PASL), which is more widely available for daily clinical use, for detecting ictal hyperperfusion. Methods: We retrospectively analyzed the findings of 1.5-T PASL with dual PLD of 1.5 s and 2.0 s in six patients and compared the findings with ictal electroencephalographic (EEG) findings. Results: In patients 1 and 2, we observed the repeated occurrence of ictal discharges (RID) on EEG. In patient 1, with PLDs of 1.5 s and 2.0 s, ictal ASL hyperperfusion was observed at the site that matched the RID localization. In patient 2, the RID amplitude was extremely low, with no ictal ASL hyperperfusion. In patient 3 with lateralized periodic discharges (LPD), we observed ictal ASL hyperperfusion at the site of maximal LPD amplitude, which was apparent at a PLD of 2.0 s but not 1.5 sec. Among three patients with rhythmic delta activity (RDA) of frequencies <2.5 Hz (Patients 4-6), we observed obvious and slight increases in ASL signals in patients 4 and 5 with NCSE, respectively. However, there was no apparent change in ASL signals in patient 6 with possible NCSE. Conclusion: The detection of ictal hyperperfusion on 1.5-T PASL might depend on the electrophysiological intensity of the epileptic ictus, which seemed to be more prominent on 1.5-T PASL than on 3-T pCASL. The 1.5-T PASL with dual PLDs showed the hemodynamics of ictal hyperperfusion in patients with RID and LPD. However, it may not be visualized in patients with extremely low amplitude RID or RDA (frequencies <2.5 Hz).

[A Case of Ruptured Cerebral Arteriovenous Malformation Associated with Hereditary Hemorrhagic Telangiectasia].

BACKGROUND: Patients with hereditary hemorrhagic telangiectasia(HHT)are known to have high rates of cerebral arteriovenous malformations(AVMs). Compared to patients with sporadic AVMs, patients with HHT are less likely to present with ruptured AVMs. CASE REPORT: A 14-year-old male patient presented with headache that had lasted for 2 days. CT revealed an intracerebral hemorrhage in the right parietal lobe, and enhanced CT revealed an AVM in the upper part of the hematoma. The size of the nidus was 20 mm, and its feeders were the right superior internal parietal artery and a branch of the anterior cerebral artery. In addition, the AVM had no deep drainer. We also found another AVM in the right temporal lobe and identified telangiectasia of the nose using digital subtraction angiography. We suspected HHT and performed whole body CT, which revealed an arteriovenous fistula in the right lung and a hematoma-like lesion in the spleen. Thus, we diagnosed the patient with HHT. His ruptured AVM was removed electively. CONCLUSION: We report a case of HHT that presented as an intracerebral hemorrhage in a patient. Based on our case study findings, it is necessary to perform long-term follow-up not only for brain AVMs but also for visceral vascular malformations in such patients, as well as perform HHT screening for families. Although such cases are rare, some features of HHT must be considered to accurately diagnose suspected HHT.

Oct-3/4 promotes migration and invasion of glioblastoma cells.

As a result of increased glioblastoma migration and invasion into normal brain parenchyma, treatment of local tumor recurrence following initial treatment in glioblastoma patients remains challenging. Recent studies have demonstrated increased Oct-3/4 expression, a self-renewal regulator in stem cells, in glioblastomas. However, little is known regarding the influence of Oct-3/4 in glioblastoma cell invasiveness. The present study established Oct-3/4-overexpressing glioblastoma cells, which were prepared from human glioblastoma patients, to assess migration, invasion, and mRNA expression profiles of integrins and matrix metalloproteinases (MMPs). Compared with control cells, Oct-3/4 expressing-glioblastoma cells exhibited increased migration and invasion in wound healing and Matrigel invasion assays. Oct-3/4 overexpression resulted in upregulated FAK and c-Src expression, which mediate integrin signals. Vinculin accumulated along the leading edges of Oct-3/4 expressing-glioblastoma cells and associated with membrane ruffles during cell migration. Oct-3/4 expressing-cells exhibited increased MMP-13 mRNA expression and MMP-13 knockdown by shRNA suppressed cell invasion into Matrigel and organotypic brain slices. These results suggested that Oct-3/4 enhanced degradation of surrounding extracellular matrix by increasing MMP-13 expression and altering integrin signaling. Therefore, Oct-3/4 might contribute to tumor promoting activity in glioblastomas.