White matter injury exacerbated anxiety-like behavior of db/db mice after distal middle cerebral artery occlusion / 中国医师进修杂志

Objective:To explore the possible mechanism of exacerbation of anxiety-like behavior in db/db mice after distal middle cerebral artery occlusion (dMCAO).Methods:The db/db mice was used to establish a type 2 diabetes mellitus model. Meanwhile, heterozygous db/+ mice and C57 wild-type (WT) mice were chosen as double control groups. Then a permanent distal middle cerebral artery occlusion model was employed as an acute ischemic stroke model. The blood glucose levels before and post-dMCAO surgery on day1, day3, and day5 were detected. The brain tissue loss at 35 days after stroke was measured by immunofluorescent staining of MAP2. The open-field test was performed to estimate anxiety-like behavior and general motor and exploring ability of the animals. Axons and myelin were immunostained with non-phosphorylated neurofilaments (SMI32) and myelin basic protein (MBP), respectively, to evaluate differences in white matter integrity in WT, db/+ and db/db mice 35 days after stroke. The correlation between SMI32/MBP and open field test parameters (time in center and corner) was analyzed. Flow cytometry was employed to detect the amount of T cells and B cells, including regulatory T cells (Tregs) in the brain tissue.Results:Blood glucose levels in db/db mice were significantly higher than db/+ mice and WT mice in both sham and dMCAO groups ( P<0.01). There was no significant difference in brain tissue loss 35 days post-stroke among db/db mice, db/+ mice, and WT mice. In the open field test, there were significant differences in the total distance of db/db mice, db/+ and WT mice in the sham and dMCAO groups. Db/db mice shorter than db/+ mice ( P<0.05), WT mice ( P<0.01), and db/+ mice shorter than WT mice ( P<0.05). There were significant time differences in the center among db/db, db/+, and WT mice in sham and dMCAO groups. In both the sham and dMCAO groups, db/db mice spent less time in the center area of the open field than WT mice ( P<0.01). In the sham group, db/+ mice spent less time in the center area than WT mice ( P<0.05). In dMCAO group, db/db mice spent less time in the center area than db/+mice ( P<0.05), and db/+ mice spent less time in the center area than WT mice ( P<0.01). For the time in the corner, in both the sham and dMCAO groups, db/db mice and db/+ mice consumed more time than WT mice ( P<0.01 or <0.05). In the dMCAO group, db/db mice spent more time in the corner than db/+ mice ( P<0.05). Referring to white matter injury, an increased SMI32/MBP ratio in EC area and CTX area (data was not shown in this article) after dMCAO in db/db, db/+ and WT mice were detected. In EC area, db/db mice have a higher SMI32 ratio than db/+ mice and WT mice: 4.24 ± 0.37 vs. 1.96 ± 0.37, 1.80 ± 0.36, both have significant differences ( P<0.01). For db/db mice and WT mice, the SMI32/MBP ratio negatively correlates with time in center and positive correlation with time in the corner. Three days after dMCAO, the total cells of CD 3+ T cells, CD 8+ cells, Tregs, in db/db mice group have significantly decreased compared to WT group: 4 079 ± 1 345 vs. 70 055 ± 3 374, 141.30 ± 28.36 vs. 2 714.00 ± 463.20, 148.00 ± 61.15 vs. 3 007.00 ± 639.90 ( P<0.01), while B cell has no change between two groups. Conclusions:By comparing the severity of anxiety-like behavior of db/db mice, the severity of white matter injury, and the number of T cells and B cells in brain tissue after dMCAO, immune-mediated brain white matter injury may aggravate db/db mice′s post-dMCAO anxiety-like behavior. Due to the gene dose effect, db/+ mice are not suitable as a control group for db/db mice in animal experiments involving anxiety-like behavior assessment.

Surgical Experience of Distal Middle Cerebral Artery Aneurysm Rupture / 대한뇌혈관외과학회지

OBJECTIVE: Distal middle cerebral artery (MCA) aneurysms are the least frequent aneurysms of the MCA, and they represent about 1.1 to 5% of all MCA aneurysms. Patients with ruptured distal MCA aneurysms generally have a poor clinical outcome. The purpose of this article is to review the characteristics of distal MCA aneurysms to avoid the complications of microsurgical dissection and clipping of distal MCA aneurysms. METHODS: A total of 1187 patients with ruptured aneurysms were treated at our hospital between January 1997 and May 2008. All patients underwent surgical procedures. Computed tomography (CT) revealed rupture of distal MCA aneurysms in 15 (1.26%) patients. The location of the aneurysm were the M2 (insular) segment in seven patients, the M2-3 junction in three and the M3 (opercular) segment in five. Brain CT images revealed the presence of both subarachnoid hemorrhage (SAH) and intracranial hemorrhage (ICH) in 11 of 15 (77.3%) patients, with a mean ICH volume of 14.5 cc (range : 5 to 32 cc). Rebleeding occurred in 7 out of the 15 (46.7%) patients. RESULTS: All the patients underwent early surgical procedures, including clipping in seven, trapping in two, bypass surgery in four, Guglielmi detachable coil embolization in one and exploratory craniotomy in one patient. The aneurysm had a fusiform appearance in 9 out of 15 cases (60%), and the mean size of the aneurysm was 10.4 mm (range : 2 to 35 mm). Three patients died due to severe brain swelling (20%). CONCLUSION: In this study, distal MCA aneurysms had a relatively fusiform shape as well as high rates of rebleeding and ICH. A good clinical outcome was associated with early surgery for adequately controlling brain swelling and preventing rebleeding.

Coil Embolization for Distal Middle Cerebral Artery Aneurysm

Middle cerebral artery (MCA) aneurysms are a common source of subarachnoid hemorrhage (SAH). But, ruptured distal MCA aneurysm is very rare, and their clinical and radiological features are poorly understood. Microsurgical repair remains the most common method used to treat distal MCA aneurysm, even though endovascular coiling has been favored recently. We report our experience of successful coiling for ruptured distal MCA aneurysm. In selected patients, coiling may be a good treatment option for ruptured distal MCA aneurysm.

Surgical Treatment of Distal Middle Cerebral Artery Aneurysms / 대한뇌혈관외과학회지

OBJECT: The aneurysms located in the distal middle cerebral artery (MCA) are uncommon and have not been well investigated previously. To clarify these lesions more fully, we undertook a retrospective analysis of the clinical features and managements of the 9 consecutive patients treated at our institution. METHODS: Nine patients with distal MCA aneurysms treated at our department between 1994 and 2003 were reviewed retrospectively. We performed analysis on the basis of clinical profiles, radiological and intraoperative findings. RESULT: In our series, the incidence of distal MCA aneurysms was 1.1% of all intracranial aneurysms and 3.7% all MCA aneurysms. There were seven ruptured and two unruptured distal MCA aneurysms. All aneurysms were presumed typical saccular aneurysms in the angiographic and intraoperative findings and there were no past medical history, evidence of previous infection, trauma and neoplastic disorders. The nine patients consisted of seven women and two men ranging in age from 42 to 61 years. Eight aneurysms were located in the left side and only one aneurysm in the right side. Five of seven ruptured patients sustained an subarachnoid hemorrhage (SAH) with intracerebral hematoma (ICH) in the initial computed tomography (CT) scans. Although three patients presented transient speech disturbance postoperatively, good clinical outcome was achived in the eight of nine patients. CONCLUSION:Distal MCA aneurysms have tendency of female and left side predominency and easily cause ICH with SAH, but majority of them showed a favorable outcome. It was difficult to find the exact location of aneurysms during dissection. To obtain successful clippng of aneurysms and avoid the operation related complications, surgeons must dissect the sylvian fissure sufficiently and retract frontal lobe carefully.