Min Bk

Detection of traumatic cerebral microbleeds by susceptibility-weighted image of MRI.

OBJECTIVE Susceptibility-weighted image (SWI) is a sensitive magnetic resonance image (MRI) technique to detect cerebral microbleeds (MBLs), which would not be detected by conventional MRI. We performed SWI to detect MBLs and investigated its usefulness in the evaluation of mild traumatic brain injury (MTBI) patients. METHODS From December 2006 to June 2007, twenty-one MTBI patients without any parenchymal hemorrhage on conventional MRI were selected. Forty-two patients without trauma were selected for control group. According to the presence of MBLs, we divided the MTBI group into MBLs positive [SWI (+)] and negative [SWI (-)] group. Regional distribution of MBLs and clinical factors were compared between groups. RESULTS Fifty-one MBLs appeared in 16 patients of SWI (+) group and 16 MBLs in 10 patients of control group [control (+)], respectively. In SWI (+) group, MBLs were located more frequently in white matters than in deep nucleus different from the control (+) group (p < 0.05). Nine patients (56.3%) of SWI (+) group had various neurological deficits (disorientation in 4, visual field defect in 2, hearing difficulty in 2 and Parkinson syndrome in 1). Initial Glasgow Coma Scale (GCS)/mean Glasgow Outcome Scale (GOS) were 13.9 +/- 1.5 / 4.7 +/- 0.8 and 15.0 +/- 0.0 / 5.0 +/- 0.0 in SWI (+) and SWI (-) groups, respectively (p < 0.05). CONCLUSION Traumatic cerebral MBLs showed characteristic regional distribution, and seemed to have an importance on the initial neurological status and the prognosis. SWI is useful for detection of traumatic cerebral MBLs, and can provide etiologic evidences for some post-traumatic neurologic deficits which were unexplainable with conventional MRI.

The effects of N-methyl-N-nitrosourea and azoxymethane on focal cerebral infarction and the expression of p53, p21 proteins.

If the activity of pro-apoptotic genes can be down-regulated by certain chemicals, cells may be protected from apoptosis. To test this hypothesis in a cerebral infarction model, we used N-methyl-N-nitrosourea (MNU) and azoxymethane (AOM), which were approved gene-modulating chemicals. A focal cerebral infarction was created by coagulation of the right middle cerebral artery and ipsilateral common carotid artery (CCA) and simultaneous transient occlusion of the contralateral CCA for 30 min in 25 adult Sprague-Dawley rats that were sacrificed 24 h later. In one group (n=7), MNU (5 mg/kg) was injected intravenously 30 min before initiation of ischemia. In another group (n=7), AOM (15 mg/kg) was administered intraperitoneally before 24 h of ischemia. The infarction volumes were checked and the brains were stained for p53 and p21 proteins. The width in micrometers of the peri-infarct area containing p53 or p21 protein-positive cells, and the number of p53 or p21 protein-positive cells (cells/HPF) were measured at an adjacent peri-infarct area. The AOM-treated group showed a significantly reduced infarction volume (by 42.5%, p<0.001), a significantly greater number of p53 positive cells (by 12.0%, p<0. 05), and a significantly wider p53 protein-positive area (by 15.6%, p<0.01) than the untreated group. AOM did not show any influence on the expression pattern of the p21 protein. MNU had no effect in the expression of p53 or p21 proteins. As a result, we concluded that AOM revealed a protective effect in ischemia by suppressing the pro-apoptotic activity of the p53 gene. Safer chemicals that can modulate apoptotic genes, if any, will provide a new therapeutic modality for cerebral infarction.

The Effect of Barbiturate Coma Therapy for the Patients with Severe Intracranial Hypertension: A 10-Year Experience

OBJECTIVE Barbiturate coma therapy (BCT) has been known to be an useful method to control increased intracranial pressure (IICP) refractory to medical and surgical treatments. We have used BCT for patients with severe IICP during the past 10 years, and analyzed our results with review of literatures. METHODS We analyzed 92 semicomatose or comatose patients with Glasgow coma scale (GCS) of 7 or less with severe IICP due to cerebral edema secondary to parenchymal damages irrespective of their causes. Forty patients who had received BCT with ICP monitoring from January 1997 to December 2006 were included in BCT group, and fifty-two patients who had been managed without BCT from January 1991 to December 1995 were divided into control group. We compared outcomes with Glasgow outcome scale (GOS) and survival rate between the two groups. RESULTS Good outcome (GOS=4 and 5) rates at 3-month after insult were 27.5% and 5.8% in BCT and control group, respectively (p<0.01). One-year survival rates were 35.9% and 12.5% in BCT and control group, respectively (p<0.01). In BCT group, the mean age of good outcome patients (37.1 +/- 14.9) was significantly lower than that of poor outcome patients (48.1 +/- 13.5) (p<0.05). CONCLUSION With our 10-year experience, we suggest that BCT is an effective treatment method for severe IICP patients for better survival and GOS, especially for younger patients.

Role of a Burr Hole and Calvarial Bone Marrow-Derived Stem Cells in the Ischemic Rat Brain: A Possible Mechanism for the Efficacy of Multiple Burr Hole Surgery in Moyamoya Disease

Objective This study investigates the role of a burr hole and calvarial bone marrow-derived stem cells (BMSCs) in a transient ischemic brain injury model in the rat and postulates a possible mechanism for the efficacy of multiple cranial burr hole (MCBH) surgery in moyamoya disease (MMD). Methods Twenty Sprague-Dawley rats (250 g, male) were divided into four groups : normal control group (n=5), burr hole group (n=5), ischemia group (n=5), and ischemia+burr hole group (n=5). Focal ischemia was induced by the transient middle cerebral artery occlusion (MCAO). At one week after the ischemic injury, a 2 mm-sized cranial burr hole with small cortical incision was made on the ipsilateral (left) parietal area. Bromodeoxyuridine (BrdU, 50 mg/kg) was injected intraperitoneally, 2 times a day for 6 days after the burr hole trephination. At one week after the burr hole trephination, brains were harvested. Immunohistochemical stainings for BrdU, CD34, VEGF, and Doublecortin and Nestin were done. Results In the ischemia+burr hole group, BrdU (+), CD34 (+), and Doublecortin (+) cells were found in the cortical incision site below the burr hole. A number of cells with Nestin (+) or VEGF (+) were found in the cerebral parenchyma around the cortical incision site. In the other groups, BrdU (+), CD34 (+), Doublecortin (+), and Nestin (+) cells were not detected in the corresponding area. These findings suggest that BrdU (+) and CD34 (+) cells are bone marrow-derived stem cells, which may be derived from the calvarial bone marrow through the burr hole. The existence of CD34 (+) and VEGF (+) cells indicates increased angiogenesis, while the existence of Doublecortin (+), Nestin (+) cells indicates increased neurogenesis. Conclusion Based on these findings, the BMSCs through burr holes seem to play an important role for the therapeutic effect of the MCBH surgery in MMD.