[Research Advances in Idiopathic Intracranial Hypertention].

Idiopathic intracranial hypertension,also known as pseudotumor cerebri,is a syndrome characterized by raised intracranial pressure of unknown cause.These patients present normal neuroimaging and cerebrospinal fluid analysis while increased intracranial pressure and associated symptoms and signs.Delay of treatment can cause severe visual impairment.There are some new understandings of this disease,and we will review the pathogenesis,diagnosis,and treatment of idiopathic intracranial hypertension.

Bromadiolone poisoning leading to subarachnoid haemorrhage: A case report and review of the literature.

WHAT IS KNOWN AND OBJECTIVE: Many cases of rodenticide poisoning have been reported. Bromadiolone, often called a super-warfarin, is a second-generation dicoumarin rodenticide with long half-life. The main clinical manifestations of bromadiolone poisoning are excessive or inappropriate bleeding of skin mucosa, digestive tract and urinary tract. However, the phenomenon of central nervous system (CNS) toxicity is an uncommon medical emergency. We present a case of SAH and intracerebral haematoma mediated by bromadiolone intoxication, revealing that bromadiolone poisoning might cause intracerebral haematoma. CASE DESCRIPTION: A 44-year-old woman presented with skin mucosa haemorrhage and haematuresis initially. The patient developed lethargy, headache, nausea and vomiting. The toxicology test result revealed that the presence of bromadiolone in her blood. Coagulation test results showed a longer prothrombin time (PT), activated partial thromboplastin time (APTT) and a high international normalized ratio (INR). SAH, frontal lobe haematoma, midline shift and brain oedema were discovered by skull CT examination. The coagulation disorders were addressed after the treatment of vitamin K and fresh frozen plasma. The intracranial symptoms were relieved after surgery and the treatment with mannitol. WHAT IS NEW AND CONCLUSION: This case suggests that bromadiolone poisoning should be diagnosed and treated as early as possible. Bromadiolone poisoning might cause SAH and intracerebral haematoma, which is rare but potentially lethal. It is important to strengthen the diagnosis and post-treatment monitoring.

[Advancement in Diagnosis and Treatment of Elevated Intracranial Pressure in Patients with Cryptococcal Meningitis].

Cryptococcal meningitis(CM)is often seen in immunocompromised patients and has become a global health concern. Elevated intracranial pressure(ICP)is a common complication of CM and often leads to poor prognosis. Monitoring and management of ICP is an important task in CM patients. Invasive intervention is often needed for the elevated ICP in CM patients due to the pathophysiological features of this condition. This article review the recent progress in the diagnosis and treatment of elevated ICP in CM patients.

Protection of Nerve Injury with Exosome Extracted from Mesenchymal Stem Cell.

OBJECTIVE: To investigate the protective effect of Exosomes from human adipose-derived mesenchymal stem cells (hAMSCs) in neural injury induced by glutamate and its possible mechanism. METHODS: Characteristics of Exosomes from hAMSCs were identified by electron microscopy and Western blot analysis. Cytokines that might play a major role in the protective effect were tested by enzyme-linked immunosorbent assay (ELISA). The protective action of Exosome and its possible signaling pathway were researched by the in vitro neural injury induced by glutamate, including control group (without Glu), Glu group (dealing with Glu), Glu+Exo group (dealing with Glu +100 ng/ml Exo), Glu+Exo+Akt group (dealing with Glu+100 ng/ml Exo+10 µmol/L Akt), Glu+Exo+Erk group (dealing with 100 ng/ml Glu+100 ng/ml Exo+10 µmol/L Erk), and Glu+Exo+TrkB group (dealing with Glu+100 ng/ml Exo +10 µmol/L TrkB). RESULTS: Exosomes from hAMSCs had similar sizes to those isolated from other kinds of cells, and expressed the characteristic proteins such as CD63, CD81, HSP70, and HSP90. Cytokines that had neurotrophic effects on Exosomes were mainly insulin-like growth factor and hepatocyte growth factor, with the concentration being 9336.49±258.63 and 58,645.50±16,014.62, respectively; brain derived neurotrophic factor, nerve growth factor,and vascular endothelial growth factor had lower levels, with the concentration being 1928.25±385.47, 1136.94±5.99, and 33.34±9.43, respectively. MTS assay showed that the PC12 cell survival rates were 0.842±0.047, 0.306±0.024, 0.566±0.026, 0.461±0.016, 0.497±0.003, and 0.515±0.034 in the control group, Glu group, Glu+Exo group, Glu+Exo+Akt group, Glu+Exo+Erk group, and Glu+Exo+TrkB group; obviously, it was significantly lower in Glu group than in control group (P=0.02), significantly higher in Glu+Exo group than in Glu group (P=0.01), and significantly lower in Glu+Exo+Akt group than in Glu+Exo group (P=0.01). CONCLUSION: Exosomes secreted from hAMSCs have protective effect against neuron damage induced by glutamate, which may be mediated through activating the PI3/K-Akt signalling pathway.

[Diagnosis and Treatment of Pituitary Carcinoma].

The early diagnosis and treatment of pituitary carcinoma is difficult. The diagnosis is often delayed, and the confirmation of a diagnosis requires the presence of distant subarachnoid,brain or systemic metastasis from the primary pituitary tumor in the sella and also needs the evidences of pathology and imaging of the primary pituitary carcinoma and metastases. Treatment of pituitary carcinoma includes surgery, radiation therapy ,hormone therapy, chemotherapy, and molecularly targeted therapy; however, these methods are mainly palliative and can not prolong the survival. The prognosis remains poor. Efforts should be made to develop more effective diagnosis and treatment options.

[Significance of pseudocapsule in the excision of pituitary adenomas in transsphenoidal surgery].

OBJECTIVE: To explore the significance of pseudocapsule in the excision of pituitary adenomas in transsphenoidal surgery. METHODS: For 22 patients with pituitary adenomas over a period of 2 years at Peking Union Medical College Hospital, resection of pseudocapsule was applied for complete tumor removal. Pituitary function test and radiological imaging were performed at pre-operation, 3 months post-operation and at subsequent 6-12 months intervals postoperatively. RESULTS: All pituitary adenomas were totally removed under microscope. The symptoms of headache, disorder of sight and visual field disappeared postoperatively in nonfunctional pituitary adenomas. The GH levels of 2/5 growth hormone secreting adenoma patients were 4.2 and 7.7 µg/L while it was under 1 µg/L for another 3. The postoperative level of prolactin was 4.3 µg/L in prolactin secreting adenoma. The level of adrenocorticotropic hormone decreased under 5 ng/L except one was 15.7 ng/L. Leakage of cerebrospinal fluid occurred intraoperatively in 3 patients and postoperatively in 1. No leakage was found after repair. Diabetes insipidus occurred in one patient and was controlled with Minirin. Pseudocapsule was confirmed by pathological examination. Special staining revealed reticulum fibers in pseudocapsule. CONCLUSION: Resection of pseudocapsule may achieve a higher remission rate without deteriorating pituitary function.

[Advances in the pathogenesis and treatment of neurosurgical emergency with coagulation disorders].

Neurosurgical emergencies including intracranial hemorrhage and head trauma have high mortality and morbidity rates and meanwhile are often accompanied with coagulation disorders. On one hand, coagulation disorder follows traumatic brain injury;on the other hand, the increasing use of anticoagulant and antiplatelet treatment for cardiovascular diseases increases the risk of death among patients with brain trauma or bleeding. Once the intracranial pressure increases, such patients need emergency surgical intervention, but coagulation disorder is a relative contraindication. This article reviews the pathogenesis and treatment of coagulation disorders in patients with neurosurgical emergency. It also analyzes clinical monitoring indices for such patients and their variations and summarizes the strategies and measures of perioperative management.

[Osmotic demyelination syndrome in patients with hyponatremia caused by neurologic disorders].

Hyponatremia is relatively common in patients with neurologic disorders, while its diagnosis and treatment remain controversial. Osmotic demyelination syndrome (ODS) has shown to be closely associated with hyponatremia. ODS patients often present as central pontine myelinolysis, extrapontine myelinolysis, or both. This article reviews the clinical manifestations, pathogenesis, and risk factors of ODS in patients with hyponatremia caused by neurologic disorders.

Atorvastatin combined with dexamethasone in chronic subdural haematoma (ATOCH II): study protocol for a randomized controlled trial.

BACKGROUND: Chronic subdural haematoma (CSDH) is a common condition in the elderly that often requires neurosurgical management. For small CSDH, evidence has emerged that statins may reduce haematoma volume and improve outcomes, presumably by reducing local inflammation and promoting vascular repair. We wish to extend this evidence in a study that aims to determine the efficacy and safety of atorvastatin combined with low-dose dexamethasone in patients with CSDH. METHODS: The second ATorvastatin On Chronic subdural Hematoma (ATOCH-II) study is a multi-centre, randomized, placebo-controlled, double-blind trial which aims to enrol 240 adult patients with a conservative therapeutic indication for CSDH, randomly allocated to standard treatment with atorvastatin 20 mg combined with low-dose dexamethasone (or matching placebos) daily for 28 days, and with 152 days of follow-up. The primary outcome is a composite good outcome defined by any reduction from baseline in haematoma volume and survival free of surgery at 28 days. Secondary outcomes include functional outcome on the modified Rankin scale (mRS) and modified Barthel Index at 28 days, surgical transition and reduction in haematoma volumes at 14, 28 and 90 days. DISCUSSION: This multi-centre clinical trial aims to provide high-quality evidence on the efficacy and safety of the combined treatment of atorvastatin and low-dose dexamethasone to reduce inflammation and enhance angiogenesis in CSDH. TRIAL REGISTRATION: ChiCTR, ChiCTR1900021659 . Registered on 3 March 2019, http://www.chictr.org.cn/showproj.aspx?proj=36157 .

[Management of pulmonary thromboembolism in post-operative neurosurgical patients].

OBJECTIVE: To summarize the diagnosis and treatment of pulmonary thromboembolism (PTE) in post-operative neurosurgical patients. METHODS: We retrospectively analyzed the clinical data of 7 patients who experienced pulmonary thromboembolism after neurosurgical operations in our department from October 2009 to March 2010. RESULTS: Of these 7 patients, 6 were confirmed with computed tomographic pulmonary angiography (CTPA) and 1 was diagnosed according to the clinical manifestations and other diagnostic examinations. All the patients were treated initially with low-dose heparin or low-molecular-weight heparin and then with warfarin. Two patients were implanted with permanent inferior vena cava filters before anticoagulation. One received anticoagulant therapy and died of respiratory failure due to pulmonary embolism on the fourth post-operative day. Six patients were discharged after significant improvement. CONCLUSIONS: Many risk factors may cause PTE peri-operatively. Post-operative CTPA may be indicated. Anticoagulation and other management strategies may be applied to improve the outcome.

[Preparation of brain targeted immunoliposomes].

To prepare a kind of effective non-viral transduction vector, which can deliver exogenous gene into the brain, this vector can be injected through vein system and has the ability to penetrate blood brain barrier. Several groups of materials proportion, type of oil phase, water-oil ratio, phosphatides-cholesterol ratio, temperature of steaming, ultrasonic temperature and time were compared for optimization. Well-constructed immunoliposomes encapsuling LacZ gene were infused into rats through tail vein. 48 h after injection, expression product beta-galactosidase of LacZ gene was detected by histochemistry staining to convince the validity of immunoliposomes as non-viral vectors. The best proportion of synthesis immunoliposomes is as following: phosphatides-cholesterol ratio is 1:1, lipids/drug is 100:1, the type of oil phrase is dichloromethane, oil-water ratio is 4:1, temperature of steaming is 30 degrees C, ultrasonic temperature and time is 10 degrees C and 5 min. At last, 10% trehalose was added as a stabilizer. The entrapment rate is 87.24% and antibody coupling rate is 69%. When immunoliposomes were infused into rats, the expression of LacZ gene could be observed in the brain and periphery organs. Through the best proportion of materials, gene delivering immunoliposomes had been synthesized successfully. This non-viral vector can deliver exogenous gene penetrating blood brain barrier and express in the brain, and will be well-used in the field of gene therapy of cerebral diseases.

[Recombinant AAV1 mediated vascular endothelial growth factor gene expression promotes angiogenesis and improves neural function: experiment with rats].

OBJECTIVE: To investigate the therapeutic effect of vascular endothelial growth factor (VEGF) gene expression mediated by recombinant AAV1 (rAAV1) vector in brain ischemia and the mechanism thereof. METHODS: Sixty-four SD rats were randomly divided into 2 equal groups and received intra-ventricular injection with rAAV1-VEGF or rAAV1-lacZ as controls. 21 days later the rats underwent transient middle cerebral artery occlusion (MCAO). Neurological severity score (NSS) was recorded 1, 2, 3, 7, 14, and 21 days after MCAO. 48 rats were sacrificed 21 days after MCAO and brains were taken out from 48 rats. Immune quantitative analysis was used to identify the quantity of VEGF expression. Immunohistochemistry was used to identify the site of VEGF expression. Immunofluorescence double labeling of von Willebrand factor (vWF) and 5-bromodeoxy-uridine (BrdU) was performed to detect the proliferation of endothelial cells. Fluorescein isothiocyanate (FITC)-dextran was infused into the caudal vein of 8 rats from each group and then the rats were killed with their brains taken out to evaluate the cerebral microvessel perfusion and microvessel density. RESULTS: The NSSs of the VEGF group 7, 14, and 21 days after MCAO were all significantly lower than those of the control group (all P < 0.05), and the VEGF165 protein expression quantity was 27 times as that of the control group (P < 0.05). Immunohistochemistry demonstrated that VEGF expression was distributed mainly in the caudate putamen, corpus callosum, choroid plexus, and hippocampus in the VEGF group, while no expression was detected in the control group. The microvessel density of the VEGF group was 157 +/- 13, significantly higher than that of the control group [(89 +/- 9), P < 0.05]. BrdU +/vWF + endothelial cells were detected in the area adjacent to the MCAO. The density of microvessel infused with FITC-dextran was (152,617 +/- 13,076) microm2/mm2 in the VEGF group, significantly higher than that of the control group [(91,658 +/- 6577) microm2/mm2 P < 0.05]. CONCLUSION: rAAV1 mediates the VEGF gene expression in multiple structures in the brain and attenuates the neurological deficit of MCAO. VEGF gene transfer may stimulate angiogenesis and improves blood supply in brain. Neovascularization may be a therapeutic strategy for brain ischemia.

[Specific expression in brain of exogenous gene by transpassing blood-brain barrier after intravenous injection].

OBJECTIVE: To study the expression of exogenous LacZ gene in brain via a delivery of OX26-pGFAP-IL. METHODS: pCMV-Liposome, OX26-pCMV-IL, OX26-pGFAP-IL and blank liposome were injected into rats via femoral vein. At 24 h post-injection, the method of Q-PCR was adopted to calculate the relative quantities of LacZ gene mRNA in brain and peripheral organs. At 48 h post-injection, the protein expression of LacZ gene was detected by the activity of beta-galactosidase and the method of histochemical stain. RESULTS: The result of Q-PCR showed that, at 24 h post-injection, the relative quantities of LacZ mRNA in OX26-pCMV-IL group (49.2 x 10(-6)) and OX26-pGFAP-IL group (44.9 x 10(-6)) were significantly higher than pCMV-liposome and blank liposome groups (P < 0.05). In peripheral organs, the relative quantity of LacZ mRNA in OX26-pCMV-IL group were significantly higher than that in OX26-pGFAP-IL group (P < 0.05). At 48 h post-injection, the activity of beta-galactosidase in OX26-pCMV-IL (0.67 pg/mg) and OX26-pGFAP-IL groups (0.92 pg/mg) were significantly higher than pCMV-liposome and blank liposome groups (P < 0.05). There was no significant difference between OX26-pCMV-IL group and OX26-pGFAP-IL group in terms of the expression of beta-galactosidase. The result of histochemical stain showed that OX26-pGFAP-IL achieved a specifically positive expression in brain and had a decreased expression in peripheral organs. CONCLUSION: OX26-pGFAP-IL injected via femoral vein can cross the brain-blood barrier and achieve a specific expression in brain under the control of GFAP promoter. OX26-pGFAP-IL decreases the non-specific expression in peripheral organs and it may be used as an non-viral gene therapy for intra-cranial diseases.

Transplantation of neural stem cells modified by human neurotrophin-3 promotes functional recovery after transient focal cerebral ischemia in rats.

The study tested the hypothesis that transplantation of human neurotrophin-3 (hNT-3) over-expressing neural stem cells (NSCs) into rat striatum after a severe focal ischemia would promote functional recovery. Rat NSCs, transduced by Flag-tagged hNT-3 gene mediated by lentiviral vector (LV), were transplanted into the striatum ipsilateral to the injury of adult rats 7 days after 2-h occlusion of the middle cerebral artery (MCAO). From 3 days to 2 weeks after transplantation, the modified cells (NSCs-hNT3, as defined by Flag immunofluorencence staining) that survived the transplantation procedures could secrete significantly higher levels of neurotrophin-3 protein in the graft sites than controls (P<0.001). Furthermore, the rats that accepted NSCs-hNT3 exhibited enhanced functional recovery on neurological and behavioral tests, compared with controlled animals transplanted with saline or untransduced NSCs. This study suggests: (1) LV is an ideal vector to transduce foreign gene into the NSCs; (2) modified NSCs could carry therapeutic genes to disease tissues and express effectively; (3) modified cells could survive in the ischemic brains and continue to secrete neurotrophin-3 abundantly for over 2 weeks, which might have values for enhancing functional recovery after stroke.

[Ferumoxide labeled Flk1+ CD31- CD34- human bone marrow mesenchymal stem cells and its in vivo tracing in the brains of Macaca Fascicularis].

OBJECTIVE: To explore the method for labeling Flk1+ CD31- CD34- human bone marrow mesenchymal stem cells (hBMSCs) with ferumoxide-PLL and evaluate the feasibility of its tracing after transplantation into the brains of Macaca Fascicularis. METHODS: The hBMSCs were incubated with ferumoxide-PLL. Trypan blue staining, Prussian blue staining, and transmission electron microscope were performed to show intracellular iron, marking efficiency, and the vigor of the labeled cells. After the hBMSCs were transplanted into the brains of cynomolgus monkeys by stereotaxis, magnetic resonance imaging (MRI) was performed to trace the cells in vivo. Cell survival and differentiation were studied with immunohistochemistry, Prussian blue staining, and HE staining. RESULTS: The marking efficiency of the ferumoxide-PLL was 96%. Iron particles were found intracytoplasmic of the hBMSCs by Prussian blue staining and transmission electron microscopy. The relaxation rates of labeled cells in MRI were 4.4 and 4.2 times higher than those of the unlabeled cells. Hypointensity area was found by MRI three weeks after transplantation. Many hBMSCs and new vessels were found in the transplantation zone by pathological and immunofluorescence methods. CONCLUSIONS: Ferumoxide-PLL can effectively label hBMSCs and thus increase its contrast in MRI results. The cells can survive in the brains of cynomolgus monkeys. The labeled hBMSCs can be traced in vivo by MRI.

A case of subdural hematoma with a medical history of hemophilia a and a review of related literature.

BACKGROUND: Intracranial hemorrhage is the most common emergency in the neurology department, and patients with a medical history of hemophilia have a risk of severe bleeding. CASE PRESENTATION: A 56-year-old man was admitted to the emergency department in our hospital. He was diagnosed with hemophilia A and subdural hematoma. We administered an infusion of factor VIII to decrease the risk of bleeding and improve the prognosis. Factor VIII infusion is the most important factor in treating hemophilia A patients. CONCLUSION: We recommend carefully checking coagulation function and the medical history once these patients are admitted, especially in the emergency department.

Prevalence and antibiotic resistance of bacteria isolated from the cerebrospinal fluid of neurosurgical patients at Peking Union Medical College Hospital.

Background: Postoperative central nervous system infections (PCNSIs) represent a serious complication, and the timely use of antibiotics guided by the identification of the causative pathogens and their antibiotic sensitivities is essential for treatment. However, there are little data regarding the prevalence of PCNSI pathogens in China. The aim of this study is to investigate the features of pathogens in patients with PCNSIs, which could help clinicians to choose the appropriate empirical antibiotic therapy. Methods: We retrospectively examined the positive CSF cultures in patients who underwent craniotomy between January 2010 and December 2015. We collected data, including demographic characteristics, type of neurosurgery, laboratory data, causative organisms and antimicrobial susceptibility testing results. Results: A total of 62 patients with 90 isolates out of 818 patients with 2433 CSF culture samples were available for data analysis. The estimated incidence and culture-positive rate of PCNSIs were approximately 0.9 and 7.5%, respectively. The predominant organism was coagulase-negative staphylococci, of which most were methicillin-resistant coagulase-negative staphylococci (MRCoNS). All were susceptible to vancomycin, linezolid, rifampicin and amoxicillin-clavulanate. Acinetobacter baumannii was the most frequent causative Gram-negative agent and was resistant to 12 out of 18 antimicrobials tested. The sensitivity rates for tigecycline and minocycline were only 40 and 33%, respectively. Conclusion: PCNSIs could lead to high mortality. Although the MRCoNS were the predominant organism, the management of Acinetobacter baumannii was a major clinical challenge with few effective antimicrobials in PCNSIs.

[Treatment of stroke in rats with bone marrow mesenchymal stem cells].

OBJECTIVE: To investigate the effects of treatment of stroke in rats with bone marrow mesenchymal stem cells (BMSCs) and mechanism thereof. METHODS: Bone marrow of a healthy volunteer was collected and the BMSCs were separated with density gradient centrifugation. The hBMSC were cultivated and harvested until the third passage. A number of adult male Sprague-Dawley rats received corresponding behavioral training before surgery and underwent transient middle cerebral arterial occlusion (MCAO) for 2 hours. Sixty of them showing the scores of 6 approximately 12 according to the modified neurological severity score system were randomly divided into 2 groups: treatment group (n = 48, injected into the cortex around the ischemic areas with hBMSCs 3x10(5)/15 microl) and control group (n = 12, injected with D-Hanks solution 15 microl 24 hours after the establishment of MCAO models. Morris water maze test, Rotarod test and adhesive-removal test were performed since the 4th day to the 32 day after transplantation once every 3 days. 1, 2, 3, and 4 weeks after the transplantation 12 rats from each group were killed randomly to take out their brains. Immunofluorescence was used to identify the migration, survival and differentiation of the hBMSC. RESULTS: A large number of hBMSC could be seen within 2 weeks after transplantation. The number of hBMSC decreased since the 21st day after transplantation and few cells could be found at the end of 1 month after. No definite evidence supported the differentiation of neural cells derived from the hBMSCs during the whole process. Morris water maze test showed that the mean escape time 1 week after transplantation of the treatment group was (69 +/- 10) s, significantly shorter than that of the control group [(120 +/- 0) s, P < 0.05] The significant difference persisted until the 4(th) week (P > 0.05). Rotarod test with the speed of 10 r/min showed that the mean latency period 10 days after transplantation of the treatment group was (167 +/- 18) s, significantly longer than that of the control group [(37 +/- 19) s, P < 0.05]. The significant difference persisted until the experimental terminal. The adhesive-removal test showed that the mean latency period 13 days after transplantation of the treatment group was (33 +/- 8) s, significant shorter than that of the control group [(84 +/- 13) s, P < 0.05]. The significant difference persisted until the experimental terminal. CONCLUSION: Injection of hBMSCs into brain cortex improves neurological functional recovery after stroke. The transplanted cells can migrate and survive for a certain period, but no hBMSC express proteins phenotype of neural cells.

[In vivo tracking of bone marrow mesenchymal stem cells labeled with superparamagnetic iron oxide after cerebral ischemia in rats by magnetic resonance imaging].

OBJECTIVE: To explore the feasibility of in vivo tracking of bone marrow mesenchymal stem cells (BMSCs) labeled with superparamagnetic iron oxide (SPIO) by magnetic resonance imaging (MRI) in rats after cerebral ischemia, and to analyze the influence of stem cell therapy on the volume of cerebral infarction. METHODS: The samples of rat bone marrow were collected. BMSCs separated by density gradient centrifugation were cultivated and harvested until the third passage. BMSCs were labeled with SPIO, which was mixed with poly-L-lysine. The labeling efficiency was evaluated by Prussian blue staining. Transient middle cerebral arterial occlusion (MCAO) was performed successfully in 18 adult Sprague-Dawley rats that scored from 6 to 12 by the modified neurological severity test. The 18 rats were then randomly divided into group A, B, and C, with 6 rats in each group and Group C was regarded as control group. BMSCs were injected into the contralateral cortex of ischemia in group A, ipsilateral corpora striata in group B, while D-Hank's solution was injected into ipsilateral corpora striata (group C) 24 hours after MCAO. MRI was performed 1 day after MCAO, 1 day and 14 days after transplantation. The volume of infarcted brain tissue was measured and analyzed. Prussian blue staining of brain tissues was performed to identify the migration of BMSCs. RESULTS: The labeling efficiency of BMSCs with SPIO was 96%. The transplanted BMSCs migrated to the ischemic hemisphere along the corpus callosum and to the border of the infarction, which was confirmed by MRI and Prussian blue staining. The changes of infarction volume were not significantly different among these three groups. CONCLUSIONS: MRI is feasible for in vivo tracking of BMSCs labeled with SPIO in rats. The stem cell therapy may not be able to affect the volume of cerebral infarction.