Assessment of central nervous system vasculitis in children based on high-resolution vascular wall imaging.

Objectives: Central nervous system vasculitis (CNSV) is a rare disease. High-resolution vessel wall imaging (HR-VWI) enables the identification of inflammatory changes within the vessel wall. Few studies have applied HR-VWI to assess CNSV in children. This study delves into the utility of HR-VWI for diagnosing and treating CNSV in children, with the aim of enhancing clinical diagnosis and efficacy evaluation. Methods: Imaging data were acquired from children who underwent HR-VWI examinations. The study meticulously analysed clinical data and laboratory tests to discern the characteristics and distribution patterns of diverse vasculitis forms. Results: In children, CNSV mainly involves medium vessels with grade 1 and 2 stenosis (grade 4 stenosis is rare), and the imaging features generally show centripetal and moderate enhancement, suggesting that this feature is specific for the diagnosis of CNSV. High-grade stenosis, concentric enhancement and strong enhancement of the vasculature indicate more severe disease activity. Remarkably, HR-VWI proved to be significantly more sensitive than magnetic resonance angiography in detecting CNSV. Among the 13 cases subjected to imaging review, 8 demonstrated a reduction or resolution of vessel wall inflammation. In contrast, five patients exhibited worsening inflammation in the vessel wall. HR-VWI demonstrated that changes in vessel wall inflammation were closely correlated with changes in brain parenchymal lesions and symptoms. Conclusion: This study underscores the diagnostic value of HR-VWI in CNSV assessment and treatment monitoring, offering a quantitative evaluation of CNSV in children.

Plaque enhancement predicts recurrence in acute ischemic stroke patients with large artery intracranial atherosclerosis.

BACKGROUND: The association between the degree of plaque enhancement and ischemic brain stroke recurrence remains unclear. We aimed to establish models to predict plaque enhancement and stroke recurrence. METHODS: Seventy-eight participants with acute ischemic brain stroke due to intracranial arterial stenosis were recruited and divided into high enhancement (HE) and non-HE groups. The relationship between imaging characteristics (degree of stenosis, minimal lumen area, intraplaque hemorrhage, and plaque burden) and the degree of plaque contrast enhancement was analyzed. Inflammatory cytokine expression was examined by flow cytometry. Independent predictors of stroke recurrence were investigated via multivariate Cox proportional hazards regression analysis. Nomogram was used to construct a prediction model. Harrell's concordance indices (c-indices) and calibration curves were used to assess the discrimination of the nomogram. A risk prediction nomogram for prognosis was constructed. RESULTS: Thirty-three participants were assigned to the HE group and 45 to the non-HE group. The degree of stenosis and plaque burden in the HE group was higher than that in the non-HE group (P<0.05). Multiple linear regression analysis showed the degree of stenosis was associated with HE (ß=0.513; P=0.000). After adjusting for confounding factors, age (HR=1.115; 95%CI=1.034-1.203, P=0.005) and HE plaques (HR=10.457; 95%CI=1.176-93.018; P=0.035) were independent risk factors of stroke recurrence, whereas cytokine levels were not statistically significant between two group. CONCLUSIONS: HE of intracranial atherosclerosis plaques is an independent factor for ischemic brain stroke recurrence.

Correlation between characteristics of intracranial atherosclerotic plaques and ischemic stroke in high-resolution vascular wall MRI.

BACKGROUND: Intracranial atherosclerotic stenosis is a major cause of ischemic stroke, accounting for 30% of ischemic strokes in Asian populations. PURPOSE: To investigate the relationship between the degree of arterial stenosis and enhancement grade of intracranial atherosclerotic disease (ICAD), the plaque characteristics in different remodeling patterns, and its potential impact. MATERIAL AND METHODS: A total of 210 patients diagnosed with ICAD were enrolled in this retrospective study. Patients were divided into the middle cerebral artery (MCA) group (101 cases), posterior cerebral artery (PCA) group (14 cases), basilar artery (BA) group (71 cases), and intracranial segment of vertebral artery (VA) group (90 cases) according to the difference of diseased vessels. Data on presence or absence of ischemic infarction, intracranial vascular position of lesions, plaque characteristics, ICAD enhancement grade, remodeling index, and degree of arterial stenosis were collected for analysis. RESULTS: The incidence of ischemic infarction in enhancement grade 2 was significantly higher than that in enhancement grade 1 in MCA group (P = 0.019). Enhancement grade 2 of ICAD was an independent risk factor for the development of ischemic infarction (odds ratio = 4.60; 95% confidence interval: 1.91-11.03; P = 0.001). There was no significant statistical difference in infarct rate between different remodeling modalities (P>0.05). CONCLUSION: Enhancement grade of ICAD is significantly associated with the degree of stenosis and the occurrence of ischemic stroke, which varies in different intracranial vessels. The pattern of vascular remodeling varies among different intracranial vessels, and the pattern of vascular remodeling has a significant impact on plaque characteristics.

A Study on the Persistent Trigeminal Artery and Its Classification Based on Magnetic Resonance Angiograph Images.

BACKGROUND: The persistent trigeminal artery (PTA) is the most common remnant of primitive circulation, communicating the developing carotid and vertebrobasilar junction. PURPOSE: This study aimed to evaluate the implementation of magnetic resonance angiography for the detection of PTA and to reclassify the variations based on Weon typing. Moreover, the correlation of various Weon types with the posterior cerebral artery (PCA), Willis ring, basilar artery (BA) dysplasia, and the relationship between PTA and arteriosclerosis were analyzed. METHODS: From November 2017 to October 2019, a total of 48,184 patients underwent magnetic resonance angiography examination in our hospital, and 79 patients were diagnosed with PTA. Of these, 70 patients with complete radiological and clinical information were included in this study. RESULTS: Among the 70 patients with complete data, 27 were classified as Weon type I (38.6%), 7 as type II (10%), 14 as type III (20%), 8 as type IV (11.4%), and 3 as type V (4.3%: type Va, 1 case; type Vb, 2 cases). The remaining 11 cases were PCA with mixed blood supply, so the new type VI was divided into 3 subtypes: type VIa, type VIb, and type VIc, and each subtype of type V was further refined into 4 subtypes. There were 32 cases of PTA with BA dysplasia, including 14 with type I (51.9%), 5 with type II (71.4%), 2 with type III (14.3%), 5 with type IV (62.5%), and 6 with type VI (54.5%). Cerebral infarction was found in 55 cases (78.6%) of PTA, among which 11 had a cerebral infarction in the posterior circulation blood supply area. There were 46 cases (65.7%) accompanied by intracranial arteriosclerosis, and in 6 cases, arteriosclerosis mainly occurred in the posterior circulation. CONCLUSIONS: We redefined the classification of PTA based on Weon typing for a better understanding of clinical symptoms and surgical risks. Moreover, PTA was correlated with the fetal origin of PCA, BA dysplasia, and posterior circulation arteriosclerosis. These factors may increase the incidence of cerebral infarction in the posterior circulation blood supply area.

HR-MRI findings of intracranial artery stenosis and distribution of atherosclerotic plaques caused by different etiologies.

OBJECTIVE: To investigate the etiology of intracranial artery stenosis and the distribution characteristics of intracranial artery atherosclerotic stenosis using high-resolution magnetic resonance imaging (HR-MRI). METHODS: A total of 262 patients with intracranial artery stenosis that underwent HR-MRI from November 2019 to December 2020 were retrospectively enrolled. The etiology of intracranial anterior and posterior circulation artery stenosis was analyzed, and the relationship between the location of plaques and the distribution characteristics of plaques and the occurrence of ischemic stroke was summarized. RESULTS: A total of 276 plaques were identified with HR-MRI. There were 101 cases (36.59%) in the middle cerebral artery (MCA), 14 cases (5.07%) in the posterior cerebral artery (PCA), 90 cases (32.62%) in vertebral artery (VA), and 71 cases (25.72%) in the basilar artery (BA). The infarct rate of ventral and superior wall MCA plaques was higher than that of dorsal and inferior wall (63.33% vs 31.25% P = 0.021) (100.00% vs 50% P = 0.022). MCA with plaques throughout the course had the greatest degree of stenosis (P < 0.001). Sphenoid segment (M1) of MCA was most susceptible (85 cases, 84.16%), MCA plaques were most common in the proximal M1 segment (35 cases, 34.65%), and most BA plaques were found in the distal segment (28 cases, 39.44%). PCA plaques were most frequently involved in traffic anterior segment (P1) (7 cases, 50.00%). CONCLUSION: HR-MRI could provide accurate imaging reference for clinical evaluation of intracranial arterial stenosis and formulation of treatment plans. The intracranial arterial plates mostly appeared in the middle cerebral artery and vertebral artery. Middle cerebral arteries with atherosclerotic plaques are more likely to narrow.

Utility of multidetector computed tomography quantitative measurements in identifying sarcopenia: a propensity score matched study.

OBJECTIVE: To evaluate the utility of multidetector computed tomography MDCT quantitative measurements in identifying sarcopenia. MATERIALS AND METHODS: The clinical data and MDCT images of 64 patients of sarcopenia and 184 non-sarcopenic participants between October 2020 and January 2021were retrospectively analyzed. Propensity score matching was used to match the sarcopenic patients with the non-sarcopenic participants. Two radiologists independently measured the cross-sectional area (CSA) of skeletal muscle and intramuscular fat tissue and CT density of skeletal muscle at the middle L3 vertebral level on CT images of all participants. Intra-observer agreement was evaluated via intraclass correlation coefficients (ICC). A receiver operating characteristic (ROC) curve was built for each variable. Correlations between CT parameters and clinical data were assessed via Pearson or Spearman correlation coefficient. RESULTS: A total of 74 participants (mean age 72 ± 4 years, range 66-85 years; 38 men and 36 women) were included, comprising 37 sarcopenic patients and 37 non-sarcopenic participants. There were no significant intergroup differences regarding age, sex ratio, and body mass index (BMI) (P < 0.05). The CSA and density of skeletal muscle measured by two radiologists were reliable (ICC ≥ 0.75, P < 0.001). Compared with the sarcopenic group, the non-sarcopenic group had a significantly greater CSA and CT density of the total skeletal muscle (TSM) and paraspinal skeletal muscle (PSM) and skeletal muscle index at L3 level (L3 SMI) (P < 0.05). The fat infiltration ratio (FIR) of TSM, PSM, and psoas muscle was significantly higher in the sarcopenic group than that in non-sarcopenic participants (P < 0.05). ROC curve analysis showed the PSM FIR + PSM CT density (PSM D) had the best predictive value for sarcopenia (AUC = 0.836). The PSM FIR and age were moderately positively correlated (r = 0.410, P < 0.001). CONCLUSION: Fat infiltration of skeletal muscle had better predictive value than L3 SMI in the diagnosis of sarcopenic. The PSM FIR + PSMD had the best predictive value for sarcopenia, which was moderately positively correlated with age.

Association Between the Cardiometabolic Index and Hyperuricemia in an Asymptomatic Population with Normal Body Mass Index.

BACKGROUND AND PURPOSE: The association between the cardiometabolic index (CMI) and hyperuricemia was investigated to provide theoretical support for the management of hyperuricemia in an asymptomatic population with normal body mass index (BMI). METHODS: A cross-sectional study was carried out among 374 asymptomatic adults with normal BMI. Traditional anthropometric indices and CMI were calculated. Anthropometric indices were divided into four quartiles and multivariate logistic analysis was used to analyze the association between these indices and hyperuricemia. Receiver operating characteristic (ROC) curves and area under the curve (AUC) were used to evaluate the power of the indices to predict hyperuricemia values. The DeLong test was used to compare the AUC of different anthropometric indices. RESULTS: After adjusting for confounding variables, the CMI exhibited a stronger association with hyperuricemia than other anthropometric indices. The odds ratio (OR) for hyperuricemia in the highest quartile of the CMI was 16.674 (confidence interval [CI]=4.424-62.846). The AUC of the CMI was 0.777 (95% CI=0.719-0.835, p<0.001), which was higher than the values for other anthropometric indices. The differences in AUC between the CMI and other indices were statistically significant; the optimal cutoff value of the CMI was 0.655, with sensitivity of 57.1% and specificity of 84.2%. CONCLUSION: The CMI, which combines waist circumference, height and blood lipid parameters, was more strongly associated with hyperuricemia than other anthropometric indices in asymptomatic population with normal BMI. The CMI may serve as a potential monitoring indicator for hyperuricemia management in asymptomatic populations with normal BMI.

The value of high-resolution MRI in the diagnosis, efficacy of treatment, and prognosis of central nervous system vasculitis.

AIM OF THE STUDY: To explore the high-resolution magnetic resonance imaging (HR-MRI) characteristics of central nervous system (CNS) vasculitis and to explore the value of HR-MRI in the treatment effect and prognosis evaluation of CNS vasculitis. MATERIAL AND METHODS: During the follow-up of 24 patients diagnosed as CNS vasculitis by the Second Hospital of Hebei Medical University, 3.0T HR-MRI was used for imaging examination and HR-MRI characteristics were analysed. RESULTS: The affected vessel wall of 24 patients showed diffuse uniform centripetal thickening. The HR-MRI examination showed varying degrees of lumen stenosis, including 5 cases (20.8%) involving a single arterial segment, and 19 cases (79.2%) involving multiple arterial segments. And most cases (92.9%) showed grade 2 enhancement of the involved vessel wall. Except for one case involving the basilar artery at the same time, the remaining 23 cases involved only the anterior circulation vessels. We analysed and compared the affected vessels between the relapsed group and the non-relapsed group, and found that the average number of involved vascular segments was 6.5 ±3.4 (3-11) in the relapsed group and 3.5 ±2.1 (1-8) in the non-relapsed group, with a significant difference between the two groups (p = 0.039). CONCLUSIONS: The CNS vasculitis was more likely to involve the anterior circulation vessels. The number of affected vascular segments in the relapsed group of CNS vasculitis was higher than in the non-relapsed group, suggesting that the more vascular segments involved, the more prone to recurrence.

Diagnostic value of HR-MRI and DCE-MRI in unilateral middle cerebral artery inflammatory stenosis.

PURPOSE: High-resolution magnetic resonance imaging (HR-MRI) has high spatial resolution and can simultaneously perform wall and lumen imaging. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) can evaluate the integrity of the blood-brain barrier. In this paper, the result of 3.0T HR-MRI and 3.0T DCE-MRI has been evaluated to explore the application value of unilateral middle cerebral artery inflammatory stenosis and changes in vascular permeability parameters of stroke events. METHODS: Thirty-six cases of neurological suspicion of central nervous system vasculitis of our hospital were selected from 20 January 2018 to 1 January 2019, who were diagnosed as unilateral middle cerebral artery M1 stenosis/occlusion by 3D TOF MRA. 3.0T HR-MRI and 3.0T DCE-MRI has been applied. RESULTS: Among the 36 patients who met the inclusion criteria, 23 patients with central nervous system vasculitis were diagnosed. The 23 patients with HR-MRI showed diffuse thickening and enhanced stenosis. The Ktrans value of 10/23 patients with acute-subacute cerebral infarction and 3/23 patients in chronic phase were significantly higher than that of the mirror side, and the Ktrans value of these patients remeasured in the same region of interest is lower than before after 6 months treatment. The Ktrans value in the target area of 10 patients without cerebrovascular events was not statistically significant compared with the mirror side. The Ktrans value of patients with acute-subacute cerebral infarction was significantly higher than that without cerebrovascular events (0.098 ± 0.038 vs. 0.007 ± 0.001, p = .000), and there was no significant difference between Ktrans in the chronic infarction group and the other two groups (0.098 ± 0.038 vs. 0.044 ± 0.012, p = .058; 0.044 ± 0.012 vs. 0.007 ± 0.001, p = .057). CONCLUSION: HR-MRI is an accurate direct imaging method and has a high value for the etiological diagnosis of central nervous system vasculitis. DCE-MRI could be an effective way to evaluate and monitor blood-brain barrier to prevent clinical ischemic stroke.

Diffusion Tensor Imaging and Fiber Tractography Reveal Significant Microstructural Changes of Cervical Nerve Roots in Patients with Cervical Spondylotic Radiculopathy.

OBJECTIVE: To delineate the fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values of patients with cervical spondylotic radiculopathy by diffusion tensor imaging and fiber bundle tracing. METHODS: Thirty patients with cervical spondylotic radiculopathy and 24 healthy volunteers were assessed using the International Standards for Neurological Classification of Spinal Cord Injury scale. All subjects underwent conventional sagittal T1- and T2-weighted imaging and horizontal 3-dimensional T2 driven equilibrium radiofrequency reset pulse and diffusion tensor imaging scan. The ADC and FA values were measured in the cervical nerve at most stenotic segment and heterolateral nonstenotic segment of patients. RESULTS: Fiber tractography revealed thinned and sparse nerve roots and disruption of the fiber bundles in patients with cervical spondylotic radiculopathy. The FA values of C5-C8 in healthy volunteers or heterolateral nonstenotic nerve of patients with cervical spondylotic radiculopathy were significantly greater than those of the stenotic cervical segments of patients with cervical spondylotic radiculopathy (both P < 0.01). Furthermore, the ADC values of C5-C8 in healthy volunteers or heterolateral nonstenotic nerve of patients with cervical spondylotic radiculopathy were significantly lower than those of the stenotic cervical segments of cervical spondylotic radiculopathy patients (both P < 0.01). CONCLUSIONS: Fiber tractography is capable of delineating microstructural changes of cervical nerve roots and cervical spondylotic radiculopathy exhibits significant changes in FA and ADC values.

Angiography with the 256-multislice spiral computed tomography and its application in evaluating atherosclerotic plaque and cerebral ischemia.

Ulceration of carotid arterial plaque is associated with cerebral events. Detection of ulcerated plaques will benefit patient from stroke and other ischemic events. The aim of this study was to evaluate morphology of atherosclerotic plaques in the carotid arteries and to assess its clinical impact in predicting cerebral events.A total of 386 patients were examined with 256-multislice spiral computed tomographic angiography (MSCTA).It was found that 356 of the 386 patients had cerebral ischemic symptoms. Specifically, 35 patients had amaurosis fugax (AmF), 178 had transient ischemic attack (TIA), and 143 had ischemic stroke. Abnormal images were found in 658 carotid arteries by MSCTA. Of the 658 abnormal images of carotid arteries, besides the 34 cases of carotid arterial occlusion, 624 cases were atherosclerotic plaques. Of the 624 plaques, 394 (63.2%) were smooth surface plaques, 161 (25.8%) were irregular surface plaques, and 69 (11.1%) were ulcerated plaques. Incidence of ulcerated plaque was higher in the ischemic stroke patients (13.1%) compared with that in the TIA group (10.3%), AmF group (6.6%), or symptom-free group (9.4%) although it was not statistically significant (P = .288). However, there was significant difference in the incidence of ischemic stroke between the ulcerated (20/69, 28.9%) and nonulcerated groups (69/555, 12.4%, P < .05, odds ratio = 2.875).These findings suggested that 256-MSCTA is an advanced imaging tool to determine not only arterial stenosis but also morphologic assessment of atherosclerotic plaques, which will benefit the patients by predicting the cerebral events in advance.

Quantitative Evaluation of Compressed L4-5 and S1 Nerve Roots of Lumbar Disc Herniation Patients by Diffusion Tensor Imaging and Fiber Tractography.

OBJECTIVE: To delineate fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values of compressed nerve roots in patients with lumbar disc herniation by diffusion tensor imaging and fiber bundle tracing and investigate the relationship between FA and ADC values and Swiss Spinal Stenosis Questionnaire and visual analog scale scores. METHODS: Twenty patients with lumbar disc herniation and 20 age- and sex-matched healthy volunteers were assessed using the Swiss Spinal Stenosis Questionnaire and visual analog scale. All subjects underwent conventional sagittal T1-weighted and T2-weighted magnetic resonance imaging, axial T2-weighted imaging, and diffusion tensor imaging and fiber tractography. RESULTS: In 20 patients with lumbar disc herniation, there were 31 nerve roots involved (9/31 L4, 15/31 L5, and 7/31 S1). Mean Swiss Spinal Stenosis Questionnaire scores of patients were 53.55% ± 11.91%, and mean visual analog scale scores were 5.96 ± 1.64. FA values of lumbar nerve roots were 0.332 ± 0.014 in healthy volunteers. FA values of compressed lumbar nerve roots were 0.251 ± 0.022, significantly lower than FA values of contralateral noncompressed nerve roots and lumbar nerve roots of healthy volunteers. ADC values of lumbar nerve roots were 1.763 ± 0.075 in healthy volunteers. ADC values of compressed lumbar nerve roots were 2.090 ± 0.078, significantly higher than ADC values of contralateral noncompressed nerve roots and lumbar nerve roots of healthy volunteers. CONCLUSIONS: Fiber tractography is capable of delineating microstructural changes of lumbosacral nerve roots, and radiculopathy in lumbar disc herniation is associated with significant changes in FA and ADC values.

Evaluation of left gastric vein in Chinese healthy adults with multi-detector computed tomography.

OBJECTIVES: To evaluate the classification and diameter of left gastric vein (LGV) in healthy Chinese adults with multi-detector computed tomography (MDCT). METHODS: MDCT angiography was performed in 234 healthy adults for the portal venous system. CT cross-sectional thin-layer reconstruction combined with maximum intensity projection, volume rendering and multiplanar reconstruction were applied. The diameter of LGV was measured at the point within 2 cm from LGV origination. RESULTS: Of 234 subjects, 11 subjects (4.70%) who did not have clear images were excluded, and 223 subjects (95.30%) with excellent images were included. The LGV was originated from the portal vein in 46.15%, splenic vein in 30.77%, portal splenic angle in 14.53%, and the left branch of the portal vein in 3.85%. The maximal diameter of LGV was 4.74 ± 0.84 mm with a 95% confidence interval of 4.63-4.85 mm, and the LGV diameter was positively correlated with the weight of patients (R = 0.26, P = 0.006). No significant difference existed in the maximal diameter of LGV at different origination sites (P = 0.35). The diameter of LGV was significantly greater in males than in females (4.90 ± 0.85 vs. 4.56 ± 0.80 mm, P = 0.002), and the maximal diameter of LGV was significantly (P = 0.02) greater in the age range of 30-39 and 40-49 years than in the range of >70 years. No statistical significance (P = 0.36) was detected in the other groups. CONCLUSION: MDCT can clearly display the detailed anatomy and variation of LGV in healthy adults, providing a normal range of LGV diameter for clinical reference for diagnosing possible portal hypertension and for possible intervention.

Quantitative Evaluation of the Substantially Variable Morphology and Function of the Left Atrial Appendage and Its Relation with Adjacent Structures.

OBJECTIVE: To investigate quantitatively the morphology, anatomy and function of the left atrial appendage (LAA) and its relation with adjacent structures. MATERIALS AND METHODS: A total of 860 patients (533 men, 62.0%, age 55.9±10.4 year) who had cardiac multidetector computed tomography angiography from May to October 2012 were enrolled for analysis. RESULTS: Seven types and 6 subtypes of LAA morphology were found with Type 2 being the most prevalent. Type 5 was more significantly (P<0.05) present in women (8.0%) than in men (4.2%). LAA orifice was oval in 81.5%, triangular in 7.3%, semicircular in 4%, water drop-like in 3.2%, round in 2.4% and foot-like in 1.6%. The LAA orifice had a significantly greater (P<0.01) major axis in men (24.79±3.81) than in women (22.68±4.07). The LAA orifice long axis was significantly (P<0.05) positively correlated with the height, weight and surface area of the patient. The LAA morphology parameters displayed strong positive correlation with the left atrium volume, aortic cross area long axis or LSPV long axis but poor correlation with the height, weight, surface area and vertebral body height of the patients. Four types of LAA ridge were identified: AI, AII, B and C with the distribution of 17.6%, 69.9%, 5.9% and 6.6%, respectively. The LAA had a significantly (P<0.05) greater distance from its orifice to the mitral ring in women than in men. The LAA had two filling and two emptying processes with the greatest volume at 45% phase but the least volume at 5% phase. The LAA maximal, minimal and emptying volumes were all significantly (P<0.05) positively correlated with the body height, weight and surface area, whereas the LAA ejection fraction had an inverse correlation with the LAA minimal volume but no correlation with the maximal volume. CONCLUSION: The LAA has substantially variable morphologies and relation with the adjacent structures, which may be helpful in guiding the LAA trans-catheter occlusion or catheter ablation procedures.

Therapeutic time window for the neuroprotective effects of NGF when administered after focal cerebral ischemia.

In the present study, we evaluated the neuroprotection time window for nerve growth factor (NGF) after ischemia/reperfusion brain injury in rabbits as related to this anti-apoptosis mechanism. Male New Zealand rabbits were subjected to 2 h of middle cerebral artery occlusion (MCAO), followed by 70 h of reperfusion. NGF was administered after injury to evaluate the time window. Neurological deficits, infarct volume, neural cell apoptosis and expressions of caspase-3 and Bcl-2 were measured. Compared to saline-treated control, NGF treatment at 2, 3 and 5 h after MCAO significantly reduced infarct volume, neural cell apoptosis and expression of caspase-3 (P < 0.01), up-regulated the expression of Bcl-2 and improved functional recovery (P < 0.01). However, treatment at latter time points did not produce significant neuroprotection. Neuroprotection treatment with NGF provides an extended time window of up to 5 h after ischemia/reperfusion brain injury, in part by attenuating the apoptosis.