PURPOSE: Patients with superficial middle cerebral artery (MCA) territory infarction may have concomitant lenticulostriate artery (LSA) territory infarction. We investigated the mechanisms thereof and the outcomes of patients with superficial MCA territory infarction according to the presence or absence of LSA involvement. MATERIALS AND METHODS: Consecutive patients with first-ever infarction in the unilateral superficial MCA territory were included in this study. They were divided into the superficial MCA only (SM) group and the superficial MCA plus LSA (SM+L) group. RESULTS: Of the 398 patients, 84 patients (21.1%) had LSA involvement (SM+L group). The SM+L group more frequently had significant stenosis of the proximal MCA or carotid artery and high-risk cardioembolic sources. Stroke severity and outcomes were remarkably different between the groups. The SM+L group showed more severe neurologic deficits (National Institute of Health Stroke Scale score 10.8±7.1 vs. 4.0±5.0, p<0.001) and larger infarct in the superficial MCA territory (40.8±62.6 cm³ vs. 10.8±21.8 cm³, p<0.001) than the SM group. A poor functional outcome (mRS >2) at 3 months was more common in the SM+L group (64.3% vs. 15.9%, p<0.001). During a mean follow-up of 26 months, 67 patients died. All-cause (hazard ratio, 2.246) and stroke (hazard ratio, 9.193) mortalities were higher in the SM+L group than the SM group. In multivariate analyses, LSA involvement was an independent predictor of poor functional outcomes and stroke mortality. CONCLUSION: LSA territory involvement is predictive of poor long-term outcomes in patients with superficial MCA territory infarction.
Carotid Stenosis/mortality/pathology ; Constriction, Pathologic/pathology ; Female ; Humans ; Infarction, Middle Cerebral Artery/mortality/*pathology ; Male ; Middle Cerebral Artery/*pathology ; Multivariate Analysis ; Severity of Illness Index ; Stroke/mortality/pathology

BACKGROUND: The pulsatility index (PI) measured by a transcranial Doppler (TCD) has been postulated to reflect the vascular resistance that is distal to the artery being examined. Therefore, pathologies of small perforating arteries may affect the PI of the proximal artery. Microangiopathy is a common vascular complication of diabetes mellitus (DM), which may contribute to the development of small infarctions involving the perforating artery, and may be reflected on the PI. METHODS: We enrolled patients with acute cerebral infarctions who were examined by TCD, MRI, and MRA and fulfilled the following criteria: 1)an infarction of less than 2 cm size involving a single perforating arterial territory; 2)no significant arterial stenosis on MRA; and 3)no cardioembolic sources. Patients were divided into either a group with DM, or without and TCD findings were compared. RESULTS: The DM group showed higher PI than non-DM (0.99 v.s. 0.85 for the right middle cerebral artery; 1.02 v.s. 0.85 for the left middle cerebral artery; and 0.94 v.s. 0.78 for the basilar artery). The mean flow velocity was comparable between the groups. Multivariate linear regression analysis revealed that the duration of DM was a significant predictor of elevated PI of the bilateral MCA and basilar artery and that age was another significant predictor in the case of basilar artery. CONCLUSIONS: The elevated PIs in DM patients suggest the possible role of diabetic microvascular complications in the development of the lacunar infarction. The PI measurement using TCD may be a useful marker of the lacunar infarction, especially in DM patients.
Arteries ; Basilar Artery ; Cerebral Infarction ; Constriction, Pathologic ; Diabetes Mellitus ; Humans ; Infarction ; Linear Models ; Magnetic Resonance Imaging ; Middle Cerebral Artery ; Pathology ; Stroke, Lacunar* ; Vascular Resistance

BACKGROUNDMotor dysfunction is common in stroke patients. Clinical electrophysiological studies suggest that transsynaptic degeneration occurred in the lower motor neurons, while pathological evidence is lacked. This study aimed to combine the electrophysiological and pathological results to prove the existence of transsynaptic degeneration in the motor system after stroke.

METHODSModified neurologic severity score, electrophysiological, and pathological assessments were evaluated in rats before middle cerebral artery occlusion (MCAO), and at 24 hours, 7 days, and 14 days after MCAO. Paired and independent-sample t-tests were applied to assess the changes of electrophysiological and pathological data.

RESULTSCompound motor action potential amplitude in the paretic side was significantly lower than the nonparetic side at both 24 hours (61.9 ± 10.4 vs. 66.6 ± 8.9, P < 0.05) and 7 days (60.9 ± 8.4 vs. 67.3 ± 9.6, P < 0.05) after MCAO. Motor unit number estimation of the paretic side was significantly less than the nonparetic side (379.0 ± 84.6 vs. 445.0 ± 89.5, P < 0.05) at 7 days after MCAO. Until 14 days after stroke, the pathological loss of motor neurons was detected. Motor neurons in 14-day MCAO group were significantly decreased, compared with control group (5.3 ± 0.7 vs. 7.3 ± 1.8, P < 0.05).

CONCLUSIONSBoth electrophysiological and pathological studies showed transsynaptic degeneration after stroke. This study identified the asynchronization in changes of electrophysiology and pathology. The abnormal physiological changes and function impairment can be detected in the early stage and recovered quickly, while the pathological loss of motor neuron can be detected only in a later stage.

Animals ; Electrophysiology ; Infarction, Middle Cerebral Artery ; pathology ; physiopathology ; Male ; Motor Neurons ; pathology ; Rats ; Rats, Sprague-Dawley ; Spinal Cord ; pathology ; physiopathology

Immunohistochemistry and double immunofluorescent labeling techniques combined with confocal laser scanning microscope analysis were used to investigate the characteristic spatial induction profile of nestin following a transient middle cerebral artery occlusion in adult rat brain. The results showed that nestin was induced in ischemic core at 1 day after reperfusion. In addition to ischemic core, the expression of nestin increased in peri-ischemic I, II and III regions at 3 days and 1 week, then it decreased and narrowed along the rim of ischemic core 2 weeks after reperfusion. Double immunofluorescent labeling showed that nestin positive cells were mostly co-stained with GFAP,a astrocyte marker, in peri-ischemic I region 3 days after reperfusion. At 2 weeks, however nestin cells showed a long process and the cells double stained with nestin and NSE,a neuonal specific marker,increased in the ischemic brain. The results suggest that cerebral ischemia induces nestin expression in damaged neurons which might favor the neuroprotection against ischemic damage.
Animals ; Brain ; metabolism ; pathology ; Brain Ischemia ; metabolism ; pathology ; Immunohistochemistry ; Infarction, Middle Cerebral Artery ; metabolism ; pathology ; Nestin ; metabolism ; Neurons ; metabolism ; Rats

Brain ; pathology ; Brain Infarction ; diagnosis ; Cerebral Angiography ; Cerebral Arterial Diseases ; diagnosis ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Posterior Cerebral Artery ; pathology

OBJECTIVETo study the dynamic changes of capillaries and inflammatory cells in different regions of brain in rat with middle cerebral artery obstruction (MCAO), and the effects of acupuncture in different frequencies on them.

METHODSIn reference to Zea-Longa's method, rat model of MCAO was established by thread-ligation. Shuigou point (DU26), the main acupoint for "awakening brain and opening apertures", was stimulated by high (180 times/s) or low (60 times/s) frequency puncturing 5 s every 12 h for 6 times totally. The amount of capillaries (AC) and inflammatory cells (AIC) in brain cortex (BC), hippocampus (Hp) and corpus striatum (CS) was counted.

RESULTSChanges in AC and AIC of all brain regions (except for CS) in rats immediately after modeling were statistically insignificant (P > 0.05). But 72 h later, AC in CS decreased, AC in Hp, AIC in BC and AIC in Hp increased significantly in the modeled rats, showing significant difference to the normal level, but AIC reduced to approach the normal. As compared with the rats un-intervened, AIC in BC and Hp was decreased in rats intervened with high frequency puncturing, AC and AIC in CS were increased in rats intervened by slow frequency puncturing (both P < 0.05).

CONCLUSIONAmount of capillaries and inflammation cells are changed dynamically in MCAO rats after brain ischemia, showing evident brain regional specificity; the ischemic improving effects of acupuncture in different frequencies are various in their action rings, also showing brain regional specificity.

Acupuncture Therapy ; methods ; Animals ; Brain ; pathology ; physiopathology ; Infarction, Middle Cerebral Artery ; pathology ; physiopathology ; therapy ; Male ; Rats ; Rats, Wistar

The involvement of apoptosis in mitochondrial toxin 3-nitropropionic acid (3-NPA)-induced ischemic tolerance to transient focal cerebral ischemia in rats and the mechanism was investigated. 3-NPA at a dose of 20 mg/kg or vehicle control was intraperitoneally into the rats. Three days later, rats were exposed to 2 h of middle cerebral artery occlusion followed by 24 h of reperfusion. Infarct volumes were assessed by 2,3,5-triphenyltetrazolinm chloride (TTC) staining 24 h after reperfusion. Neural cell apoptosis in cerebral ischemic penumbra was detected by terminal deoxynucleotidyl transferase-mediated dUTP-biotin in situ nick end labeling (TUNEL) and flow cytometry methods (FCM). The results showed that as compared to the vehicle-treated group, pretreatment with 3-NPA could reduce the infarct volume by 23.3% and decrease the number of TUNEL-positive neural cells and apoptotic percentage by 47% (P<0.05) and 44.9% (P<0.01), respectively. It was concluded that the development of 3-NPA-induced ischemic tolerance in brain might be related to the decreases in neural cell apoptosis.
Animals ; Apoptosis ; drug effects ; Cerebral Cortex ; blood supply ; Cerebrovascular Circulation ; DNA Damage ; Infarction, Middle Cerebral Artery ; pathology ; Ischemic Attack, Transient ; chemically induced ; pathology ; Ischemic Preconditioning ; Male ; Middle Cerebral Artery ; pathology ; Nitro Compounds ; Propionates ; Rats ; Reperfusion Injury ; pathology

The purpose of this study was to identify time-related changes in clinical, MRI, histopathologic, and immunohistochemical findings associated with ischemic stroke in dogs. Additionally, the association of cerebrospinal fluid (CSF) and tissue levels of interleukin (IL)-6 with clinical prognosis was assessed. Ischemic stroke was induced by permanent middle cerebral artery occlusion (MCAO) in nine healthy experimental dogs. The dogs were divided into three groups according to survival time and duration of the experimental period: group A (survived only 1 day), group B (1-week experimental period), and group C (2-week experimental period). Neurologic status was evaluated daily. Magnetic resonance imaging (MRI) was performed according to a predetermined schedule. Concentration of IL-6 in CSF was measured serially after ischemic stroke. Postmortem examination was performed for all experimental dogs. During histopathological examination, variable degrees of cavitation and necrosis due to neuronal cytopathic effects, such as pyknotic nuclei and cytoplasmic shrinkage, were observed on the affected side of the cerebral cortex in all dogs. Immunohistochemistry specific for IL-6 showed increased expression in the ischemic lesions. CSF IL-6 concentrations and ischemic lesion volumes 1 day after ischemic stroke were significantly higher in group A compared to groups B and C.
Animals ; Brain Ischemia/*etiology ; Dogs ; Female ; *Immunohistochemistry ; *Infarction, Middle Cerebral Artery ; *Magnetic Resonance Imaging ; Male ; Stroke/*pathology

OBJECTIVETo explore a method for combining Fluoro-Jade B (FJB) staining with immunofluorescent staining in rats with focal cortical infarction.

METHODPermanent distal middle cerebral artery occlusion (dMCAO) was induced in rats by electrocoagulation. The rat models were randomized into two groups, and frozen sections of the brain tissues from each group were stained with FJB followed by immunofluorescent staining or in the reverse order.

RESULTSFJB staining followed by immunofluorescence staining clearly visualized both FJB-positive and immunofluorescence-positive cells in the frozen sections, but the staining protocol in the reverse sequence failed to clearly show the immunofluorescence-positive cells.

CONCLUSIONFJB staining prior to immunofluorescence staining does not affect the staining effect of protein immunofluorescent staining and better visualizes the positive cells.

Animals ; Brain ; pathology ; Fluoresceins ; chemistry ; Fluorescent Antibody Technique ; methods ; Fluorescent Dyes ; chemistry ; Infarction, Middle Cerebral Artery ; Rats ; Staining and Labeling ; methods

The aim of the present study was to assess the clinical and histopathological findings in a canine model of ischemic stroke. Cerebral ischemic stroke was induced by middle cerebral artery occlusion in four healthy beagle dogs using silicone plugs. They showed neurological signs of forebrain dysfunction such as reduced responsiveness, head turning, circling, postural reaction deficits, perceptual deficits, and hemianopsia. These signs gradually regressed within 4 weeks without therapy. On magnetic resonance imaging, T2 hyperintensity and T1 hypointensity were found in the cerebral cortex and basal ganglia. These lesions were well-defined and sharply demarcated from adjacent brain parenchyma with a homogenous appearance. No abnormalities of the cerebrospinal fluid were observed. At necropsy, atrophic and necrotic lesions were observed in the cerebral cortex. The cerebral cortex, basal ganglia, and thalamus were partially unstained with triphenyl-tetrazolium chloride. Histopathologically, typical features of infarction were identified in cortical and thalamic lesions. This study demonstrates that our canine model resembles the conditions of real stroke patients.
Animals ; Behavior, Animal/physiology ; Brain/metabolism/pathology ; Cerebral Infarction/*etiology/*pathology ; Cerebrospinal Fluid/chemistry/cytology ; Disease Models, Animal ; *Dogs ; Infarction, Middle Cerebral Artery/*complications/*pathology ; Magnetic Resonance Imaging ; Male