Relationship between cerebrovascular reserve capacity and white matter lesions in the elderly based on magnetic resonance imaging / 中国辐射卫生

Objective To investigate the relationship between cerebrovascular reserve (CVR) capacity and white matter lesions in elderly people. Methods We included 315 participants aged ≥ 60 years in Jinan area of Shandong Province from May 2018 to July 2019. They underwent transcranial Doppler ultrasonography for assessing CVR, breath holding index (BHI), and arterial pulsatility index (PI). According to CVR capacity, they were divided into normal CVR group (CVR ≥ 20%, n = 206) and impaired CVR group (CVR < 20%, n = 109). Magnetic resonance imaging was performed to evaluate periventricular, subcortical, and total white matter hyperintensity (WMH) volumes and Fazekas scores. Results Compared with the normal CVR group, the impaired CVR group showed significantly higher volumes of periventricular, subcortical, and total WMHs and significantly higher proportions of Fazekas scores ≥ 2 (P < 0.01). Periventricular, subcortical, and total WMH volumes were negatively correlated with CVR (r = −0.70, −0.66, −0.73, P < 0.01) and BHI (r = −0.64, −0.65, −0.68, P < 0.01) and positively correlated with PI (r = 0.60, 0.65, 0.65, P < 0.01). After adjusting for confounding factors, periventricular, subcortical, and total WMH volumes were still negatively correlated with CVR and BHI (P < 0.01) and positively correlated with PI (P < 0.01). The logistic regression analysis showed that the risks of periventricular, subcortical, and total Fazekas score ≥ 2 in the impaired CVR group were 1.96 times (95% confidence interval [CI]: 1.17−3.27, P < 0.01), 1.84 times (95% CI: 1.11−3.05, P < 0.05), and 2.33 times (95% CI: 1.30−4.18, P < 0.01) that of the normal CVR group, respectively. Conclusion Impaired CVR is an independent risk factor for white matter lesions in the elderly.

Cerebrovascular reserve capacity of patients with ischemic cerebral white matter lesions / 实用医学杂志

Objective To investigate the changes of cerebrovascular reserve capacity (CVR) in patients with ischemic white matter lesions (WML). Methods 126 patients with WML were divided into mild lesion, moderate lesion, severe WML groups and a normal control group by brain MRI. Blood pressure, blood sugar, blood fat were measured and past medical histories were recorded in details. All the patients were routinely examined using TCD to evaluate CVR. Hypercapnia was induced by inhaling the CO2 they breathed themselves and hypocapnia was done by voluntary hyperventilation. Results Age, hypertension, diabetes mellitus and Apo-A were the independent risk factors for WML. Compared with the controls , CVR decreased significantly in the severe and moderate WML groups (P < 0.05). The extent of WML negatively correlated to the cerebrovascular reserve capacity (rs = -0.273, -0.392). Conclusions Age, hypertension, diabetes mellitus and Apo-A are the independent risk factors for WML. CVR is significantly decreased in the WML.

Study on relationship between changes of cerebrovascular reserve capacity in patients with symptomatic middle cerebral artery ischemia / 重庆医学

Objective To investigate the changes of middle cerebral artery(MCA) in patients with ischemic cerebrovascular re-serve capacity(CVR) and its related factors .Methods 80 patients of MCA stenosis diagnosed by transcranial Doppler(TCD) and (or) magnetic resonance imaging(MRI) were divided into asymptomatic group(n=52) and symptom group(n=28) ,and selected 30 healthy people without cerebral vascular stenosis and stroke risk factors as control group .All subjects underwent TCD combined with breath holding test in patients with CVR ,clinical data were compared in patients with cerebrovascular stenosis ,Logistic appli-cation of single factor and multi factor regression were used to analyed the factors affecting CVR .Results The breath holding index (BHI)of symptom group was 0 .44 ± 0 .14 ,significantly lower than that of the asymptomatic group 0 .75 ± 0 .22 and control group 0 .98 ± 0 .27(P<0 .05) .Patients with smoking index ,symptom group drinking index ,hypertension ,hyperlipidemia ,diabetes ,family history of stroke ,carotid intima-media thickness(IMT) were significantly higher than that in the asymptomatic group(P<0 .05) . Logistic regression analysis showed that smoking ,hypertension ,hyperlipemia ,diabetes ,IMT were associated with BHI(P<0 .05) . Conclusion Symptomatic MCA ischemia in patients with decreased CVR ,CVR changes and smoking index in patients with stroke risk index ,drinking ,hypertension and other factors are related to lower CVR ,and has a certain value in cerebral ischemic event pre-diction .

Clinical significance of transcranial Doppler and end-tidal carbon dioxide partial pressure on cerebrovascular reserve capacity in cerebral vessels stenosis patients / 中国医师进修杂志

Objective To study the clinical significance of cerebrovascular reserve (CVR) capacity in cerebral vessels stenosis (CVS) patients with transcranial Doppler (TCD) and end-tidal carbon dioxide partial pressure (PETCO2).Methods Fifty-two CVS patients were divided into two groups:one blood vessel stenosis group (22 cases) and multi blood vessels stenosis group (30 cases).Forty-five normal persons were selected as control group.All the groups were routinely examined with TCD and PETCO2.Hypercapnia was induced by inhaling the carbon dioxide who breathed himself,and hypocapnia was induced by voluntary hyperventilation to investigate the CVR capacity.Results (1)The vasodilator reserve of affected side of one blood vessel stenosis group [(3.16 ± 2.73)％/mm Hg,1 mm Hg =0.133 kPa],the heavier side of multi blood vessels stenosis group [(2.41 ± 1.25)％/mm Hg],and control group [(3.75 ± 1.77)％/mm Hg] had significant difference (F =3.866,P ＜ 0.05).The vasodilator reserve of heavier side of multi blood vessels stenosis group was significantly lower than that of control group (t =-2.657,P ＜ 0.05).The overall reserve of affected side of one blood vessel stenosis group [(3.13 ± 1.38)％/mm Hg],the heavier side of multi blood vessels stenosis group [(2.01 ± 1.89)％/mm Hg],and control group [(3.51 ±0.92)％/mm Hg] had significant difference (F =5.905,P ＜ 0.05).The overall reserve of heavier side of multi blood vesse stenosis group was significantly lower than that of control group and affected side of one blood vessels stenosis group (t =-3.468,2.582,P ＜ 0.05).(2) There was no significant difference among the 3 groups in PETCO2 when eupnea,hypocapnia and hypercapnia.(3) The extent of vascular disease correlated negatively with the vasodilator reserve and overall reserve (r =-0.433 and-0.475,P＜0.05).Conclusions TCD and PETCO2 are simple,economic and effective methods for assessing CVR capacity.The CVR capacity is reduced in patients with cerebral vessels changes.

Study of cerebrovascular reserve capacity in obstructive sleep apnea-hypopnea syndrome / 中国综合临床

Objective To assess cerebrovascular reserve capacity in patients with obstructive sleep apnea-hypopnea syndrome(OSAHS).Methods One hundred and fourteen patients with OSAHS and 43 normal persons were enrolled in this study.The patients were divided into mild,moderate,severe according to apnea hypopnea index (AHI) and LSaO2 (lowest arterial oxygen saturation).All the patients and normal persons were routinely examined using transcranial Doppler (TCD) and end-tidal carbon dioxide partial pressure(ETCO2) to evaluate cerebrovascular reserve.Hypercapnia was induced by inhaling the CO2 which produced by the patients themselves,and hypocapnia was elicited by voluntary hyperventilation.Results CVR in the severe and moderate OSAHS were significantly lower than that in the control group [ (1.80 ± 1.34) ％/mm Hg and (1.43 ±1.05)％/mm Hg vs (2.93 ±0.93)％/mm Hg,P ＜0.05] when patients in the condition of hypocapnia.And there was no significant difference on CRV between the mild OSAHS group and control group [ (2.53 ±1.83 ) ％/mm Hg vs ( 2.93 ± 0.93 ) ％/mm Hg,P ＞ 0.05 ].When patients in the condition of Hypercapnia,CRV in the severe and moderate OSAHS were also significantly lower than that in the control group [ ( 1.83 ±1.32) ％/mm Hg and (1.08 ± 1.00)％/mm Hg vs (3.32 ± 1.53)％/mm Hg,P ＜ 0.05),AHI was negatively correlated with the cerebrovascular reserve at the condition of hypercapnia and hypocapnia (r=-0.665,-0.721; P ＜ 0.05 ).Conclusion Inhaling CO2 is a effective method for assessing CVR.Cerebrovascular reserve capacity is associated with AHI.Reduced CVR causes hemodynamics change being severe hypoxia in the moderate and severe OSAHS.

The Serial Change of Cerebral Hemodynamics by Vascular Territory after Extracranial-Intracranial Bypass Surgery in Patients with Atherosclerosis of Cerebral Arteries / 핵의학분자영상

PURPOSE: To assess the effect of extracranial-intracranial (EC-IC) bypass surgery on hemodynamic improvement, we evaluated serial regional cerebral hemodynamic change of the middle cerebral artery (MCA) in symptomatic patients with atherosclerotic occlusion of the internal carotid artery (ICA) or MCA using (99m)Tc-ECD acetazolamide stress brain perfusion SPECT (Acetazolamide SPECT). MATERIAL AND METHODS: The patients who had suffered a recent stroke with atherosclerotic ICA or MCA occlusion underwent EC-IC bypass surgery and Acetazolamide SPECT at 1 week before and three to six months after surgery. For image analysis, attenuation corrected images were spatially normalized to SPECT templates with SPM2. Anatomical automated labeling was applied to calculate mean counts of each Volume-Of-Interest (VOI). Seven VOIs of bilateral frontal, parietal, temporal regions of the MCA territory and the ipsilateral cerebellum were defined. Using mean counts of 7 VOIs, cerebral perfusion index and perfusion reserve index were calculated. RESULTS: Seventeen patients (M:F=12:5, mean age: 53+/-2yr) were finally included in the analysis. The cerebral blood flow of the parietal region increased at 1 week (p=0.003) and decreased to the preoperative level at 3-6 months (p=0.003). The cerebrovascular reserve of the frontal and parietal regions increased significantly at 1 week after surgery (p<0.01) and improved further at 3-6 months. CONCLUSION: Cerebrovascular reserve of the MCA territory was significantly improved at early postoperative period after EC-IC bypass and kept improved state during long-term follow-up, although cerebral blood flow did not significantly improved. Therefore, cerebrovascular reserve may be a good indicator of postoperative hemodynamic improvement resulted from bypass effect.

Neurological Improvement after Cranioplasty in Patients with Surgical Bony Defects : The Usefulness of Acetazolamide Activated (99m)Tc-HMPAO SPECT

OBJECTIVE: The purpose of this study is to examine the influence of cranioplasty on dynamics of cerebral blood flow(CBF) and cerebrovascular reserve capacity(CVRC), and to investigate the usefulness of single photon emission computed tomography (SPECT) as a prognostic factor for neurological improvement after cranioplasty. METHODS: Between March 2003 and December 2005, a prospective study was performed on 24 patients who had undergone total 25 cranioplasty operations. Cerebral blood flow velocities in the middle cerebral artery(MCA) and internal carotid artery (ICA) were obtained by transcranial Doppler ultrasonography(TCD). The CVRC was assessed by SPECT in the natural state and after stimulation with 1g of acetazolamide. Neurological improvement after cranioplasty was compared between patients who showed hyperactivity to acetazolamide-activated SPECT (Group 1, n=7) and hypoactivity to acetazolamide-activated SPECT (Group 2, n=17). These measurements were obtained two weeks prior to and two weeks after cranioplasty. RESULTS: The blood flow velocities at the opposite site to the cranioplasty as well as at the cranioplasty site were significantly increased (P<0.05). Compared with Group 2, there was significant increase in CBF and neurological imrovement after cranioplasty in Group 1. CONCLUSION: Among patients with surgical bony defects, the patients who had normal reactivity of the CVRC showed a significant increase in CBF and neurological improvement after cranioplasty. The authors suggest that CVRC measurement prior to surgery may be an important prognostic factor for neurological improvement after cranioplasty.

Effectiveness of Bypass Surgery in Treatment and Prevention for Cerebrovascular Occlusive Disease

To study the effect of extracranial-intracranial(EC/IC) bypass on symptomatic patients with hemodynamic cerebral ischemia, we prospectively reviewed 76 patients who underwent EC/IC bypass surgery in patients with occlusive cerebrovascular disease. A series of 76 patients treated in a 7 years period met following criteria. (1) symptomatic internal carotid artery(ICA) or middle cerebral artery(MCA) obstruction or stenosis over 80%. (2) decrease in basal cerebral blood flow(CBF) over 10%. (3) decreased reactivity of CBF in response to acetazolamide. Among these, the types of ischemic episodes were transient ischemic attack(TIA) or reversible ischemic neurological deficit(RIND) in 39, minor stroke in 22, and major stroke in 15. Based on our criteria, superficial temporal artery(STA)-MCA anastomosis was performed in 67 cases and EC-IC bypass grafting using saphenous vein or radial artery in 9. Average follow up period was 26 months(3 months~7 year). Patency of bypass was confirmed by postoperative angiography or magnetic resonence angiography(MRA) in all case except four cases. Of the 72 patients with patiency of bypass, 68 patients(94%) have had an excellent to good outcome with improvement of preoperative neurologic or cognitive dysfunction, 3 patients showed no improvement of preoperative neurologic symptoms and remaining one patient had new developed deficit. All 72 patients with patency of bypass had experienced no further cerebral ischemic events during following period. Postoperative significant improvement of CBF to acetazolamide was showed in 68 cases(94%) of the 72 cases with patency of bypass, while the basal CBF showed significant improved in 31cases. Postoperative permanent neurologic deficit occurred only in one. In view of these finding, the author suggest that EC-IC bypass surgery is a reliable and resonably safe method for establishing new pathways of collateral circulation to the brain and to be considered as an appropriate therapy for improvement of the cerebrovascular reserve capacity in patients with hemodynamic cerebral ischemia, defined using the strict selection criteria employed in this study.

Improvement of Cerebrovascular Reserve Capacity by Bypass Surgery in Patients with Hemodynamic Cerebral Ischemia

To study the effect of extracranial-intracranial(EC/IC) bypass on symptomatic patients with hemodynamic cerebral ischemia, we prospectively reviewed 14 patients who underwent EC/IC bypass surgery. A series of 14 patients treated in a 2 years period met the following criteria, 1) symptomatic internal carotid artery(ICA) or middle cerebral aetery(MCA) obstruction or stenosis over 80M, 2) decrease in basal cerebral blood flow(CBF) over 10%, 3) hyporeactivity to acetazolimide of CBF Amomg these, the type of ischemic episode was transient ischemic attack(TIA) or reversible ischemic neurological deficit(RIND) in 4, minor stroke in 8, and major stroke in 2. Of these, 10 patients had multiple episode of ischemic attack. CT or MRI were showed infarction of the MCA territory in 3, border zone infarction in 5, basal ganglia infarction in 2 and multiple lacunar infarction in 4. Based on our criteria, superficial temporal artery(STA)-MCA anastomosis was performed in 13 cases and EC-IC bypass grafting using radial artery in one. Average follow up period was 24 months. Postoperative course was uneventful in 12 patients. One patient suffered a postoperative stroke with complete recovery and another suffered operative wound infection. Of the 14 patients 12(85.7 % ) have had an excellent to good outcome with complete resolution or significant improvement of preoperative neurologic symptom, remaining two show no improvement of preoperative neurologic deficit. Bypass patency was confirmed by postoperative angiography in all cases except for one. Postoperative follow up studies of the basal CBF and response to the acetazolamide of the CBF showed significant increased CBF activity to acetazolamide in 12 cases(85. 7%) while the basal CBF was essentially unchanged in all cases except for two. In view of these finding, the authors suggest that EC-IC bypass surgery to be considered as an appropritate therapy for improvement of the cerebrovascular reserve capacity in patients with hemodynamic cerebral ischemia, defined using the strict selection criteria employed in this study.