Ipsilateral MCA Research Articles

Clinical significance of STA-MCA double anastomosis for hemodynamic compromise in post-JET/COSS era

Even after the recent randomized clinical trials JET and COSS, it is still unclear that impaired cerebrovascular reactivity (CVR) to acetazolamide and oxygen extraction fraction (OEF) can identify the candidates for superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis. This prospective study was aimed to evaluate the benefits of STA-MCA "double" anastomosis on long-term outcome in patients with reduced cerebral blood flow (CBF) and CVR (Type 3 ischemia) and elevated OEF attributable to occlusive carotid diseases. This study included 49 patients with reduced CBF and CVR on SPECT in the ipsilateral MCA area. Using (15)O-gas PET, OEF was also measured in all patients. STA-MCA double anastomosis was recommended to the patients with Type 3 and elevated OEF. Those with Type 3 but normal OEF were medically treated. Of 36 patients with Type 3 and elevated OEF, 25 consented to surgery. No perioperative morbidity or mortality were noted. The other 11 patients with Type 3 and elevated OEF were medically treated. Annual incidence of ipsilateral stroke was 0.7% and 6.5% in surgically and medically treated patients with Type 3 and elevated OEF, respectively (P = 0.0188). None of patients with Type 3 but normal OEF developed ipsilateral stroke during follow-up periods. STA-MCA "double" anastomosis significantly decreased OEF. STA-MCA "double" anastomosis may still have the potential to reduce the risk of recurrent ipsilateral stroke in hemodynamically compromised patients. Further studies would be essential to advance diagnosis, surgical procedures, and perioperative managements to bring out maximal effects of bypass surgery.

Bilateral middle cerebral artery aneurysms: a comparative study of unilateral and bilateral approaches

The best surgical method for the treatment of patients with bilateral middle cerebral artery (bMCA) aneurysms has not been fully determined yet. The main purpose of this study is to compare the surgical results of unilateral and bilateral approaches to bMCA aneurysms including mean operation time, mean hospital stay, and mean cost, in the experience of the same neurosurgical team. Between January 2001 and June 2010, 22 patients with bMCA aneurysms were surgically treated in our institution. In 12 cases (54.5 %), ipsilateral and contralateral MCA aneurysms were successfully clipped via unilateral approach. In the remaining 10 cases, bilateral approach was necessary because of some technical difficulties. Although the surgical results were almost the same, mean operation time and mean hospital stay were, respectively, 46 and 37 % shorter and mean cost per person was 23 % lower for the patients in the unilateral group. In addition, the severity of brain edema, total length of the contralateral (A1+M1) segment, and the configuration of contralateral aneurysm were found to be the determinant parameters affecting the feasibility of the unilateral approach. To our knowledge, this is the first study in the literature that compares the clinical outcomes of unilateral and bilateral approaches to bMCA aneurysms. The results of surgery for both approaches are almost the same. However, the unilateral approach has certain advantages compared to the bilateral approach. Therefore, the unilateral approach may be a good alternative in surgical management of patients with bMCA aneurysms in selected cases and the abovementioned parameters can help the neurosurgeon in patient selection.

Abstract 2215: Utility of Upfront Arterial and Perfusion Imaging among Ischemic Stroke Patients Presenting within the 4.5 hour Time Window

Background: Although perfusion imaging is being evaluated as a tool to select acute ischemic stroke patients who are most likely to benefit from reperfusion therapies beyond the standard time windows, there is limited data on the utility of perfusion imaging within the IV thrombolytic time window. Methods: A new upfront comprehensive stroke imaging protocol was initiated at Emory University Hospital on July 1, 2010 to include CT angiography (CTA) of the head and neck and CT perfusion (CTP) of the head after non-contrast head CT. All patients presenting within 4.5 hours from last known normal time to Emory University Hospital with suspected stroke were prospectively identified from July 1 to December 31, 2010. Patients with POC Creatinine >1.7, allergy to contrast dye, current metformin use, pregnancy, intracranial hemorrhage (ICH) on non-contrast head CT or who declined consent were excluded from the protocol. Impact of CTA and CTP on the clinical management was recorded prospectively by stroke team members. Results: During the study period, 87 patients met eligibility criteria for the CTA/CTP protocol of which 83 (95%) underwent this upfront comprehensive imaging protocol and 30 (34%) received IV thrombolytic. CTA identified large vessel occlusion in 24 (29%) patients, including 5 with NIHSS ≤ 10 and 3 with NIHSS ≤ 5. CTP identified decreased cerebral blood volume > 1/3 of the ipsilateral MCA territory in 38% of anterior circulation large vessel occlusions. Overall, stroke team members reported that CTA and/or CTP aided their clinical management in 39 (47%) cases, including aiding in identification of a non-stroke diagnosis (n=18), triage to the NICU (n=9), early triage to endovascular therapy (n=4) and initiation of IV thrombolytic for low NIHSS with large vessel occlusion (n=3). There were no symptomatic ICHs and no contrast-induced nephropathy requiring dialysis during the study period. Door-to-needle time ≤ 60 minutes was achieved in only 23% of patients receiving IV thrombolysis during the study period but had improved to 39% in the subsequent 6 month period, similar to the pre-CTA/CTP protocol. Conclusions: An upfront CTA/CTP protocol to evaluate patients with acute ischemic stroke presenting within 4.5 hours aided stroke team decision making in nearly half of cases. Implementation of a CTA/CTP protocol was associated with a learning curve of 6 months before door-to-needle time ≤ 60 minutes returned to similar rates as the pre-CTA/CTP protocol.

Abstract 2852: Hyperdense MCA Sign- Objective Criteria for Measurement

Background and Objective Hyperdense middle cerebral artery (HDMCA) sign is an early sign seen on CT head after acute ischemic stroke indicating acute arterial thrombosis. We aimed to measure HDMCA sign objectively. Methods We conducted a retrospective analysis of prospectively collected data from 151 cases of acute ischemic stroke eligible for IV rt-PA by time criteria, admitted to Mayo Clinic from March, 2002 through June, 2011. Admission CT Head was studied to identify HDMCA sign. All patients had either 24 hour CT head or MRI head to confirm the stroke in the same vessel territory. MCA was measured in Hounsfield units and was compared to the contralateral MCA. Receiver Operating Characteristic (ROC) curve analysis was performed to calculate sensitivity and specificity. Results Mean admission NIHSS score was 11±7. HDMCA sign was seen in 93 (62%) patients. ROC curve analysis for ipsilateral MCA Hounsfield units had an area under the curve 0.88 (p<0.001, CI 0.83-0.94) which showed 50 HU or more had 48% sensitivity and 98% specificity. Ratio of ipsilateral to contralateral MCA HU had an area under the curve 0.94 (p<0.001, CI 0.90-0.98) which showed ratio of 1.23 had 67% sensitivity and 98% specificity. A combination of either ipsilateral HU more than equal to 50 or a ratio of ipsilateral to contralateral MCA HU more than equal to 1.23 had 77% sensitivity, 95% specificity, 96% positive predictive value and 72% negative predictive value. Conclusion A combination of ipsilateral HU more than equal to 50 or a ratio of ipsilateral to contralateral MCA HU more than equal to 1.23 can objectively identify HDMCA sign with good sensitivity and high specificity.

Dynamic changes in blood flow of a bypassed superficial temporal artery with unstable internal carotid artery stenosis

Background:There are limited indications for superficial temporal artery to middle cerebral artery (STA–MCA) bypass in the treatment of cerebral atherosclerotic disease. However, recent reports emphasize that STA–MCA bypass may be beneficial for select patients. In this report, we describe a case in which a flow-dependent STA–MCA bypass was achieved in a patient with unstable internal carotid artery (ICA) stenosis.Case Description:A 51-year-old woman presented with left ICA occlusion. A severely elongated mean transit time (MTT) indicated misery perfusion. STA–MCA bypass was performed immediately and blood flow through the graft appeared excellent on magnetic resonance angiography (MRA). Two weeks later, MRA revealed normal anterograde ICA blood flow and the bypass graft was not visible. Three years later, the left ICA stenosis again became severe and the patient developed contralateral hemiparesis. She underwent endovascular surgery and the ipsilateral MCA became occluded during the procedure. The STA–MCA bypass graft appeared immediately after the MCA occlusion and became a major provider of blood flow to the ipsilateral MCA area. She recovered with almost no deficit.Conclusion:This is a rare case which shows that dynamic flow changes through an STA–MCA bypass can occur with variable ICA blood flow. STA–MCA bypass can be beneficial for the treatment of unstable ICA stenosis.

Localization of the Internal Maxillary Artery for EC-IC Bypass through the Middle Cranial Fossa: A Cadaveric Study

Background: The internal maxillary artery (IMAX) is a promising arterial pedicle to function as a donor vessel for extracranial-to-intracranial (EC-IC) bypass procedures. The access to the IMAX through the anterior portion of the middle fossa floor allows a much shorter interposition graft to be used to create a bypass to the ipsilateral MCA and prevents a second incision in the neck. This procedure has already been done successfully in the operating room; however, one of the challenges to solidify this technique has been the need to establish a reliable method to localize the IMAX through the middle fossa floor based on skull base landmarks. The purpose of this cadaveric study is to establish such relationships between the position of the IMAX as approached through the middle fossa floor and identifiable bony landmarks in the skull base.

Intraoperative complications of endovascular management for intracranial aneurysms

Objective To summarize the clinical experience of endovascular intervention for intra-cranial aneurysms, especially in the respect of the technique and management of intra-operative complications. Method The clinical data of 60 patients with intra-cranial aneurysms treated with endovascular intervention in the past 3 years were analyzed. The relevant literature especially with regard to the practical technique described was reviewed so as to potentiall minimize and properly manage the intra-operative complications. Results A total of 69 sacciform aneurysms and one dissecting aneurysm located at left vertebral artery (VA) were detected by using digital subtraction angiography (DSA) in 60 patients. There were 65 saccular aneurysms obliterated with constructive approach, and five of them treated with stent-assisted technique and four of them treated with ballon-assisted technique. The VA dissecting aneurysm was obliterated with coils by deconstructive approach with complete occlusion of its parent vessel. There were a total of 53 complete occlusions of aneurysms accounted for 76.81% of 69 sacciform aneurysms in 51 patients ( 85 % ) and eight subtotal occlusion of aneurysms (95 % ～ 99 % occlusion) accounted for 13.56% of total sacciform aneurysms in five patients (8.47%) and four incomplete occlusion of aneurysms ( ＜ 95% occlusion) accounted for 6.78% of total sacciform aneurysms in three patients (5.08%), and one was failure in operation. The rupture of aneurysms occurred during operation in4 patients (6.78%). Two senile patients suffered from intra-opeartive symptomatic thromboembolisn. One patient had stent shifting and spring coil dislocated and moved into the M3 segment of the ipsilateral MCA. Vasospasm occurred in 15 patients during operation, and most of them received endovascular intervention 3 days after the initial ictus. The rate of good recovery was 93.3% at discharge from hospital (the modified Rankin Scales, mRS＜ 2). There were 55 patients followed up for up 24 months after discharge, and excellent recovery rate was found in 51 patients ( mRS ＜ 2), and 3 died.During the follow-up period, no aneurismal recanalization or rupture was noticed in all patients. Conclusions The endovascular intervention is a safe and effective approach to the intra = cranial aneurysms. Advances in the skill of technique and proper management will decrease the complications during operation and improve the prognosis of patients. Key words: Intracranial aneurysm; Endovascular treatment; Coil; Embolization; Subarachnoid hemorrhage; Intraoperative complication; Aneurysm, ruptured; Vasospasm

Lesion Patterns of Small Deep Infarcts Have Different Clinical and Imaging Characteristics

Background: The mechanisms underlying small deep infarcts in the subcortical area are unknown. This study used coronal diffusion-weighted imaging (DWI) to investigate clinical and radiological findings in patients with small deep infarcts. Methods: This was a retrospective study of consecutively admitted patients with small deep infarcts in the subcortical area. We divided the patients into two groups as follows: (1) those with isolated lesion (IL) defined as an IL in the parenchyma by coronal DWI (group A), and (2) those with linear lesion (LL), defined as a LL extending to the basal surface on coronal DWI (group B). Results: A total of 86 patients were included in this study, with 43 patients in each group. Neurological decline and ipsilateral MCA stenosis were observed more frequently in group B than in group A. Fluid-attenuated inversion recovery (FLAIR) signals showed that white-matter hyperintensity was more severe in group A than in group B (p = 0.015). Conclusions: This study suggests that LL patterns of small deep infarcts may result in a higher rate of neurological decline and ipsilateral MCA stenosis than IL patterns.

Ischemic stroke of the cortical “hand knob” area: stroke mechanisms and prognosis

Cortical ischemic stroke affecting the precentral "hand knob" area is a rare but well known stroke entity. To date, little is known about the underlying stroke mechanisms and the prognosis. Twenty-nine patients admitted to our service between 2003 and 2007 were included in the study on the basis of an acute ischemic infarct of the cortical "hand knob" area confirmed by diffusion-weighted magnetic resonance imaging with contralateral hand paresis. For all patients clinical, epidemiological as well as imaging data at the time point of admission were analysed retrospectively and follow-up data on all patients was obtained. The majority (n = 21/72%) had an isolated infarct of the cortical "hand knob" area. In 23 (79%) patients it was a first ever stroke. Ten patients (34%) had ipsilateral extracranial stenosis of the internal carotid artery (ICA), whereas potential cardiac embolic sources were less frequent (n = 4/14%). No patient exhibited ipsilateral MCA stenosis. All but two patients (93%) had marked atherosclerotic alterations of the ICA. Hypertension was the most prevalent vascular risk factor (n = 23/79%). At follow-up (mean 25.0 months, range 0.4-47.4 months) no patient had died and only one (3%) experienced a recurrent stroke. The majority of patients (79%) reported improvement of hand paresis, 17 (59%) were asymptomatic (modified Rankin score = 0). Only one patient was significantly disabled due to a recurrent stroke. In conclusion, ischemic infarcts affecting the cortical "hand knob" area are frequently associated with atherosclerotic changes of the carotid artery, suggesting an arterio-arterial thrombembolic stroke mechanism. It mostly reflects first ever ischemic stroke, and follow-up data suggest a rather benign course.

Endovascular Treatment of Primitive Persistent Trigeminal Artery Aneurysm Associated with Middle Cerebral Artery Aneurysm

We report the case of a primitive trigeminal artery aneurysm associated with an ipsilateral middle cerebral artery aneurysm. A 64-year-old Caucasian woman suffered from a severe acute headache. A head CT scan displayed subarachnoid hemorrhage and subsequent cerebral angiography showed right, wide-necked persistent trigeminal artery and ipsilateral middle cerebral artery aneurysms. The patient underwent embolization of both aneurysms with Guglielmi detachable coils. The association of a PPTA aneurysm and an ipsilateral MCA aneurysm has not been reported in the English literature.

Hemodynamic changes in ipsi- and contralateral cerebral arterial territories after carotid endarterectomy using positron emission tomography

Background The purpose of this study was to characterize ipsi- and contralateral cerebral hemodynamics before and after CEA. Methods Cerebral blood flow, CBV, and MVTT were measured in 10 patients before and after CEA using PET. Absolute and relative values of these parameters were calculated bilaterally for the entire arterial territories and hemispheres. Results For all territories in both hemispheres, the mean absolute postoperative CBF was significantly increased compared with preoperative CBF ( P < .05). Only in MCA was this increase higher in the ipsilateral than in the contralateral hemisphere ( P = .02). Cerebral blood volume was unaffected, whereas MVTT decreased in ipsilateral MCA ( P = .05). Conclusions The present findings suggest that, on the first day after CEA, absolute CBF is increased in all arterial territories on both ipsi- and contralateral sides, but that there are only minor changes in the relative distribution, whereas the CBV was unaffected.

TCD Evaluation before and after Stenting in Patients with Severe Primary Carotid Artery Stenosis versus Restenosis

To evaluate cerebral hemodynamics before and after carotid angioplasty and stenting (CAS) using transcranial Doppler (TCD). Sixty-eight patients (52 men; mean age 69+/-9.5 years) with severe carotid stenosis (83.4%+/-10.2%) were examined by TCD before and 2 months after CAS. Thirty-two (47%) patients had primary carotid stenosis and 36 (53%) had restenosis after carotid endarterectomy (CEA). A broad TCD protocol was employed to estimate cerebral hemodynamics, including assessment of velocities (V) and asymmetry of cerebral blood flow velocity (CBFV) in the middle cerebral artery, (MCA) anterior cerebral artery (ACA), and basilar artery (BA); the pulsatility indexes; and flow acceleration. Ipsilateral MCA mean velocities before stenting were 46.3+/-12.6 cm/s in the primary stenosis group and 47.1+/-12.3 cm/s in restenosis group; after stenting, the velocities were 53.8+/-12.1 and 52.7+/-9.6 cm/s, respectively (p<0.005 for both groups). MCA asymmetry by Vmean before CAS was higher in the primary stenosis group (27.6%+/-2.4% versus 19.8%+/-2.3%, p<0.05). After stenting, this index was significantly lower in both groups: 16.4%+/-2.4% and 12.3%+/-2.3%, respectively (p<0.0001 for each group). All other TCD parameters improved significantly in both groups after CAS as well (p<0.05), showing the strong hemodynamic effect of this procedure. CAS effectively improves cerebral hemodynamics in patients with severe primary and restenosis of the internal carotid artery.

TCD Evaluation Before and After Stenting in Patients With Severe Primary Carotid Artery Stenosis Versus Restenosis

PURPOSE To evaluate cerebral hemodynamics before and after carotid angioplasty and stenting (CAS) using transcranial Doppler (TCD). METHODS Sixty-eight patients (52 men; mean age 69+/-9.5 years) with severe carotid stenosis (83.4%+/-10.2%) were examined by TCD before and 2 months after CAS. Thirty-two (47%) patients had primary carotid stenosis and 36 (53%) had restenosis after carotid endarterectomy (CEA). A broad TCD protocol was employed to estimate cerebral hemodynamics, including assessment of velocities (V) and asymmetry of cerebral blood flow velocity (CBFV) in the middle cerebral artery, (MCA) anterior cerebral artery (ACA), and basilar artery (BA); the pulsatility indexes; and flow acceleration. RESULTS Ipsilateral MCA mean velocities before stenting were 46.3+/-12.6 cm/s in the primary stenosis group and 47.1+/-12.3 cm/s in restenosis group; after stenting, the velocities were 53.8+/-12.1 and 52.7+/-9.6 cm/s, respectively (p<0.005 for both groups). MCA asymmetry by Vmean before CAS was higher in the primary stenosis group (27.6%+/-2.4% versus 19.8%+/-2.3%, p<0.05). After stenting, this index was significantly lower in both groups: 16.4%+/-2.4% and 12.3%+/-2.3%, respectively (p<0.0001 for each group). All other TCD parameters improved significantly in both groups after CAS as well (p<0.05), showing the strong hemodynamic effect of this procedure. CONCLUSION CAS effectively improves cerebral hemodynamics in patients with severe primary and restenosis of the internal carotid artery.

Position statement on the coverage of anticonvulsant drugs for the treatment of epilepsy

<h3>Introduction/purpose</h3> Flow-diverting Pipeline stents are commonly used for endovascular treatment of cerebral aneurysms but can be associated with delayed ipsilateral intracerebral hemorrhage. Although intra-aneurysmal hemodynamic changes have been studied, parent vessel and intracranial hemodynamics after Pipeline stenting are unknown. Here, we examine the impact of Pipeline stenting on parent artery and distal intracranial hemodynamics. <h3>Materials and methods</h3> Records of patients with internal carotid cerebral aneurysms treated with Pipeline stenting at our institution were retrospectively reviewed. Patients were included if flows were obtained after stenting using quantitative magnetic resonance angiography. Flow volume rate and mean, systolic, and diastolic flow velocities were measured in the internal carotid artery (ICA, cervical segment) and middle cerebral artery (MCA, M1 segment). Pulsatility index [(systolic - diastolic flow velocity)/mean flow velocity], resistance index [(systolic - diastolic flow velocity)/systolic flow velocity], and wall shear stress (WSS) were calculated for each vessel. Means were compared between ipsilateral and contralateral ICA and MCA using two-tailed Wilcoxon signed-rank tests. <h3>Results</h3> Nine patients were included, mean age 51 years. All aneurysms were located in the cavernous or paraclinoid segments of the ICA. Within the parent vessel, mean flow velocity (18.1 vs. 23.4 cm/s, <i>P = 0</i>.04) and diastolic velocity (15.4 vs. 20.2 cm/s, <i>P = 0</i>.04) were significantly lower than in the &nbsp;contralateral ICA, and systolic velocity was also lower (20.8 vs. 26.9 cm/s, <i>P = 0</i>.06) but not as significantly (Figure 1A). These lower flow velocities were accompanied by higher, although non-significant, pulsatility (0.31 vs. 0.29, <i>P = 0</i>.93) and resistance indices (0.26 vs. 0.25, <i>P = 0</i>.87) and slightly lower flow (248.1 vs. 277.6 mL/min, <i>P = 0</i>.61) in the parent vessel. In the ipsilateral MCA, however, pulsatility (0.19 vs. 0.30, <i>P = 0</i>.06) and resistance indices (0.17 vs. 0.25, <i>P = 0</i>.04) were significantly lower, and flow higher (152.1 vs. 135.6 mL/min, <i>P = 0</i>.17), than in the contralateral MCA (Figure 1B). These lower resistances were accompanied by a higher trend in ipsilateral versus contralateral MCA mean flow velocity (29.9 vs. 26.8 cm/s, <i>P = 0</i>.37), systolic velocity (32.9 vs. 31.3 cm/s, <i>P = 0</i>.86), diastolic velocity (27.3 vs. 23.5 cm/s, <i>P = 0</i>.17), and WSS (26.8 vs. 23.9 dynes/cm², <i>P = 0</i>.44). <h3>Conclusion</h3> After Pipeline stenting, there appears to be alteration in the elasticity of the stented ICA segment, with significantly lower flow velocities in the ipsilateral versus contralateral ICA. Conversely, there was an increase in flow velocities and WSS and significantly lower resistance in the ipsilateral MCA, suggesting the possible role of altered distal hemodynamics in delayed ipsilateral hemorrhages. <h3>Disclosures</h3> S. Shakur: None. V. Aletich: None. S. Amin-Hanjani: None. F. Charbel: None. A. Alaraj: None.

Patterns of core and penumbra in acute MI occlusion and their clinical correlates

P51 Background and Purpose: The ischemic penumbra is composed of neurons that are functionally impaired but structurally intact, and thus potentially salvageable. Identifying the penumbra and its relationship with the ischemic core may lead to a more physiologic selection of patients who might benefit from recanalization therapy. We sought to explore the core/penumbra relationship by quantitatively measuring cerebral blood flow (CBF) in patients with acute M1 occlusion. Methods: 19 patients with M1 occlusion proven by CT angiography or conventional cerebral angiography underwent a Xe-CT/CBF study within 6 hours of symptoms onset. Mean CBF values were measured in the ipsilateral cortical MCA territory. The core was defined as areas with CBF&lt; 8 ml/100g/min and the penumbra was defined as areas with CBF 9–20 ml/100g/min. Findings were correlated with the admission NIH stroke scale (NIHSS). Results: In 6/19 patients (31.5%)(group 1), the size of the penumbra was greater than twice the size of the core. In 8/19 patients (42.1%) (group 2), the size of the penumbra was approximately equal the size of the core. In 5/19 patients (26.8%)(group 3) the size of the penumbra was less than half the size of the core. The median core volumes for each of the three groups, expressed as percentage of core relative to ipsilateral cortical MCA territory, increased from group 1 to group 3. While there was a trend towards a correlation between the admission NIHSS and the combined core and penumbral volumes, no such correlation could be established between admission NIHSS and core or penumbral volumes alone. Conclusions: In the first 6 hours after M1 occlusion, penumbral volumes that are larger than or equal to core volumes are present in 14 out of 19 patients. A smaller core volume is associated with an increased penumbra to core ratio. The admission NIHSS in patients with M1 occlusion correlates with the combined volumes of core and penumbra.

Ipsilateral activation of the unaffected motor cortex in patients with hemiparetic stroke

Background and purpose: Recent research has shown that following stroke patients can display ipsilateral activity reflecting a functional link between the undamaged hemisphere and the affected upper limb on the same side of the body. In the present study the capacity for ipsilateral activation is documented during recovery by using transcranial magnetic stimulation (TMS) and transcranial Doppler (TCD). Methods: Fourteen patients affected by hemispheric stroke were examined with TMS and TCD within 48 h of onset, and again 6 months later. Neurological signs were scored with reference to the NIHSS, and patients executed a thumb to finger opposition task so as to further estimate the motor deficit. Twenty healthy volunteers represented the control population. Results: (1) Both TMS and TCD yielded homogeneous results showing ipsilateral activity between affected hands and undamaged hemispheres. On stimulating the motor cortex 3 cm anterior and 3 cm lateral to Cz, a scalp site remote from the primary motor area, ipsilateral motor evoked potentials (iMEPs) from hand muscles were found in recovered patients. (2) In 8 controls iMEPs with smaller amplitudes than patients could be obtained by stimulating only the left hemisphere. (3) TCD revealed increased blood flow velocity in the ipsilateral MCA by activating the recovering hand (10.5±3.3%; P<0.001). Conclusion: TMS reveals a specific area in the motor cortex from which ipsilateral MEPs can be elicited and both TMS and TCD indicate that an ipsilateral corticospinal tract can be accessible in some adult controls or becomes unmasked after cerebral damage.

Patterns of core and penumbra in acute MI occlusion and their clinical correlates

P51 Background and Purpose: The ischemic penumbra is composed of neurons that are functionally impaired but structurally intact, and thus potentially salvageable. Identifying the penumbra and its relationship with the ischemic core may lead to a more physiologic selection of patients who might benefit from recanalization therapy. We sought to explore the core/penumbra relationship by quantitatively measuring cerebral blood flow (CBF) in patients with acute M1 occlusion. Methods: 19 patients with M1 occlusion proven by CT angiography or conventional cerebral angiography underwent a Xe-CT/CBF study within 6 hours of symptoms onset. Mean CBF values were measured in the ipsilateral cortical MCA territory. The core was defined as areas with CBF Results: In 6/19 patients (31.5%)(group 1), the size of the penumbra was greater than twice the size of the core. In 8/19 patients (42.1%) (group 2), the size of the penumbra was approximately equal the size of the core. In 5/19 patients (26.8%)(group 3) the size of the penumbra was less than half the size of the core. The median core volumes for each of the three groups, expressed as percentage of core relative to ipsilateral cortical MCA territory, increased from group 1 to group 3. While there was a trend towards a correlation between the admission NIHSS and the combined core and penumbral volumes, no such correlation could be established between admission NIHSS and core or penumbral volumes alone. Conclusions: In the first 6 hours after M1 occlusion, penumbral volumes that are larger than or equal to core volumes are present in 14 out of 19 patients. A smaller core volume is associated with an increased penumbra to core ratio. The admission NIHSS in patients with M1 occlusion correlates with the combined volumes of core and penumbra.

Three-dimensional measurement of cerebral microvascular plasma perfusion, glial fibrillary acidic protein and microtubule associated protein-2 immunoreactivity after embolic stroke in rats: a double fluorescent labeled laser-scanning confocal microscopic study

Early astroglial response to post-ischemic microvascular hypoperfusion may contribute to progressive cerebral microcirculatory impairment and ischemic neuronal injury. Using laser-scanning confocal microscopy and three fluorescent probes, we measured in three-dimensions cerebral microvascular plasma perfusion, astrocytic reactivity, and neuronal injury assessed by fluorescein isothiocyanate (FITC)-dextran, GFAP immunoreactivity, and microtubule associated protein-2 (MAP2) immunoreactivity, respectively, in rats subjected to 2 h of middle cerebral artery occlusion. Three-dimensional quantitative analysis revealed that 2 h of embolic ischemia resulted in a significant ( P<0.05) reduction of cerebral microvascular plasma perfusion in the ipsilateral cortex and subcortex. Tissue within the ipsilateral cortex and subcortex with low plasma perfusion exhibited a significant ( P<0.05) increase in GFAP immunoreactivity compared with the homologous contralateral tissue. Three-dimensional re-constructed images showed that prominent GFAP immunoreactive astrocytes surrounded large vessels with decreased plasma perfusion in downstream capillaries in the ipsilateral MCA territory when compared to the vessels in the contralateral homologous tissue. Triple fluorescence probe-stained sections showed that tissue with decreased plasma perfusion and with increased GFAP immunoreactivity was accompanied by a reduction of MAP2 immunoreactivity. The present study demonstrates that an impairment of microvascular perfusion induces an early increase in GFAP immunoreactivity, and reactive astrocytes may contribute to a further reduction of cerebral microvascular plasma perfusion. The three-dimensional quantitative imaging analysis used in the present study provides a means to investigate parenchymal cellular responses to changes of cerebral microvascular plasma perfusion after MCA occlusion.

Carotid angioplasty and stenting in high-risk patients

BACKGROUND To examine our initial experience in carotid stenting (CS) for the prevention of stroke in patients with high-grade carotid stenoses. METHODS The authors performed 26 CS procedures in 25 carotid vessels in 22 patients over a 15-month period. All carotid stenoses treated, except one, were 70% or greater. Of all CS procedures, 84% were performed for obstructing atherosclerotic plaques. CS was performed in one patient each for carotid dissection and pseudoaneurysms caused by a gunshot wound, post-radiation stenosis, post-carotid endarterectomy (CEA) restenosis, and a flow-obstructing post-CEA intimal flap. Of all patients, 68.2% were symptomatic, with a history of stroke or transient ischemic attacks ipsilateral to the treated carotid artery. In addition, 36.4% of our patients were either hospitalized or required skilled nursing care before CS because of severe neurologic deficits. Using the Sundt CEA-risk classification system, 59.1% of our patients were classified as Grade III and 40.9% were Grade IV pre-CS. All but one patient had either a compelling medical or anatomic reason for endovascular treatment of their carotid disease. We used both Wallstents and Palmaz stents, and all procedures were performed via the transfemoral route. Three procedures were performed in conjunction with detachable platinum coil embolization for multiple carotid pseudoaneurysms, a residual carotid “stump” after previous ICA thrombosis, and an ipsilateral MCA saccular aneurysm. RESULTS We had a 96.2% procedural technical success rate. There was one death in our series 3 weeks post-CS attributable to myocardial infarction. Despite a high 30-day combined death, stroke, and ipsilateral blindness rate of 27.3% (6/22 patients), only two ipsilateral strokes directly related to CS occurred (7.7% per procedures performed) from which one patient recovered fully within 5 days. The average follow-up post-CS was 5.9 months (range, 3 weeks–15 months). Of successfully treated vessels, 58.3% have undergone 6-month follow-up vascular imaging, which has revealed a 14.3% rate of occlusion or restenosis greater than 50%. At or beyond 1 month post-CS, 19 of 21 surviving patients (90.5%) were ambulatory, fluent of speech, and independent, and none has thus far suffered a delayed stroke or TIA. CONCLUSION CS seems to be a reasonable alternative to medical management for the treatment of carotid disease in patients deemed to be poor candidates for standard carotid surgery. Longer term follow-up is necessary to assess the durability of carotid revascularization using CS.

巨大動脈瘤に対する総頸動脈即時結紮腋窩動脈-中大脳動脈皮質枝間介在伏在静脈バイパスグラフトの1応用例

Recently combined ligation of ICA and STA-MCA anastomosis has become the treatment of choice for unclippable giant aneurysms of the ICA. However, ischemic complications have been reported in 10-25% of the cases that underwent this procedure, because of the limited flow provided by the STA-MCA bypass and of thrombo-embolic ischemia originating from the stump of the occluded ICA and thrombosing aneurysm.An interposed long saphenous vein bypass graft was utilized between the axillary artery and the angular branch of the middle cerebral artery instead of STA-MCA anastomosis to treat a patient with an unclippable giant aneurysm of the cavernous portion of the right ICA combined with acute ligation of CCA. Ten minute manual compression of the right CCA developed neither abnormality of EEG nor ischemic symptoms. Angiography also demonstrated a good cross-filling of the ipsilateral carotid region. However, a SPECT subtraction study revealed 70% reduction of flow in the ipsilateral MCA region by manual compression of the right carotid artery. Intraoperative measurement of the flow through the vein graft was 80ml/min. CCA ligated acutely on the third postoperative day after the patency of the vein graft bypass was assured. A postoperative angiogram revealed that the giant aneurysm was thrombosed successfully. There was a good filling of the left MCA territory through the graft and ACA through the anterior communicating artery from the contralateral circulation. Thus the ICA giant aneurysm was isolated, trapped and thrombosed. The postoperative SPECT study revealed a normal CBF at rest in both hemispheres. By compressing the vein graft bypass, 60% reduction of CBF in the MCA territory was demonstrated in the subtraction image of the SPECT. A three year follow-up revealed good patency of the vein graft with no ischemic symptoms.Acute ligation of CCA provides less chance of emboly, and a vein graft bypass from the axillary artery can provide an immediate postoperative high flow without carrying thrombi from the ICA stump. The giant aneurysm of the intracranial ICA is isolated from ipsilateral cerebral circulation. Thus, both hemodynamic and thrombo-embolic ischemia can be avoided.