Temporal Artery-middle Cerebral Artery Bypass Research Articles

Treatment of pediatric ischemia moyamoya disease by direct bypass combined with multiple burr hole

To investigate the treatment outcome of superficial temporal artery-middle cerebral artery bypass (STA-MCA) combined with multiple burr hole (MB) in pediatric ischemia moyamoya disease. A total of 31 pediatric patients with ischemic moyamoya disease who were admitted to Beijing Tiantan hospital from 2010 to 2013 were divided into two groups which were STA-MCA + MB surgery group (n = 16) and STA-MCA surgery only group (n = 15). In all patients, the number of patients with symptom improvement was 24 (77.4%), the number of patients with no symptom improvement was 5 (16.1%) and with symptom deterioration was 2 (6.5%). The postoperative modified rankin scale (mRS) in STA-MCA + MB group was significantly lower than that in STA-MCA group (P < 0.05). The treatment outcome of STA-MCA combined with MB is superior to STA-MCA bypass surgery only and doesn't increase the incidence of complication.

Apparent Diffusion Coefficient and Transient Neurological Deficit after Revascularization Surgery in Moyamoya Disease

Transient neurological deficits are relatively common after direct revascularization surgery for moyamoya disease (MMD). Although recent evidence has revealed the clinical features and pathophysiology, preoperative predictors have remained unclear. This study investigated whether the apparent diffusion coefficient (ADC) in normal-appearing white matter (NAWM) on magnetic resonance imaging could offer a predictor of postoperative transient neurological deficits. This study included adult patients with MMD who underwent superficial temporal artery-middle cerebral artery bypass. Preoperative ADCs were measured in NAWM on ipsilateral hemisphere. Single photon emission computed tomography (SPECT) with (123)I-iodoamphetamine was performed on postoperative days 2-6. Relationships between mean ADC and postoperative transient neurological deficits were assessed. Twenty of the 26 subjects (76.9%) experienced transient neurological deficits. Focal hyperemia on postoperative SPECT appeared in 11 of the 20 subjects with postoperative transient neurological deficits and 1 of the 6 subjects without (P=.12). Mean ADCs in patients with and without postoperative transient neurological deficits were 748.3±12mm(2)/second×10(-6) and 679.7±21.9mm(2)/second×10(-6), respectively (P=.0091). Preoperative ADC elevation in NAWM may indicate postoperative transient neurological deficits not only in patients with postoperative hyperemia on SPECT, but also in patients with this pathology.

Operation of superficial temporal artery-middle cerebral artery(STA-MCA)bypass combined with temporal muscle sticking therapy adult moyamoya disease

Objective To investigate the clinical effect of operation of superficial temporal artery-middle cerebral artery(STA-MCA)bypass combined with temporal muscle sticking in the treatment of adult moyamoya disease. Methods A retrospective analysis was the data of operation, including preoperative evaluation, operation method,postoperative follow-up. Results Postoperative complications occurred in 5 cases, including 3 cases of intracranial hemorrhage,2 cases of cerebral infarction. During the follow-up of 6-35 months, no recurrent hemorrhage cases,1 cases of cerebral infarction, TIA remission rate was 93.5%. Postoperative cerebral blood flow of 38 cases significantly improved compared with preoperative by SPET, accounted for 86.3%. Cerebral blood flow of 41 cases was well compensated by vascular bridge, accounted for 91%. Conclusion Operation of STA-MCA bypass combined with temporal muscle sticking can significantly reduce the incidence of stroke, fewer complications, which is an ideal method in the treatment of adult moyamoya disease. Key words: Moyamoya Disease; Surgical Procedures, Operative; Treatment Outcome

Improvement in cerebral hemodynamic parameters and outcomes after superficial temporal artery-middle cerebral artery bypass in patients with severe stenoocclusive disease of the intracranial internal carotid or middle cerebral arteries.

Both the older and the recent extracranial-intracranial (EC-IC) bypass trials for symptomatic carotid occlusion failed to demonstrate a reduction in stroke recurrence. However, the role of superficial temporal artery (STA)-middle cerebral artery (MCA) bypass in patients with symptomatic intracranial stenoocclusive disease has been rarely evaluated. The authors evaluated serial changes in various cerebral hemodynamic parameters in patients with severe stenoocclusive disease of the intracranial internal carotid artery (ICA) or middle cerebral artery (MCA) and impaired cerebral vasodilatory reserve (CVR), treated by STA-MCA bypass surgery or medical treatment. Patients with severe stenoocclusive disease of the intracranial ICA or MCA underwent transcranial Doppler (TCD) ultrasonography and CVR assessment using the breath-holding index (BHI). Patients with impaired BHI (< 0.69) were further evaluated with acetazolamide-challenge technitium-99m hexamethylpropyleneamine oxime ((99m)Tc HMPAO) SPECT. STA-MCA bypass surgery was offered to patients with impaired CVR on SPECT. All patients underwent TCD and SPECT at 4 ± 1 months and were followed up for cerebral ischemic events. A total of 112 patients were included. This total included 73 men, and the mean age of the entire study population was 56 years (range 23-78 years). (99m)Tc HMPAO SPECT demonstrated impaired CVR in 77 patients (69%). Of these 77 patients, 46 underwent STA-MCA bypass while 31 received best medical treatment. TCD and acetazolamide-challenge (99m)Tc HMPAO SPECT repeated at 4 ± 1 months showed significant improvement in the STA-MCA bypass group. During a mean follow-up of 34 months (range 18-39 months), only 6 (13%) of 46 patients in the bypass group developed cerebral ischemic events, as compared with 14 (45%) of 31 patients receiving medical therapy (absolute risk reduction 32%, p = 0.008). STA-MCA bypass surgery in carefully selected patients with symptomatic severe intracranial stenoocclusive disease of the intracranial ICA or MCA results in significant improvement in hemodynamic parameters and reduction in stroke recurrence.

Efficacy of extracranial-intracranial arterial bypass surgery for giant anterior circulation aneurysms

Objective To investigate the surgical methods and efficacy of extracranial-intracranial (EC-IC) arterial bypass surgery for the treatment of giant anterior circulation aneurysms. Methods The clinical data of 11 patients with giant anterior circulation aneurysm treated with EC-IC artery bypass surgery at Sichuan Province People's Hospital from March 2010 to June 2014 were analyzed retrospectively. The vascular patency assessment was conducted by CT angiography and digital subtraction angiography (DSA). The selection of graft vessels, surgical methods, and clinical effect were investigated. Results Seven patients used external carotid artery-great saphenous vein-middle cerebral artery M2 segment bypass, 2 used external carotid artery-radial artery-middle cerebral artery M2 segment bypass, and 2 used superficial temporal artery-middle cerebral artery M4 segment bypass. The grafted vessels were patent in 9 cases after procedure; the grafted vessels were occluded in 2 cases, and the proportion of vascular patency was 9: 11. One patient performed emergency superficial temporal artery-middle cerebral artery bypass, his blood vessel was occluded at day 3 after procedure. His contralateral limb was paralyzed after surgery and his muscle strength? was grade Ⅲ. One patient had vascular occlusion? at 6 months after surgery,? and he did not have any symptoms of nerve? function? defect. The follow-up period ranged from 6 months to 51 months (mean 18.3 months). The Glasgow outcome scale scores at 6 months after surgery: 10 patients were good (4-5), 1 was poor (3), and no patients died. Conclusions EC-IC arterial bypass surgery is a safe and effective method for the treatment of giant anterior circulation aneurysms. The detailed and individualized treatment scheme may improve the surgical results. Key words: Intracranial aneurysm; Cerebral revascularization; Anterior circulation

Abstract 74: Improvement in Cerebral Hemodynamic Parameters and Outcome after Superficial Temporal Artery- Middle Cerebral Artery Bypass in Patients with Severe Steno-occlusive Disease of Intracranial Carotid and Middle Cerebral Artery

Background and Objective: Older and the recent extracranial-intracranial (EC/IC) bypass trials for symptomatic carotid occlusion failed to demonstrate reduction in stroke recurrence. However, role of superficial temporal artery-middle cerebral artery (STA-MCA) bypass in patients with symptomatic intracranial steno-occlusive disease has been evaluated scarcely. We evaluated serial changes in various cerebral hemodynamic parameters in patients with severe steno-occlusive disease of intracranial internal carotid (ICA) or middle cerebral artery (MCA) and impaired cerebral vasodilatory reserve (CVR), treated with STA-MCA bypass surgery or medical treatment. Methods: Patients with severe steno-occlusive disease of intracranial ICA or MCA underwent transcranial Doppler (TCD) ultrasonography and CVR assessment using breath-holding index (BHI). Patients with impaired BHI (&lt;0.69) were further evaluated with acetazolamide-challenged hexamethylpropyleneamine-oxime single-photon emission computed tomography (HMPAO-SPECT). STA-MCA bypass surgery was offered to patients with impaired CVR on SPECT. All patients underwent TCD and SPECT at 4±1 months and followed-up for cerebral ischemic events. Results: A total of 112patients (73males, mean age 56yrs; range 23-78yrs) were included. HMPAO-SPECT demonstrated impaired CVR in 77 (69%) patients. Of them, 46 underwent STA-MCA bypass while 31 received best medical treatment. TCD and acetazolamide-challenged HMPAO-SPECT repeated 4±1months showed significant improvement in STA-MCA bypass group. During follow-up (mean 34months; range 18-39months), only 6/46 (13%) patients in bypass group developed cerebral ischemic events as compared to 14/31 (45%) cases on medical therapy (absolute risk-reduction 32%, p=0.008). Conclusion: STA-MCA bypass surgery in carefully selected patients with symptomatic severe intracranial steno-occlusive disease results in significant improvement in hemodynamic parameters and reduction in stroke recurrence.

Surgical Revascularization During the Acute Phase of Stroke Caused by Near Occlusion of the Cervical Internal Carotid Artery

An 83-year-old woman was admitted with a diagnosis of transient symptoms with a left hemisphere infarction due to atherosclerosis. Despite the best medical treatments, her neurological symptoms gradually deteriorated. The color Doppler ultrasound (CDUS) and digital subtraction angiography (DSA) demonstrated a near occlusion of the left cervical internal carotid artery. Because the intracranial internal carotid artery (ICA) seemed patent on DSA, although CDUS also suggested that the intracranial ICA was also occluded, carotid endarterectomy was performed. However, magnetic resonance angiography performed immediately after the operation showed distal occlusion of the ICA. A superficial temporal artery-middle cerebral artery (MCA) bypass was performed immediately to rescue the region that was perfused by the MCA. The neurological symptoms stabilized after the operation. It is often difficult to assess the patency of the intracranial ICA by DSA if distal ICA flow is slow and faint. Although the pulsed Doppler waveform can be affected by the site of the distal occlusion, CDUS would be a good addition to the preoperative evaluation. And if the patency of the ICA distal to the stenosis cannot be confirmed, especially in emergent settings, a superficial temporal artery-MCA bypass can be a good treatment option.

特発性頚部内頚動脈解離5症例の臨床的検討

Spontaneous cervical arterial dissection (SCAD) is a non-traumatic tear or disruption in the walls of the internal carotid arteries. SCAD is the leading cause of stroke in patients <45 years of age, accounting for almost one-fourth of strokes in this population. However, standard criteria for its treatment have not been established. Therefore, we reviewed five cases of SCAD (four men, one woman; mean age 47.0 ± 12.7 years) treated between November 2009 and January 2013 to determine the appropriate treatment. Three patients had cerebral infarctions; of them, two underwent revascularization surgery. One was treated with superficial temporal artery-middle cerebral artery bypass (STA-MCA bypass) and ligation of the cervical internal carotid artery. The other was treated with radial artery grafted external carotid artery-MCA bypass and ligation of the cervical internal carotid artery. The other three patients were treated with conservative therapy, which included an antithrombotic agent in two. Only one patient was not treated with an antithrombotic agent because he had no cerebral ischemia. Of all patients, only one, who was treated with STA-MCA bypass and ligation of the cervical internal carotid artery, progressed to cerebral ischemia. SCAD is reversible in most cases. Therefore, conservative therapy is recommended, except in cases of progressing hemodynamic ischemia and requirement of revascularization because there is no time for recovery.

もやもや病に対するSTA-MCA bypass術における局所脳血流量の定量的評価システムの開発

Transient neurological deterioration is relatively common after superficial temporal artery-middle cerebral artery bypass surgery for the treatment of moyamoya disease. Evaluation of postoperative cerebral blood flow (CBF) indicated that these symptoms could be associated with hemodynamic alteration. To prevent permanent neurological damage, timely and adequate management of this status is required. However, there is currently no intraoperative evaluation system to predict transient neurological deterioration in the postoperative period. Therefore, in this preliminary study, we evaluated quantitative cortical blood flow using indocyanine green videoangiography, ultrasonic blood flowmeter, and a dedicated software in a case of moyamoya disease. As a result, substantial increase of focal cortical blood flow was calculated by the software. However, no postoperative neurological deterioration was observed, and the postoperative CBF evaluation showed no hyperemia or ischemic status. This system might be useful; however, further evaluation is essential.

クラニアルアプローチ法による浅側頭動脈－中大脳動脈バイパス術後の開口による浅側頭動脈血流の評価

クラニアルアプローチ法による浅側頭動脈－中大脳動脈バイパス術後の開口による浅側頭動脈血流の評価

The therapeutic effect of superficial temporal artery-middle cerebral artery bypass in the treatment of Moyamoya disease

Objective To evaluate the therapeutic effect of superficial temporal artery-middle cerebral artery(STA-MCA) bypass in the treatment of Moyamoya disease.Methods From April 2009 to June 2013,STAMCA bypass operatioas were performed in 28 patients (15 females/13 males,age 6-49 years) with Moyamoya disease.The frontal and parital branches of the superficial temporal artery were separated under the microscope,then anastomosed with the M3 or M4 segment of middle cerebral artery.All clinical and radiological data were retrospectively reviewed.Results All of the operations were successful.Postoperative CT angiography or DSA imaging demonstrated patency of the bypass in all patients.CT perfusion obviously demonstrated improvement of cerebral perfusion.The ischemic symptoms were relieved in most of the patients.3 patients suffered transient ischemic attack (TIA).In 4 patients,the incision showed small amount of exudate and wound healing delayed.During the follow-up period,no cerebral homorrhage or infarction was observed.Conclusion This study showed that the superficial temporal artery-middle cerebral artery bypass could achieve good therapeutic effect in the treatment of Moyamoya disease during the short-term follow-up,but its long-term outcome needs further study. Key words: Moyamoya disease; Superficial temporal artery-middle cerebral artery bypass; Treatment outcome

Early postoperative infarction out of the middle cerebral artery distribution following superficial temporal artery-middle cerebral artery bypass: clinical features and pathogenesis

Early postoperative infarction out of the middle cerebral artery distribution following superficial temporal artery-middle cerebral artery bypass: clinical features and pathogenesis

Factors associated with delayed intracerebral hemorrhage after superficial temporal artery-middle cerebral artery bypass in steno-occlusive cerebrovascular diseases

Background Intra-cerebral hemorrhage (ICH) is a devastating complication that can result from superficial temporal artery-middle cerebral artery (STA-MCA) bypass in patients undergoing treatment for steno-occlusive cerebrovascular disease (CVD). There is a clinical need to find the possible risk factors to prevent ICH, as it is a significant cause of mortality and morbidity. The aim of the study was to investigate the factors associated with delayed ICH after STA-MCA bypass in patients with steno-occlusive CVDs. Methods We retrospectively analyzed the records of 163 patients seen from 2002 to 2011 with STA-MCA bypass for steno-occlusive cerebrovascular diseases at the Department of Neurosurgery, Xuan Wu Hospital, Beijing. Demographic and clinical data, including age, gender, vascular risk factors, preoperative syndrome, preoperative National Institutes of Health Stroke Scale (NIHSS), ipsilateral ischemic lesions, classification of steno-occlusive CVDs, donor branches of STA, graft patency, postoperative hypertension, and postoperative-increased MCA velocity were recorded and analyzed. Binary Logistic regression served to identify factors associated with delayed ICH after STA-MCA bypass. Results We identified 8 (4.9%) patients with delayed ICH after STA-MCA bypass. Patients with hypertension, preoperative stroke, ipsilateral ischemic lesions, postoperative hypertension and postoperative-increased MCA velocity were significantly more prone to experiencing delayed ICH after STA-MCA bypass. Logistic regression analysis shows ipsilateral ischemic lesions, postoperative hypertension, and postoperative-increased MCA velocity remained independent predictors for delayed ICH after STA-MCA bypass. Conclusion Despite the varied associated factors in patients with steno-occlusive CVDs, ipsilateral ischemic lesions, postoperative hypertension, and postoperative-increased MCA velocity could be associated with delayed ICH after STA-MCA bypass.

Abstract T MP26: Role of 99tc-hmpao Spect in the Assessment of Cerebral Hemodynamic Parameters After Superficial Temporal Artery- Middle Cerebral Artery Bypass in Patients With Severe Steno-Occlusive Disease of Intracranial Carotid and Middle Cerebral Artery

Background and Objective: Although superficial temporal artery-middle cerebral artery (STA-MCA) bypass surgery in patients with symptomatic carotid occlusion failed to demonstrate any benefit, its role in symptomatic intracranial steno-occlusive disease has been evaluated scarcely. We evaluated changes in hemodynamic parameters in patients with severe steno-occlusive disease of intracranial internal carotid (ICA) or middle cerebral artery (MCA) who underwent STA-MCA bypass for impaired cerebral vasodilatory reserve (CVR). Methods: Patients with severe steno-occlusive disease of intracranial ICA or MCA underwent transcranial Doppler (TCD) evaluation and CVR assessment using breath-holding index (BHI). Patients with impaired BHI (&lt;0.69) were further evaluated with acetazolamide-challenged 99Tc-HMPAO-SPECT. STA-MCA bypass surgery was offered to patients with impaired CVR on SPECT. TCD and SPECT were repeated in all patients at 4±1 months and they were followed-up for cerebral ischemic events. Results: Of the 126 patients (80 male, mean age 56yrs; range 23-78yrs) that fulfilled our inclusion criteria, 84 (67%) showed impaired CVR HMPAO-SPECT. Fifty (60%) of them underwent STA-MCA bypass while 34(40%) received best medical treatment. TCD and acetazolamide-challenged HMPAO-SPECT repeated 4±1 months after surgery showed significant improvement in STA-MCA bypass group. TCD BHI improved from a median (IQR) of -0.05 to 1.1 (p&lt;0.001). Compared to 98% patients with impaired CVR on pre-operative SPECT, only 20% showed abnormal results on post-operative imaging (p&lt;0.001). During follow-up (mean 35 months; range 8 to 49months), only 6/50 (12%) patients in bypass group developed cerebral ischemic events as compared to15/34 (44%) cases on medical therapy (absolute risk reduction 32%, p=0.006). Conclusion: 99Tc-HMPAO SPECT with acetazolamide challenge is a reliable tool for the assessment of cerebral vasodilatory reserve in patients with severe steno-occlusive disease of intracranial ICA or MCA. STA-MCA bypass surgery in carefully selected patients results in significant improvement in hemodynamic parameters and reduction in stroke recurrence.

The efficacy of superficial temporal artery-middle cerebral artery bypass in treatment of athero-occlusive cerebrovascular disease: a single center experience

The efficacy of superficial temporal artery-middle cerebral artery bypass in treatment of athero-occlusive cerebrovascular disease: a single center experience

Preliminary study of neurocognitive dysfunction in adult moyamoya disease and improvement after superficial temporal artery-middle cerebral artery bypass.

ObjectiveMoyamoya disease (MMD) is a chronic cerebrovascular occlusive disease of unknown etiology. In addition, the neurocognitive impairment of adults with MMD is infrequently reported and, to date, has not been well described. We attempted to determine both the neurocognitive profile of adult moyamoya disease and whether a superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis can improve the neurocognitive impairment in exhibiting hemodynamic disturbance without stroke.MethodsFrom September 2010 through November 2012, 12 patients with angiographically diagnosed MMD underwent STA-MCA anastomosis for hemodynamic impairment. Patients with hypoperfusion and impaired cerebrovascular reserve (CVR) capacity but without evidence of ischemic stroke underwent a cognitive function test, the Seoul Neuropsychological Screening Battery (SNSB). Five patients agreed to undergo a follow-up SNSB test. Data from preoperative and postoperative neurocognitive function tests were compared and analyzed.ResultsFive of 12 patients were enrolled. The median age was 45 years (range, 24-55 years). A comparison of preoperative to postoperative status of SNSB, memory domain, especially delayed recall showed significant improvement. Although most of the domains showed improvement after surgery, the results were not statistically significant.ConclusionIn our preliminary study, large proportions of adult patients with MMD demonstrate disruption of cognitive function. This suggests the possibility of chronic hypoperfusion as a primary cause of the neurocognitive impairment. When preoperative and postoperative status of cognitive function was compared, memory domain showed remarkable improvement. Although further study is needed, neurocognitive impairment may be an indication for earlier intervention with reperfusion procedures that can improve cognitive function.

Occlusion of M1 segment after superficial temporal artery-middle cerebral artery bypass in a giant M1 aneurysm with Onyx-34 injected via a double-lumen balloon under balloon inflation

A 29-year-old patient attended our institution for recurrent strokes related to a giant partially thrombosed M1 aneurysm. Superficial temporal artery-middle cerebral artery (STA-MCA) bypass and subsequent occlusion of both the...

Perfusion-Weighted Magnetic Resonance Imaging Used in Assessing Hemodynamics following Superficial Temporal Artery-Middle Cerebral Artery Bypass in Patients with Moyamoya Disease

Background: The best strategy to assess the changes in brain hemodynamics following superficial temporal artery (STA)-middle cerebral artery (MCA) bypass in patients with Moyamoya disease remains unknown. The purpose of the present study was to assess cerebral hemodynamics using perfusion-weighted magnetic resonance imaging (PWI) before and after STA-MCA bypass surgery in patients with Moyamoya disease. Methods: STA-MCA bypass surgeries were performed on 23 symptomatic cerebral hemispheres in 21 patients (11 females/10 males, age 11-62 years) with Moyamoya disease due to cerebral ischemic attacks or intracranial hemorrhages. Brain PWI images were obtained in the frontal lobes, the temporal lobes, the occipital lobes, and the basal ganglia before and after STA-MCA bypass surgery. The relative parameters cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) derived from PWI were calculated. All patients underwent CT angiography or MR angiography after surgery in order to confirm the patency of bypass. Results: According to preoperative PWI, there was significant hypoperfusion in the symptomatic temporal and frontal lobes. According to postoperative PWI, the regional CBF had increased in both the temporal and frontal lobes on the operative side (p < 0.05, versus preoperative data). In the postoperative CBV maps, there was a significant decrease in the occipital lobe on the operative side (p < 0.05, versus preoperative data). The postoperative MTT in the temporal lobe, frontal lobe and basal ganglia area on the operative side was short, relative to the preoperative MTT (p < 0.05). The CT angiography or MR angiography imaging demonstrated patency of the bypass in all patients after surgery. During the follow-up period, all patients showed significant improvement in neurological function postoperatively. Conclusions: This study demonstrates that STA-MCA bypass is a safe and effective surgical treatment for Moyamoya disease. PWI enables an effective and objective assessment of hemodynamics before and after STA-MCA bypass surgery in patients with Moyamoya disease.

Moyamoya Associated with Down Syndrome: Management Strategies

Introduction: We describe four patients with Down syndrome and moyamoya who were referred for possible cerebral revascularization. The unique features associated with these cases are presented. Methods: A retrospective case review of all inpatient and outpatient records and neuroimaging studies was performed. Results: Three of the four patients were women; all had bilateral moyamoya. Ages ranged from 18 to 34 years. One patient presented with repeated transient ischemic episodes (TIAs) despite antiplatelet therapy. One had repeated “spells” that mimicked complex partial seizures, but seizure activity could not be demonstrated on electroencephalogram. One patient presented with a minor stroke, and the final patient presented with headaches only with no evidence of ischemia. Superficial temporal artery-middle cerebral artery (STA-MCA) bypass was performed in two patients, bilateral in one. One patient underwent bilateral pial synangiosis procedures. One patient was managed with aspirin alone. Conclusions: Down syndrome may be associated with moyamoya. Patients with Down syndrome who develop symptoms of cerebral ischemia should be evaluated for this condition. Cerebral revascularization may be warranted in selected cases, and results have been favorable in these patients.

Cerebral Hyperperfusion Syndrome After Superficial Temporal Artery-middle Cerebral Artery Bypass for Severe Intracranial Steno-occlusive Disease

Intracranial stenoses carry increased risk for cerebral ischemia. We perform external carotid-internal carotid (EC-IC) artery bypass in our patients with severe stenosis of the intracranial internal carotid (ICA) or middle cerebral artery (MCA) with impaired cerebral vasodilatory reserve (CVR). To evaluate cerebral hemodynamics and cerebral hyperperfusion syndrome (HPS) in patients who develop focal neurological deficits after EC-IC bypass surgery. Patients with severe intracranial ICA or MCA stenosis and impaired CVR on transcranial Doppler (TCD) derived breath-holding index (BHI) were evaluated with acetazolamide-challenged technetium-99m hexamethylpropyleneamineoxime-single-photon emission computed tomography (SPECT). EC-IC bypass surgery was offered to patients with impaired CVR on SPECT. Close monitoring was performed in patients developing focal neurological deficits within 7 days of surgery. Of 112 patients with severe intracranial ICA/MCA stenosis, 77 (69%) showed impaired CVR and 46 (41%) underwent EC-IC bypass. Transient neurological deficits within 7 days of surgery developed in 8 (17%). HPS was confirmed by CT perfusion and/or SPECT in 7 cases. A strong correlation was observed between HPS and preoperative TCD-BHI values (0%, 6.3%, and 41% in patients with BHI 0.3-0.69, 0-0.3 and <0, respectively; P = .012). HPS patients showed more than a 50% increase in MCA flow velocity on TCD (compared with preoperative values) on the operated side (63.3% vs 3.3% on control side, P < .001). Meticulous control of blood pressure and hydration led to rapid and complete resolution of neurological deficits in all cases. Symptomatic cerebral HPS is common in the early postoperative period after EC-IC bypass surgery. Early diagnosis and appropriate management might prevent the complications of this syndrome.