Initial Magnetic Resonance Angiography Research Articles

Perimesencephalic Subarachnoid Hemorrhage in Pregnancy: A Case Report

Abstract Perimesencephalic subarachnoid hemorrhage (P-SAH) is a benign subset of subarachnoid hemorrhage. Only two cases of P-SAH during pregnancy have been reported in the literature. We describe a case of P-SAH detected at 29 weeks’ gestation, arose with severe bilateral frontal headache, neck rigidity, and vomiting. A diagnosis of P-SAH was confirmed on magnetic resonance angiography with no evidence of vascular malformation or bleeding sources and conservatively treated. Hemorrhage, vasospasm, and cerebellar edema observed on initial magnetic resonance angiography resolved after two months. The clinical course of P-SAH during pregnancy appears to be favorable. Our case shows for the first time in literature that magnetic resonance angiography is a valid diagnostic test for P-SAH during pregnancy that circumvents radiological risk associated with conventional imaging.

A thread of hope for successful revascularization for acute embolic basilar artery occlusion due to miserable vertebral artery stump syndrome. A technical report

Acute basilar artery occlusion (BAO) is associated with major morbidities and a high mortality rate. The prevalence of acute BAO is 10.4% among patients treated with thrombectomy for acute large vessel occlusion. Vertebral artery stump syndrome (VASS) reportedly causes ischemic stroke with tandem occlusions as vertebral artery (VA) origin occlusion and BAO. The pathogenesis of ischemic stroke due to VASS can be attributed to thrombi or emboli. Acute embolic BAO due to VASS accounted for 2 of 25 cases (8.0%) of BAO treated using thrombectomy between April 2014 and May 2019 in our registry. VASS must be considered as one cause of BAO. With the initial Magnetic resonance angiography on arrival, it is difficult to distinguish between BAO due to simple cardiogenic embolus and due to embolus caused by VASS rapidly. In patients suffering from acute embolic BAO due to VASS, the presence of VA origin occlusion makes endovascular therapy (EVT) difficult to perform. Here, we report consecutive cases of thrombectomy for acute embolic BAO due to VASS, showing markedly different outcomes. VA origin occlusion severely limits the technical options for EVT. Visualization or conjecture of the origin of both or dominant VAs conceivably offers the possibility of successful EVT and may allow good outcomes.

Subarachnoid hemorrhage due to de novo dissecting vertebral artery aneurysm in a patient with Guillain‐Barré syndrome

AbstractA 51‐year‐old man with Guillain‐Barré syndrome developed a dissecting vertebral artery aneurysm. Initial magnetic resonance angiography showed no abnormality, including dissecting aneurysm of the bilateral vertebral arteries. He developed subarachnoid hemorrhage. Radiological examination revealed bilateral dissecting vertebral artery aneurysms. The left ruptured dissecting vertebral artery aneurysm was treated by stent‐assisted coil embolization with preservation of the affected vertebral artery. Although it is rare, there is a possibility that dissection of the intracranial artery might occur in a patient with Guillain‐Barré syndrome in a short period of time. The dissecting aneurysm might be formed by external force to the vertebral artery, and the aneurysm might subsequently rupture due to hypertension.

Rescue Stenting Using Neuroform Atlas Stent During Coiling Protrusion for Ruptured Intracranial Aneurysms

Endovascular coiling is generally considered as an effective treatment option for ruptured intracranial aneurysms. Increasing operator experience and quality of tools determined an improvement of endovascular cerebral aneurysms' treatment. However, procedure-related complications still occur. The purpose of this study is to report a series of rescue stenting procedures with the Neuroform Atlas (NA) open-cell stent, for intraprocedural complications during coil embolization in patients with ruptured intracranial aneurysms. Between April 2016 and January 2018, 12 consecutive coil protrusions that occurred during ruptured aneurysms' embolizations were rescued using NA stenting together with tirofiban therapy. Follow-up was performed with initial magnetic resonance angiography (MRA) at 1 month and then MRA plus standard digital subtraction angiography at 11-13 months after the procedure. Technical success was achieved in 100% of patients. No NA stent delivery/deployment complication occurred. Initial MRA showed complete occlusion of the aneurysm, with evidence of blood flow into parent vessels in 12 out of 12 cases. At 11-13 months, MRA and digital subtraction angiography showed 10 complete occlusion cases and 1 partial occlusion case. At 2 months, 1 death occurred due to subarachnoid hemorrhage. The open-cell NA stent represents a rescue option for coil protrusion during endovascular treatment of ruptured intracranial aneurysms allowing regular restoration of blood flow and minimizing thromboembolic events.

Comparison of Rates of Growth between Unruptured and Ruptured Aneurysms Using Magnetic Resonance Angiography

Growth is a key risk factor for rupture of unruptured cerebral aneurysms. There are few reports of investigations into the actual growth of ruptured intracranial aneurysms. The aim of the present study was to ascertain the risk of rupture of aneurysms based on the growth of unruptured and ruptured aneurysms. Changes in size on magnetic resonance angiography (MRA) were examined in 50 patients with ruptured cerebral aneurysms. Images obtained before and after subarachnoid hemorrhage were used. Moreover, changes in aneurysm size were retrospectively examined in 73 patients with 100 unruptured cerebral aneurysms that were followed serially with MRA that was performed using a 1.5-T or 3-T system. The size of the aneurysm was determined by measuring the maximum diameter on maximum intensity projection MRA images. Based on these data, the annual growth rates (mm growth/year) of unruptured and ruptured aneurysms were calculated and compared. The median annual growth rate of ruptured aneurysms was significantly greater than that of unruptured aneurysms (.69 versus .077 mm/year, P < .01). The annual growth rates of ruptured aneurysms showed a negative correlation between the duration from initial MRA to the time of rupture. A high annual growth rate is a key risk factor for aneurysm rupture. This finding provides strong evidence for the treatment of unruptured cerebral aneurysms.

Diagnosis of vertebral artery dissection in childhood posterior circulation arterial ischaemic stroke.

Review a series of children with posterior circulation arterial ischaemic stroke (PCAIS) to identify diagnostic modality and associations in cases of vertebral artery dissection (VAD). Retrospective analysis of 30 cases of childhood PCAIS identified from two tertiary centres over 11 years. Clinical and demographic details were recorded. Brain and cerebrovascular imaging were reviewed. Aetiology was classified using the Childhood Arterial Ischaemic Stroke Standardized Classification and Diagnostic Evaluation criteria. Outcome was evaluated using standardized paediatric stroke outcome scores. Logistic regression was used to explore variables associated with diagnosis. Twenty-three patients were male (77%) and 7 were female (23%). VAD was the most commonly identified aetiology, in 15 cases (50%). Aetiology was undetermined in 12 (40%), probable cardioembolism in two, and reversible cerebral vasoconstriction syndrome in one. In those with VAD, diagnosis was made on initial magnetic resonance angiography (MRA) in six (40%). Further cases of VAD were diagnosed with catheter angiography (n=6), computed tomographic angiography (n=1), or follow-up MRA (n=2). Presence of multiple infarcts was associated with a diagnosis of VAD. Endoluminal cerebrovascular imaging increases the rate of diagnosis of VAD in childhood PCAIS and should especially be considered if there are multiple infarcts.

Isolated Posterior Inferior Cerebellar Artery Dissection as a Cause of Ischemic Stroke: Clinical Features and Prognosis

Background: The purpose of this study was to clarify the incidence, clinical and radiological features and outcomes of isolated posterior inferior cerebellar artery (PICA) dissection in isolated PICA territory infarctions. Methods: We retrospectively reviewed consecutive inpatients with ischemic stroke secondary to isolated PICA dissection from our stroke database between January 2004 and December 2013 and reviewed the literature with regard to those patients. Results: Of 167 consecutive patients with an isolated PICA territory infarction, a total of 10 patients (6.0%, 3 women, 48.1 ± 7.1 years) were diagnosed as having an isolated PICA dissection. Patients with PICA dissection were younger (p < 0.001), more commonly experienced headache at onset (p = 0.008), less commonly had hyperlipidemia (p = 0.044) and showed a lower modified Rankin Scale score at discharge (p = 0.002) when compared with patients without arterial dissection. In 6 of these 10 patients, PICA dissections had not been suspected on initial magnetic resonance angiography (MRA) and were confirmed by follow-up MRA or digital subtraction angiography. In the follow-up period (median 1.5 years, interquartile range 0.5-6.3 years), there were no recurrent ischemic or hemorrhagic stroke events. Conclusions: Isolated PICA dissection as an etiological mechanism in isolated PICA territory infarctions may be more common than was previously recognized to be. The diagnosis of PICA dissection is often difficult and requires close and repeated morphological evaluation. We should carefully identify PICA dissections as a possible cause of PICA territory infarctions.

Noninvasive Qureshi Grading Scheme Predicts 90-Day mRS in Patients with Acute Ischemic Stroke.

The Qureshi grading scheme is an effective classification system for evaluating the severity of acute arterial occlusion. However, this scheme is of limited utility because it is based on invasive angiography. In this study, we assessed whether a relationship between a noninvasive Qureshi score, based on magnetic resonance angiography (MRA) or computed tomography angiography (CTA), and 90-day functional outcome could be observed in patients with acute ischemic stroke. A stroke neurologist evaluated all patients with acute ischemic stroke who presented to the emergency room within 12 hour of symptom onset. Two neurologists independently assessed the noninvasive Qureshi score from initial MRA or CTA. We assessed the relationship between the noninvasive Qureshi grading scheme and clinical outcome on day 90. Of a total 125 patients, 75 underwent MRA and 50 underwent CTA. Interobserver reliability showed good agreement (κ = .62). The noninvasive Qureshi score for MRA or CTA and that for CTA alone were directly associated with a good 90-day functional outcome (odds ratio, .672; P = .016 and odds ratio, .511; P = .042). The noninvasive Qureshi scheme using MRA or CTA provides meaningful information about long-term functional outcomes in patients with acute ischemic stroke.

Factors Associated with Early Recanalization Failure following Intravenous rt-PA Therapy for Ischemic Stroke

Background: Although intravenous recombinant tissue-type plasminogen activator (rt-PA) therapy can be effective for ischemic stroke, a considerable percentage of patients do not receive any benefit as a result of early recanalization failure. We aimed to investigate the factors associated with early recanalization failure following intravenous rt-PA therapy. Methods: Patients with acute ischemic stroke and internal carotid artery (ICA) or middle cerebral artery occlusion on initial magnetic resonance angiography (MRA) who received intravenous rt-PA therapy within 3 h of stroke onset and underwent follow-up MRA within 8 h after treatment were enrolled. Baseline characteristics, stroke features, onset to treatment time, initial National Institutes of Health Stroke Scale (NIHSS) score, initial Alberta Stroke Programme Early CT Score on diffusion-weighted imaging-ASPECTS (Alberta Stroke Program Early Computed Tomography Score), the presence of ICA or M1 origin (the residual length <5 mm) (ICA/M1 origin occlusion), initial vital signs, and laboratory findings were recorded. Early recanalization on the follow-up MRA within 8 h was evaluated by modified Mori grade: grade 0, no reperfusion; grade 1, movement of thrombus; grade 2, partial recanalization, and grade 3, complete recanalization. Results: Seventy subjects (35 women, 77 ± 12 years) were enrolled. The median (interquartile range: IQR) NIHSS score was 18 (12.5-24), and the mean onset to treatment time was 141 ± 54 min. ICA was occluded in 29%, M1 origin in 17%, M1 middle in 13%, M1 distal in 26% and M2 in 15%. The median (IQR) pretreatment diffusion weighted imaging-ASPECTS was 8 (6-9), and follow-up time of MRA was 65 min (59-70) after rt-PA therapy. Thirty-two subjects (46%) showed modified Mori grade 0; 10 (14%), grade 1; 9 (13%), grade 2, and 19 (27%), grade 3. Multivariate analyses revealed ICA/M1 origin occlusion (OR 3.71, 95% CI 1.03-14.87, p = 0.044), and C-reactive protein (per 0.1-mg/dl increment, OR 1.19, 95% CI 1.03-1.44, p = 0.013) were independently associated with subjects with no recanalization (grade 0-1), whereas age (per years old, OR 0.93, 95% CI 0.86-0.99, p = 0.014) and high-density lipoprotein cholesterol (per 1-mg/dl increment, OR 0.94, 95% CI 0.89-0.98, p = 0.004) were inversely associated with those. Conclusion: ICA/M1 origin occlusion and C-reactive protein were positively and high-density lipoprotein cholesterol was negatively associated with early recanalization failure.

Bowhunter's Syndrome Diagnosed with Provocative Digital Subtraction Cerebral Angiography

Bowhunter's syndrome, also known as rotational occlusion of the vertebral artery, involves posterior circulation ischemia resulting from dynamic compromise of the dominant vertebral artery. This case highlights the importance of provocative digital subtraction angiography in making the diagnosis. A 41-year-old man presented for outpatient neurological evaluation for “lightheadedness” of several years' duration provoked by leftward head rotation. The only abnormality identified on initial magnetic resonance angiography was atresia of the nondominant left vertebral artery. Conventional digital subtraction angiography (DSA) followed by provocative DSA revealed development of a dynamic stenosis of the right vertebral artery involving the extraforaminal segment just superior to the C1 vertebra. Noncontrast computed tomography of the cervical spine confirmed ossification of the posterior right atlanto-occipital membrane leading to a near complete bony arcuate foramen. Following neurosurgical decompression, the patient demonstrated complete resolution of all neurologic symptoms. Bowhunter's syndrome is a unique clinical entity that must be considered in the evaluation of patients with symptoms of posterior circulation ischemia. Provocative DSA remains the preferred modality for definitive diagnosis.

Delayed Post-traumatic Pseudoaneurysmal Formation of the Intracranial Ophthalmic Artery After Closed Head Injury -Case Report-

A 42-year-old male presented with a rare case of delayed aneurysmal formation of the intracranial ophthalmic artery after closed head injury manifesting as subarachnoid hemorrhage. Initial magnetic resonance angiography revealed no aneurysmal formation, but angiography 7 days after the injury demonstrated an intracranial ophthalmic artery aneurysm. Follow-up computed tomography angiography demonstrated enlargement of the aneurysm. The aneurysm was successfully treated by surgical resection. Histological examination revealed that the aneurysm was a pseudoaneurysm. Traumatic intracranial aneurysm (TICA) is rare and usually occurs in the peripheral arteries of the cerebral circulation or the basal portion of the internal carotid artery. The present case shows that failure to demonstrate an aneurysm on the initial angiography in the acute stage does not exclude the presence of traumatic aneurysm. This case clearly shows the time course of development of a TICA of the ophthalmic artery after closed head injury.

Magnetic Resonance Angiography Detection of Vascular Aneurysms in Patients With Kawasaki Disease and Coronary Artery Aneurysms

Kawasaki disease is a systemic panvasculitis that causes coronary artery aneurysms in approximately 15% to 25% of untreated patients. Systemic vascular aneurysms may also occur in medium-sized arteries throughout the body and may lead to increased morbidity and mortality in patients with Kawasaki disease. We report a case of diffuse systemic aneurysm formation in a 2-year-old patient with Kawasaki disease with coronary artery aneurysms. Full-body magnetic resonance angiography (MRA) imaging was utilized both in the acute phase and again prior to cardiac catheterization performed at 6 months from the acute illness. The initial MRA detected aneurysmal dilatation of the common and internal iliac arteries bilaterally in the acute phase. Subsequent MRA performed prior to cardiac catheterization 6 months later demonstrated resolution of the iliac artery lesions. Full-body MRA may be useful in screening for associated systemic vascular aneurysms in patients with Kawasaki disease and associated coronary artery aneurysms.

Magnetic resonance angiography in reversible cerebral vasoconstriction syndromes

To investigate the evolution and clinical significance of vasoconstriction on magnetic resonance angiography (MRA) in patients with reversible cerebral vasoconstriction syndromes (RCVS). Patients with RCVS were recruited and followed up with MRA examinations until normalization of vasoconstriction or for 6 months. The vasoconstriction severity of the major cerebral arterial segments (M1, M2, A1, A2, P1, P2, and basilar artery) was scored on a 5-point scale: 0 (0-<10%), 1 (10-<25%), 2 (25-<50%), 3 (50-<75%), and 4 (> or =75%). Subjects with at least 1 segment with a vasoconstriction score > or =2 were eligible for the study. Initial mean scores of single or combined arterial segments were used to predict ischemic complications. Seventy-seven patients with RCVS (8 men/69 women; average age 47.7 +/- 11.6 years) finished the study with a total of 225 MRAs performed. The mean number of arterial segments involved was 5.3 +/- 3.0 in the initial MRA. Vasoconstriction scores reached their maximum 16.3 +/- 10.2 days after headache onset, close to the average timing of headache resolution (16.7 +/- 8.6 days). Vasoconstriction evolved in a parallel trend among different arterial segments. Seven (9.1%) patients developed posterior reversible encephalopathy syndromes (PRES). Six (7.8%) patients had ischemic stroke. A logistic regression model demonstrated that the M1-P2 combined score was associated with highest risk of PRES (odds ratio [OR], 11.6, p = 0.005) and ischemic stroke (OR, 3.4; p = 0.026). MRA evaluation in patients with RCVS is valid. Vasoconstriction was pervasive and outlasted headache resolution. Vasoconstrictions in M1 and P2 are important determinants for PRES and ischemic stroke.

Syndrome de vasoconstriction cérébrale réversible

Reversible cerebral vasoconstriction syndrome (RCVS) is more frequent than previously thought and is probably underdiagnosed. The mean age of onset is 42 years, and it affects slightly more women than men. RCVS is attributed to a transient, reversible dysregulation of cerebral vascular tone, which leads to multifocal arterial constriction and dilation. More than half the cases (60%) are secondary to exposure to vasoactive substances (e.g., cannabis, antidepressants, and nasal decongestants) or occur in the postpartum period. RCVS has a characteristic clinical and radiological course, developing in a single phase after a sudden onset, and there is generally no new event after 1 month. The main pattern of presentation begins with recurrent thunderclap headaches, often triggered by sexual activity or various Valsalva's maneuvers, over a period of 1 to 3 weeks. Seizures and focal neurological deficits are less frequent and generally start after the headaches. Cortical subarachnoid hemorrhage (22%), intracerebral hemorrhage (6%), seizures (3%), and reversible posterior leukoencephalopathy (9%) are early complications, occurring mainly within the first week. Ischemic events, including TIAs (16%) and cerebral infarction (4%), occur significantly later than hemorrhagic strokes, mainly during the second week. Diagnosis requires the demonstration of the characteristic "string and beads" on cerebral angiography and can be difficult, for 21% of patients have a normal initial magnetic resonance angiography (MRA) and 9% both a normal MRA and a normal transcranial Doppler. In these cases, the initial investigations must be repeated after a few days. The final diagnosis is made when a follow-up MRA shows resolution or at least marked improvement of the arterial abnormalities within 12 weeks. RCVS is sometimes associated with other large artery lesions of the head and neck, including dissections and unruptured aneurysms, especially during the postpartum period. Nimodipine is the treatment most often recommended. In our experience, it is not especially effective in severe RCVS. Relapses are possible but rare and have not yet been reported in prospective series. Although the exact pathophysiology remains speculative, strong recommendations against vasoactive substances appear prudent.

Early Recanalization Rate of Major Occluded Brain Arteries after Intravenous Tissue Plasminogen Activator Therapy Using Serial Magnetic Resonance Angiography Studies

Purpose: The present study investigated early recanalization rate of major occluded arteries after tissue plasminogen activator (t-PA) infusion using serial magnetic resonance angiography (MRA) studies. Methods: Consecutive stroke patients treated with t-PA within 3 h of onset were prospectively studied. Four serial MRA studies were conducted: before, immediately, 24 h and 5–7 days after t-PA infusion. Results: Initial MRA demonstrated occluded brain arteries in 64 patients: M1 occlusion, 30 patients; M2, 12, and internal carotid artery (ICA), 22. Combining M1 and M2 occlusion, the recanalization rates (complete and partial) were 52.3% (19.0 and 33.3%) within 1 h, 80.9% (47.6 and 33.3%) at 24 h and 87.8% (73.2 and 14.6%) 7 days after t-PA infusion. However, the recanalization rate of ICA occlusion was 31.8% (4.5 and 27.3%) within 1 h, 51.1% (14.3 and 47.6%) at 24 h and 66.7% (38.9 and 27.8%) 7 days after t-PA infusion. Complete recanalization rate at 24 h and 7 days was lower in ICA occlusion than M1 and M2 occlusion (p = 0.014 and p = 0.016). Conclusion: Within 1 h after t-PA infusion, approximately half the patients with major arteries occlusion had early recanalization. ICA occlusion is resistant to intravenous t-PA therapy compared with middle cerebral artery occlusion.

Recanalization between 1 and 24 hours after t-PA therapy is a strong predictor of cerebral hemorrhage in acute ischemic stroke patients

Intravenous administration of tissue plasminogen activator (t-PA) can improve clinical outcomes in patients with acute ischemic stroke. The most important complication of t-PA therapy is intracerebral hemorrhage (ICH). The aim of this study was to use serial MRI studies to identify independent predictors of symptomatic and asymptomatic ICH after t-PA therapy. Consecutive anterior-circulation ischemic stroke patients treated with t-PA within 3 h of stroke onset were studied prospectively. To identify the presence of recanalization in the occluded arteries and the presence of ICH, MRI, including diffusion weighted imaging (DWI), T2*, and magnetic resonance angiography (MRA), was performed before and 1 h, 24 h, and 5-7 days after t-PA thrombolysis. The independent predictors of ICH were determined using multivariate logistic regression analysis. 41 patients (21 males, 20 females; mean age, 73.2+/-10.7 years) were enrolled, and 19 ICHs (1 symptomatic, 18 asymptomatic) were observed on T2*. The initial MRA demonstrated occluded brain arteries in 31 patients (75.6%), of which follow-up MRA at 1 h, 24 h, and 5-7 days after t-PA therapy revealed recanalization in 48.4%, 80.0%, and 90.0% of patients, respectively. The frequency of recanalization within 1 h after t-PA therapy did not differ between ICH and No-ICH groups, but the ICH group had more frequent recanalization between 1 h and 24 h after t-PA than the No-ICH group (50.0% vs. 4.5%, P=0.001). The ICH group had arterial fibrillation (AF) more frequently than the No-ICH group (78.9% vs. 27.3%, P=0.001). Compared to the No-ICH group, the NIHSS score was higher (16.4+/-5.7 vs. 11.5+/-6.5, P=0.011) and the ASPECTS-DWI value (a normal DWI has an ASPECTS-DWI value of 11 points) was lower (7.3+/-2.4 vs. 8.9+/-1.9, P=0.019) in the ICH group. Multivariate logistic regression analysis demonstrated that the presence of recanalization between 1 and 24 h after the end of t-PA infusion (OR: 20.2; CI: 1.0-340.9; P=0.037) was the only independent predictor of ICH. Recanalization of occluded arteries between 1 and 24 h but not within 1 h after t-PA infusion should be independently associated with symptomatic and asymptomatic ICH after t-PA therapy.

Atrial fibrillation as an independent predictor for no early recanalization after IV-t-PA in acute ischemic stroke

Intravenous administration of tissue plasminogen activator (t-PA) dissolves the clot and can improve clinical outcome in patients with acute ischemic stroke. However, lack of early recanalization frequently does not result in good outcome. We prospectively studied acute stroke patients treated with t-PA and examined clinical factors associated with no early recanalization of occluded arteries after t-PA administration using serial magnetic resonance angiography (MRA). NIHSS score was obtained before and at 24h after t-PA administration. Subjects comprised 49 consecutive stroke patients treated with t-PA. Initial MRA before t-PA infusion demonstrated occluded arteries in 37 patients. Of the 37 occluded arteries, follow-up MRA within 30min after t-PA administration revealed complete recanalization in 6 patients, partial recanalization in 12, and no early recanalization in 19. Neurological worsening (total NIHSS score increased by > or =4) occurred in 0 of 18 patients with recanalization and 4 of 19 patients with no recanalization (P=0.039). Atrial fibrillation (AF) and hypertension were more frequent in patients with non-early recanalization than in patients with recanalization (73.7% vs. 38.9%, P=0.03; 73.6% vs. 38.9%, P=0.03, respectively). However, no differences were observed in other clinical factors between groups. Multivariate logistic regression analysis demonstrated AF (OR: 9.3; CI: 1.5-55.8, P=0.015) as the only independent factor associated with no recanalization. No early recanalization after t-PA administration was observed in 51.4% of acute stroke patients with occluded arteries and was significantly associated with neurological worsening. AF was independently associated with no recanalization after t-PA administration.

Factors Affecting the Angiographic Recanalization and Early Clinical Improvement in Middle Cerebral Artery Territory Infarction After Thrombolysis

Factors affecting the angiographic recanalization (AR) and clinical improvement (CI) still remain unclear in patients receiving thrombolytic therapy. To elucidate factors related to AR and early CI in patients with middle cerebral artery (MCA) or internal carotid artery (ICA) occlusion. Retrospective study. Department of Neurology, Asan Medical Center, Seoul, South Korea. We studied 42 patients who (1) underwent diffusion-weighted magnetic resonance (MR) imaging and MR angiography within 6 hours after onset, (2) had MCA territory infarction, (3) had nonvisualization of the MCA or the ICA on initial MR angiography, (4) were treated with thrombolytics, and (5) underwent follow-up MR imaging and MR angiography at day 2 or 3. Successful AR and CI were achieved in 31 and 16 patients, respectively. Angiographic recanalization was related to CI (P<.01), lower follow-up National Institutes of Health Stroke Scale scores (P<.05), the absence of a dominant ipsilateral posterior cerebral artery (P<.01) on initial MR angiography, and the sparing of the internal capsule on both initial (P<.05) and follow-up (P<.01) MR imaging. Clinical improvement was associated with the absence of ICA (vs MCA) flow signals (P<.05), the sparing of the internal capsule (P<.01), and marginally, with the infarct volume change (P = .06). In patients with MCA or ICA occlusion, CI after thrombolysis is related to the AR and the sparing of the critical motor pathway. The presence of a dominant ipsilateral posterior cerebral artery may predict poor AR after thrombolysis.

Early Detection of Cerebral Arterial Occlusion on Magnetic Resonance Angiography: Predictive Value of the Baseline NIHSS Score and Impact on Neurological Outcome

The presence of a thrombus on initial arteriography is directly related to the baseline NIHSS score. Magnetic resonance angiography (MRA) offers a noninvasive and rapid assessment of large cerebral vessel patency. We aimed at evaluating (1) the baseline NIHSS score as a tool for predicting the likelihood of an occluded artery on MRA and (2) the course of stroke within the first week according to the presence of a cerebral arterial occlusion. Patients were enrolled in this prospective study according to the following criteria: (1) acute cerebral ischemia with a neurological deficit lasting >1 h, and (2) brain MRI performed within 24 h of stroke onset. The NIHSS score assessment was performed on admission and at day 1 and day 7. The MRI protocol included: (1) T2-weighted Turbo spin echo, (2) echo-planar imaging isotropic diffusion, (3) T2*-gradient echo sequence, and (4) time of flight MRA (3D TOF Turbo MRA). The presence of a symptomatic cerebral arterial occlusion on MRA was systematically screened. Fifty-four patients were studied. Median age was 60 years. Mean time from stroke onset to NIHSS assessment was 170 ± 95 min. The mean baseline NIHSS score was 13.5 ± 7.3. The mean time from stroke onset to MRI was 384 ± 171 min. MRA was readable in 50 cases. An arterial occlusion was detected in 23 patients (46%). The median baseline NIHSS score was significantly higher in the group of patients with occlusion than in the group of patients without occlusion (18 vs. 7, p = 0.01). The predictive probability to demonstrate an arterial occlusion was related to the baseline NIHSS score. None of the patients with an NIHSS score of 1–6 (11 patients) had visible occlusion, whereas 9 (43%) out of 21 patients with an NIHSS score of 7–15 and 14 (78% ) out of 18 patients with an NIHSS score above 16 had an arterial occlusion. For an increase by one point in the NIHSS score, the odds ratio for the presence of occlusion was 1.28 (95% CI: 1.11–1.46). The course of the stroke as assessed by follow-up NIHSS score was significantly more severe if an occlusion was detected. Median day 0, day 1 and day 7 NIHSS score were, respectively, 18, 16 and 13 in patients who had an occlusion versus 7, 4 and 0 in patients who had no visible occlusion (p < 0.01). A direct relation between the baseline NIHSS score and the likelihood of the presence of an occlusion on initial MRA is demonstrated. The presence of a cerebral arterial occlusion on MRA is significantly linked to a poor neurological outcome.

Stroke and fibromuscular dysplasia: Confirmation by renal magnetic resonance angiography

Childhood stroke is uncommon and may require extensive evaluation to elucidate an underlying cause. A 9-year-old boy had clinical and magnetic resonance imaging (MRI) features of an ischemic event in the left middle cerebral artery territory. Magnetic resonance angiography (MRA) revealed beading of the left middle cerebral artery, consistent with irregular blood flow secondary to turbulence or luminal narrowing. Conventional angiography of the cerebral vessels confirmed the findings of cerebral MRA and raised further the suspicion of fibromuscular dysplasia (FMD). MRA of the renal vessels was subsequently performed, revealing beading of the left renal artery and confirming the diagnosis of FMD. MRA, a rapid and less invasive technique associated with far less morbidity and mortality as compared with conventional angiography, may prove to be as sensitive as conventional angiography in detecting the changes of FMD. MRA of the renal arteries should be performed with initial cranial MRI and MRA in children who present with cerebral infarction of possible vascular origin. This may obviate the need to perform further investigations and may make early diagnosis possible at the first MRI scan and under a single general anesthetic.