Byeong Hoon Lim

Emergency carotid artery stenting in patients with acute ischemic stroke due to occlusion or stenosis of the proximal internal carotid artery: a single-center experience

Background The feasibility, safety and effectiveness of emergency carotid artery stenting (eCAS) in patients with acute ischemic stroke (AIS) due to proximal internal carotid artery (ICA) stenosis or occlusion are still controversial. In this study we analyzed our experience with eCAS in patients with AIS. Methods Twenty-two eCAS procedures for proximal ICA stenosis or occlusion were performed in 22 patients at our institution between January 2011 and November 2013. The mean time from stroke symptom onset to presentation was 204 min (range 50–630 min) and the mean initial score on the National Institutes of Health Stroke Scale (NIHSS) was 12.55 (range 5–23). Ten patients had total occlusion of the proximal ICA and the remaining 12 patients had near total occlusion or severe stenosis (mean degree 90.7%, range 80–100%). Eleven patients also had tandem occlusion on the more distal intracranial arteries. Results Successful stent insertion was achieved in all patients and additional thrombectomy using a Solitaire stent or Penumbra aspiration catheter achieved a Thrombolysis In Cerebral Infarction grade of more than 2a in all patients with distal tandem occlusion. Procedure-related complications occurred in one patient (cerebral hyperperfusion syndrome) who recovered successfully. The mean NIHSS score at discharge was 3.55 (range 0–18). The mean modified Rankin Scale score at 3 months was 1±1.67 (range 0–6). Conclusions eCAS in patients with AIS due to proximal ICA stenosis or occlusion appears to be a technically feasible and effective method for achieving good clinical outcomes.

Comparison of Solitaire thrombectomy and Penumbra suction thrombectomy in patients with acute ischemic stroke caused by basilar artery occlusion

Background and purpose Acute ischemic stroke (AIS) caused by basilar artery occlusion (BAO) is a very severe neurological disease with a high mortality rate and poor clinical outcomes. In this study, we compared our experience of mechanical thrombectomy using the Solitaire stent (Solitaire thrombectomy) and manual aspiration thrombectomy using the Penumbra reperfusion catheter (Penumbra suction thrombectomy) in patients with AIS caused by BAO. Materials and methods Between March 2011 and December 2011, 13 patients received Solitaire thrombectomy. In January 2012, the Korean Food and Drug Administration banned the use of the Solitaire stent as a thrombectomy device, and a further 18 patients received Penumbra suction thrombectomy until December 2013. We compared parameters between patients treated with each device. Results Successful recanalization rates (Thrombolysis in Cerebral Infarction (TICI) score ≥2b: 84.6% vs 100%, p=0.168) and clinical outcomes (judged by the modified Rankin Scale scores recorded at 3 months: 3.6±2.6 vs 3.2±2.6, p=0.726) were not significantly different between the two groups. However, complete recanalization rates (TICI score of 3: 23.1% vs 72.2%, p=0.015) and total procedure times (101.9±41.4 vs 62.3±34.8 min, p=0.044) were significantly higher, and shorter, respectively, in patients treated by Penumbra suction thrombectomy. Conclusions The two thrombectomy devices were associated with similar recanalization rates and clinical outcomes in patients with AIS caused by BAO. However, Penumbra suction thrombectomy seemed to allow more rapid and complete recanalization than Solitaire thrombectomy.

Carotid artery stenting in patients with near occlusion: a single-center experience and comparison with recent studies.

OBJECTIVE The optimal management strategy for carotid artery near occlusion is still controversial. Nevertheless, prior studies about carotid artery stenting in patients with near occlusion reported both technically and clinically inspiring results. To define the effectiveness, safety, and clinical outcomes of carotid artery stenting in patients with near occlusion, we analyzed our experiences and compared with recent studies. METHODS We performed 24 carotid artery stenting procedures in 24 patients with near occlusion between January 2010 and July 2012. The patient group comprised 20 men (83.3%) and four women (16.7%) with a mean age of 69.5 years (range, 53-85 years). Eighteen patients had prior stroke or transient ischemic attack (75%), and six patients were asymptomatic (25%). RESULTS Successful stent insertion was achieved in 23 of 24 patients (95.8%). Cerebral hyperperfusion syndrome and post-procedural vascular events occurred in four patients, and all of these developed within 24h after the procedure (17.4%; two: hyperperfusion syndrome, two: acute myocardial infarction). The mean follow-up period after carotid artery stenting was 16.7±9.2 months (range, 6-32 months). No stroke related to carotid artery stenting or significant restenosis of the inserted stent developed during the follow-up period. CONCLUSIONS Carotid artery stenting in patients with near occlusion seems to be a technically feasible and effective method to prevent stroke recurrence. But hyperperfusion syndrome and post-procedural vascular event rates may be high, as shown in this study.

A case of spontaneous spinal epidural hematoma mimicking a stroke.

Introduction:For intravenous (IV) thrombolytic therapies to be effective, a correct diagnosis of acute ischemic stroke must be made within 3 hours from the onset of symptoms, a relatively short window period. However, obtaining a diagnosis in the time frame is not easy; a wide variety of conditions mimic a stroke, including seizures, migraine, and even a spinal mass, and often these are diagnosed as acute ischemic stroke and receive thrombolytic therapy. Case Report:A patient presented suffering progressive and fluctuating painful triparesis coupled with acute onset dissociated sensory loss. The patient complained of dysarthria and transient altered mentality at the onset of symptoms; therefore, we suspected an ischemic infarction of the brainstem and spinal cord accompanied by vertebral artery dissection. As the time at diagnosis was 2 hours 30 minutes after symptom onset, we started IV thrombolytic treatment using recombinant tissue plasminogen activator. Magnetic resonance imaging during the recombinant tissue plasminogen activator infusion revealed a spontaneous spinal epidural hematoma (SSEH) of the cervical and thoracic spine, leading the patient to undergo an emergency surgery. Conclusions:SSEH is an uncommon clinical condition, and a manifestation of SSEH with anterior spinal artery syndrome is also rare. Furthermore, an emergency operation after IV thrombolytic treatment is an extraordinary situation.

MRI in Tolosa‐Hunt Syndrome Associated With Facial Nerve Palsy

A 44‐year‐old woman developed a severe right frontotemporal headache, retro‐orbital pain, and, later, diplopia owing to right sixth nerve palsy. The brain MRI demonstrated strong enhancement of the right cavernous sinus. The sixth nerve palsy and headache improved with steroid therapy after 6 weeks. At that time, she suffered right peripheral facial nerve palsy. Enhancement of the distal canalicular and labyrinthic segment of the right facial nerve was found on contrast‐enhanced MRI. To our knowledge, this is a very rare case of Tolosa‐Hunt syndrome with facial nerve palsy, with simultaneous enhancement of the cavernous sinus and facial nerve on contrast‐enhanced MRI.

Teaching NeuroImages: Glossopharyngeal neuralgia with syncope Heart rate and blood pressure change

A 53-year-old man was admitted for recurrent syncope. For 2 years he had experienced a severe paroxysmal stabbing pain in the left oropharynx, starting at the submandibular area and then radiating to …

Initial factors affecting the clinical outcome after successful recanalization via MR-based mechanical thrombectomy in patients with acute ischemic stroke due to basilar artery occlusion

Background and purpose To determine the initial factors, including patient characteristics, stroke etiology and severity, time factors, and imaging findings, that could affect the clinical outcome of patients with acute ischemic stroke (AIS) caused by basilar artery occlusion (BAO) where successful recanalization was achieved via mechanical thrombectomy. Methods Between March 2011 and December 2014, 35 patients with AIS caused by BAO received MRI/MR angiography-based mechanical thrombectomies, and recanalization was achieved with a Thrombolysis In Cerebral Infarction score of >2b. The patients were divided into a good outcome group (n=19), defined as those with a modified Rankin Scale (mRS) score of 0–2 at 3 months after stroke onset, and a poor outcome group (n=16), defined as a mRS score of 3–6. The differences between the groups were analyzed. Results Initial National Institutes of Health Stroke Scale (NIHSS) score (good vs poor: 17.9±8.9 vs 27.6±8.5, p=0.003), posterior circulation Acute Stroke Prognosis Early CT Score (pc-ASPECTS) based on initial diffusion-weighted images (DWI) (good vs poor: 7.8±1.6 vs 5.4±1.8, p=0.001), pc-ASPECTS based on contrast staining on the post-thrombectomy control CT (good vs poor: 9.2±1.5 vs 6.3±2.2, p<0.001), and presence of contrast staining in the brainstem on that CT (good vs poor: 15.8% vs 81.6%, p<0.001) were significantly different between the groups. Conclusions Patients with AIS caused by BAO with a lower initial NIHSS score, fewer lesions on initial DWI, and less contrast staining on the post-thrombectomy control CT have higher probabilities of a good clinical outcome after successful recanalization via a mechanical thrombectomy.

Serial Magnetic Resonance Images of a Right Middle Cerebral Artery Infarction : Persistent Hyperintensity on Diffusion-Weighted MRI Over 8 Months

A lesion that is hyperintense on diffusion-weighted imaging (DWI) and hypointense on the apparent diffusion coefficient (ADC) map is a characteristic magnetic resonance imaging (MRI) finding in acute ischemic infarction. In some cases, however, these findings can persist for a few months after infarct onset. It is thought that these finding reflect the different evolution speeds of the infarcted tissue. We report a patient with a right middle cerebral artery territory infarction with persistent hyperintensity on DWI and hypointensity on the ADC map for over 8 months. To our knowledge, this is the most persistent case of hyperintensity lesion on DWI and the serial MRI images of this patient provide important information on the evolution of infarcted tissue.

Relationship between Hyperventilation-Induced Electroencephalographic Changes and PCO2 Level.

Background and Purpose: We conducted this study to define the relationship between the hyperventilation-induced EEG changes (HV-EEG changes) and PCO2 Methods: In consecutive EEG recordings of 190 patients, we gathered data on PCO2 during the hyperventilation procedure. The data included baseline PCO2 (B-PCO2), PCO2 after 5 min of hyperventilation (5 min-PCO2), the mean value of the PCO2 (M-PCO2), and the difference between B-PCO2 and 5 min-PCO2 (ΔPCO2). We divided the enrolled patients into two groups by hyperventilation response (response group and no-response group), presence of epilepsy (epileptic group and non-epileptic group) and age (child-adolescent group and adult group) repeatedly. We compared the four variables between the two groups in each pair. Results: ΔPCO2 was 14.2±5.0 mmHg (mean±SD) in response group (n=48) and 12.4±5.0 in no-response group (n=142; p=0.033) for all the patients. For adult patients only, 5 min-PCO2 was 24.3±3.4 in response group (n=30) and 26.2±4.6 in no-response group (n=115; p=0.048), and ΔPCO2 was 15.8±4.0 and 12.9±5.0, respectively (p=0.004). In non-epileptic patients, 5min-PCO2 was 23.4±2.2 in response group (n=7) and 26.3±3.8 in no-response group (n=44; p=0.026), and ΔPCO2 was 15.9±4.3 and 12.7±3.9, respectively (p=0.053). Conclusions: In adults and non-epileptic patients, ΔPCO2 and 5 min-PCO2 may be crucial to the induction of EEG changes by hyperventilation. PCO2 could be a crucial factor for provoking HV-EEG changes in a limited group of patients.

Atorvastatin pretreatment attenuates kainic acid-induced hippocampal neuronal death via regulation of lipocalin-2-associated neuroinflammation

Statins mediate vascular protection and reduce the prevalence of cardiovascular diseases. Recent work indicates that statins have anticonvulsive effects in the brain; however, little is known about the precise mechanism for its protective effect in kainic acid (KA)-induced seizures. Here, we investigated the protective effects of atorvastatin pretreatment on KA-induced neuroinflammation and hippocampal cell death. Mice were treated via intragastric administration of atorvastatin for 7 days, injected with KA, and then sacrificed after 24 h. We observed that atorvastatin pretreatment reduced KA-induced seizure activity, hippocampal cell death, and neuroinflammation. Atorvastatin pretreatment also inhibited KA-induced lipocalin-2 expression in the hippocampus and attenuated KA-induced hippocampal cyclooxygenase-2 expression and glial activation. Moreover, AKT phosphorylation in KA-treated hippocampus was inhibited by atorvastatin pretreatment. These findings suggest that atorvastatin pretreatment may protect hippocampal neurons during seizures by controlling lipocalin-2-associated neuroinflammation.