Improving the Prognosis of Patients With Acute Ischemic Stroke Treated in the Late Time Window After the Introduction of Advanced Imaging Software: Benefits From Thrombectomy in the Extended Time Window

Background@#Mechanical thrombectomy (MT) of ischemic stroke was recommended as a clinical guideline in 2015, and the indication for time was expanded in 2018 based on two clinical studies. We aimed to compare and analyze the prognosis of patients treated under the extended time indication before and after the introduction of advanced software. @*Methods@#We obtained data from medical records between 2016 to 2020. From 2016 to 2017, patients who did not receive MT who visited the hospital within 24 hours from the last normal time (LNT) were classified as standard medical treatment (SMT) group. Among patients who underwent MT between 2019 and 2020, patients who visited the hospital between 6-24 hours from the LNT were classified into the extended MT (EMT) group. Good outcome was defined as 3-months modified rankin scale (mRS) ≤ 2, and a poor outcome as mRS ≥ 4. @*Results@#From 2016 to 2017, 1,058 patients were hospitalized for ischemic stroke, of which 60 (5.7%) received MT, and 27 patients were classified into the SMT group. Among 1,019 patients between 2019 and 2020, 85 (8.3%) received MT, and 24 patients were in the EMT group. Among the SMT group, only 3 had a good prognosis, and 24 (88.9%) had a poor prognosis. However, in the EMT group, 10 (41.7%) had a good prognosis, and 9 (37.5%) had a poor prognosis. The SMT group had a 49.1 times higher risk of poor prognosis compared to the EMT group (P = 0.008). @*Conclusion@#The number of patients with ischemic stroke who receive MT has increased by using advanced imaging software. It was confirmed that patients treated based on the extended time indication also had a good prognosis.

Case of Moyamoya Disease Aggravated during the Treatment of Behçet’s Disease

Behçet’s disease (BD) is a multi-organ involved inflammatory disorder described by recurrent oral ulcers and other systemic manifestations. Almost all the clinical manifestations of BD are believed to be due to vasculitis. On the other hand, the cerebral arteries are rarely involved. Moyamoya disease (MMD) is an unusual chronic cerebrovascular disorder that is described by bilateral progressive stenosis or occlusion of the internal carotid artery and an abnormal collateral vascular network. A 32-year-old woman with MMD was referred for fever, oral pain, and diarrhea, and was diagnosed with BD. Her MMD was aggravated during treatment with high dose steroids to control the intestinal BD and a reduction in the MMD medication due to gastrointestinal bleeding. This is the first reported case of intestinal BD in a patient previously diagnosed with MMD, who experienced aggravation of her MMD after the cessation of MMD medication due to aggravated intestinal BD.

The Olfactory Groove Schwannoma Attached to the Cribriform Plate: A Case Report

The olfactory groove schwannoma is a quite rare tumor. We report a case of a 49-year-old woman with an olfactory groove schwannoma attached to the cribriform plate without olfactory dysfunction. She had no specific neurological symptoms other than a headache, and resection of the tumor showed it to be a schwannoma. About 19 months after the operation, a follow-up MRI showed no evidence of tumor recurrence. Surgical resection through subfrontal approach could be one of the curative modality in managing an olfactory groove schwannoma. An olfactory groove schwannoma should be considered in the differential diagnosis of anterior skull base tumors.

Solitary Fibrous Tumor of Central Nervous System: A Case Report

Solitary fibrous tumor (SFT) is a rare neoplasm of mesenchymal origin, especially in the central nervous system (CNS). Reported herein is a case of SFT of CNS in a 63-year-old female patient who had confused mentality, without other neurological deficit. The brain MRI showed an ovoid mass in the right frontal lobe. The tumor was surgically removed grossly and totally, and the pathologic diagnosis was SFT. At 55 months after the surgery, the tumor recurred at the primary site and at an adjacent area. A second operation was thus done, and the tumor was again surgically removed grossly and totally. The pathologic diagnosis was the same as the previous, but the Ki-67 index was elevated. Ten months later, two small recurring tumors in the right frontal skull base were found in the follow-up MRI. It was decided that radiation therapy be done, and MRI was done again 3 months later. In the follow-up MRI, the size of the recurring mass was found to have decreased, and the patient did not manifest any significant symptom. Follow-up will again be done 18 months after the second surgery.

Transvenous Embolization of Cavernous and Paracavernous Dural Arteriovenous Fistula through the Facial Vein: Report of 12 Cases / 신경중재치료의학

PURPOSE: The aim of this study was to evaluate the feasibility and safety of the transfacial venous embolization of cavernous or paracavernous dural arteriovenous fistula (DAVF) in which approach via inferior petrosal sinus (IPS) was not feasible. MATERIALS AND METHODS: We identified the cases of transfacial venous embolization of cavernous sinus (CS) or adjacent dural sinuses from the neurointerventional database of three hospitals. The causes and clinical and angiographic outcomes of transfacial venous embolization were retrospectively evaluated. RESULTS: Twelve patients with CS (n = 11) or lesser wing of sphenoid sinus (LWSS, n = 1) DAVF were attempted to treat by transvenous embolization via ipsilateral (n = 10) or contralateral (n = 2) facial vein. Trans-IPS access to the target lesion was impossible due to chronic occlusion (n = 11) or acute angulation adjacent the target lesion (n = 1). In all twelve cases, it was possible to navigate through facial vein, angular vein, superior ophthalmic vein, and then CS. It was also possible to further navigation to contralateral CS through intercavernous sinus in two cases, and laterally into LWSS in one case. Post-treatment control angiography revealed complete occlusion of the DAVF in eleven cases and partial occlusion in one patient, resulting in complete resolution of presenting symptom in eight and gradually clinical improvement in four patients. There was no treatment-related complication during or after the procedure. CONCLUSION: In the cavernous or paracavernous DAVF in which trans-IPS approach is not feasible, the facial vein seems to be safe and effective alternative route for transvenous embolization.

A Case of Miller Fisher Syndrome in a Patient with Systemic Lupus Erythematosus / 대한내과학회지

Neuropsychiatric events are common in patients with systemic lupus erythematosus (SLE). The estimated incidence of neuropsychiatric SLE (NPSLE) is 30 to 40%. However, NPSLE poses a difficult diagnostic challenge because a variety of conditions should be considered in the differential diagnosis, especially when patients present with uncommon or rare NPSLE features. We herein describe a 49-year-old man with SLE who initially presented with diplopia, ptosis, and gait disturbance that had developed 1 week after an upper respiratory tract infection. He was finally diagnosed with Miller Fisher syndrome (a variant of Guillain-Barre syndrome) according to clinical symptoms, anti-GQ1b antibody positivity, and neurological study results. The patient recovered without sequelae with intravenous immunoglobulin therapy. This is the first report to describe a case of Miller Fisher syndrome that developed in a patient with SLE in Korea and suggests that Miller Fisher syndrome should be included as a differential diagnosis of NPSLE.

Delayed Cerebral Metastases from Completely Resected Cardiac Myxoma: Case Report and Review of Literature

Cardiac myxoma is the most common benign tumor of the heart. However, low incidence of recurrence and metastasis has been reported. A 49-year-old female patient was admitted in the hospital due to sudden onset of left side weakness. Magnetic resonance imaging (MRI) of brain showed multifocal areas of diffusion restriction on diffusion weighted images. Echocardiography was performed to evaluate the cause of embolic brain infarction and cardiac myxoma was found in the left atrium. The patient underwent complete excision of the mass. One year later, the patient was readmitted with symptoms of dysarthria. Brain MRI showed newly developed multiple hemorrhagic metastatic lesions. The patient underwent radiotherapy of the metastatic lesions. Although rare, cardiac myxoma can cause delayed metastasis. We report a rare case of delayed multiple cerebral metastases from the completely resected cardiac myxoma.

Endovascular Treatments of Traumatic Carotid and Vertebral Vascular Injuries

OBJECTIVE: The purpose of this report is to determine the safety and efficacy of endovascular therapy in the management of craniocervical vascular injuries. METHODS: Fifteen patients with traumatic carotid and vertebral lesions were treated using therapeutic endovascular methods. In 13 patients with blunt trauma, five patients had a carotid-cavernous fistula, 8 had a dissecting pseudoaneurysm or arterial dissection. One of two penetrating patients had complete transection of the vertebral artery, and the other had an internal carotid artery-internal jugular vein fistula with two pseudoaneurysms. Endovascular therapy was accomplished by implanting the balloons, porous or polytetrafluoroethylene covered stent, and/or embolic materials including coils or glue. RESULTS: All fistulas and pseudoaneurysms were successfully embolized with coils, glue, or stents. Most of all parent arteries except two patients were preserved. Sacrifice of the parent artery was inevitable in cases of thrombus formation due to coil migration into the parent artery and the existing transaction of the parent artery. No additional surgical procedures for vascular lesions were required. There were no delayed neurological or vascular complications. Additionally, no lesions recurred during follow-up periods (mean 26.9 months). CONCLUSION: From the author's experiences, the endovascular therapy using stents, balloons, and coils is both feasible and safe in treatment of the traumatic vascular injuries. Long-term follow-up review of these repairs will be requisite to provide a full evaluation of the safety and efficacy of these devices.

Magnetic Resonance Imaging of the Ischemic Penumbra: Diffusion-Perfusion Mismatch in Acute Stroke Patients / 대한뇌혈관외과학회지

The ischemic penumbra is defined as functionally impaired but salvageable ischemic brain tissue surrounding an irreversibly damaged core. Therefore, rapid and precise identification of the penumbra is of considerable interest for decision-making in acute stroke treatment. The region with perfusion abnormality but no diffusion lesion (the so-called diffusion-perfusion mismatch) identifies tissue that is hypoperfused but that not yet experienced advanced bioenergetic failure and represents the penumbra. Thus, diffusion-perfusion mismatch are predicted to have the most lesion growth and may benefit most from any perfusion-altering therapies. The time window available for salvage of the penumbra in selected patients may be much longer than the traditional, presumed 3- to 6-hour window and that diffusion-perfusion MRI has the ability to identify these patients. Multimodal MRI allows therapeutic decisions to be based on individual patient pathophysiological information, allowing the time window to be extended in appropriate patients.

Endovascular Treatment of Wide-necked Aneurysms with a Stent and Detachable Coils / 대한뇌혈관외과학회지

Wide-necked aneurysms, whether they are small or large, have remained a significant challenge for endovascular treatment. Several methods, such as balloon remodeling technique or use of three-dimensional coil, are introduced for this, however, they do not produce satisfactory results. We describe the efficacy and limitations in treating the wide-necked aneurysms with stent-assisted coil embolization technique.

Reversal of Apparent Diffusion Coefficient (ADC) Following Transient Focal Cerebral Ischemia in Cats

PURPOSE: To determine the minimal threshold ADC ratio suggesting reversible ischemia in a temporary model of MCAO. MATERIALS AND METHODS: Seven Korean cats weighing 3-3.5 kg were used as a temporary model of MCAO. The MCA was occluded for 1 hour, and diffusion-weighted images (DWI), and ADC and regional cerebral blood volume (rCBV) maps, were obtained at 1, 3, 6 and 24 hours after reperfusion using a 1.5T MR unit. The Cats were sacrificed 24 hours after imaging. Triphenyl tetrazolium chloride (TTC) staining of brain slices was performed, and DWI images and TTC-stained brain slices were compared with the naked eye. Reversible ischemia was defined as the area of high signal intensity at 1-hour DWI that normalized at follow-up DWI and in which TTC staining was normal. Using the ADC image obtained at 1 hour after reperfusion, 60 ADC ratios were obtained in the periphery of the infarct and reversible ischemia. Tissue survival showing normal TTC staining was used for final determination. The sensitivity and specificity of each ADC ratio was obtained and an ROC curve was plotted. RESULTS: Five of seven cats showed the reversible ischemia. An area of high signal intensity was seen on DWI images obtained 1 hour after reperfusion, and this improved at follow-up imaging. The distribution of the ADC ratio in the periphery of the infarct core was 0.71-0.81, and in the periphery of reversible ischemia it was 0.79-0.93. The ADC ratio of 0.80 obtained 1 hr after reperfusion predicted the survival of the ischemic tissue with 93% sensitivity and 90% specificity. The ADC ratio of the reversible ischemia was 0.82+/-0.03 at 1 hour after reperfusion, and this was higher than that of the infarct, which was 0.74+/-0.03. CONCLUSION: The minimal threshold ADC ratio suggesting reversible ischemia in this temporary model of MCAO was 0.80.

Significance of 99mTc-ECD SPECT in Acute and Subacute Ischemic Stroke: Comparison with MR Images Including Diffusion and Perfusion Weighted Images

99mTc-ECD SPECT is valuable for the evaluation of cell viability and function. The purpose of the present study was to evaluate the significance of 99mTc-ECD brain SPECT in ischemic stroke. We compared 99mTc-ECD brain SPECT with perfusion and diffusion weighted images (PWI, DWI). Ten patients with acute and early subacute ischemic stroke were included in this prospective study. T2-weighted images (T2WI), DWI, PWI and 99mTc-ECD SPECT were obtained during both the acute/early subacute and late subacute stages. In the case of PWI, time to peak (TTP) and regional cerebral blood volume (rCBV) maps were obtained. The rCBV map and 99mTc-ECD SPECT images were compared in 8 lesions using delta AI. The asymmetry index (AI) was calculated as (Ci - Cc) X 200 / (Ci + Cc); where Ci is the mean number of pixel counts of an ipsilateral lesion and Cc is the mean number of pixel counts of the normal contralateral hemisphere. delta AI was defined as AIacute - AIsubacute in the ischemic core and periphery. PWI and 99mTc-ECD SPECT detected new lesions of the hyperacute stage or of evolving stroke more accurately than T2WI and DWI. 99mTc-ECD SPECT was able to localize the infarct core and peri-infarct ischemia in all lesions in both the acute and the subacute stages. delta AI was higher in the rCBV map than in the 99mTc-ECD SPECT images in the ischemic core (p = 0.063) and in the periphery (p = 0.091). In the 99mTc-ECD SPECT images, delta AI was higher in the ischemic core than in the periphery (p = 0.028). During the subacute stage, 99mTc-ECD SPECT detected all the lesions without the pseudonormalization seen in the MR images of 5/11 lesions. Based on this study, 99mTc-ECD SPECT is comparable to PWI in terms of its ability to detect acute stroke and is more useful than PWI in the case of subacute infarction.

Emergency Endovascular Treatment of Internal Carotid Artery Injury During a Transsphenoidal Approach for a Pituitary Tumor: Case Report

Carotid artery injury is a very rare, but life threatening complication that can occur during a transsphenoidal approach. We experienced one case of carotid artery injury during a transsphenoidal pituitary tumor surgery. The patient was immediately treated by a balloon occlusion and complete packing of the cavernous carotid artery using Guglielmi detachable coils (GDCs) and the rest of the tumor was removed after the carotid occlusion. The patient recovered without showing any neurological deficits.

Comparison of Orbital Pseudotumor and Lymphoma: Clinical and Radiological Findings

PURPOSE: To compare the clinical and radiological findings of orbital pseudotumor with those of orbital lymphoma. MATERIALS AND METHODS: The clinical and radiological features of 12 orbital pseudotumors were compared with those of 17 orbital lymphomas, the nature of all lesions being confirmed by tissue biopsy. Twenty-four CT scans and nine MR images were retrospectively reviewed and compared, with special focus on the location of a tumor in the orbit, the invasion of periorbital structures, tumor margin, bilaterality, and signal intensity. The initial symptoms at admission were also classified and compared. RESULTS: In 50% of cases, orbital pseudotumors were located in both extraconal and intraconal space; 75% involved two or more extraocular muscles, and 33% involved the optic nerve. Margins were either infiltrative (75%) or ill-defined (92%). As for orbital lymphomas, 64% occupied extraconal space, invading one or less extraocular muscle (76%) and conjunctiva (29%). Seventy-one percent had a sharp margin, and 65% were lobulated or round. In pseudotumors, orbital pain and visual loss were major symptoms, while in lymphomas a painless orbital mass was the initial symptom. CONCLUSION: CT or MR image analysis of lesion location, margin, and the involvement of adjacent extra-ocular muscle or optic nerves may help differentiate between orbital lymphoma and orbital pseudo tumor.

Complications of Diagnostic Intra-arterial Cerebral Angiography in Ischemic Cerebrovascular Diseases

BACKGROUND: Intra-arterial cerebral angiography, which is a prerequisite for carotid endarterectomy and angioplasty, carries some risks but provides the best visualization of the cerebral vasculatures. We attempted to examine the inci-dence of complications associated with cerebral angiography in patients with ischemic stroke. METHODS: We retrospec-tively reviewed the medical records of patients with ischemic stroke or transient ischemic attack (TIA) who underwent the digital subtraction cerebral angiography. Four hundred nineteen procedures were performed between October 1994 and August 1999. The systemic, local, and neurologic complications were evaluated. The neurologic complications were defined as occurrences of any new focal neurologic deficits or progressions of the preexisting neurologic deficits during or within 24 hours after the procedure. RESULTS: There were 5 systemic (1.2%), 17 local (4.1%), and 10 neuro-logic (2.4%) complications. The neurologic complications were reversible within 7 days in 6 (1.4%) and were persistent after 7 days in 4 (1.0%). Six out of 10 patients with neurologic complications had previous stroke or TIA. The angio-graphic studies revealed the stenosis or obstruction of the relevant arteries in 7 patients. CONCLUSIONS: Cerebral angiog-raphy in patients with ischemic stroke was associated with 1.4 % reversible and 1.0% persistent neurologic complica-tions, all of which developed after the angiographic procedure. The history of previous stroke or TIA and the presence of severe stenosis or occlusion of the symptomatic arteries may carry a high risk of neurologic complications. (J Korean Neurol Assoc 19(4):354~358, 2001)

MR Imaging of Trigeminal Neuropathy

Research Institute of Radiological Science, Yonsei University The trigeminal nerve is the largest of the cranial nerves and has both sensory and motor functions. It can be divided into proximal (brainstem, preganglionic, gasserian ganglion, and cavernous sinus) and distal (extracranial opthalmic, maxillary, and mandibular) segments. Patients with trigeminal neuropathy present with a wide variety of symptoms, and lesions producing those symptoms may occur anywhere along the protracted course of the trigeminal nerve, from its distal facial branches to its nuclear columns in the brainstem. The purpose of this article is to illustrate the normal anatomy of the trigeminal nerve and associated various pathologic conditions. These are arranged anatomically according to their site of interaction with it.

Diffusion-weighted image and MR spectroscopic analysis of a case of MELAS with repeated attacks

We report the clinical and MR manifestations of an 18 year-old girl with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome. Recurrent status epilepticus caused reversible cytotoxic edema on diffusion-weighted images (DWI). Initial and one month follow-up MR spectroscopy, after seizure control, showed some discrepancies in the ratio of metabolites. N-acetylaspartate (NAA) partially recovered (NAA/creatine (Cr) ratio: 1.27-->1.84). This was because of a normalization of decreased NAA due to cellular dysfunction as a result of status epilepticus. A low ratio of NAA/Cr due to abnormal mitochondria remained in the decreased state. Reversible NAA/Cr ratios in the acute lesion suggested that NAA reflects the neuronal function as well as the level of neuronal structural damage. The altered NAA/Cr ratio better correlated with the abnormal signal intensity area of T2-weighted images (T2WI) and DWI than the lactate (Lac)/Cr ratio. With conservative treatment with anti-epileptics not accompanied by coenzyme Q or sodium dichloroacetate, lactate persistently increased (Lac/Cr ratio: 1.01-->1.21) because of the continued production of lactate in cells with respiratory deficiency, which is the main pathology of MELAS.

Hippocampal and Neocortical Metabolite Ratio in Patients with Complex Partial Seizure: Short TE and Long TE Techniques Using Single Voxel Proton MR Spectroscopy

PURPOSE: To compare hippocampal and neocortical metabolite ratios using single-voxel proton MR spectroscopy with different echo times in patients with complex partial seizure. MATERIALS AND METHODS: Using a GE Signa 1.5 T scanner with STEAM and PRESS sequences, automated single voxel proton MRS was used to determine metabolite ratio differences in the hippocampus and neocortex of nine complex partial seizure patients [mesial temporal sclerosis (n=5), status epilepticus (n=1), tumor (n=1), cortical dysplasia (n=1), occipital lobe epilepsy (n=1)]. A total of 20 examinations were performed in the region of the hippocampus (n=17), temporal neocortex (n=1), and parieto-occipital gray matter (n=1). Voxel size range was 5.2 -17.4 cm 3. The calculated creatine (Cr) peak was employed as an internal reference and the relative ratio of N-acetylaspartate (NAA) and choline (Cho) was calculated for both short and long echo times using an automated PROBE/SV (GE Medical Systems) package. Each NAA/Cho ratio obtained using both PRESS and STEAM techniques was compared by means of statistical analysis (paired Student t-test). RESULTS: Using PRESS (long TE, 272 ms), NAA/Cho ratios were successfully calculated in 16 of 20 examinations; in four this was not possible due to noise levels of the Cr and Cho peaks. Using STEAM (short TE, 30 ms) NAA/Cho ratios were successfully calculated in 19 of 20 examinations; in one, the Cho peak could not be measured. Using PRESS and STEAM, mean and standard deviations for the NAA/Cho ratio were 1.22 +/-0.50 and 1.16 +/-0.36, respectively. There were no statistically significant differences in this ratio between the short and long TE method (p <0.01). CONCLUSION: In complex partial seizure patients, no significant metabolite differences were found between short and long echo times of single voxel proton MR spectroscopy. The metabolite ratio at different echo times can be reliably obtained using this simplified and automated PROBE/SV quantitation method.

MR Imaging Findings of Generalized Tonic Clonic Seizure Induced Brain Changes

PURPOSE: To evaluate MRI signal changes in the brain induced by generalized tonic clonic seizure. MATERIALS AND METHODS: Six patients who underwent MRI within three days of generalized tonic clonic seizure were retrospectively reviewed. Diffusion-weighted images were added in three patients during initial exami-nation, and in six, the follow-up MRI was performed nine days to five months after the onset of seizure. We evaluated the patterns of signal change, location of the lesion and degree of contrast enhancement, and the signal change seen on diffusion weighted images. We also compared the signal changes seen on initial and follow-up MRI. RESULTS: In all six patients, MR images showed focally increased T2 signal intensity, and swelling and increased volume of the involved cortical gyrus. In five, the lesion was mainly located in the cortical gray matter and subcortical white matter; namely, in the bilateral cingulate gyri, and the bilateral parieto-occipital, left parietal, left frontoparietal, and left temporal lobe. In the remaining patient, the lesion was located in the right hippocampus. Two patients showed bilateral lesions and one showed multiple lesions. In four patients, T1- weighted images revealed decreased signal intensity of the same location, and in one, gyral contrast enhancement was noted. On diffusion-weighted images, three patients showed increased signal intensity. Follow-up MRI demonstrated complete resolution of the abnormal signal change (n=5), or a decrease(n=1). CONCLUSION: A transient increase in MR signal intensity with increased volume was noted in cortical and subcortical white matter after generalized tonic clonic seizure. This finding reflects the vasogenic and cytotoxic edema induced by seizure and can help exclude etiologic lesions such as tumors, inflammation and demyelinating disease that induce epilepsy.

Usefulness of "Double-catheter" Technique in GDC Treatment of Intracranial Wide-necked Aneurysm

Purpose: To describe two different methods of "double-catheter" techniques for the treatment of wide-necked intracranial aneurysms. MATERIALS AND METHODS: Using two microcatheters simultaneously, we treated two wide-necked ophthalmic aneurysms and one wide-necked basilar bifurcation aneurysm. In the two cases of ophthalmic aneurysms, the two microcatheters were placed in the aneurysm sac, thus allowing two coils to be braced across the aneurysmal neck before either was detached. In the case of the basilar bifurcation aneurysm, a microcatheter was placed in the posterior cerebral artery (PCA), and another within the aneurysm lumen. When making the first frame with a GDC, we tried to ensure that the frame of the coil and the microcatheter in the PCA did not over-lap. Then, through the microcatheter positioned at the PCA, angiography was performed and flow pattern and dye-disappearance time were evaluated. Subsequent coils were introduced, but in order to preserve PCA flow, not beyond the frame of the first coil. RESULTS: All three aneurysms were successfully embolized without parent artery compromise and the patients were discharged in good neurological condition. CONCLUSION: The "double-catheter" technique can provide a valuable option for treating wide-necked aneurysms, especially when 'balloon remodeling' is not feasible and/or the relationship between the aneurysmal neck and adjacent parent artery cannot be ascertained.