Rescue Endovascular Treatment to Prevent Neurological Deterioration in Acute Symptomatic Bilateral Vertebral Artery Occlusion.

Bilateral vertebral artery occlusive disease has been considered as a favorable condition with good collaterals. However, the prognosis of acute ischemic stroke secondary to symptomatic bilateral vertebral artery occlusion (BVAO) and endovascular treatment (EVT) has rarely been reported. We retrospectively selected patients with acute ischemic stroke admitted for symptomatic BVAO between January 2020 and February 2023. All patients with ischemic stroke were evaluated for ischemic lesion and arterial status using brain imaging and angiography. The prognosis of acute stroke with symptomatic BVAO was compared between EVT and conventional treatment. Outcomes were evaluated using modified Rankin Scale (mRS) score at 3 months follow-up. Within the study period, 17 of 2,655 acute ischemic stroke patients were diagnosed with ischemic stroke with symptomatic BVAO. The median age of these patients was 70 (interquartile range 44-89) years, and 13 (76%) were male. Seven patients received emergent EVT with stenting and 10 patients received conventional medical treatment only. Nine of 10 patients with conventional treatment had in-hospital stroke progression and developed new ischemic lesions in the pons and midbrain. Five patients with fetal and hypoplastic posterior communicating artery presented bilateral cerebral peduncular lesions. At 3 months follow-up, 6 patients (35%) had favorable outcomes (mRS 0-2), of which 5 were treated with vertebral artery stenting and 1 received conventional treatment. Ischemic stroke in patients with acute symptomatic BVAO is uncommon. However, stroke progression is common, and the prognosis of most patients is poor. Rescue management such as EVT might be considered for symptomatic BVAO.

Endovascular Reperfusion Therapy in Minor Stroke with Neurologic Deterioration beyond 24 Hours from Onset.

PURPOSE: Patients with minor stroke (National Institutes of Health Stroke Scale score ≤5) and large vessel occlusion (LVO) often experience neurological deterioration >24 hours after onset. However, the efficacy of endovascular reperfusion therapy in these patients remains unclear. The aim of this study was to determine the efficacy and safety of reperfusion therapy in patients with minor stroke and neurological deterioration >24 hours after onset. MATERIALS AND METHODS: Data were retrospectively reviewed from patients between January 2019 and April 2022 who met the following criteria: (1) minor stroke and small definitive ischemic lesions at initial visit, (2) onset to neurological deterioration >24 hours, (3) cortical signs, Alberta Stroke Program Early computed tomography (CT) Score >6 points, and large artery occlusion confirmed by CT angiography at neurological deterioration. Efficacy and safety outcomes were based on final thrombolysis in cerebral infarction (TICI), incidence of symptomatic intracranial hemorrhage (ICH), and mortality. Outcomes were assessed using the modified Rankin Scale (mRS) at 3 months. Good outcome was defined as a mRS of 0, 1, or 2. RESULTS: Data from 26 patients (38.4% female, mean age 75.8 years) were analyzed; 18 (69.2%) had a good outcome. A final TICI of 2b or 3 was observed in 24 (92.3%) patients. No other adverse events, including dissection, vasospasm or distal embolization, were observed during the procedures. Hemorrhagic events occurred in 8 patients after the procedure; however, there were no symptomatic ICHs. Good prognostic factors were younger age (P=0.062) and carotid stenting (P=0.025). CONCLUSION: Endovascular reperfusion therapy performed in selected patients with minor stroke, LVO, and neurological deterioration >24 hours after stroke onset demonstrated favorable outcomes and safety.

Endovascular Treatment of Symptomatic Basilar Artery Stenosis.

PURPOSE: While symptomatic basilar artery (BA) stenosis is associated with a higher risk of recurrent stroke or death, there is no consensus on the management of these patients who are refractory to antiplatelet therapy. This study retrospectively assesses the outcomes of endovascular treatment (EVT) for symptomatic BA stenosis. MATERIALS AND METHODS: We conducted a retrospective review of patients with symptomatic BA stenosis who underwent EVT, including angioplasty or stenting, from 2006 to 2018. A total of 15 patients, who experienced transient ischemic attacks or strokes despite dual antiplatelet therapy, were included. EVT was performed under local anesthesia after pretreatment with antiplatelet medications. Angiographic follow-up was performed at 12 and 24 months post-EVT. Clinical outcomes were evaluated using the modified Rankin Scale (mRS). RESULTS: EVT was successfully completed in all patients. Peri/post-procedural complications occurred in 33% of cases, including in-stent thrombosis, intracranial hemorrhage, and pontine infarction. At long-term follow-up (mean 98.5±80.5 months), 73.3% of patients achieved a favorable functional outcome (mRS≤2) without disability or mortality. Patients with unfavorable outcomes had previous infarcts, with 2 experiencing new pontine infarctions after stenting. CONCLUSION: This study suggests that EVT, including angioplasty and stenting, may offer promise as a treatment option for symptomatic BA stenosis refractory to medical therapy. However, the procedure carries a notable risk of complications, especially in patients with severe stenosis and previous infarcts. Careful patient selection, based on clinical and radiological criteria, is crucial.

Estimation of brain tissue response by electrical stimulation in a subject-specific model implemented by conductivity tensor imaging.

Electrical stimulation such as transcranial direct current stimulation (tDCS) is widely used to treat neuropsychiatric diseases and neurological disorders. Computational modeling is an important approach to understand the mechanisms underlying tDCS and optimize treatment planning. When applying computational modeling to treatment planning, uncertainties exist due to insufficient conductivity information inside the brain. In this feasibility study, we performed in vivo MR-based conductivity tensor imaging (CTI) experiments on the entire brain to precisely estimate the tissue response to the electrical stimulation. A recent CTI method was applied to obtain low-frequency conductivity tensor images. Subject-specific three-dimensional finite element models (FEMs) of the head were implemented by segmenting anatomical MR images and integrating a conductivity tensor distribution. The electric field and current density of brain tissues following electrical stimulation were calculated using a conductivity tensor-based model and compared to results using an isotropic conductivity model from literature values. The current density by the conductivity tensor was different from the isotropic conductivity model, with an average relative difference |rD| of 52 to 73%, respectively, across two normal volunteers. When applied to two tDCS electrode montages of C3-FP2 and F4-F3, the current density showed a focused distribution with high signal intensity which is consistent with the current flowing from the anode to the cathode electrodes through the white matter. The gray matter tended to carry larger amounts of current densities regardless of directional information. We suggest this CTI-based subject-specific model can provide detailed information on tissue responses for personalized tDCS treatment planning.

Contraindications and Complications of Full Endoscopic Lumbar Decompression for Lumbar Spinal Stenosis: A Systematic Review.

OBJECTIVE: The purpose of this study was to suggest appropriate indications and contraindications for full endoscopic surgery and to predict the prognosis for the incidence of complications by reviewing the literature on full endoscopic lumbar decompression for various spinal stenoses and systematically analyzing the contraindications and complications of endoscopic surgery. METHODS: We searched the PubMed/MEDLINE database to identify articles on full endoscopic decompression for lumbar spinal stenosis. The levels of evidence in all studies were classified according to the method adopted by the North American Spine Society (NASS) 2005. Full endoscopic lumbar decompression was divided into interlaminar and transforaminal decompressions. We selected articles that contained preoperative contraindications and complications during and after surgery. We analyzed the evidence level and classified the prescribed contraindications and complications according to the literature. RESULTS: We identified 362 articles, of which 57 met our criteria, with evidence ranging from levels I to V. After reviewing the literature on full endoscopic lumbar decompression, pure back pain without neurogenic symptoms and instability/deformities requiring stabilization were found to be contraindications. Also, in transforaminal decompression, central stenosis or complex foraminal stenoses were contraindications. Dysesthesia (most common), untreated pain, dural tear, disc herniation, infection, incomplete decompression, and other complications have been reported as complications of transforaminal decompression. On the other hand, dural tear (most common), epidural hematoma, transient dysesthesia, untreated pain, motor weakness, and other complications have been reported in interlaminar decompression. CONCLUSIONS: Full endoscopic lumbar surgery, including transforaminal and interlaminar decompression, is a safe and effective surgical option for treating lumbar spinal stenosis; however, it is important to select the transforaminal or interlaminar approach according to the indication.

Chronic Headache Attributed to Vertebrobasilar Insufficiency.

Vertebrobasilar insufficiency, a condition characterized by poor blood flow to the posterior portion of the brain, can cause headaches. However, the exact underlying mechanism is not yet fully understood. The patient enrolled in our study reported experiencing intermittent headaches radiating from the left shoulder, similar to chronic tension-type headaches. His aggravated headache and severe left vertebral artery stenosis were detected by brain computed tomography angiography. Stent insertion successfully expanded the patient's narrowed left vertebral artery orifice. Subsequently, the patient's headaches improved without recurrence during the one-year follow-up period. In summary, chronic headaches attributed to vertebrobasilar insufficiency in this study, improved after stent insertion to reverse severe left vertebral artery stenosis.

Factors Distinguishing Proximal and Distal Internal Carotid Artery Occlusions in Patients with Acute Ischemic Stroke.

Acute internal carotid artery (ICA) occlusions cause extensive brain ischemia. Accurate determination of the occlusion site facilitates rapid revascularization interventions and improves prognosis. However, proximal ICA occlusions, as determined with computed tomography (CT) angiography, often are located more distally. Therefore, we assessed clinical and imaging factors associated with the accurate determination of occlusion sites. In this observational study, we evaluated 102 patients who presented acute ischemic stroke symptoms and had a CT angiography within 6 h, showing proximal ICA occlusion. The participants were divided into two groups, depending on whether there was correspondence between digital subtraction angiography and CT angiography regarding the occlusion location. Proximal occlusions were, accordingly, categorized as "true" (correspondence) or "false" (no correspondence; distal). Demographic, clinical, and imaging features were analyzed. Multivariate regression analysis was performed to identify factors predicting the correspondence between actual ICA occlusion sites and those detected by CT angiography. The shape (Odds ratios, OR = 646.584; Confidence interval, CI = 21.703-19263.187; p < 0.001) and the length (OR = 0.696; CI = 0.535-0.904; p = 0.007) of the ICA occlusion and atrial fibrillation (OR = 0.024; CI = 0.002-0.340; p = 0.006) were significant factors. The cut-off length of ICA stump at 6.2 mm, the sensitivity was 71%, and the specificity was 70% (area under the ROC curve = 0.767).

Pedunculated mucinous cystic neoplasm of the liver: a case report.

In 2010, the World Health Organization classified mucin-producing bile duct tumors of the liver into two distinct entities; mucinous cystic neoplasm of the liver (MCN-L) and intraductal papillary mucinous neoplasm of the bile duct. We present the case of a patient with MCN-L having a uniquely pedunculated shape. A 32-year-old woman was referred to our institution with a diagnosis of biliary cystic neoplasm. She had undergone left salpingo-oophorectomy for ovarian cancer 15 years ago. Imaging studies showed an 8 cm-sized well defined, multiloculated cystic lesion suggesting a mucinous cystic neoplasm. The cystic mass was pedunculated at the liver capsule and pathologically diagnosed as MCN-L. The mass was resected with partial hepatectomy. The patient recovered uneventfully. She was discharged 7 days postoperatively. The patient has been doing well for 6 months after the operation. The patient will be followed up annually because of the favorable postresection prognosis of MCN-L.

Tension Pneumocephalus Caused by Ethmoidal Roof Fracture: Emergent Surgical Decompression.

Tension pneumocephalus is a neurosurgical emergency that occurs when air is trapped in the intracranial cavity, leading to brain compression and causing severe neurological symptoms such as decreases in motor function, sensory function, and consciousness. Most cases of pneumocephalus require conservative treatment; however, because of the possible fatal complications, rapid diagnosis and appropriate treatment are important. Here, we present the case of an 81-year-old male patient who had undergone head trauma three hours prior to being admitted to our emergency room (ER) because of mental cloudiness. The radiologic findings showed tension pneumocephalus caused by an ethmoidal roof fracture. Emergency reconstruction of the ethmoidal roof with craniotomy was performed to remove the intracranial air using normal saline irrigation. By sharing our experience with this case, we hope to provide an option for the treatment of such cases.

Delayed Onset Acute Subdural Hematoma after Burr Hole Drainage in a Patient with Chronic Subdural Hematoma and Liver Cirrhosis.

Although acute intracranial bleeding after burr hole drainage for chronic subdural hematoma (SDH) is rare, it could still occur and is associated with a poor clinical outcome. Although rare, most of them occur immediately or within a few days after drainage, especially in patients who are on antiplatelet drugs or anticoagulants. We report an unusual case of delayed-onset acute SDH that developed 14 days after burr hole drainage of chronic SDH in a 54-year-old man with liver cirrhosis and thrombocytopenia. The possible pathophysiological mechanisms of this rare entity are discussed, and the relevant literature is reviewed.

Prevalence of Unruptured Intracranial Aneurysms: A Single Center Experience Using 3T Brain MR Angiography.

PURPOSE: The purpose of this study was to evaluate the prevalence and risk factors of unruptured intracranial aneurysms (UIAs), which can help establish guidelines of treatment for asymptomatic Korean adults using 3T magnetic resonance angiography (MRA). MATERIALS AND METHODS: Our Institutional Review Board approved this retrospective study, and informed consent was waived. All patients consisted of healthy individuals who underwent brain MRA using 3T magnetic resonance imaging between January 2011 and December 2012 as part of a routine health examination. Patient data and follow-up results were obtained from medical records. RESULTS: A total of 2,118 individuals (mean age=53.9±9.6 years, male:female=1,188:930) who had undergone brain MRA were enrolled in the study. UIAs were found in 80 patients with 105 UIAs (3.77%). Female predominance (55% in UIA vs. 43.47% in non-UIA, P=0.0416) and hypertension were more common in the UIA group (43.75% vs. 28.8%, P=0.004, respectively). The mean size of the aneurysms was 3.10±1.62 mm, and they were all saccular in shape and asymptomatic. The UIAs were most common in the internal carotid artery (59.1%), internal carotid-posterior communicating artery (15.2%), middle cerebral artery (9.5%), anterior communicating artery (8.6%), anterior cerebral artery (4.8%), and vertebral artery (2.9%). Twenty-eight of 80 patients (35%) had multiple aneurysms. The incidence of UIAs increased significantly with age (P=0.014). CONCLUSION: In single center experience, we demonstrated the characteristics and prevalence of UIAs in asymptomatic adults, which may help establish guidelines or therapeutic standards for UIAs.

Asymptomatic unruptured intracranial aneurysms in the older people.

PURPOSE: Unruptured intracranial aneurysm commonly occurs in the older people. Because the rupture risk increases with age, the factors associated with aneurysms might be different according to age. We aimed to evaluate unruptured intracranial aneurysm characteristics in healthy, symptom-free older patients. METHODS: Patients who visited the health examination center of two regional university hospitals and underwent computed tomography angiography between March 2001 and March 2017 were included. The putative aneurysm risk factors were identified; the aneurysm size and shape were determined by CT angiography, and measuring the ASPECT and dome/neck ratios. All images were interpreted independently by a neurosurgeon and a neurologist for improving size measurement accuracy. RESULTS: The unruptured intracranial aneurysm prevalence was 2.23% and 2.75% in the patients aged ≤ 60 and > 60 years, respectively. Among the younger group, female sex [odds ratio (OR), 1.85; P = 0.002], age (OR, 1.05; P < 0.001), hypertension (OR, 1.88; P < 0.001), coronary artery disease (OR, 0.26; P < 0.001), smoking (OR, 2.04; P < 0.001), and stroke family history (OR, 1.36; P = 0.047) were independently associated with aneurysm; anterior communicating artery aneurysms were the largest. Among the older group, female sex (OR, 1.76; P = 0.005), hypertension (OR, 2.54; P < 0.001), coronary artery disease (OR, 0.27; P < 0.001), and stroke family history (OR, 1.94; P = 0.003) were independently associated with aneurysm; internal carotid artery aneurysms were the largest. CONCLUSIONS: The factors related to unruptured intracranial aneurysm formation varied by age, and coronary artery disease protected against aneurysm formation regardless of age. The factors affecting unruptured intracranial aneurysm formation are different according to age and aneurysm location.

Correction to: Asymptomatic unruptured intracranial aneurysms in the older people.

The article Asymptomatic unruptured intracranial aneurysms in the older people, written by Sang Woo Ha, Pahn Kyu Choi, Ji Eun Oh, Jung Soo Park and Hyun Goo Kang was originally published electronically on the publisher's internet portal (currently SpringerLink) on 29 October 2018 without open access.

Twiddler's Syndrome: A Rare Hardware Complication in Spinal Cord Stimulation.

Twiddler's syndrome is an uncommon hardware complication involving the lead and pulse generators in cardiac pacemakers and defibrillators, deep brain stimulators, and vagal nerve stimulators. However, until very recently, it had not been reported in spinal cord stimulation (SCS). Considering the incidence of hardware complications of spinal cord stimulation, there may be an underreporting of Twiddler's syndrome due to lack of awareness. Two cases of Twiddler's syndrome as a hardware complication of SCS were identified between 2005 and 2015. One patient with hardware failure due to Twiddler's syndrome refused to have a revision surgery. The other patient who had a lead migration associated with coiling of the lead and twisting of pulse generator needed a revision surgery. Twiddler's syndrome in patients treated with SCS is an uncommon but important adverse event. Awareness of characteristic presentation and radiologic finding is essential in the identification of Twiddler's syndrome in SCS.

Cerebrospinal Fluid Egress from the Quadripolar Deep Brain Stimulation Electrode for Anterior Nucleus of the Thalamus for Refractory Epilepsy.

Deep brain stimulation (DBS) of the anterior nucleus of the thalamus (ANT) is an effective treatment for refractory epilepsy. Due to the unique location of ANT in the thalamus facing the lateral and third ventricles, transventricular DBS lead placement is an essential part of ANT DBS. However, there is no report regarding hardware problems including impedance variability in transventricular ANT DBS due to limited experience. A 45-year-old male patient with previously effective, bilateral ANT DBS presented with increasing seizure frequency and a shortened battery longevity within 2 years. Magnetic resonance imaging showed that the left-sided DBS lead was in the third ventricle leaning on the medial wall of ANT. Electrode revision was performed. Upon disconnecting the proximal lead from the extension connection, cerebrospinal fluid egress through fine gaps between the metallic electrode contacts, and electrode spacing was observed. This case raises a concern about the transventricular approach for ANT lead placement because the currently available DBS electrode lead is not waterproofed. A careful, longitudinal follow-up of DBS impedance for ANT DBS is warranted.

Occipital Neuralgia from C2 Cavernous Malformation.

A unique case is presented of chronic occipital neuralgia (ON) caused by cavernous malformation (CM) in the intramedullary C2 spinal cord and subsequent pain relief and remodeling of allodynic pain following dorsal root rhizotomy. A 53-year-old male presented with a 30-year history of chronic allodynic, paroxysmal lancinating pain in the greater and lesser occipital nerves. Typically, the pain was aggravated with neck extension and head movement. Magnetic resonance imaging showed a CM in the right posterolateral side of the intramedullary C2 cord. Considering potential risks associated with removal of the lesion, intradural C1-3 dorsal root rhizotomy with dentate ligament resection was performed. The paroxysmal lancinating pain of ON was significantly alleviated, and the remodeling of the extent of allodynic pain was noted after C1-3 dorsal root rhizotomy. These changes gradually occurred during the second postoperative month, and this effect was maintained for 24 months postoperatively. Significant reduction in chronic allodynic pain of secondary ON caused by cervicomedullary CM involving central sensitization in the trigeminocervical complex was observed with reduction of irritating, afferent input with C1-C3 dorsal root rhizotomy.

Intraoperative Neurophysiological Monitoring (Motor and Somatosensory Evoked Potentials) in Dorsal Root Entry Zone Lesioning for Brachial Plexus Avulsion Pain.

AIMS: To address the feasibility and importance of intraoperative neurophysiological monitoring (IONM) in dorsal root entry zone (DREZ) lesioning for brachial plexus avulsion pain. METHODS: Muscle motor evoked potential (mMEP) and somatosensory evoked potential (SSEP) were applied during DREZ lesioning for brachial plexus avulsion pain. RESULTS: IONM of mMEPs and SSEPs was feasible for monitoring of the spinal cord during DREZ lesioning. With the exception of 3 unrecordable mMEPs in ipsilateral arms, mMEPs were preserved and referenced to look for changes according to lesioning in 6 upper extremities (66.6%) and 8 lower extremities. All 3 patients with >50% reduction in baseline mMEP amplitude after lesioning in either the ipsilateral upper or lower extremities showed postoperative ataxia and weakness of the lower extremities (100%). Only 2 out of 9 patients (22.2%) with brachial plexus avulsion pain had discernible baseline SSEPs in the ipsilateral upper extremities. One of 2 patients with discernible SSEPs in the upper extremities showed significant SSEP events during the DREZ lesioning and experienced postoperative ataxia and weakness in the legs despite the absence of a SSEP event in the lower extremities. CONCLUSION: Significant events on IONM were common during DREZ lesioning for brachial plexus avulsion pain and were closely related to the occurrence of postoperative neurological deficits.

Adjacent Bilateral Stress Pedicle Fractures after Instrumented Lumbar Fusion: A Case Report.

Bilateral pedicle stress fractures are rare even in the elderly. Bilateral pedicle fractures are due to post-surgical complications at the level of fusion or stress related activities in most cases. The authors describe a unique case of adjacent L4 bilateral pedicle fractures, which developed 4 years after anterior lumbar interbody fusion with bone cement augmented screw fixation at the L5-S1 level. As far as the authors' knowledge, no similar case has been previously reported in the literature. The pathophysiological mechanism of this rare entity is discussed with review of relevant literature.