Cerebral foreign body granulomas after mechanical thrombectomy: Two case reports and a review of the literature.

OBJECTIVES: A foreign body granuloma after an endovascular intervention is a rare complication. Some cases of foreign body granulomas, especially after coil embolization, have been reported. However, only four cases of foreign body granulomas after mechanical thrombectomy (MT) have previously been reported. The current study reports two cases of post-MT foreign body granulomas, including a biopsy-proven case. MATERIAL AND METHODS: Case 1: A 73-year-old woman presented with complete occlusion of the right middle cerebral artery. Cerebral angiography and MT were successfully performed with improvement in clinical symptoms. Left hemiparesis and a disturbance in attention appeared after discharge and progressed slowly. She was re-admitted to our hospital 120 days after cerebral infarction owing to foreign body granulomas diagnosed on biopsy. Case 2: A 78-year-old man presented with occlusion of the left cervical internal carotid artery and the left middle cerebral artery. Cerebral angiography, percutaneous transluminal angioplasty, and MT were successfully performed. On the 34th day, he experienced progressive consciousness disorder because of foreign body granulomas. Both cases were successfully treated with steroid therapy. RESULTS: MRI after steroid treatment showed the disappearance of most nodular lesions and improvement of the encephalopathy. CONCLUSIONS: The cause of the granuloma may be an allergic reaction to the hydrophilic polymers that peel from endovascular devices. Steroid therapy is an effective treatment; therefore, neurologists should consider this complication when neurological symptoms or signs on image appears or worsens. A reliable diagnosis is important for prompt treatment.

Coaxial Method of PTA Balloon and Aspiration catheter using the delivery wire of a stent retriever for tandem occlusion: CoMBAt tandem occlusion.

PURPOSE: Tandem occlusion, in which the intracranial artery is obstructed along with proximal carotid occlusive or stenotic lesions, occurs in 10-15% of patients with large vessel occlusion. Our study introduces a novel technique for tandem occlusion treatment that involves the simultaneous coaxial deployment of a percutaneous transluminal angioplasty balloon and aspiration catheters with the delivery wire of a stent retriever. After percutaneous transluminal angioplasty of the carotid lesion with a thin balloon catheter, the aspiration catheter was advanced over the balloon to eliminate the ledge between the catheter tip and delivery wire. After balloon removal, intracranial thrombectomy was performed using an aspiration catheter and stent retriever. This study aimed to evaluate the safety and efficacy of this approach. MATERIALS AND METHODS: Medical records of patients with acute stroke due to tandem occlusion treated using our technique were analyzed for its effectiveness and safety. The puncture-to-recanalization time, modified thrombolysis in cerebral infarction (mTICI) grade, functional prognosis and incidence of hyperperfusion were assessed. RESULTS: Seven patients were included in this study. In all patients, mTICI 2b-3 recanalization was achieved after smooth delivery of the aspiration catheter from the carotid lesion to the intracranial thrombus. The median puncture-to-recanalization time was 52 min. Ninety days post-stroke onset, six of seven patients had a modified Rankin Scale score of 0-2, and none of the patients had perioperative hyperperfusion syndrome. CONCLUSION: Our technique allows simultaneous treatment of carotid and intracranial lesions, leading to faster recanalization. Furthermore, percutaneous transluminal angioplasty with a thin balloon may reduce the risk of hyperperfusion.

Visual suppression of vestibulo-ocular reflex in patients treated with carotid artery revascularization: A potential biomarker for cerebral perfusion.

BACKGROUND: Carotid endarterectomy (CEA) and carotid artery stenting (CAS) are common treatments for ischemic stroke prevention in patients with carotid artery stenosis. However, the beneficial effects of CEA/CAS for cerebral hypoperfusion due to carotid artery stenosis have yet to be fully established. As dizziness is a common symptom in patients with carotid artery stenosis, we aimed to evaluate the effects of CEA/CAS on cerebral function in patients with carotid artery stenosis, using equilibrium function tests. METHODS: This prospective observational cohort study included 50 patients who had carotid artery stenosis and were scheduled to undergo CEA or CAS. Before CEA/CAS, we quantitatively evaluated the vestibulo-ocular reflex (VOR) and vestibular evoked myogenic potential (VEMP), as indicators of brainstem/inner ear functions related to balance, and visual suppression of VOR, as an indicator of cerebral control over the brainstem reflex related to balance. These were then compared with supratentorial cerebral blood flow (CBF). Changes in VOR, VEMP, visual suppression of VOR, CBF, and dizziness after CEA/CAS were also evaluated. RESULTS: The visual suppression rates of VOR correlated with supratentorial CBFs before CEA/CAS (correlation coefficient = 0.47, p = 0.003). The visual suppression rates of VOR (p < 0.001) and supratentorial CBFs (p = 0.003) were improved by CEA/CAS, while VOR and VEMP did not change. Symptoms of dizziness improved after CEA/CAS. CONCLUSIONS: Our results suggest that visual suppression of the VOR may be a novel and practical marker for the beneficial effects of CEA/CAS on supratentorial cerebral function.

Efficacy and safety of thrombectomy for acute ischaemic stroke in patients with pre-stroke mRS scores of 2-3: Real-world evaluation from an open-label, prospective, multicentre, observational study.

BACKGROUND: This study assessed the efficacy and safety of thrombectomy for acute ischaemic stroke in a population with pre-stroke modified Rankin scale (mRS) scores of 2-3 using real-world data. METHODS: Our sample set included 2313 consecutive patients enrolled in the Kanagawa Registry of Intravenous and Endovascular Treatment of Acute Ischemic Stroke registry between January 2018 and June 2020 in 40 stroke centres in Kanagawa Prefecture, Japan. Patients treated with intravenous tissue plasminogen activator (t-PA), thrombectomy, or both were included. Patients with pre-stroke mRS scores of 4-5 and those treated only with intra-arterial thrombolysis were excluded. The primary outcome of this study was an mRS score of 0-3 at 90 days after onset to assess the efficacy of thrombectomy for pre-stroke disabled individuals. We performed multivariate logistic regression analyses to investigate independent factors for a 90-day mRS score of 0-3. We also performed nearest-neighbour within-calliper matching between thrombectomy and t-PA only. RESULTS: After excluding patients meeting the exclusion criteria, we analysed data of 2136 consecutive patients, of which 315 (14.7%) had pre-stroke disabilities (mRS score 2-3). A 90-day mRS score of 0-3 was achieved by 33.3% of patients with pre-stroke mRS scores of 2-3. According to multivariate analysis, the National Institutes of Health Stroke Scale (NIHSS) score was an independent factor. Furthermore, after propensity-score matching, thrombectomy showed considerable superiority for achieving a 90-day mRS score of 0-3. CONCLUSION: Intravenous t-PA and especially thrombectomy were safe and effective for the population with pre-stroke disabilities, particularly for patients with low NIHSS scores.

Increased door-to-puncture time during off-duty hours results in poor treatment outcomes for acute ischemic stroke: A subanalysis of the K-NET registry.

BACKGROUND: For patients who undergo endovascular treatment for acute ischemic stroke, the total time for treatment may increase during off-duty hours leading to worse outcomes. The present study compared endovascular treatment outcomes for on-duty and off-duty hours and examined factors that could be responsible for the prolonged treatment of patients in a multicenter registry. METHODS: The study group comprised 1571 patients listed in the multicenter stroke registry (K-NET) who had undergone endovascular treatment between January 2018 and June 2020. The modified Rankin Scale (mRS), evaluated at 90 days after stroke onset, was utilized as the primary outcome. Patients were divided into on-duty and off-duty patients based on admission time. Multivariate logistic regression analysis was used to identify the independent factors that increased the time from admission to puncture during the off-duty period. RESULTS: The mean mRS score at 90 days after stroke onset was 2.9, similar in both on-duty and off-duty patients, with no significant difference (p = 0.77); however, significant differences were observed in time from door-to-puncture (74.7 vs. 88.8, p < 0.01). Additionally, the mRS score at 90 days worsened significantly for door-to-puncture time >60 min in the off-duty period. Multivariate logistic regression analysis revealed that a low National Institute of Health Stroke Scale (NIHSS) score, high pre-mRS score, posterior circulation, and diabetes were independent indicators of door-to-puncture time >60 min during the off-duty period. CONCLUSION: Door-to-puncture time >60 min during off-duty hours was associated with poor outcomes related to low NIHSS, high pre-mRS, posterior circulation, and diabetes.

Antiplatelet Loading Effects Prior to Endovascular Treatment: Carotid Artery Stenosis versus Unruptured Cerebral Aneurysms.

Objective: Carotid artery stenosis and cerebral aneurism may have different platelet functions and antiplatelet responses because these diseases have different etiologies. In this study, we compared the antiplatelet loading effects prior to endovascular treatment between carotid artery stenosis and unruptured cerebral aneurysm (UCA) patients. Methods: Nine patients with asymptomatic carotid artery stenosis (ACS), 14 with symptomatic carotid artery stenosis (SCS), and 20 with unruptured cerebral aneurysms were enrolled in this study. Antiplatelet (aspirin + clopidogrel) loading effects prior to endovascular treatment were evaluated using light transmission aggregometry and platelet aggregate detection methods. Results: Although there are differences in the prevalence of atherosclerosis risk factors, maximum aggregation rates in light transmission aggregometry and platelet aggregation-prone properties were not different in the three disease groups. Conclusion: Preoperative dual antiplatelet therapy with aspirin and clopidogrel may be appropriate for both carotid artery stenosis and cerebral aneurism patients even though their conditions and background factors differ.

Aneurysms Arising from Persistent Arteries in the Vertebrobasilar Paramedian Longitudinal Axis: Two Case Reports.

A 50-year-old man and a 69-year-old woman with consciousness disturbance were diagnosed to have suffered from subarachnoid hemorrhage (SAH) involving the posterior fossa. In both cases, the initial 3D CT angiogram failed to reveal the SAH source in the vertebrobasilar system. Delayed 3D rotational angiography revealed aneurysms on unfamiliar aberrant arteries. One was a dissecting aneurysm located between the proximal part of the posterior inferior cerebellar artery and the distal part of the intracranial vertebral artery. It was trapped and resected; the patient subsequently presented with lateral medullary symptoms. The other aneurysm was between the distal posterior and the distal anterior inferior cerebellar artery. It was successfully embolized; there were no complications. We think that the aberrant aneurysm-harboring vessels encountered in these two patients were primitive arteries on or adjacent to the vertebrobasilar paramedian longitudinal axis and that they persisted past the embryologic stage. Such aneurysms arising from unfamiliar persistent arteries beside the brainstem are extremely rare but must be considered when the SAH source is not detected in the trunk of the vertebrobasilar system.

Effects of cerebellar magnetic stimulation on chronic post-lateral medullary infarction dizziness: A proof-of-principle cohort study.

BACKGROUND AND PURPOSE: Lateral medullary infarction (LMI) sometimes causes long-lasting dizziness. Although the precise mechanism of chronic post-LMI dizziness is unknown, a cerebellar control disorder of the vestibulo-ocular reflex (VOR) has been reported in such patients. We conducted a proof-of-principle cohort study to assess the potential efficacy of cerebellar repetitive transcranial magnetic stimulation (rTMS) as treatment for chronic post-LMI dizziness. METHODS: We first applied cerebellar rTMS in healthy volunteers (n = 11) and showed that cerebellar intermittent theta burst stimulation (iTBS) affected vestibulocerebellar neural activity. Then, between September and December 2015, we enrolled six patients (aged≥20 years) with chronic post-LMI dizziness (duration≥6 months), applied cerebellar rTMS (iTBS for 5 days), and followed these patients up for up to 25 months for clinical symptoms (Dizziness Handicap Inventory [DHI]), signs (nystagmus), and VOR gain. RESULTS: Four of the six patients completed the study without complications. After rTMS, DHI scores were reduced (mean pre-rTMS DHI score minus post-rTMS DHI score was 13.0 [P = 0.036]) with disappearance of the ipsilesional nystagmus characteristic of the post-LMI dizziness. Reduction in the absolute VOR gain (mean pre- rTMS gain minus post-rTMS gain in the ipsilesional direction was 0.135 [P = 0.036] and that in the contralesional direction was 0.137 [P = 0.031]) were also associated with reduced DHI scores. Relative cerebellar blood flow to the brainstem was increased in four of five patients. The effects of cerebellar rTMS did not always persist, and three of four patients elected to undergo more than one rTMS series. The repeat cerebellar rTMS treatments had same beneficial effects. CONCLUSION: Our study showed, for the first time, the potential efficacy of cerebellar rTMS for treatment of chronic post-LMI dizziness. The short duration of the cerebellar rTMS effects can be compensated for by repeating the rTMS treatment every few months. Further large-scale randomized studies are warranted to confirm our findings.

Comparative study of ipsilesional and contralesional repetitive transcranial magnetic stimulations for acute infarction.

BACKGROUND AND PURPOSE: Repetitive transcranial magnetic stimulation (rTMS) is reported to improve chronic post-stoke hemiparesis. However, application of rTMS during the acute phase of post-stroke has not fully been investigated. We investigated the safety and the efficacy of intermittent theta-burst stimulation (iTBS) of the affected motor cortex and 1-Hz stimulation of the unaffected hemisphere during the acute phase in patients with hemiparesis due to capsular infarction. METHODS: Twenty one patients who met the study criteria were randomly assigned to receive, starting within 7days after stroke onset and for a period of 10days, iTBS of the affected motor cortex hand area (n=8), 1-Hz stimulation of the unaffected motor cortex hand area (n=7), or sham stimulation (n=6). Upper limb motor function was evaluated before rTMS and 12weeks after onset of the stroke. Evaluation was based on the Fugl-Meyer Assessment (FMA), Stroke Impairment Assessment Set (SIAS), Modified Ashworth Scale (MAS), grip strength, and motor evoked potential (MEP) amplitude in the first dorsal interosseous (FDI) muscle. RESULTS: Both iTBS applied to the affected motor cortex hand area and 1-Hz stimulation applied to the unaffected motor cortex hand area enhanced motor recovery. In comparison to sham stimulation, iTBS increased the SIAS finger-function test score, and 1-Hz stimulation decreased the MAS wrist and finger score. CONCLUSIONS: Ipsilesional iTBS and contralesional 1-Hz stimulation applied during the acute phase of stroke have different effects: ipsilesional iTBS improves movement of the affected limb, whereas contralesional 1-Hz stimulation reduces spasticity of the affected limb.

Common and specific risk factors for ischemic stroke in elderly: Differences based on type of ischemic stroke and aging.

BACKGROUND: The risk factors among the types of ischemic stroke (atherothrombotic cerebral infarction: ATI, cardio-embolic infarction: CEI, lacunar infarction: LI) in aged stroke patients have rarely been compared to each other. METHODS: We compared the clinical parameters of 300 elderly patients with ischemic stroke, age 65-98years, to 100 age-matched control patients. RESULTS: Comparison by parametric test and logistic regression analysis between all 300 and 100 control patients showed higher systolic and diastolic blood pressures (p<0.001, p=0.03), lower estimated glomerular filtration rate (eGFR) (p=0.01), larger cardiothoracic ratio (CTR) (p<0.001), smoking (p<0.01) and possibly poor adherence to anti-hypertensive agents in the ischemic stroke patients (p<0.001). Comparisons among three types (n=100 for each) showed the highest atheromatous risk factors for ATI to be hemoglobin A1c (p=0.01) and low-density lipoprotein (p<0.001) and for CEI to be largest cardiac load, indicated by largest left atrial dimension (p<0.001), and CTR (p<0.001). Triglyceride level was found to be a borderline risk factor for LI (p=0.054). Comparison between those aged <74 versus ≥75years (n=150 for each) showed a lower eGFR (p=0.02) and larger right atrial dimension (p<0.001) in patients ≥75. CONCLUSION: The risk factors were quite different among the subtypes and aging.

Spontaneous, headshaking, and positional nystagmus in post-lateral medullary infarction dizziness.

BACKGROUND AND PURPOSE: Lateral medullary infarction (LMI) sometimes causes long-lasting dizziness. However, the characteristics of nystagmus in patients with post-LMI dizziness are unknown. We undertook a prospective, comparative study of nystagmus in patients with and without post-LMI dizziness to determine the characteristic pattern of nystagmus of chronic post-LMI dizziness. METHODS: We evaluated and compared nystagmus under spontaneous, head-shaking, and positional testing conditions in 12 patients with post-LMI dizziness and in 6 patients without post-LMI dizziness. RESULTS: In the dizziness group, contralateral spontaneous nystagmus, ipsilateral head-shaking nystagmus, and horizontal direction-changing geotropic positional nystagmus were observed in patients in whom the LMI had occurred <60days previously (subacute period). In patients with dizziness in whom the LMI had occurred >90days previously (chronic period), the nystagmus was ipsilateral under all conditions. In the non-dizziness group, ipsilateral nystagmus was observed in 1 of the 2 subacute patients only after head-shaking and in 1 of the 4 chronic patients only during positional testing. CONCLUSIONS: Ipsilateral nystagmus observed under all spontaneous, head-shaking, and positional testing conditions characterizes chronic post-LMI dizziness.

Rapidly progressive dementia caused by a superior sagittal sinus dural arteriovenous fistula: a case report.

We describe the case of a 72-year-old man who presented with dementia that had progressed rapidly over a few months. Laboratory analysis of blood and cerebrospinal fluid (CSF) showed no abnormalities, with the exception of a slightly increased CSF protein level. Results of routine magnetic resonance imaging (MRI) including diffusion-weighted imaging (DWI) and magnetic resonance angiography (MRA) were unremarkable. However, detailed neuroimaging studies including contrast-enhanced T1-weighted MRI and conventional angiography revealed a superior sagittal sinus (SSS) dural arteriovenous fistula (DAVF). After endovascular embolization and surgical interruption of all arteries feeding the DAVF, the dementia reversed. We should be aware of the possibility of DAVF as the cause of rapidly progressive dementia even if routine MRI reveals no or only minimal abnormality.

Gaze palsy and exotropia in internuclear ophthalmoplegia.

BACKGROUND AND PURPOSE: Unilateral gaze palsy associated with internuclear ophthalmoplegia (INO), i.e., one-and-a-half syndrome, is well known. Exotropia can also be associated with INO, but it has been reported only rarely. We sought to determine the frequencies and courses of gaze palsy and exotropia in INO. METHODS: Patients hospitalized with acute-onset INO during the period January 2009 through December 2013 were identified from our clinical registry. Associated gaze palsy and exotropia were evaluated in the identified patients. RESULTS: Twenty-five patients with unilateral INO and 7 patients with bilateral INO were included in this study. Of the 25 patients with unilateral INO, 4 (16.0.0%) had ipsilateral gaze palsy (one-and-a-half syndrome), 8 (32.0%) had exotropia (non-paralytic pontine exotropia), and 6 (24.0%) had both ipsilateral gaze palsy and exotropia (paralytic pontine exotropia). Six (85.7%) of the 7 patients with bilateral INO had exotropia. The gaze palsy persisted more than 1 week in 40.0% of patients, whereas the exotropia disappeared within 1 week in 92.9% of patients when the INO was unilateral. CONCLUSION: Exotropia is not uncommon in the acute stage of INO. However, it is often overlooked because of its short duration.

Isolated unilateral oculomotor paresis in pure midbrain stroke.

BACKGROUND AND PURPOSE: Pure midbrain stroke can cause isolated unilateral oculomotor paresis. We attempted to determine whether there is a difference in the oculomotor paresis pattern between pure midbrain infarction and midbrain hemorrhage. METHODS: Pure midbrain stroke patients who presented with isolated unilateral oculomotor paresis were identified from a group of 2447 consecutive patients hospitalized for acute cerebral infarction or hemorrhage during the period May 2008 through April 2014. Detailed oculomotor findings were evaluated in the identified patients per the cause of the stroke. RESULTS: Five patients with infarct and 1 with hemorrhage became our study subjects. Lesions were located in the paramedian area of the midbrain involving the oculomotor fascicles. The pupillary sphincter and inferior rectus muscles were selectively spared in the infarct patients, whereas these muscles were selectively affected in the hemorrhage patient. CONCLUSION: Fibers in the oculomotor fascicle that innervate the levator palpebrae, superior rectus, and inferior oblique muscles appear to be more susceptible to ischemic damage than those that innervate the pupillary sphincter and inferior rectus muscles. Isolated impairment of the pupillary sphincter and inferior rectus muscles may be suggestive of a non-ischemic process.