Impact of introducing endovascular treatment on acute ischemic stroke outcomes: A shift from an era of medical management to thrombectomy in Japan.

BACKGROUND: Endovascular treatment (EVT) has increasingly become the standard treatment of acute cerebral large vessel occlusion (LVO). We evaluated the impact of introducing EVT on LVO therapy in a single center where intravenous thrombolysis (IVT) had been the only recanalization therapy. MATERIALS AND METHODS: Between April 2013 and March 2017, 354 consecutive patients with LVO admitted to our institution were analyzed. We compared outcomes between two chronological groups before (Pre-EVT group) and after (Post-EVT group) introducing EVT in April 2015. We assessed prognostic factors for favorable outcomes (modified Rankin scale score ≤2 at 90 days). RESULTS: In the Pre-EVT group, all 140 patients were treated medically, including 30 patients (21%) undergoing IVT. In the Post-EVT group, 118 patients (55%) underwent EVT, and the remaining 96 patients treated medically, including six patients (3%) undergoing IVT. The proportion undergoing recanalization therapy with IVT or EVT significantly increased after introducing EVT (21% versus 58%, p < 0.001). The rate of patients achieving favorable outcomes also significantly increased (14% versus 31%, p < 0.001). In multivariate regression analysis, introducing EVT was an independent predictive factor after adjusting for age, stroke severity and extent, and time (p = 0.005). The arrival time in patients with helicopter transport was significantly shorter than that with ground ambulance for a distance of more than 10 km (p < 0.001). CONCLUSIONS: This study demonstrated that the introduction of EVT improved outcomes of acute LVO patients, increasing the opportunity to receive recanalization therapy. Further efforts to establish medical systems to provide EVT are required throughout the country.

RNF213-related susceptibility of Japanese CADASIL patients to intracranial arterial stenosis.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), caused by NOTCH3, primarily affects small cerebral arteries; however, stenosis of major intracranial arteries has occasionally been reported. Recent studies identified a close association between the c.14576G>A (p.R4859K, rs112735431) variant of the ring finger protein 213 (RNF213) gene and sporadic intracranial arterial stenosis (ICAS). To determine whether RNF213 is associated with ICAS in CADASIL, we genotyped rs112735431 for 124 patients with CADASIL. The c.14576G>A carrier rate in CADASIL patients with ICAS (4/17; 23.5%) was significantly higher compared with those without ICAS (2/107; 1.9%) (P = 0.0032). Among patients with ICAS, frequency of territorial infarction was significantly higher in c.14576G>A carriers (75.0%) than in non-carriers (20.0%) (P = 0.0410). In addition, rate of ≥50% stenosis or occlusion tended to be higher in c.14576G>A carriers (4/4; 100%) than in non-carriers (6/13; 46.2%) (P = 0.1029). We conclude that RNF213 is a gene associated with susceptibility to ICAS in CADASIL patients. MRA follow-up and close observation are necessary for CADASIL patients with the RNF213 variant, as they may be predisposed to ICAS.

Stent Expansion and In-Stent Thrombus Sign in the Trevo Stent Retriever Predict Recanalization and Possible Etiology During Mechanical Thrombectomy: A Case Series of 50 Patients with Acute Middle Cerebral Artery Occlusion.

BACKGROUND: Interaction between the stent retriever and clot is a key factor for recanalization during mechanical thrombectomy. The aim of this study was to evaluate the association between radiographically apparent features during thrombectomy and angiographic outcomes using the Trevo stent retriever with a fully radiopaque strut. METHODS: We retrospectively reviewed 50 patients with acute middle cerebral artery occlusion who were treated with the Trevo. Patients were divided into groups that achieved (first-pass recanalization group, n = 21) or did not achieve (non-first-pass recanalization group, n = 29) a modified Thrombolysis in Cerebral Ischemia score of 2b or 3 with the first-pass procedure. Patients were also divided into a thromboembolic (n = 39) and atherosclerotic (n = 11) group by occlusion etiology. We evaluated radiographic findings of the Trevo's strut (e.g., degree of stent expansion and filling defect of the thrombus in the strut [in-stent thrombus sign]) during the first-pass procedure. RESULTS: Median stent expansion was significantly greater in the first-pass recanalization group than in the non-first-pass recanalization group (60% vs. 34%; P < 0.01) and in the thromboembolic group than in the atherosclerotic group (45% vs. 31%; P < 0.01). The receiver operator characteristic curve showed moderate capacity for prediction of recanalization and etiology, with an area under the curve of 0.83 and 0.73, respectively. In-stent thrombus sign was significantly more common in the thromboembolic group than in the atherosclerotic group (86% vs. 10%; P < 0.01). CONCLUSIONS: Greater stent expansion was associated with recanalization after thrombectomy. The in-stent thrombus sign may be useful for etiology prediction. These radiographic findings could provide useful real-time feedback during procedures, reflecting clot-stent interaction.

Mechanical Thrombectomy for Acute Ischemic Stroke Patients Aged 80 Years or Older.

BACKGROUND: There are limited data about the prognostic factors predicting outcomes after mechanical thrombectomy with stent retrievers for the elderly. Here, we evaluated outcomes in elderly patients in a real-world setting. METHODS: Between April 2015 and January 2017, 80 patients with anterior intracranial acute large vessel occlusion, who had lived independently before ictus, were treated with mechanical thrombectomy using a stent retriever at our institute. We compared outcomes between patients ≥80 years old (n = 36) and those <80 years old (n = 44), and assessed prognostic factors for favorable outcomes (modified Rankin Scale score 0-2) at 90 days in all patients. RESULTS: There was no significant difference in baseline National Institutes of Health Stroke Scale score and Alberta Stroke Program Early Computed Tomography Score between the 2 groups. Successful revascularization (modified Thrombolysis in Cerebral Infarction [mTICI] scores 2b/3) (83% versus 93%, P = .286), complete recanalization (mTICI 3) (47% versus 50%, P = .826), and favorable outcomes (42% versus 57%, P = .261) were achieved more often in those <80 years old, but differences did not reach statistical significance. Multivariate regression analysis showed that baseline National Institutes of Health Stroke Scale (P = .013) and mTICI scores of 3 (P = .006) were significant predictive factors, but being ≥80 years old and baseline Alberta Stroke Program Early Computed Tomography Score were not. In those ≥80 years old, mTICI score of 3 was an influential factor for favorable outcome (P = .017). CONCLUSIONS: Being aged 80 years or older was not a significant predictor for outcomes after mechanical thrombectomy, whereas complete recanalization was an influential predictor of outcome in the elderly.

Mechanical Thrombectomy Using the Trevo ProVue in 50 Consecutive Patients with Anterior Circulation Stroke: A Single-Center Experience after Approval of the Stent Retriever in Japan.

Mechanical thrombectomy using the stent retriever has been proven to be effective for select patients with acute ischemic stroke. We evaluated our early experience using the device after its approval in 2014 in Japan, with a special emphasis on the occlusion site. Fifty consecutive endovascular revascularization procedures for treating anterior acute large vessel occlusion were performed using the Trevo ProVue as the first-line device at our institute between April 2015 and March 2016. Focusing on the involvement of the M1-M2 bifurcation with deployment or retrieval of the stent retriever, we regarded the middle cerebral artery M1 mid-portion as the boundary and divided the cases into proximal (n = 26) and distal (n = 24) groups. We assessed the overall clinical outcome and compared the outcome between the two groups. Among 50 patients (median age, 80 years; National Institutes of Health Stroke Scale score (NIHSS) score, 20), successful (modified Thrombolysis in Cerebral Infarction score (TICI) 2b or 3) or complete revascularization (TICI 3) was achieved in 41 patients (82%; 88% in the proximal group vs 75% in the distal group, P = 0.28) and in 27 patients (54%; 73% vs 33%, P = 0.01), respectively. Symptomatic intracranial hemorrhage occurred in three patients (6%; 4% vs 8%, P = 0.60). A good outcome (mRS score 0 to 2) was obtained in 25 patients at 90 days (50%; 54% vs 46%, P = 0.78). Mechanical thrombectomy using the Trevo ProVue was safe and effective in patients with acute cerebral artery occlusion, especially for proximal occlusions. The efficacy of the procedure for distal occlusions was somewhat inferior to those for proximal occlusions, which might be resolved by next generation devices.

A Mobile Schwannoma of the Cervical Spinal Cord: Case Report and Review of the Literature.

BACKGROUND AND IMPORTANCE: Mobile schwannomas have been reported in the lumbar spine and occasionally in the thoracic spine. However, to the best of our knowledge, this is the first known report of a cervical mobile schwannoma. Mobile schwannomas require careful preoperative and intraoperative evaluation of their localization because tumor mobility may result in surgery at the wrong level. CLINICAL PRESENTATION: A 68-year-old man had complained of clumsiness in his left hand for 10 years. An initial magnetic resonance image (MRI) showed an intradural extramedullary tumor at the C5 to C7 levels, deformation of the adjacent spinal cord, and unusual dilatation of the subarachnoid space from the C7 to T1 levels. A subsequent MRI revealed that the tumor had moved to the C6 to T1 levels. We diagnosed the lesion as a mobile tumor of the cervical spinal cord. The patient underwent a C6-C7 laminectomy with an additional partial laminectomy of C5 and T1. Intraoperative ultrasonography helped localize the tumor. Transdural ultrasonography and direct observation confirmed the tumor mobility. The tumor was completely removed. The histological diagnosis was schwannoma. CONCLUSION: We observed an extremely rare case of a mobile schwannoma of the cervical spine. Unusually dilated subarachnoid space adjacent to the tumor can be a diagnostic sign of tumor mobility, regardless of vertebral level. Repeated MRI studies are useful to preoperatively confirm tumor mobility. Intraoperative ultrasonography is valuable for the real-time localization of such mobile tumors to avoid potentially performing surgery at the wrong vertebral level.

Elevated Release of Beta-thromboglobulin and Platelet Factor 4 in Cerebral Infarction Patients with Branch Atheromatous Disease: A Preliminary Report.

This study evaluated the levels of the platelet activation markers beta-thromboglobulin (beta-TG) and platelet factor 4 (PF4) in patients with branch atheromatous disease (BAD). Patients with newly diagnosed cerebral infarctions were recruited into the study; those with cardiogenic cerebral infarctions were excluded. Beta-TG and PF4 levels were measured before therapeutic intervention and compared between patients with and without BAD; Welch's t-test was used to determine significant differences between the groups. A total of 15 subjects were enrolled in the study, and 8 were diagnosed with BAD. Beta-TG (P = 0.031) and PF4 (P = 0.041) levels were significantly higher in the BAD patients than in the non-BAD patients. Platelet activity is normally elevated in patients with cerebral infarctions, but is elevated to an even greater extent in BAD patients. The evaluation of beta-TG and PF4 levels may be beneficial for the elucidation of BAD.

Mechanical Endovascular Recanalization in a Patient with Middle Cerebral Artery Occlusion by Tumorous Emboli Originating from Cardiac Myxoma.

Cardiac tumor is a rare cause of cerebral embolic infarction which has no established therapeutic strategies. Although some cases were successfully treated by recombinant tissue-plasminogen activator (rt-PA), this article indicates the effectiveness of emergency mechanical thrombectomy for tumorous type of emboli which do not respond to rt-PA. A 34-year-old man presented with ischemic stroke and right middle cerebral artery (MCA) occlusion by cardiac tumor originating emboli. Intravenous rt-PA therapy was ineffective, but mechanical endovascular thrombectomy using Merci Retriever was successful. His neurological deficit began to improve and good outcome was obtained at discharge. The embolus was histologically identical to a cardiac myxoma, confirmed and treated successfully by surgery later. We report the first successfully treated tumorous embolic stroke case with cardiac tumor by using Merci Retriever. Emergency mechanical thrombectomy would be an option for elastic hard myxoma emboli.

Spinal cord stimulation and intrathecal baclofen therapy: combined neuromodulation for treatment of advanced complex regional pain syndrome.

OBJECTIVE: Spinal cord stimulation (SCS) is one of the widely used procedures for the treatment of complex regional pain syndrome (CRPS). However, complete pain relief is rarely achieved, and the SCS effect diminishes over time. Recently intrathecal baclofen (ITB) therapy is reported to be a modality for treating fixed dystonia related to CRPS. Other reports have suggested that ITB therapy can enhance the effect of SCS in patients with neuropathic pain. We report the effectiveness of combined SCS and ITB therapy, focusing on the role of ITB therapy as an adjunctive therapy for controlling symptoms of advanced CRPS. METHODS: Five affected extremities of 4 patients with CRPS (2 male; mean age, 32.5 years) refractory to conservative treatment were evaluated retrospectively. Three patients underwent SCS implantation first, with ITB pumps being implanted a few years later. Bolus ITB injection was administered under temporary percutaneous SCS in 1 patient. Pain intensity was evaluated using the visual analogue scale (VAS) before and after ITB administration. RESULTS: Pain relief of more than 50% was observed in the upper extremity of 1 patient and one of more than 30% was observed in 2 patients. The mean pain reduction rate in all 4 patients was 28.9% before and 43.8% after treatment. All patients, including those without any improvements in VAS score, showed decreased postural abnormalities after combined SCS and ITB therapy. Improvement in postural abnormalities, such as fixed dystonia or paroxysmal tremor-like movements, resulted in overall pain relief by reducing pain fluctuations. CONCLUSIONS: Combined SCS and ITB neuromodulation decreases pain intensity in refractory CRPS cases or improves associated abnormal dystonic posture and movement disorders and reduces pain fluctuations.

Intraoperative pre- and post-craniofacial reconstruction intracranial pressure (ICP) monitoring in children with craniosynostosis.

INTRODUCTION: One of the goals of cranial vault expansion performed in patients with craniosynostosis (CS) is to reduce the harmful effects associated with elevated intracranial pressure (ICP). Until now, clear guidelines on when cranial vault expansion should take place have not been established except in unacceptable cosmetic deformities. MATERIALS AND METHODS: This paper illustrates the potential benefit of ICP monitoring in determining the time of surgery. The ICP of six patients (ranging from 7 months to 8 years) was measured before and after surgery. For the first time, we regulated end-tidal carbon dioxide, the position and movements, the level of sedation and the monitoring site of our patients under anesthesia to report accurate ICP readings. RESULTS: The mean pre- and postoperative ICPs were 14.7 and 4.2 mmHg, respectively. Pressure sensor was placed through a burr hole under general anesthesia and remained through all stages of recording. Though ICP monitoring has been reported before, the physiological fluctuations of ICP and patient's condition affected results. Under our ICP monitoring protocol, the six-patient study represents a suggestion to standardize ICP measurements under certain conditions in order to improve the reproducibility of ICP monitoring and therefore establish the need for optimal timing of cranial vault expansion in pediatrics. CONCLUSION: Although we cannot clearly define the indications and establish normal pediatric ICP values from the result of this study because of the small number of cases and some other limitations, this is a new approach to define ICP increase as a potential indication for surgery in CS.